WO2014091528A1 - Diffractive multifocal ophthalmic lens and production method thereof - Google Patents

Diffractive multifocal ophthalmic lens and production method thereof Download PDF

Info

Publication number
WO2014091528A1
WO2014091528A1 PCT/JP2012/008031 JP2012008031W WO2014091528A1 WO 2014091528 A1 WO2014091528 A1 WO 2014091528A1 JP 2012008031 W JP2012008031 W JP 2012008031W WO 2014091528 A1 WO2014091528 A1 WO 2014091528A1
Authority
WO
WIPO (PCT)
Prior art keywords
zone
diffractive
diffraction
light
amplitude
Prior art date
Application number
PCT/JP2012/008031
Other languages
French (fr)
Japanese (ja)
Inventor
安藤　一郎
Original Assignee
株式会社メニコン
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社メニコン filed Critical 株式会社メニコン
Priority to PCT/JP2012/008031 priority Critical patent/WO2014091528A1/en
Priority to JP2014525250A priority patent/JP5993950B2/en
Publication of WO2014091528A1 publication Critical patent/WO2014091528A1/en

Links

Images

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/18—Diffraction gratings
    • G02B5/1866—Transmission gratings characterised by their structure, e.g. step profile, contours of substrate or grooves, pitch variations, materials
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/14—Eye parts, e.g. lenses, corneal implants; Implanting instruments specially adapted therefor; Artificial eyes
    • A61F2/16—Intraocular lenses
    • A61F2/1613—Intraocular lenses having special lens configurations, e.g. multipart lenses; having particular optical properties, e.g. pseudo-accommodative lenses, lenses having aberration corrections, diffractive lenses, lenses for variably absorbing electromagnetic radiation, lenses having variable focus
    • A61F2/1616—Pseudo-accommodative, e.g. multifocal or enabling monovision
    • A61F2/1618—Multifocal lenses
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/14—Eye parts, e.g. lenses, corneal implants; Implanting instruments specially adapted therefor; Artificial eyes
    • A61F2/16—Intraocular lenses
    • A61F2/1613—Intraocular lenses having special lens configurations, e.g. multipart lenses; having particular optical properties, e.g. pseudo-accommodative lenses, lenses having aberration corrections, diffractive lenses, lenses for variably absorbing electromagnetic radiation, lenses having variable focus
    • A61F2/1654—Diffractive lenses
    • G—PHYSICS
    • G02—OPTICS
    • G02C—SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES
    • G02C7/00—Optical parts
    • G02C7/02—Lenses; Lens systems ; Methods of designing lenses
    • G02C7/04—Contact lenses for the eyes
    • G02C7/041—Contact lenses for the eyes bifocal; multifocal
    • G02C7/044—Annular configuration, e.g. pupil tuned
    • G—PHYSICS
    • G02—OPTICS
    • G02C—SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES
    • G02C2202/00—Generic optical aspects applicable to one or more of the subgroups of G02C7/00
    • G02C2202/20—Diffractive and Fresnel lenses or lens portions

Definitions

  • the present invention relates to an ophthalmic lens such as a contact lens and an intraocular lens that is used for the human eye and exhibits a correction action on a human eye optical system, and more particularly for a multifocal eye having a diffractive structure having a novel structure.
  • the present invention relates to a lens and a manufacturing method thereof.
  • an ophthalmic lens has been used as an optical element for correcting refractive error in an optical system of the human eye or an alternative optical element after extracting a lens.
  • contact lenses that are used by being attached to the human eye and intraocular lenses that are used by being inserted into the human eye are used directly by the human eye to provide a large field of view and reduce the sense of discomfort. It can be used widely.
  • Examples of a method for realizing such a multifocal ophthalmic lens include a refractive multifocal ophthalmic lens that forms a plurality of focal points based on the refraction principle and a diffractive multifocal ophthalmic lens that forms a plurality of focal points based on the diffraction principle. It has been known.
  • the latter diffractive type ophthalmic lens has a plurality of concentric diffractive structures formed in the optical part of the lens, and a plurality of focal points are formed by the mutual interference action of light waves that have passed through the diffractive structures (zones). Is to give.
  • a diffractive multifocal lens has a diffractive structure in which the distance between diffraction zones gradually decreases from the center of the lens toward the periphery in accordance with a certain rule called Fresnel spacing. Multi-focality is achieved using origami. Usually, the 0th-order diffracted light is used as a focal point for far vision, and the + 1st-order diffracted light is used as a focal point for near vision. By the distribution of the diffracted light, a bifocal lens having a focal point for near and near can be obtained.
  • An example of a diffractive multifocal lens that can generate such a perspective focus is US Pat. No. 5,144,483 (Patent Document 1).
  • a diffractive multifocal intraocular lens has been put to practical use as an intraocular lens to be inserted after the above-described cataract surgery, and it is effective as an intraocular lens that can be viewed both far and near without glasses. It recognized.
  • FIG. 93 shows data that can grasp the problem of the blood vision in a general diffractive multifocal lens.
  • FIG. 93 (a) shows a case where a diffractive multifocal ophthalmic lens designed based on the technical content shown in US Pat. No. 5,144,483 by Cohen is placed on an optical bench and passed through the lens. It shows a resolution chart taken. This is a measurement result at a far vision focal position of a diffractive multifocal ophthalmic lens designed to form a 0th order diffracted light for far vision and a + 1st order diffracted light for near vision. Compared with the case of the single focus lens shown in FIG.
  • the brightness of the bright highlight portion is somewhat lowered and appears to be grayish. Further, it can be seen that light blur occurs in the shadow portion of the background without the target, and the contrast is lowered as a whole.
  • diffractive multifocal intraocular lenses that are currently in practical use, those having a diffractive structure called apodization developed from the basic specifications of Cohen are known. W. Andrew Maxwell et al.
  • this is formed because the component of the light for near-field imaging becomes a kind of stray light and is mixed into the focal image plane for distance vision.
  • the intensity of the small peak group (hereinafter referred to as a side band) is extremely small compared to the intensity of the main peak, but the intensity is increased because these peaks are integrated in a broad light source. Is amplified. Further, as described above, even in a slight light blur, it is easily perceived in an environment where there is a contrast difference between light and dark. Therefore, a situation that cannot be ignored even with a weak sideband can occur.
  • Such a sideband distribution is formed as a wave phenomenon of light.
  • the light passing through each diffraction zone is located at the image plane position of the far vision focus. Gives an amplitude distribution reflecting the characteristics of the zone.
  • FIG. 95 (b) shows an example of the amplitude of light that is emitted from a distant point light source and passes through each zone to form a focal image plane.
  • a total amplitude distribution is obtained by combining the amplitudes of the light beams that have passed through the zones (A, B, C) (FIG. 95 (c)).
  • the conjugate absolute value of the amplitude becomes the light intensity (FIG. 95 (d)).
  • the intensity distribution formed on the image plane after the light emitted from the point light source passes through the lens is referred to as a point spread function.
  • the intensity distribution from the edge of the chart letters and figures to the shadow part of the background is a bright highlight Intensity distribution sharply cut off from the part.
  • an edge intensity distribution the intensity distribution formed on the image plane by such an object (light source) via the lens
  • the edge intensity distribution it is possible to grasp the degree of light blur by knowing the edge intensity distribution. Since such a broad object or light source can be considered to be composed of many point-like light sources, the point spread function corresponding to each point light source is accumulated over the optical conjugate position of the focal image plane. Then, the edge intensity distribution can be obtained.
  • FIG. 96 is a conceptual diagram comparing the intensity distribution for such an edge between a general single focus lens and a diffractive multifocal lens. Assume that there is a light source in which a highlight portion and a shadow portion are clearly divided as shown in FIG. If the point spread function of the single focus lens and the diffractive multifocal lens has a distribution as shown in FIGS. 96B and 96C, the respective edge intensity distributions are shown in FIGS. 96D and 96E. As shown. At first glance, it seems that there is no difference in the edge intensity distribution between the two, but when the vicinity of the shadow portion of the edge is enlarged, a clear difference is recognized (FIG. 96 (f)).
  • the single focus lens shows the intensity distribution of sharply cut edges, while the diffractive multifocal lens shows a distribution with a certain bulge in the shadow portion near the edges.
  • This bulge part represents the intensity of light that has oozed out into the shadow part, and if this is large, it will be observed as light bleed.
  • This bulge varies depending on the intensity and distribution of the sideband of the point spread function, but as a whole, the bulge becomes larger as the sideband intensity is larger. Further, if the appearance position of the side band is close to the main peak, the swelling occurs near the edge portion. As a result, glare such as wrinkles is recognized near the object when the object is viewed. Further, if the sideband is separated from the main peak, the edge intensity distribution tends to show a gentle shelf-like distribution. If the shelf strength is high with this distribution, the wrinkles may appear to spread out.
  • Patent Document 2 discloses a design method in which a lens is aspherical in order to improve MTF (modulation transfer function).
  • MTF modulation transfer function
  • the MTF is improved by making the lens aspherical together with the diffractive structure.
  • the MTF represents a change in contrast with respect to the spatial frequency.
  • An increase in the MTF value is almost the same as an improvement in the ability to identify and resolve an object at each frequency.
  • Patent Document 3 the cause of such a problem is that light scattering at the relief edge portion of the diffraction grating formed discontinuously in the shape of the grating forming the diffraction structure causes a decrease in contrast.
  • a design method for smoothly forming the edge portion and a specification of a diffractive lens including the design method are described.
  • the main cause of the blood vision is the influence of the sideband in the point spread function.
  • Such a sideband is formed by mixing light forming another focal point, and it is considered that the contribution of scattered light is small. Therefore, it is considered that the contrast improvement effect cannot be expected so much by the method according to the prior document.
  • the document does not mention anything about the bleeding of light, and does not show any information suggesting the solution.
  • Patent Document 4 proposes an ophthalmic lens having an asymmetric structure in which the lens surface is divided into a diffractive structure and a refractive region structure with respect to the geometric center of the lens in order to improve this problem. ing. In these divided structures, it is possible to prevent a decrease in contrast by finely adjusting the light distribution ratio in the diffraction structure region.
  • the prior literature does not mention any light bleeding and means for solving the problem.
  • the point spread function In general, when an asymmetric structure is introduced with respect to the center of the lens, the point spread function also exhibits an asymmetric and distorted distribution. Many sidebands may also be generated. Thus, such an asymmetric structure may rather exacerbate the light bleed and sometimes lead to undesirable effects such as double images. Also, the manufacture of such an asymmetric structure has the problem that it is much more difficult and time consuming and expensive than manufacturing a symmetrical structure.
  • the easiest way to prevent the contrast reduction of multifocal ophthalmic lenses and reduce light blur is to increase the amount of light distributed to the corresponding focus. For example, if light blur is to be reduced in far vision, the amount of light distributed to the focal point for far vision is increased. However, increasing the amount of light distributed to a specific focus reduces the amount of light distributed to other focal points. For example, if the amount of light distribution for the far vision focus is increased, the sideband of the point spread function of the far vision focus may be reduced, but the intensity of the sideband is increased at other focal points. As a result, the focus position where a lot of light is distributed may give a view with high contrast and less blurred vision, but the quality of the view is inevitably deteriorated at the remaining focus positions.
  • Patent Document 5 discloses a method for obtaining an intensity distribution of an image plane in which halo and glare are hardly perceived by changing the amount of light distribution by changing the height of the phase plate in the diffraction zone.
  • a profile that reduces the amount of light distributed from the phase plate in the vicinity of the diffraction zone is described as an example, assuming that the halo and glare are less likely to be perceived if the skirt of the image surface intensity distribution is smoothed. .
  • this method is merely a measure for changing the amount of light distributed to each focal position, and the design of such a multifocal lens is inevitably a biased design in which only specific focus characteristics are regarded as important. Therefore, it is not possible to provide a multifocal ophthalmic lens that can be substantially used.
  • Patent Documents 2 to 5 have proposed several methods for solving this with respect to the improvement of contrast, but concrete methods for suppressing this against the blur of light. There is nothing that is shown in.
  • the multifocal eye that improves the edge intensity distribution at the target focus position and the resulting blurred vision without significantly changing the amount of distribution to multiple focal points from the intended design value. There are no specific examples of lenses yet.
  • the present invention aims to improve the blurred vision, which is a major problem in the multifocal ophthalmic lens as described above, and is obtained as a result based on the elucidation of the generation mechanism of the blurred vision. Based on this knowledge, a new solution has been found. Based on the new technical idea thus obtained, in order to realize a diffractive multifocal ophthalmic lens with an improved blood vision, the present invention provides a novel manufacture of a diffractive multifocal ophthalmic lens. It is an object of the present invention to provide a method and a diffractive multifocal ophthalmic lens having a novel structure.
  • the amplitude function is a function (distribution) that mathematically describes the characteristics as a wave of light.
  • Phase modulation generally refers to a structure or method provided in a lens that changes the phase of light incident on the lens in some way.
  • the phase function is a function that represents a change in phase within the exponent part of Equation 1 or the cos function.
  • the phase function variable is mainly a position r in the radial direction from the center of the lens, and is used to represent the phase ⁇ of the lens at the point r.
  • the optical axis is a rotationally symmetric axis of the lens, and here refers to an axis extending through the center of the lens to the object space and the image side space.
  • the image plane refers to a plane perpendicular to the optical axis at a certain point in the image side space where the light incident on the lens is emitted.
  • the 0th order focal point refers to the focal position of the 0th order diffracted light.
  • the focus position of the + 1st order diffracted light is referred to as the + 1st order focus.
  • the 0th-order focal image plane refers to the image plane at the focal position of the 0th-order diffracted light.
  • the phase position of the phase phi n and the inner diameter r n-1 position of the outer diameter r n zone phi n Basically, the absolute value of ⁇ 1 is set to be equal to the reference plane (line), that is,
  • the blaze phase function ⁇ (r) is expressed as shown in Equation 2.
  • the phase shift amount is defined as a phase shift amount when a phase function ⁇ (r) is shifted by ⁇ in the ⁇ axis direction with respect to the reference line (plane) of the r ⁇ coordinate system.
  • the relationship with the phase function ⁇ ′ (r) newly obtained by shifting ⁇ is as shown in Equation 3.
  • the unit of the phase shift amount is radians.
  • Equation 4 The relationship between ⁇ n and ⁇ n-1 is as shown in Equation 4. This positional relationship is shown in FIG.
  • the function ⁇ ′ (r) newly set by introducing the phase shift amount ⁇ can also be used as one form of the phase function.
  • phase function of blaze when the phase shift amount ⁇ is introduced is expressed as in Equation 2 to Equation 5.
  • phase constant refers to the constant h defined by Equation 6 in the blaze-shaped phase function.
  • Relief is a general term for minute uneven structures formed on the surface of a lens obtained by specifically converting the lens to the actual shape reflecting the optical path length corresponding to the phase defined by the phase profile.
  • a specific method for converting the phase profile into a relief shape is as follows.
  • a positive phase in the phase profile means that the light is delayed, if the light is incident on a region having a high refractive index, it is the same as the case where the positive phase is given.
  • the point spread function refers to the intensity distribution formed on the image plane at the focal position by the light emitted from one point passing through the lens. It is also called PSF (Point Spread Function). In the present invention, it means the intensity distribution formed on the image plane of the far vision focal position unless otherwise specified. It is synonymous with “image plane intensity distribution at the focal position for far vision” in the above-described image plane intensity distribution.
  • Edge intensity distribution refers to the intensity distribution at the border of light and darkness formed on the image plane by the transition region between the highlight portion and the shadow portion via the lens in a wide light source having a certain brightness. In the present invention, it is used as a measure of light bleeding.
  • a one-dimensional finite linear light source extending on the x-axis of the object-side space is assumed as a broad light source as shown in FIG.
  • the light intensity distribution I ( ⁇ ) formed on the image plane by the light source passing through the lens is a convolution (superimposition) between the light source when the intensity distribution of the light source is O (x) and the point spread function is PSF ( ⁇ ). (Equation 8).
  • (a) is a linear light source having a finite length composed of many point light sources existing on the x axis
  • (b) is a lens
  • (c) is the ⁇ axis of each point light source on the image plane.
  • the point spread function formed above (d) is a state in which the number of constituent point light sources is increased and the corresponding point spread functions are densely packed
  • (e) is the sum of the point spread functions. It represents the intensity distribution.
  • an area surrounded by a broken line is an edge intensity distribution.
  • the Fresnel interval refers to one form of zone interval determined according to a certain rule in the zone configuration of the diffractive lens.
  • rn the outer diameter of the nth zone
  • the first zone outer diameter (radius) in Formula 12 that defines the Fresnel interval is normally determined by Formula 13, but may be set using an arbitrary value.
  • the Fresnel interval type diffractive lens used in the present invention is different from the Fresnel lens using the refraction principle, and refers to a lens using the diffraction principle having an interval according to the above formula.
  • the first aspect of the present invention relating to a diffractive multifocal ophthalmic lens includes an optical part provided with a plurality of concentric diffraction zones, and at least two focal points are provided by the optical part.
  • the blur vision is suppressed by reducing the amplitude distribution of the sideband region at the first focal point on the image plane at the first focal point which is one of the focal points.
  • the present invention is characterized by a diffractive multifocal ophthalmic lens in which a canceling region that gives diffracted light is provided in a region corresponding to a pupil diameter of photopic vision in the optical unit.
  • a cancellation zone that is a diffraction zone that reduces the amplitude distribution of light other than the light that forms the first focus on the image plane at the first focus.
  • the lens it is formed in a canceling area within the passage area of the light beam that passes through the pupil in the photopic vision state. Therefore, the amplitude distribution on the image plane caused by light other than the light forming the first focal point, which is considered to be a major cause of the sideband, is suppressed, and as a result, the appearance of the image at the first focal point is suppressed. Quality will be improved.
  • the target light whose amplitude distribution is reduced by the diffracted light in the cancellation zone does not have to be all light other than the light that forms the first focus.
  • diffracted light that forms a single or a plurality of focal points other than the first focal point may be the target light, and an amplitude distribution located in a single or a plurality of regions on the image plane at the first focal point.
  • the diffracted light to be given may be targeted.
  • a second aspect of the present invention relating to a diffractive multifocal ophthalmic lens is the diffractive multifocal ophthalmic lens according to the first aspect, wherein the first focus is zero order of the diffractive structure in the diffraction zone. It is given by Origami.
  • the first focus is given by the 0th-order diffracted light of the diffractive structure, which is the main focus forming factor of the diffractive multifocal ophthalmic lens.
  • a third aspect of the present invention relating to a diffractive multifocal ophthalmic lens is the diffractive multifocal ophthalmic lens according to the first or second aspect, wherein the first focus is a far vision focus, and The other focus has a near vision focus.
  • the suppression of the blood vision which is likely to be a problem especially in daytime distance vision, is more effectively exhibited.
  • the amplitude distribution of the diffracted light that gives the near vision focus on the image plane at the far vision focus is considered to be the main cause of the blurred vision.
  • the “near vision focus” is a focus located at a distance closer to the far focus, and includes, for example, not only the near vision focus in the case of two focus but also the intermediate vision focus in the case of multiple focus. .
  • a fourth aspect of the present invention relating to a diffractive multifocal ophthalmic lens is the diffractive multifocal ophthalmic lens according to any one of the first to third aspects, wherein the cancel region is the plurality of diffraction zones. Are provided in a region excluding the diffraction zone at the innermost circumference.
  • the innermost diffraction zone is the starting point for multifocal formation, and is the zone that focuses on the multifocal formation function. At the same time, blur vision can be suppressed.
  • the radius is at least 0.3 mm or more and 2.5 mm or less from the lens center. It is preferable that a canceling area is provided.
  • the canceling region is provided within a range of at least 0.3 mm and a radius of 2.5 mm or less from the lens center.
  • the cancellation area can be surely provided in the area excluding the innermost diffraction zone of the optical unit, while the pupil diameter in the daytime when the blurry vision is likely to be a problem can be sufficiently covered, and the blurry vision is more reliably achieved. Can be suppressed.
  • a fifth aspect of the present invention relating to a diffractive multifocal ophthalmic lens is the diffractive multifocal ophthalmic lens according to any one of the first to fourth aspects, wherein the diffraction zone modulates the phase of light. It is formed with a diffractive structure characterized by a phase function to obtain.
  • the diffraction zone is formed with a diffraction structure characterized by a phase function for modulating the phase of light.
  • the diffraction structure can be designed more accurately without reducing the amount of transmitted light compared to the case of an amplitude modulation type diffractive structure combined with a light transmitting zone and a non-transmitting zone.
  • a sixth aspect of the present invention relating to a diffractive multifocal ophthalmic lens is a diffractive multifocal ophthalmic lens according to any one of the first to fifth aspects, wherein at least part of the diffractive structure in the diffraction zone is provided.
  • the phase function is a blazed function.
  • a formula for specifying and designing the position and size of the sideband peak group that causes the blurred vision is obtained. Simplification is possible, and simulation by a computer can be simplified and shortened. Further, it becomes possible to manufacture with higher accuracy, and a more precise design can be performed. That is, the blood vision can be further reduced.
  • a seventh aspect of the present invention relating to a diffractive multifocal ophthalmic lens is the diffractive multifocal ophthalmic lens according to any one of the first to sixth aspects, wherein the phase function of the diffractive structure in the diffraction zone is blaze.
  • C-th in the case where the amplitude of the light that has passed through each of the i-th diffraction zone and the j-th diffraction zone is intensifying each other on the image plane at the first focal point.
  • the positions of the diffraction zones are set so as to substantially satisfy the following formula 14 as a condition for the light passing through each diffraction zone to weaken the amplitude of each other.
  • the amplitude that most contributes to or conforms to the amplitude of the sideband that is the cause of the blood vision is identified, the combination of the zones that constitute the amplitude is extracted, and a series of relational expressions including Expression 14 is obtained.
  • the cancel zone for reducing the amplitude can be arranged at a desired position as the c-th diffraction zone. As a result, it is possible to obtain a diffractive structure in which the sideband is reduced and the edge intensity distribution is reduced when convolved.
  • At least a part of the diffractive structure in the diffraction zone has a periodic structure with Fresnel spacing.
  • the periodic structure of the Fresnel interval may be provided in at least a part of the diffraction zone.
  • a periodic structure of the Fresnel interval is adopted in combination with a non-Fresnel interval periodic structure such as an equally spaced diffraction zone. Is possible.
  • a ninth aspect of the present invention relating to a diffractive multifocal ophthalmic lens is a diffractive multifocal ophthalmic lens according to any one of the first to eighth aspects, wherein the phase function of the diffractive structure in the diffraction zone is blaze.
  • the diffractive structure in the diffractive zone being a periodic structure of Fresnel spacing
  • the position of the c-th diffraction zone and the position of the i-th diffraction zone correspond to the respective diffraction It is set so as to substantially satisfy the following formula 15 as a condition for the light passing through the zone to weaken the amplitude.
  • the diffraction zone providing the first focus may be a periodic structure with Fresnel spacing.
  • the Fresnel spacing may be a periodic structure between the c-th diffraction zone and the i-th diffraction zone, which are cancellation zones. It is not necessary to have a periodic structure.
  • a tenth aspect of the present invention relating to a diffractive multifocal ophthalmic lens is the diffractive multifocal ophthalmic lens according to any one of the first to ninth aspects, wherein at least a part of the diffractive structure in the diffraction zone is provided. , Which has a periodic structure with equal intervals.
  • At least a part of the diffractive structure in the diffractive zone has an equally spaced periodic structure. This makes it easier to formulate the sideband that is the cause of the blood vision, and it is possible to easily specify the position and size and design the cancellation area.
  • An eleventh aspect of the present invention relating to a diffractive multifocal ophthalmic lens is the diffractive multifocal ophthalmic lens according to any one of the first to tenth aspects, wherein the diffractive structure in the diffractive zone has the canceling function.
  • the slope of the function of the blaze shape in the diffraction zone of the region has the opposite sign to the slope of the blaze shape of the diffraction zone in the region other than the cancellation region.
  • the slope of the function of the blaze shape in the diffraction zone of the cancel region has the opposite sign to the slope of the blaze shape of the diffraction zone of the region other than the cancel region.
  • a region where the amplitude of the amplitude generated in the diffraction zone of the cancellation region is reversed appears.
  • a twelfth aspect of the present invention relating to a diffractive multifocal ophthalmic lens is the diffractive multifocal ophthalmic lens according to any one of the first to eleventh aspects, wherein the diffractive zone in the cancel region is the diffractive zone. At least one of the position setting in the zone, the phase setting of the function of the blaze shape in the diffraction zone, and the inclination setting of the function of the blaze shape in the diffraction zone is set differently.
  • the diffraction zone of the cancellation region and the diffraction zone other than the cancellation region include the position setting of the diffraction zone, the phase setting of the function of the blaze shape in the diffraction zone, and the blaze in the diffraction zone. At least one of the shape function inclination setting and the inclination setting is set differently. This makes it possible to find a condition that can further reduce the sideband that is the cause of the blood vision. Note that two or all three may be readjusted to find a condition that can further reduce the sideband that causes the blurred vision.
  • the relative position, phase, and inclination of the blaze between the diffraction zones in the cancellation area are expressed by a predetermined function representing the blaze shape of the diffraction zone. And can be done efficiently by changing the specific constants related to the slope.
  • a thirteenth aspect of the present invention relating to a diffractive multifocal ophthalmic lens is a diffractive multifocal ophthalmic lens according to any one of the first to twelfth aspects, wherein the diffractive structure in the diffraction zone corresponds to a phase.
  • the relief structure reflects the optical path length.
  • the diffractive structure in the diffractive zone is constituted by a relief structure reflecting the optical path length corresponding to the phase.
  • the phase function can be accurately constructed as a real-shaped diffractive structure, and the diffractive structure can be manufactured with high accuracy.
  • the target blood vision can be accurately reduced.
  • the first aspect of the present invention relating to a method for manufacturing a diffractive multifocal ophthalmic lens that can be suitably employed for manufacturing a diffractive multifocal ophthalmic lens having a structure according to the present invention as described above is a concentric circle.
  • the optical unit is provided with a plurality of diffraction zones, and at least two focal points are provided by the optical unit, and the blur vision at the first focal point which is one of the focal points is suppressed.
  • a method for producing a diffractive multifocal ophthalmic lens that employs the following steps (i) to (iv) is characterized.
  • a basic shape setting step for setting a plurality of diffraction zones in the optical unit to which at least two focal points are given.
  • An amplitude information acquisition step of obtaining an amplitude distribution of light provided on the image plane at the first focus by the plurality of diffraction zones set in the basic shape setting step.
  • a reduction target determination step of determining a sideband to be reduced in the amplitude distribution of the light obtained in the amplitude information acquisition step.
  • a cancel zone that suppresses the amplitude distribution of the sideband which is considered to be a major cause of the blurred vision on the image plane at one focal point, is a passing region of the light beam that passes through the pupil in the photopic vision state.
  • the setting of the diffraction zone in the basic shape setting step can be performed by determining a basic phase profile of a diffractive structure that provides a plurality of focal points required for a diffractive multifocal ophthalmic lens. .
  • a side band having a large influence on the blood vision is preferentially selected.
  • a diffraction order close to the peak edge and having a large diffraction order is first or second. The next sideband is selected.
  • the diffractive multifocal ophthalmic lens according to the first aspect has been determined as a reduction target in the reduction target determination step when manufacturing the diffractive multifocal ophthalmic lens.
  • the sideband amplitude and area amplitude data are obtained, the amplitude function of light on the image plane at the first focus is obtained from the amplitude data, and the reduction effect that is offset against the sideband amplitude function is obtained.
  • This is a method of manufacturing a diffractive multifocal ophthalmic lens that employs a canceling diffraction zone that gives an amplitude function of light that affects the above as the canceling region.
  • an algorithm such as a fast Fourier transform is applied to the diffraction zone in the cancel region that reduces the sideband determined in the reduction target determination step in an offset manner. It becomes possible to set with high precision by calculation using.
  • the following equation 16 representing the amplitude function from each diffraction zone at the focal image plane position of the 0th-order diffracted light is preferably used as a basic equation, and this basic equation is mathematically expressed.
  • a third aspect of the present invention relating to a method for manufacturing a diffractive multifocal ophthalmic lens is a method for manufacturing a diffractive multifocal ophthalmic lens according to the first or second aspect, wherein the diffractive structure in the diffraction zone is formed.
  • the phase function is a blazed function, and the first focal point is given by the 0th-order diffracted light of the diffractive structure in the diffraction zone.
  • the objective cancellation zone is utilized by using a mathematical analysis result, and the efficiency is improved. It becomes possible to adjust and reset again.
  • a diffractive multifocal ophthalmic lens when manufacturing a diffractive multifocal ophthalmic lens according to the third aspect, i is formed on the image plane at the first focus.
  • the positions of the c-th diffraction zone are such that the light beams that have passed through the respective diffraction zones weaken the amplitude of each other.
  • the amplitude that has a large influence on the amplitude of the sideband that is the cause of the blood vision is efficiently identified, the combination of the zones that constitute the amplitude is selected, and the amplitude is further reduced to reduce the sideband. It is possible to efficiently set a zone capable of suppressing the band at an appropriate position.
  • a fifth aspect of the present invention relating to a method for manufacturing a diffractive multifocal ophthalmic lens, when manufacturing a diffractive multifocal ophthalmic lens according to the third aspect, i
  • the position of the c-th diffraction zone and the position of the i-th diffraction zone correspond to each diffraction zone.
  • the imaging characteristic based on the Fresnel interval is set by changing and setting the relative position of the i-th diffraction zone and the c-th diffraction zone using Equation 15.
  • the c-th diffraction zone as the cancellation zone can be efficiently designed while maintaining the above.
  • a sixth aspect of the present invention relating to a method for manufacturing a diffractive multifocal ophthalmic lens, in manufacturing a diffractive multifocal ophthalmic lens according to the third aspect, the function of the blaze shape is shifted in the phase axis direction.
  • This is a method for manufacturing a diffractive multifocal ophthalmic lens that is adjusted so that the diffraction zone of the cancellation region weakens the amplitude corresponding to the sideband.
  • the c-th diffraction zone as the cancellation zone can be efficiently designed by changing and setting the relative phase shift amount of the c-th diffraction zone with respect to the i-th diffraction zone. It can. That is, for example, a function corresponding to each of the i-th and c-th diffraction zones on the coordinates defining the blaze-shaped phase function at each lens radius position (r) is a predetermined phase ( ⁇ ) in the phase axis direction on the coordinates.
  • the setting in this aspect can be performed by adjusting by relatively shifting.
  • a seventh aspect of the present invention relating to a method for manufacturing a diffractive multifocal ophthalmic lens is the function of the blaze shape in the diffraction zone of the cancel region when manufacturing a diffractive multifocal ophthalmic lens according to the third aspect.
  • the diffractive multifocal eye is set so that the amplitude corresponding to the sideband is weakened by setting the sign of the tilt of the diffractive zone to a sign opposite to that of the blazed shape in the region other than the canceling region. It is a manufacturing method of a lens.
  • any one of the design methods according to the fourth to seventh aspects described above may be selected and used as necessary, or may be combined in a necessary number as appropriate. It is also possible to design and manufacture the c-th diffraction zone as a cancellation zone, and thus the target diffractive multifocal ophthalmic lens.
  • the eighth aspect of the present invention related to the method for manufacturing a diffractive multifocal ophthalmic lens is the sixth aspect related to the adjustment of the position of the diffraction zone according to the fourth or fifth aspect related to the manufacturing method and the manufacturing method. Adjusting the phase shift amount ⁇ of the diffraction zone according to the method and adjusting the tilt of the blazed shape of the diffraction zone according to the seventh aspect of the manufacturing method in combination with at least two. Is a method for manufacturing a diffractive multifocal ophthalmic lens in which the amplitude corresponding to is set so as to weaken.
  • FIG. 4 is a cross-sectional model diagram of the contact lens corresponding to the IV-IV cross section of FIG. 3.
  • FIG. 4 is a cross-sectional model diagram for explaining a relief shape formed on the back surface of the contact lens shown in FIG. 3.
  • FIG. 1 The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and the modification 1 (broken line) of the comparative example 2.
  • FIG. The simulation result of the intensity distribution on the optical axis in the modification 2 of the comparative example 2.
  • FIG. The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and the modification 2 of the comparative example 2 (broken line).
  • the phase profile of 3rd embodiment (solid line) and comparative example 2 (broken line) of this invention The simulation result of the intensity distribution on the optical axis in this embodiment.
  • the phase profile of 8th embodiment (solid line) and the comparative example 8 (broken line) of this invention The simulation result of the intensity distribution on the optical axis in the comparative example 8 (a) and this embodiment (b). The simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and the comparative example 8 (broken line). The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and Comparative Example 8 (broken line). The phase profile of 9th embodiment (solid line) and comparative example 9 (broken line) of this invention. The simulation result of the intensity distribution on the optical axis in Comparative Example 9 (a) and this embodiment (b).
  • the simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and Comparative Example 10 (broken line).
  • the simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and 4th embodiment (broken line).
  • Simulation results of amplitude functions at phase shift amounts ⁇ 0 (a), ⁇ 0.5 ⁇ (b), and 0.5 ⁇ (c).
  • the simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment solid line
  • 4th embodiment broken line
  • the mechanism of such a phenomenon is first described for the purpose of improving the blood vision, and a method for improving the blood vision based on such a mechanism is described. Then, the new imaging characteristics found from such a method will be described, and it will be explained that it can be applied to multifocal lenses that have recently become increasingly necessary. Such methods and characteristics will be described based on specific examples.
  • the blur of light is the light intensity distribution at the edge portion extending in the radial direction of the image plane indicated by the convolution between the point spread function and the light source intensity distribution. Therefore, reducing the intensity distribution of the light that causes the bleeding can be achieved by reducing the peak intensity of the sideband of the point spread function that is the basis to a level at which the bleeding is not noticeable.
  • the blur of light called “Blood Vision” is observed outdoors when the weather is fine, or when you look far away in a bright environment (approximately 100 to 100000 lux in illuminance), which is said to be a photopic vision at standard brightness such as indoors. Since it is easily perceived, it is desirable to set a diffractive structure that reduces the peak intensity of the sideband in the focal image plane for far vision in the diffraction zone region within the pupil diameter of a person in such a photopic state. .
  • the range of the pupil diameter (radius) of a person in the photopic state varies depending on individual differences, gender, race differences, age differences, etc., and is difficult to determine uniformly. And a minimum of about 0.75 mm to a maximum of 2.5 mm. Therefore, it is desirable that the diffractive structure in which the sideband peak intensity is reduced is set so as to be within the pupil in the photopic state in consideration of such a range.
  • a diffraction zone for generating a plurality of focal points is set in a lens having a specific refractive surface. If the focal point for far vision is set by the 0th-order diffracted light in this diffractive structure, the light emitted from this region when the phase function of the nth zone is ⁇ (r) is the 0th-order focused image.
  • the amplitude function E ( ⁇ ) formed on the surface is expressed by the following equation (17).
  • the amplitude function in this case is expressed by the above equation (16).
  • a ( ⁇ ) be an amplitude function that reduces the amplitude of the sideband that causes the bleeding of light in the amplitude distribution from a region other than this zone
  • the amplitude function E ( ⁇ ) from this region is A ( ⁇ 2)
  • the procedure (1) will be described in the case of the first embodiment of the present invention to be described later.
  • P add 2 (Diopter)
  • ⁇ 546 nm
  • the outermost diameter (radius) of the diffractive structure is 1 in consideration of the average pupil diameter of the human eye at standard brightness during the daytime when blood vision is often perceived.
  • the range is 5 to 3.5 mm.
  • Each diffraction zone has a blazed phase function, and the phase constant h defined by Equation 6 is 0.5.
  • the blaze level difference as an actual shape is obtained by the above formula 7.
  • Step (2) is a dedicated simulation software for designing a diffractive lens, for example, a diffraction calculation simulation method used in the present invention or a commercially available wave optical design / analysis software (trade name: Virtual Lab (manufactured by Light Trans)) Etc. can be used to calculate the amplitude distribution.
  • the phase function is represented by a blazed linear linear equation
  • the diffraction zone radius obtained in step (1) is set to the above-described diffraction zone radius.
  • the phase function of each diffraction zone is specifically obtained by substituting into Equation 2 or Equation 5, and the amplitude for each diffraction zone is calculated by substituting this phase function into Equation 16.
  • the intensity distribution of light is calculated as the absolute value of its conjugate by adding the amplitudes for each diffraction zone.
  • step (3) assume the state of light blur and specify the sideband area for canceling this.
  • sidebands with relatively high intensity existing in the peripheral region in the sideband distribution are easily perceived as spreading blurs, and therefore it is desirable to specify the sideband peak so that the range of such blurring is narrowed.
  • the amplitude cancels the sideband specified in the procedure (3).
  • the phase function ⁇ (r) in the cancellation region can be estimated. It should be noted that the phase function of the zone for emitting the amplitude of the light for canceling gives a large change to the light distribution ratio at each focal position including a far, near, or intermediate region designed at a desired ratio. It is desirable that it is determined within a range.
  • Equation 18 shows that the amplitude function is represented by a cos function that periodically changes with the Sinc function as an envelope. That is, it is considered that the Sinc function dominates and represents the global periodic distribution, while the cosine function dominates and represents a minute period change in detail.
  • the point ⁇ r where the amplitude weakens is Is expressed by the following equation (20).
  • the different zones (r c to r c-1 ) are the two zones (r i to r i-1 and r j to r at that position).
  • the amplitude that most contributes to or conforms to the amplitude of the sideband is identified, the combination of zones constituting the amplitude is extracted, and the amplitude is reduced by the series of relational expressions of Equations 19, 20, and 14.
  • zones r c to r c-1 , zones r i to r i-1 , r j to r j-1 are defined as R 1, when R 2, R 2 to the number 14 can be represented as the number 15 with the number 12.
  • the calculation software used was that which can calculate the amplitude distribution and intensity distribution from each zone based on a diffraction integral formula derived from a theory known in the field called scalar diffraction theory. Using such calculation software, the intensity distribution on the optical axis and the intensity distribution on the image plane (or point spread function) were calculated.
  • the intensity distribution on the optical axis was plotted with respect to the distance on the optical axis with the lens as the base point.
  • the intensity with respect to the distance in the radial direction from the center of the image plane was plotted in the direction where the radial angle of the image plane was zero.
  • the amplitude function the one represented by Equation 18 is used, and the amplitude function is plotted by plotting the amplitude value with respect to the radial distance from the center of the image plane in the same manner as the point spread function.
  • the edge intensity distribution is obtained by translating the numerical data of the point spread function obtained from the simulation calculation by shifting N ⁇ in the radial direction of the image plane based on the formula 11, and adding up the entire integration range.
  • the zone range to be calculated is approximately the maximum diameter (radius) of the diffraction zone of the lens, taking into account the average pupil diameter of the human eye at normal daytime brightness, where blood vision is often perceived.
  • the range was within 1.5 to 2.5 mm, and the entire zone shown in each table was subject to calculation unless otherwise specified.
  • the zone range to be calculated is set so that the aperture diameters to be calculated are substantially the same.
  • the vertical axis of the point spread function and the edge intensity distribution diagram is displayed as an absolute value of the calculated intensity, and the intensity value scale in comparison between each embodiment and the comparative example is Constant.
  • the value of the horizontal axis of the image plane coordinates is required. It should be noted that this is limited to the focal position. What is necessary is just to convert the position of the image surface at the time of changing into a different focal distance using the following Formula 21.
  • FIG. 3 schematically shows a rear view of the optical unit 12 of the ophthalmic lens 10 that is a contact lens according to the first embodiment of the diffractive multifocal ophthalmic lens of the present invention.
  • a cross-sectional view of the optical unit 12 of the same-eye lens 10 is schematically shown.
  • the ophthalmic lens 10 has a central large area as an optical part 12, and a known peripheral part and edge part are formed on the outer peripheral side of the optical part 12.
  • the optical part 12 is formed with an optical part front surface 14 having a substantially spherical crown-shaped convex surface as a whole and an optical part rear surface 16 having a substantially spherical crown-shaped concave surface as a whole.
  • the optical portion 12 of the ophthalmic lens 10 has a generally bowl-like shape with a slightly thin central portion when the lens is used for correcting myopia, and the central portion when used for correcting hyperopia.
  • Such an ophthalmic lens 10 is mounted directly on the cornea of the eyeball. Therefore, it is desirable that the optical part 12 of the ophthalmic lens 10 has a diameter of approximately 4 to 10 mm.
  • the optical unit 12 of the ophthalmic lens 10 has an optical unit front surface 14 and an optical unit rear surface 16 as refractive surfaces.
  • the first focal point is set for the refracted light (0th-order diffracted light) by the optical unit front surface 14 and the optical unit rear surface 16, and in this embodiment, the far vision focal point is set.
  • a conventionally known resin material made of various polymerizable monomers having optical properties such as light transmittance, a gel-like synthetic polymer compound (hydrogel) and the like are preferably used.
  • a gel-like synthetic polymer compound hydrogel
  • PMMA polymethyl methacrylate
  • Poly-HEMA polyhydroxyethyl methacrylate
  • the diffractive structure 20 is formed on the rear surface 16 of the optical part in the present embodiment.
  • a plurality of diffractive structures 20 are concentrically formed around the lens central axis 18 and include reliefs 21 that are undulated in the radial direction and extend in an annular shape continuously in the circumferential direction of the lens.
  • the diffracted + first-order light from the diffractive structure 20 sets a focal point (near vision focus) having a smaller focal length than the far vision focus.
  • each diffractive structure 20 is called a zone (diffraction zone) or an annular zone, and is characterized by a phase function that can modulate the phase of light.
  • FIG. 5A shows an enlarged sectional view in the radial direction of the relief 21 on the rear surface 16 of the optical part.
  • the size of the relief 21 is exaggerated for easy understanding.
  • the shape of the relief 21 has a stepped shape that rises to the right, reflecting the original shape of the rear surface 16 of the optical part of the ophthalmic lens 10.
  • the optical unit rear surface 16 corresponds to the reference line in the r- ⁇ coordinate (FIG. 97) described in the above definition. There is no difference. Further, in FIG.
  • the lower area from the relief 21 is a contact lens base material, and the upper area is an external medium.
  • the shape of the original optical unit rear surface 16 of the ophthalmic lens 10 is removed, that is, as shown in FIG. 5B, the optical unit rear surface 16 is linear in the radial direction.
  • the study of the shape of the relief 21 will be promoted as a proper x coordinate axis.
  • the relief 21 extends concentrically around the lens central axis 18 and protrudes outward (upward in FIGS. 4 to 5) of the ophthalmic lens 10. And an undulating shape having a valley line 24 projecting inward (downward in FIGS. 4 to 5) of the ophthalmic lens 10.
  • the lattice pitch refers to the radial width dimension between the ridge line 22 and the valley line 24.
  • the zone is defined between the ridge line 22 and the valley line 24, and each zone is assigned zone numbers 2, 3,...
  • the zone radius is the outer peripheral radius of each zone, in other words, the concentric circles of the ridge line 22 or the valley line 24 positioned outside the center of the concentric circle (in this embodiment, the lens central axis 18) in each zone.
  • the radius from the center. Therefore, the lattice pitch is the radial width dimension of each zone, and the lattice pitch of a predetermined zone is the difference between the zone radius of the zone and the zone radius of a zone having a zone number one smaller than the zone.
  • the diffractive structure 20 having a relief structure is described together with a specific example of a contact lens.
  • the diffractive structure 20 will be described using a phase function or a phase profile that is a basis of a relief design. Therefore, in the future, unless otherwise specified, the phase profile as the diffractive structure 20 will be represented by the r- ⁇ coordinate system shown in FIG.
  • FIG. 6 is an enlarged cross-sectional view of the phase profile 26 in which each zone according to the first embodiment of the present invention is configured by a blazed phase function, and the shape of a Fresnel zone plate (phase profile 28) as a comparative example 1. Indicates. Details of the phase profile 26 of the present embodiment are shown in Table 1 below, and details of the phase profile 28 of the comparative example are shown in Table 2 below.
  • Comparative Example 1 is configured with a Fresnel interval such that the additional refractive power P add for determining the near vision focus position is 2 (Diopter) with respect to the far vision focus, and is shown in FIG.
  • the intensity distribution of the point spread function at the far vision focus of Comparative Example 1 is indicated by a broken line in FIG. This intensity distribution is an enlarged view around the main peak. In the subsequent intensity distribution diagrams of the point spread function, they are also shown in an enlarged view. It was found that when the edge intensity distribution is calculated from this intensity distribution, the broken line in FIG. 9 is obtained. In the diffractive lens of Comparative Example 1, it is expected that bleeding of light based on such edge intensity distribution is observed.
  • the positions and intervals of the first zone and the second zone are the same as those in Comparative Example 1, and the second zone is the c-th zone of Formula 14, and the positions and intervals of the zones after the third zone are set as follows. It is reset using related mathematical formulas. That is, in the present embodiment, the second zone is set as a canceling area, and the diffraction zone in the canceling area and the diffraction zone other than the canceling area are set with different position settings in the diffraction zone. .
  • all zones except the third zone are determined so that the additional refractive power P add is a Fresnel interval of 2 (Diopter).
  • the present embodiment is the same up to the second zone of Comparative Example 1, but the fourth zone and the fifth zone have the positional relationship based on Equation 14 and the second zone and the fourth zone are formed in order to form the Fresnel interval. A gap will occur between them. In this embodiment, this gap is also considered as one of the constituent zones and is handled as the third zone. In the following embodiments, the case where such a gap occurs is also treated as one of the constituent zones.
  • FIG. 7B shows the intensity distribution on the optical axis of the aperture including up to the sixth zone of the present embodiment.
  • the interval between the third zones is slightly narrowed, but the intensity distribution on the optical axis is not changed as compared with Comparative Example 1 (FIG. 7A), and the reset operation makes it possible to transmit light to the near and far. It can be seen that there is little impact on distribution.
  • the point spread function indicated by the solid line in FIG. 8 shows a distribution in which the side band in the region where ⁇ is about 0.3 to 0.36 mm is clearly reduced, and the edge intensity distribution (FIG. 9) as a result of convolution. It can be seen that the intensity also decreases at the solid line.
  • the edge intensity distribution shown here is a simulation result with a one-dimensional linear light source, and the light source is a two-dimensional surface. It should be noted that this difference is further magnified when having a shape spread. In other words, when actually looking at an object, many of the target objects have a two-dimensional extent, and even if there is a slight difference in the simulation results, this improvement degree for a two-dimensional object is enhanced and clear blurring is reduced. It becomes. From the above, it can be seen that the present embodiment has a phase profile that can reduce the edge intensity without changing the near / far intensity ratio.
  • FIG. 10 shows a phase profile 30 as a second embodiment of the present invention and a phase profile 32 as a comparative example 2. Details of the phase profile 30 of the present embodiment are shown in Table 3, and details of the phase profile 32 of Comparative Example 2 are shown in Table 4.
  • Comparative Example 2 the aperture diameter of the calculation target of Comparative Example 1 is enlarged and the calculation target is up to the sixth zone, and the phase constant and the additional refractive power are the same as those of Comparative Example 1.
  • the intensity distribution, the point spread function, and the edge intensity distribution on the optical axis of Comparative Example 2 are shown in FIG. 11A, the broken line in FIG. 12, and the broken line in FIG.
  • the position and interval from the first zone to the third zone are the same as in Comparative Example 2, the third zone is the c-th zone of Formula 14, and the positions and intervals of the zones after the fourth zone are related. It is reset using mathematical formulas. That is, in the present embodiment, the third zone is set as a canceling area.
  • FIG. 14 shows a phase profile 34 as Modification 1 of the second embodiment of the present invention and a phase profile 36 as Modification 1 of Comparative Example 2. Details of the phase profile 34 of the present embodiment are shown in Table 5 below, and details of the phase profile 36 of Modification 1 of Comparative Example 2 are shown in Table 6 below.
  • the third zone is set as a cancellation area.
  • the present embodiment it is possible to reduce the edge strength distribution while avoiding the manufacturing difficulty by providing the blaze structure in the fourth zone having a narrow interval in the second embodiment by substituting the refractive region. It is an example to show.
  • the intensity distribution, point spread function, and edge intensity distribution on the optical axis of this embodiment are shown in FIG. 15B, the solid line in FIG. 16, and the solid line in FIG. It can be seen that even when the fourth zone is a refractive region, the effect of reducing the edge strength is maintained as in the second embodiment.
  • the fourth zone generated as a gap in this way has a low ratio in the diffractive structure 20, and therefore, even a refracting region as shown in this example or another easily manufactured diffractive structure 20 has little influence.
  • phase constant (h) of the fourth zone in Comparative Example 2 is set to 0.45 in order to match the far and near intensity ratio on the optical axis of this embodiment. It has been reworked.
  • FIG. 18 shows the phase profile 30 as the second embodiment of the present invention and the phase profile 38 as the second modification of the second comparative example.
  • Table 7 shows details of the phase profile 38 of the second modification of the second comparative example.
  • Modification 2 of Comparative Example 2 is obtained by changing the phase constant (h) of Comparative Example 2 so as to obtain an edge intensity distribution similar to that of the second embodiment. Specifically, the phase constant (h) from the first zone to the third zone was set to 0.6, and the phase constant (h) from the fourth zone to the sixth zone was set to 0.4. Thereby, it can be seen that the edge intensity distribution of almost the same degree as in the second embodiment can be achieved (FIG. 20), and the intensity distribution on the optical axis is substantially the same (FIG. 19).
  • the edge intensity distribution must be reduced by changing the light distribution ratio between the near and far distances and the other focal positions.
  • the simple operation of resetting the arrangement between zones based on the above it is possible to reduce the intensity of the edge without greatly changing the target distribution ratio of near and near light, and to suppress the bleeding of light. .
  • the method of adjusting the distribution of light to each focus by changing the phase constant (h) is to reduce the edge intensity and balance the appearance at each focus position in the method of the present invention. Since it is useful, it is possible to use such a change of the phase constant (h) in combination.
  • FIG. 22 shows a phase profile 40 as a third embodiment of the present invention and a phase profile 32 as a comparative example 2. Details of the phase profile 40 of the present embodiment are shown in Table 8 below.
  • the positions and intervals of the first zone to the third zone are reset using related mathematical formulas without changing the positions and intervals of the fourth zone to the sixth zone of Comparative Example 2 as they are.
  • the third zone is set as a canceling area.
  • FIG. 23 shows the intensity distribution on the optical axis of this embodiment.
  • the radius of the first zone is smaller than those of Comparative Examples 1 and 2 and the first and second embodiments so that the inner zone including the third zone also has the Fresnel interval.
  • the radius of the first zone is different from the normal Fresnel interval and there is a gap as in the fourth zone, it is equivalent to the comparative example 2 (FIG. 11 (a)) at the far and near focal positions. It can be seen that a clear peak is formed. Therefore, it can be seen that the light distribution at each focal position initially set by the resetting operation has little influence.
  • the edge intensity distribution in this case is shown in FIG. From this figure, it can be seen that the swelling of the edge strength is reduced as compared with Comparative Example 2 (broken line).
  • the sideband strength around 0.27 mm increased (FIG. 24).
  • the strength of the peripheral portion of the edge can be reduced, in some cases, the strength may slightly increase inside the edge.
  • the edge intensity in this area increases.
  • the diffractive zone necessary for sufficiently expressing the multifocal function within a small aperture diameter From the point that an area can be set, it is useful as a contact lens for elderly people whose pupil diameter has decreased with aging, or an intraocular lens inserted into the eye after cataract surgery.
  • Equations 19, 20, and 14 can be similarly applied to the diffraction structure 20 having an interval other than the Fresnel interval.
  • the diffractive structure 20 having equally spaced regions with equal zone intervals can also form multifocals, which is useful as a diffractive multifocal ophthalmic lens.
  • An example of reducing the edge strength for the diffractive structure 20 having such equally spaced regions will be described below. First, an example of reducing the amplitude distribution in the region where the equally spaced zones are adjacent will be described.
  • FIG. 26 shows a phase profile 42 as a fourth embodiment of the present invention and a phase profile 44 as a comparative example 4. Details of the phase profile 42 of the present embodiment are shown in Table 9 below, and details of the phase profile 44 of Comparative Example 4 are shown in Table 10 below.
  • the intensity distribution on the optical axis of the aperture including up to the sixth zone of Comparative Example 4 is shown in FIG.
  • the diffractive lens including the equidistant region has a characteristic that a peak capable of generating a focal point is formed also in the intermediate region by light emitted from the equidistant region. Such a characteristic is effective as a multifocal ophthalmic lens that can also visually recognize an object in an intermediate region such as when looking at a personal computer monitor.
  • the first zone to the third zone are the same as those in the comparative example 4, the third zone is the c-th zone of Formula 14, and the equidistant region between the fifth zone and the sixth zone is calculated based on this formula.
  • FIG. 27 (b) shows the intensity distribution on the optical axis for the aperture diameter including up to the sixth zone of the present embodiment. It can be seen that focus forming peaks are generated not only in the vicinity but also in the middle, and the intensity ratio of each focus position is almost the same as that of Comparative Example 4 (FIG. 27A). From this, it can be seen that there is almost no influence on the light distribution to each focal point by performing the resetting of the zone.
  • An edge intensity distribution based on the convolution of the point spread function is shown in FIG. 29 (solid line).
  • the position of the third zone is fixed as in Comparative Example 4, and the position of the equidistant region is set using a mathematical formula so as to send out a wave that cancels this at a point where the amplitude of the equidistant region strengthens.
  • the intensity distribution on the optical axis of the aperture including up to the fifth zone of Comparative Example 5 is shown in FIG. It can be seen that Comparative Example 5 also has an intermediate region focal point formation peak due to the equidistant region other than the near peak.
  • the phase constant is slightly changed as shown in Table 11 in order to match the intensity ratio of each focal point with Comparative Example 5.
  • the interval is exactly the same as that of the comparative example except that the interval is narrowed so that the interval of the third zone is slightly compressed.
  • FIG. 32B shows the intensity distribution on the optical axis at the aperture diameter including up to the fifth zone of the present embodiment.
  • the intensity ratio in Example 5 is the same as that in Comparative Example 5.
  • FIG. 35 shows a phase profile 50 as a sixth embodiment of the present invention and a phase profile 52 as a comparative example 6. Details of the phase profile 50 of the present embodiment are shown in Table 13, and details of the phase profile 52 of Comparative Example 6 are shown in Table 14.
  • the intensity distribution on the optical axis of the aperture including up to the fifth zone of Comparative Example 6 is shown in FIG. It can be seen that Comparative Example 6 also shows an intermediate region focus formation peak due to the inclusion of equally spaced regions in addition to the near peak. In addition, it can be seen that the near focus position is closer to the lens side than in the previous embodiments by setting the additional refractive power P add to 2.5 (Diopter).
  • ⁇ 0.26 mm.
  • the edge intensity in such a case is as shown in FIG. 38 (broken line), and it can be seen that the intensity distribution is swollen. From this edge intensity distribution, it is expected that the blur of light increases in the vicinity of the edge of the image.
  • the interval is exactly the same as that of Comparative Example 6 except that the interval of the third zone is narrowed to be slightly compressed.
  • FIG. 36B shows the intensity distribution on the optical axis at the aperture diameter including up to the fifth zone in Example 6. It can be seen from this that even if the zone is reset, the intensity ratio of each focal position has almost no influence.
  • FIG. 39 shows a phase profile 54 as a comparative example 7 and a phase profile 56 as a seventh embodiment of the present invention. Details of the phase profile 56 of the present embodiment are shown in Table 15, and details of the phase profile 54 of Comparative Example 7 are shown in Table 16.
  • the interval is the same as that of Comparative Example 7 except that the third zone is compressed and the interval is narrowed.
  • FIG. 40B shows an intensity distribution on the optical axis for the aperture diameter including up to the sixth zone of the present embodiment. Compared with Comparative Example 7, it shows a slightly different intensity distribution, such as a reduced number of peaks, but it can be seen that multifocals can be formed.
  • the edge intensity distribution at this time is as shown in FIG.
  • the first zone to the third zone in the center are configured by a Fresnel interval such that the additional refractive power P add is 2 (Diopter), and the fourth zone from the fourth zone to the seventh zone is the fourth zone.
  • the intensity distribution on the optical axis of Comparative Example 8 is shown in FIG. In this case as well, although not adjacent to each other, there are equidistant regions, and it can be seen that there are peaks that can form a plurality of focal points from the near region to the intermediate region.
  • the interval to the second zone is the same as that in Comparative Example 8, and the second zone is set as the c-th zone of Formula 14, and the arrangement of equally spaced regions is calculated based on the mathematical formula.
  • the i-th zone is the fourth zone
  • the j-th zone is the sixth zone
  • the intervals of the remaining zones are the same as those in the comparative example 8, except that the third zone is compressed and the interval is narrowed.
  • FIG. 44B shows the intensity distribution on the optical axis for the aperture diameter including up to the seventh zone of the present embodiment.
  • the intensity of the near vision focus peak is slightly smaller than that of Comparative Example 8, it can be seen that the intensity distribution is similar to that of Comparative Example 8 and can form multiple focal points.
  • the edge intensity distribution at this time is as shown in FIG. 46 (solid line), and it can be seen that the intensity of the protruding area decreases and becomes a gentle distribution. Therefore, it can be seen that the diffractive lens having such a phase profile can suppress the bleeding of light.
  • FIG. 47 shows a phase profile 62 as a ninth embodiment of the present invention and a phase profile 64 as a comparative example 9. Details of the phase profile 62 of this embodiment are shown in Table 19, and details of the phase profile 64 of Comparative Example 9 are shown in Table 20.
  • the fresnel interval is determined by calculating the radius of the fourth zone as the first zone radius r 1 when the Fresnel interval of Formula 12 is determined.
  • the comparative example 9 has a reverse arrangement in which an equally-spaced region exists in the center and a fresnel interval is arranged in the periphery thereof.
  • FIG. 48A shows the intensity distribution on the optical axis for the aperture diameter including up to the sixth zone.
  • the distance to the fourth zone is the same as that in Comparative Example 9, and the third, fourth, and sixth zones are the j, i, and cth zones of Equation 14, and the outer diameter of the fifth zone is the first.
  • the positions of the fifth zone and the sixth zone are reset so that the Fresnel interval becomes one radius. That is, in the present embodiment, the sixth zone is set as a canceling area.
  • the calculation is performed by reversing the sign of the ⁇ value of the appearance position of the amplitude to be canceled in Equation 14 from the previous calculation examples. did.
  • FIG. 48B shows the intensity distribution on the optical axis for the aperture diameter including up to the sixth zone of the present embodiment.
  • the intensity distribution is almost the same as that of Comparative Example 9, and it can be seen that even if such a resetting operation is performed, there is almost no influence on the light distribution to the near and far.
  • FIG. 49 solid line
  • FIG. 50 solid line
  • FIG. 50 solid line
  • phase profile 66 shows a phase profile 66 as the tenth embodiment of the present invention and a phase profile 68 as the comparative example 10.
  • FIG. Details of the phase profile 66 of this embodiment are shown in Table 21, and details of the phase profile 68 of Comparative Example 10 are shown in Table 22.
  • Comparative Example 10 in the diffractive structure 20 composed of the Fresnel interval and the equidistant region shown in the fourth to ninth embodiments, the Fresnel interval region is replaced with the equidistant region, and the central first zone and the second zone are changed.
  • the comparative example 10 shows an example of the diffractive structure 20 that is formed of equidistant regions although the whole area and the interval are different without using the Fresnel interval as before.
  • the peak intensity at each focal position is larger than in Comparative Example 10.
  • the relative ratio of the peaks at the respective focal positions is substantially the same as in Comparative Example 10, and it can be seen that such resetting operation does not significantly affect the intensity distribution on the optical axis.
  • the point spread function of this embodiment is shown in FIG. 53 (solid line).
  • the point spread function and the edge intensity distribution are displayed as relative intensities normalized by their maximum intensity.
  • the above is a simple operation that simply resets the position of the zone using a series of relational expressions, and has a point image with little effect on the light distribution behavior to each focal point of the diffractive multifocal ophthalmic lens.
  • a method for designing a diffractive lens in which the sideband of the spread function is reduced and, as a result, light bleeding is suppressed, and the specifications of the diffractive lens obtained thereby are described.
  • the position may be reset by slightly changing ⁇ r in Expression 20, or may be reset by changing q r in Expression 14 without directly changing ⁇ r .
  • the position of the zone calculated from Equation 14 may be set by directly shifting. An example in which the edge intensity distribution is controlled by slightly shifting the position of the zone from the calculated value of Equation 14 is shown below.
  • FIG. 56 shows a phase profile 70 according to the eleventh embodiment of the present invention and a phase profile 42 according to the fourth embodiment. Details of the phase profile 70 of the present embodiment are shown in Table 23, and details of the phase profile 42 of the fourth embodiment are shown in Table 9. In the present embodiment, the third zone is set as a cancellation area.
  • FIG. 57 shows the intensity distribution on the optical axis of the aperture including up to the sixth zone of the present embodiment. From the figure, since the moving amount is small even if the fifth zone and the sixth zone are shifted inward by 0.03 mm as a whole, the fourth example of FIG. 27A and the fourth example of FIG. It can be seen that there is no significant change in the intensity distribution of the peak at each focal position as compared to the intensity distribution on the optical axis of the embodiment.
  • the point spread function of this embodiment is shown in FIG. 58 in comparison with the fourth embodiment.
  • the calculated position may be used as it is for the zone position to be reset from the equation (14), or such a formula can be used as an estimated value for the first stage of the zone position relationship for further balancing. Alternatively, fine adjustment may be made before and after this so as to obtain an edge intensity distribution.
  • the sideband peak can be changed by changing the phase shift amount ⁇ based on some embodiments. It is shown that the edge strength can be reduced as a result.
  • FIG. 60 shows a phase profile 72 as a twelfth embodiment of the present invention and a phase profile 74 of Comparative Example 12. Details of the phase profile 72 of the present embodiment are shown in Table 24, and details of the phase profile 74 of Comparative Example 12 are shown in Table 25.
  • This is a phase profile of a diffractive multifocal ophthalmic lens constructed at equal intervals of 35 mm.
  • the phase profile of Comparative Example 12 is indicated by a broken line in FIG.
  • the intensity distribution on the optical axis of this profile is shown in FIG. In such a phase profile, it can be seen that the focus generation peak is formed not only in the perspective but also in the intermediate region due to the presence of the equidistant region, which is useful as a multifocal ophthalmic lens.
  • the intensity distribution on the optical axis of the present embodiment is substantially the same as that of the comparative example 12 as shown in FIG. 61B, and distribution of light to each focal point by introducing such a phase shift amount ⁇ . It turns out that there is almost no influence.
  • the edge intensity distribution (solid line in FIG. 63) also reflects the change in the point spread function, and it can be seen that the bulge observed in Comparative Example 12 is dented and the intensity is reduced. Therefore, it can be seen that the present embodiment reduces light bleeding.
  • Equation 18 The sideband reduction effect by varying the phase shift amount ⁇ will be described in more detail. From Equation 18, it can be seen that ⁇ can directly modulate the phase of the cos function. As shown in FIG. 64, when the phase shift amount ⁇ is introduced, the phase of the amplitude function is changed, and the amplitude position can be shifted as the wave advances or delays. The behavior of the amplitude function based on Equation 18 of this embodiment is shown in FIG. 65 (the amplitude function of the first zone is not displayed). Comparing before adding the phase shift amount ⁇ (FIG. 65 (a)) and after applying the phase shift amount ⁇ (FIG. 65 (b)), a zone in which ⁇ is applied to the phase shift amount ⁇ , that is, cancellation.
  • the amplitude of the diffraction zone in the working area is slightly shifted.
  • the phase shift amount ⁇ is small, it can be seen that the sideband peak is reduced as a result of the mutual interference of the entire zone.
  • the phase shift amount ⁇ may be introduced in any zone, and may be set not only in one place but also in a plurality of places. Further, the phase shift amount ⁇ may be given a positive shift as well as a negative shift. Moreover, when setting to a some zone, a positive / negative code
  • the value of the phase shift amount ⁇ and the zone to be applied may be set so that the target amplitude can be canceled or reduced. Desirably, it is desirable to set so as not to affect the light distribution behavior to each focal position of the set profile. Further, another example of edge strength reduction using the phase shift amount ⁇ will be described.
  • phase profile 66 shows a phase profile 76 as a thirteenth embodiment of the present invention and a phase profile 78 of Comparative Example 13.
  • FIG. Details of the phase profile 76 of this embodiment are shown in Table 26, and details of the phase profile 78 of Comparative Example 13 are shown in Table 27.
  • FIG. 3 is a phase profile of a diffractive multifocal ophthalmic lens configured at an equal interval of 3 mm.
  • the phase profile of Comparative Example 13 is indicated by a broken line in FIG.
  • the intensity distribution on the optical axis of such a profile is shown in FIG. In such a phase profile, it can be seen that the focus generation peak is formed not only in the perspective but also in the intermediate region due to the presence of the equidistant region, which is useful as a multifocal ophthalmic lens.
  • the zone interval is exactly the same as that of Comparative Example 13, but it is ⁇ 0.2 ⁇ with respect to the blaze of the fourth zone, and the blaze of the sixth zone.
  • the intensity distribution on the optical axis of the present embodiment is substantially the same as that of Comparative Example 13 as shown in FIG. 67B, and the distribution of light to each focal point by introducing such a phase shift amount ⁇ . Can be seen to have little effect.
  • the edge intensity distribution (solid line in FIG. 69) also reflects the change in the point spread function, and it can be seen that the bulge observed in Comparative Example 13 is dented and the intensity is reduced. Therefore, it can be seen that the present embodiment reduces light bleeding.
  • the edge intensity distribution can be reduced only by changing the phase shift amount ⁇ in addition to resetting the zone position, and light bleeding can be suppressed.
  • FIG. 70 (a) shows the phase profile 80 of Comparative Example 14
  • FIG. 70 (b) shows the phase profile 82 as the fourteenth embodiment of the present invention. Details of the phase profile 82 of this embodiment are shown in Table 28, and details of the phase profile 80 of Comparative Example 14 are shown in Table 29.
  • the intensity distribution on the optical axis of such a profile is shown in FIG. Due to the existence of the equidistant region, peaks for focus generation are formed not only in the perspective but also in the intermediate region.
  • the fourth zone is a refracting region, the far-intensity ratio is relatively increased.
  • Such a profile is useful as a multifocal ophthalmic lens focusing on far vision.
  • the edge intensity based on the spread function is as shown in FIG. 73 (broken line), and the intensity distribution has a bulge. Therefore, even in such a profile, light bleeding may occur.
  • FIG. 70B shows the profile of this embodiment.
  • the blaze set with the phase constant (h) of ⁇ 0.2 has a slope opposite to the blaze of the other zones.
  • the fourth zone is set as the canceling region, and the diffraction zone in the canceling region has a sign of the inclination of the blaze shape in the diffraction zone different from that in the diffraction zone other than the canceling region. Is set.
  • the intensity distribution and the point spread function on the optical axis of this profile are shown in FIG. 71 (b) and FIG. 72 (solid line), respectively.
  • a region where the Sinc pole was positive before the variable may be negative after the variable.
  • the phase of the cos function does not change even when the phase constant (h) is varied, in the region where the poles of the Sinc function are opposite to each other, the polarity of the amplitude function as a whole is reversed by the inversion of the poles. The area that will become. If this region corresponds to the appearance position of a harmful sideband such as a blur of light, the amplitude of the sideband can be reduced or canceled by this method.
  • the variable range of the phase constant (h) may be determined in consideration of the position and strength of the target sideband, and is not particularly limited.
  • FIG. 75 (a) shows the phase profile 84 of Comparative Example 15
  • FIG. 75 (b) shows the phase profile 86 as the fifteenth embodiment of the present invention. Details of the phase profile 86 of the present embodiment are shown in Table 30, and details of the phase profile 84 of Comparative Example 15 are shown in Table 31.
  • the phase constant (h) of the fifth zone is 0, and only this is the refractive region.
  • the intensity distribution on the optical axis of such a profile is shown in FIG. Due to the existence of the equidistant region, peaks for focus generation are formed not only in the perspective but also in the intermediate region.
  • the diffractive lens having this profile is useful as a multifocal ophthalmic lens.
  • the point spread function of such a profile is shown in FIG. 77 (broken line).
  • the edge intensity based on the spread function is as shown in FIG. 78 (broken line), and the intensity distribution has a bulge. Therefore, even in such a profile, light bleeding may occur.
  • the intensity distribution on the optical axis and the point spread function of this profile are shown in FIG. 76 (b) and FIG. 77 (solid line), respectively. It can be seen that the intensity distribution on the optical axis is almost the same as that of Comparative Example 15, and that the introduction of blaze in the opposite direction has little influence on the distribution of light to each focal point.
  • the method for reducing the sideband intensity, reducing the edge intensity, and suppressing the bleeding of light may be used alone or in combination. Next, an example in which each method is combined will be described.
  • phase profile 88 shows a phase profile 88 according to the sixteenth embodiment of the present invention and a phase profile 30 according to the second embodiment. Details of the phase profile 88 of the present embodiment are shown in Table 32, and details of the phase profile 30 of the second embodiment are shown in Table 3.
  • Comparative Example 16 is the second embodiment, and in the second embodiment, it is used here as a comparative example to show that the bleeding of light is further suppressed by a combination of methods.
  • the profile is such that the position of the blaze is shifted in the ⁇ direction corresponding to the introduced phase shift amount. The intensity distribution on the optical axis of such a profile is shown in FIG.
  • FIG. 83 shows the phase profile 90 as the seventeenth embodiment of the present invention and the phase profile 42 of the fourth embodiment. Details of the phase profile 90 of the present embodiment are shown in Table 33, and details of the phase profile 30 of the fourth embodiment are shown in Table 9.
  • Comparative Example 17 is the fourth embodiment, and in the fourth embodiment, it is used here as a comparative example in order to show that the bleeding of light is further suppressed by the combination of methods.
  • the profile is such that the position of the blaze is shifted in the ⁇ direction corresponding to the introduced phase shift amount.
  • the intensity distribution of the profile on the optical axis is shown in FIG. 84B in comparison with Comparative Example 17 (FIG. 84A).
  • FIG. 87 shows a phase profile 92 according to the eighteenth embodiment of the present invention and a phase profile 86 according to the fifteenth embodiment. Details of the phase profile 92 of the present embodiment are shown in Table 34, and details of the phase profile 30 of the fifteenth embodiment are shown in Table 30.
  • Comparative Example 18 is the fifteenth embodiment, and in the fifteenth embodiment, it is used here as a comparative example to show that light bleeding is further suppressed by a combination of methods.
  • the profile is such that the position of the blaze is shifted in the ⁇ direction corresponding to the phase shift amount introduced.
  • the intensity distribution of the profile on the optical axis is shown in FIG. 88 (b) in comparison with Comparative Example 18 (FIG. 88 (a)).
  • the edge intensity can be more effectively reduced by the combination of the respective methods, and as a result, a diffractive multifocal ophthalmic lens with greatly improved light bleeding can be obtained.
  • the third zone can be recognized as a canceling area, but the fifth and seventh zones are canceled when viewed as a reduction effect of the edge strength by the variation method of the phase shift amount ⁇ . It is recognized that it falls under the business domain.
  • it is not necessary to interpret a specific or one zone as a canceling area in a limited manner.
  • the contact lens material is a hydrous soft contact lens containing 2-hydroxyethyl methacrylate as the main component and a water content of about 37.5%.
  • the lens diameter is 14 mm
  • the optical part diameter is 8 mm
  • the base curve is 8.5 mm.
  • the refractive index of the lens substrate is 1.438
  • the refractive index of the medium is 1.335
  • the wavelength is 546 nm
  • the phase profiles of Example 5 and Comparative Example 5 are converted into a relief structure, and such a relief is formed on the rear surface of the lens.
  • the provided contact lens was produced.
  • the prototype contact lens is immersed in a glass cell filled with physiological saline, the cell is placed in front of the camera lens, and an indoor fluorescent lamp is photographed. The light intensity distribution at the edge of the fluorescent lamp is examined. It was.
  • FIG. 91 (a) is a photograph of an edge portion of a fluorescent lamp taken through a contact lens having a phase profile of Comparative Example 5. Light blur is observed in the range shown in this figure.
  • FIG. 91B is a photograph of the edge portion of the fluorescent lamp taken through the contact lens having the phase profile of Example 5, and it can be seen that the blur of light at the edge portion is reduced as compared with Comparative Example 5.
  • the intensity distribution (FIG. 92) of the edge portion measured in the actual photograph data is similar to the theoretically obtained edge intensity distribution of FIG. 34, and the result as simulated is obtained. I understand.
  • the sideband intensity in the point spread function can be reduced with little change in the light distribution ratio to each focal position, and the edge intensity can also be reduced.
  • a diffractive multifocal ophthalmic lens in which light bleeding is suppressed can be obtained.
  • the diffractive structure 20 shown in each of the above embodiments may be set on either the front surface or the rear surface of the target ophthalmic lens 10. Or you may install in the inside of a lens. Further, as described in, for example, Japanese Patent Application Laid-Open No. 2001-42112, the diffractive structure 20 according to the present invention can be formed on a laminated surface made of two materials having different refractive indexes.
  • the focus position to which the present invention can be applied is not particularly limited to the far vision focus, and other focus positions such as the near vision focus or the intermediate vision focus are 0.
  • the method of the present invention is equally applicable when formed with the next diffracted light.
  • the ophthalmic lens 10 specifically includes contact lenses, glasses, intraocular lenses, and the like. Furthermore, the present invention can be applied to a corneal insertion lens that is implanted in the corneal stroma and corrects visual acuity, or an artificial cornea.
  • contact lenses it is preferably used for hard oxygen-permeable hard contact lenses, water-containing or non-water-containing soft contact lenses, and oxygen-permeable water-containing or non-water-containing soft contact lenses containing a silicone component. be able to.
  • the intraocular lens can be suitably used for any intraocular lens such as a hard intraocular lens or a soft intraocular lens that can be folded and inserted into the eye.
  • the problem of the blood vision, waxy vision, or petroleum jelly vision pointed out by the conventional diffractive multifocal intraocular lens can be solved.
  • the entire diffraction structure 20 has a single grating pitch ( ⁇ r).
  • ⁇ r grating pitch
  • equidistant regions consisting of, composed of a plurality of equidistant regions with different lattice pitches ( ⁇ r), or zones of a single lattice pitch ( ⁇ r) are arranged at regular intervals.
  • Those composed of a repetitive periodic structure those composed of a repetitive periodic structure in which zones of different lattice pitches ( ⁇ r) are alternately arranged, and further, zones of a single lattice pitch ( ⁇ r) are arranged at irregular intervals.
  • a configuration in which the equally spaced region is configured in combination with a region having an interval according to another rule is also included in the aspect of the present invention.
  • a combination of an equally spaced region and a region having a Fresnel interval is included in the present invention.
  • another zone a zone that does not constitute the equidistant region
  • the number, size, etc. of other zones may be constant among the zones constituting the equally spaced region or may be different from each other according to the required optical characteristics.
  • the configuration form of the diffractive structure 20 including the equidistant regions is not limited to the above example because various permutations and combinations other than the above example are conceivable.
  • the lattice pitch ( ⁇ r), the phase constant h, the phase shift amount ( ⁇ ), or the configuration of the equidistant region the blood vision is reduced, and an appropriate position in the near or near middle
  • ophthalmic lens ophthalmic lens
  • 12 optical unit
  • 20 diffractive structure
  • 26, 42, 72, 82 phase profile

Landscapes

  • Health & Medical Sciences (AREA)
  • Ophthalmology & Optometry (AREA)
  • Physics & Mathematics (AREA)
  • General Health & Medical Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • Oral & Maxillofacial Surgery (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Vascular Medicine (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Transplantation (AREA)
  • Engineering & Computer Science (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Cardiology (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Eyeglasses (AREA)
  • Diffracting Gratings Or Hologram Optical Elements (AREA)
  • Prostheses (AREA)

Abstract

In a diffractive multifocal ophthalmic lens capable of forming multiple focus points, in order to reduce blurred vision which may become problematic in distance vision in photopic environments in particular, a study of the mechanism of blurred vision was undertaken, and a diffractive multifocal ophthalmic lens which was found on the basis of a solution based on the study results and which has a novel structure capable of effectively decreasing blurred vision and improving quality of sight, and a method of producing the same, are provided. In this diffractive multifocal ophthalmic lens (10), a cancellation region which imparts an amplitude distribution for destructively decreasing the sideband, which is the main cause of blurred vision on the image surface in a focus point, is formed within a region in an optical area (12) that corresponds to the pupil diameter in a photopic state.

Description

回折型多焦点眼用レンズとその製造方法Diffractive multifocal ophthalmic lens and manufacturing method thereof
　本発明は、人眼に用いられて人眼光学系への矯正作用等を発揮するコンタクトレンズおよび眼内レンズなどの眼用レンズに係り、特に新規な構造の回折構造を備えた多焦点眼用レンズとその製造方法に関する。 The present invention relates to an ophthalmic lens such as a contact lens and an intraocular lens that is used for the human eye and exhibits a correction action on a human eye optical system, and more particularly for a multifocal eye having a diffractive structure having a novel structure. The present invention relates to a lens and a manufacturing method thereof.
　従来から、人眼の光学系における屈折異常の矯正用光学素子や水晶体摘出後の代替光学素子などとして、眼用レンズが用いられている。そのなかでも、人眼に装着して用いられるコンタクトレンズや、人眼に挿入して用いられる眼内レンズは、人眼に直接に用いられて大きな視野を提供すると共に、見え方の違和感を軽減することができることから、広く利用されている。 Conventionally, an ophthalmic lens has been used as an optical element for correcting refractive error in an optical system of the human eye or an alternative optical element after extracting a lens. Among them, contact lenses that are used by being attached to the human eye and intraocular lenses that are used by being inserted into the human eye are used directly by the human eye to provide a large field of view and reduce the sense of discomfort. It can be used widely.
　ところで、近年では老眼年齢に達した人達においても継続してコンタクトレンズを使用する人が増えている。かかる老眼となった人は焦点の調節機能が低下しているため、近くのものにピントが合わせにくいという症状が現れる。よって、かかる老眼患者に対しては近くのものにも焦点を合わせることのできる多焦点コンタクトレンズが必要となる。また、白内障手術を施術された患者においては調整機能を司る水晶体が除去されるため、その代替としての眼内レンズを挿入しても近方が見づらいという症状が残る。かかる眼内レンズにおいても複数の焦点を有する多焦点機能を有することが必要となっている。このように近年の高齢者社会を反映して多焦点眼用レンズの必要性は非常に高まっている。 By the way, in recent years, people who have reached presbyopia age continue to use contact lenses. The person with such presbyopia has a reduced focus adjustment function, so that a symptom that it is difficult to focus on a nearby object appears. Thus, for such presbyopic patients, a multifocal contact lens is required that can focus on nearby objects. Further, in patients who have undergone cataract surgery, the crystalline lens that controls the adjustment function is removed, so that the symptom that it is difficult to see the vicinity remains even if an intraocular lens is inserted as an alternative. Such intraocular lenses are also required to have a multifocal function having a plurality of focal points. Thus, the need for a multifocal ophthalmic lens is greatly increased reflecting the recent elderly society.
　かかる多焦点眼用レンズを実現する方法としては、屈折原理に基づき複数の焦点を形成する屈折型多焦点眼用レンズと回折原理に基づき複数の焦点を形成する回折型多焦点眼用レンズの例が知られている。後者の回折型の眼用レンズにおいては、レンズの光学部に同心円状に複数形成された回折構造を備えており、かかる複数の回折構造（ゾーン）を通過した光波の相互干渉作用によって複数の焦点を与えるものである。それ故、屈折率の相違する境界面からなる屈折面での光波の屈折作用によって焦点を与える屈折型レンズに比して、レンズ厚さの増大を抑えつつ大きなレンズ度数を設定することが出来る等の利点がある。 Examples of a method for realizing such a multifocal ophthalmic lens include a refractive multifocal ophthalmic lens that forms a plurality of focal points based on the refraction principle and a diffractive multifocal ophthalmic lens that forms a plurality of focal points based on the diffraction principle. It has been known. The latter diffractive type ophthalmic lens has a plurality of concentric diffractive structures formed in the optical part of the lens, and a plurality of focal points are formed by the mutual interference action of light waves that have passed through the diffractive structures (zones). Is to give. Therefore, it is possible to set a large lens power while suppressing an increase in the lens thickness as compared with a refractive lens that focuses by the refracting action of a light wave on a refracting surface composed of a boundary surface having a different refractive index. There are advantages.
　一般に回折型多焦点レンズは、フレネル間隔というある規則に従いレンズ中心から周辺に向うにつれて回折ゾーンの間隔が徐々に狭くなった回折構造を有するものであり、かかる構造から生成する０次回折光と１次回折光を利用して多焦点とするものである。通常は、０次回折光を遠方視用の焦点とし、＋１次回折光を近方視用の焦点とする。かかる回折光の分配によって遠近用の焦点を有するバイフォーカルレンズとすることができる。かかる遠近用の焦点を生成し得る回折多焦点レンズの例として、米国特許５１４４４８３（特許文献１）が挙げられる。 In general, a diffractive multifocal lens has a diffractive structure in which the distance between diffraction zones gradually decreases from the center of the lens toward the periphery in accordance with a certain rule called Fresnel spacing. Multi-focality is achieved using origami. Usually, the 0th-order diffracted light is used as a focal point for far vision, and the + 1st-order diffracted light is used as a focal point for near vision. By the distribution of the diffracted light, a bifocal lens having a focal point for near and near can be obtained. An example of a diffractive multifocal lens that can generate such a perspective focus is US Pat. No. 5,144,483 (Patent Document 1).
　また、近年では、前記した白内障手術後に挿入する眼内レンズとして回折型の多焦点眼内レンズが実用化され、眼鏡なしで遠方も近方も見ることが可能な眼内レンズとしての有効性が認められている。 In recent years, a diffractive multifocal intraocular lens has been put to practical use as an intraocular lens to be inserted after the above-described cataract surgery, and it is effective as an intraocular lens that can be viewed both far and near without glasses. It recognized.
　ところが、このような回折型多焦点レンズでは、特に眼内レンズとしての適用例が増えるに伴って、未だ解決すべき問題点の存在が明らかとなってきている。それは見え方に関するもので、回折型多焦点眼内レンズが埋殖された患者においては物を見る時、靄がかかったような、あるいは霧の中で物を見ているような愁訴があると言われている。この症状は、なんとなくぼんやりと物が見えることからブラードビジョン（ｂｌｕｒｒｅｄ　ｖｉｓｉｏｎ）などと称されている。見え方の程度によってはワクシービジョン（ｗａｘｙ　ｖｉｓｉｏｎ）、あるいはワセリンビジョン（ｖａｓｅｌｉｎｅ　ｖｉｓｉｏｎ）という呼び方で言い表わされることもあり、油脂が薄く付着したガラス越しに物を見ているように見えることもある。 However, in such a diffractive multifocal lens, as the number of applications as an intraocular lens increases, it has become clear that there are still problems to be solved. It is related to the appearance, and in patients with a diffractive multifocal intraocular lens, there is a complaint that when looking at an object, it looks hazy or looks at the object in the mist. It is said. This symptom is referred to as “blurred vision” because the object can be seen vaguely. Depending on how it looks, it is sometimes referred to as “waxy vision” or “vaseline vision”, and it may appear to look through the glass with a thin layer of oil and fat. is there.
　すなわち、ＪＯＵＲＮＡＬ　ＯＦ　ＣＡＴＡＲＡＣＴ　＆　ＲＥＦＲＡＣＴＩＶＥ　ＳＵＲＧＥＲＹ，第３５巻（２００９），９９２－９９７におけるＭａｒｉａ　Ａ. Ｗｏｏｄｗａｒｄらの“Ｄｉｓｓａｔｉｓｆａｃｔｉｏｎ　ａｆｔｅｒ　ｍｕｌｔｉｆｏｃａｌ　ｉｎｔｒａｏｃｕｌａｒ　ｌｅｎｓ　ｉｍｐｌａｎｔａｔｉｏｎ”と題した論文（非特許文献１）では、回折多焦点眼内レンズを含む多焦点眼内レンズ挿入患者の不満例についての詳細な検討結果が報告されている。その中でブラードビジョンの主訴が、回折多焦点眼内レンズが挿入された２８眼のうち２７眼に認められたと報告されている。かかる症状を呈した患者の多くが後発白内障として知られる術後合併症を発症していたが、著者達は、合併症の発症前からブラードビジョンを訴えていた症例が多いことに注意を喚起しており、ブラードビジョンが多焦点眼内レンズによって起こっている可能性を指摘している。 That is, JOURNAL OF CATARACT & REFRACTIVE SURGERY, Volume 35 (2009), 992-997 in Maria A. Woodward et al. Detailed examination results have been reported on dissatisfied patients with multifocal intraocular lens insertion including an inner lens. Among them, the chief complaint of Blood Vision was reported in 27 eyes out of 28 eyes in which a diffractive multifocal intraocular lens was inserted. Although many patients with such symptoms developed postoperative complications known as secondary cataracts, the authors noted that many patients complained of blood vision before the onset of complications. And pointed out the possibility that blood vision is caused by multifocal intraocular lenses.
　さらに、一般的な回折型多焦点レンズにおいて、ブラードビジョンの問題を把握することのできる資料を、図９３に示す。図９３（ａ）は、Ｃｏｈｅｎによる米国特許第５１４４４８３号明細書（特許文献１）に示された技術内容に基づき設計された回折型多焦点眼用レンズを光学ベンチ上に設置し、該レンズを通して撮影された解像度チャートを示すものである。これは、０次回折光を遠方視用、＋１次回折光を近方視用の焦点形成用として設計された回折型多焦点眼用レンズの遠方視用焦点位置における測定結果である。図９３（ｂ）に示す単焦点レンズの場合と比較すると、明るいハイライトの部分の輝度が幾分低下し、灰色がかったように見える。また、視標のない背景のシャドー部には光の滲みが発生しており、全体的にコントラストが低下していることが分かる。現在実用化されている回折型多焦点眼内レンズの中には前記Ｃｏｈｅｎの基本仕様から発展させたアポダイゼーションといわれる回折構造を設けたものが知られている。Ｗ. Ａｎｄｒｅｗ　Ｍａｘｗｅｌｌらはかかるタイプのレンズを含む多焦点眼内レンズのベンチテストでの解像度チャートの撮影結果を示している（“Ｐｅｒｆｏｒｍａｎｃｅ　ｏｆ　ｐｒｅｓｂｙｏｐｉａ－ｃｏｒｒｅｃｔｉｎｇ　ｉｎｔｒａｏｃｕｌａｒ　ｌｅｎｓｅｓ　ｉｎ　ｄｉｓｔａｎｃｅ　ｏｐｔｉｃａｌ　ｂｅｎｃｈ　ｔｅｓｔｓ”，ＪＯＵＲＮＡＬ　ＯＦ　ＣＡＴＡＲＡＣＴ　＆　ＲＥＦＲＡＣＴＩＶＥ　ＳＵＲＧＥＲＹ，第３５巻（２００９），頁１６６―１７１（非特許文献２））。その結果も図９３（ａ）と同様にハイライト部の輝度の低下、及び背景シャドー部への光の滲みが認められている。 Furthermore, FIG. 93 shows data that can grasp the problem of the blood vision in a general diffractive multifocal lens. FIG. 93 (a) shows a case where a diffractive multifocal ophthalmic lens designed based on the technical content shown in US Pat. No. 5,144,483 by Cohen is placed on an optical bench and passed through the lens. It shows a resolution chart taken. This is a measurement result at a far vision focal position of a diffractive multifocal ophthalmic lens designed to form a 0th order diffracted light for far vision and a + 1st order diffracted light for near vision. Compared with the case of the single focus lens shown in FIG. 93 (b), the brightness of the bright highlight portion is somewhat lowered and appears to be grayish. Further, it can be seen that light blur occurs in the shadow portion of the background without the target, and the contrast is lowered as a whole. Among diffractive multifocal intraocular lenses that are currently in practical use, those having a diffractive structure called apodization developed from the basic specifications of Cohen are known. W. Andrew Maxwell et al. Show the results of the resolution chart in the bench test of a multifocal intraocular lens including this type of lens (“Performance of prespoopia-correcting intramolecularTranchantlOlCtFlC” & REFRACTIVE SURGERY, Volume 35 (2009), pages 166-171 (Non-Patent Document 2)). As a result, as in the case of FIG. 93 (a), a decrease in luminance in the highlight portion and a blur of light in the background shadow portion are recognized.
　このように一般的な回折型多焦点眼用レンズでは、コントラスト差のある環境下で物を見た場合に、全体的にコントラストが低下し、光の滲みが生じて結果として霞がかかったような見え方、即ちブラードビジョンの問題を引き起こすことを、図９３からも理解することができる。多焦点レンズにおいては複数の焦点位置に光を配分するので、各焦点位置のハイライト部の輝度が低下するのは避けられない。しかし、人の生理的な不満は主にハイライト部の輝度の低下よりもシャドー部への光の滲みによってもたらされるものであるため、光の滲みを抑制することがブラードビジョンの改善につながると考えられる。光の滲みは多焦点レンズ、特に同時視型と呼ばれる多焦点レンズの結像特性を反映した現象の一つで、その成因に関して以下のように説明される。 In this way, with a general diffractive multifocal ophthalmic lens, when an object is viewed in an environment with a difference in contrast, the overall contrast is reduced, and light blurring occurs, resulting in wrinkles. It can also be understood from FIG. 93 that it causes a problem of visual appearance, that is, a blood vision problem. In a multifocal lens, since light is distributed to a plurality of focal positions, it is inevitable that the brightness of the highlight portion at each focal position is lowered. However, human physiological dissatisfaction is mainly caused by light blurring in the shadow area rather than a decrease in brightness in the highlight area. Conceivable. The blur of light is one of the phenomena reflecting the imaging characteristics of a multifocal lens, particularly a multifocal lens called a simultaneous vision type, and its cause is explained as follows.
　たとえば遠近の２焦点を有する回折型多焦点レンズでは、遠方からやってくる光は遠方視用焦点位置で光の振幅が最大限強め合って結像するとともに、近方視用焦点位置でも振幅が強め合うように設計されている。遠方からの光は遠方視用焦点の像面中心に主ピークを形成するが、近方視用焦点位置で強め合った光は、その後拡散して遠方視用焦点の像面位置に到達することとなる（図９４（ａ））。一見すると遠方視用焦点の像面では図９４（ｂ）に示すようにかかる遠方視用焦点を形成する主ピークしか存在しないように見えるが、拡大すると図９４（ｃ）のように主ピークの周りに小ピーク群が存在していることが分かる。これは、前記したように近方結像用の光の成分が一種の迷光となって遠方視用焦点像面に紛れ込むこととなり、形成されたものである。このように小ピーク群（以下、サイドバンドと称することとする）の強度は主ピークの強度と比較すると極めて小さなものであるが、広がりのある光源ではこれらピークが積算されることになるので強度は増幅される。また前記したように明暗のコントラスト差のある環境下においては、僅かな光の滲みでも知覚されやすくなる。したがって微弱なサイドバンドでも無視しえない状況が発生しうるのである。 For example, in a diffractive multifocal lens having two near and far focal points, light coming from a distance forms an image with the maximum amplitude of the light at the far vision focal position, and also increases at the near vision focal position. Designed to be Light from a distance forms a main peak at the center of the image plane of the far vision focus, but the light strengthened at the near vision focus position then diffuses and reaches the image plane position of the distance vision focus. (FIG. 94 (a)). At first glance, it appears that there is only a main peak forming the far vision focus as shown in FIG. 94 (b) on the image plane of the far vision focus, but when enlarged, the main peak becomes as shown in FIG. 94 (c). It can be seen that there are small peak groups around. As described above, this is formed because the component of the light for near-field imaging becomes a kind of stray light and is mixed into the focal image plane for distance vision. In this way, the intensity of the small peak group (hereinafter referred to as a side band) is extremely small compared to the intensity of the main peak, but the intensity is increased because these peaks are integrated in a broad light source. Is amplified. Further, as described above, even in a slight light blur, it is easily perceived in an environment where there is a contrast difference between light and dark. Therefore, a situation that cannot be ignored even with a weak sideband can occur.
　かかるサイドバンドの分布は光の波動現象として形成されるものであり、図９５に示すように回折型多焦点レンズでは各回折ゾーンを通過した光は、遠方視用焦点の像面位置にそれぞれのゾーンの特性を反映した振幅分布を与える。図９５（ｂ）は遠方の点状光源から発せられた光が各ゾーンを通過して焦点像面になす光の振幅の一例を示すものである。各ゾーン（Ａ，Ｂ，Ｃ）を通過した光の振幅を合成したものが全体の振幅分布となる（図９５（ｃ））。そして、この振幅の共役絶対値が光の強度となる（図９５（ｄ））。このように点状の光源から発せられた光がレンズを通過した後、像面になす強度分布を点像広がり関数と称す。 Such a sideband distribution is formed as a wave phenomenon of light. As shown in FIG. 95, in the diffractive multifocal lens, the light passing through each diffraction zone is located at the image plane position of the far vision focus. Gives an amplitude distribution reflecting the characteristics of the zone. FIG. 95 (b) shows an example of the amplitude of light that is emitted from a distant point light source and passes through each zone to form a focal image plane. A total amplitude distribution is obtained by combining the amplitudes of the light beams that have passed through the zones (A, B, C) (FIG. 95 (c)). Then, the conjugate absolute value of the amplitude becomes the light intensity (FIG. 95 (d)). The intensity distribution formed on the image plane after the light emitted from the point light source passes through the lens is referred to as a point spread function.
　物を見る時、たとえば前記解像度チャートなどの文字や図形がハイライト部で構成された物体を見る時、チャートの文字や図形の視標の縁から背景のシャドー部にかけての強度分布は明るいハイライト部から急激に切れ落ちた強度分布を示す。このような物体（光源）がレンズを介して像面に形成する強度分布をエッジの強度分布と称すと、エッジ強度分布を知ることによって光の滲みの程度を把握することができる。かかる広がりのある物体や光源は数多くの点状の光源から構成されていると考えることができるので、各点光源に対応する点像広がり関数を焦点像面の光学共役位置に亘って重ねて積算すればエッジの強度分布を得ることができる。 When looking at an object, for example, when looking at an object in which characters and figures such as the resolution chart are composed of highlighted parts, the intensity distribution from the edge of the chart letters and figures to the shadow part of the background is a bright highlight Intensity distribution sharply cut off from the part. When the intensity distribution formed on the image plane by such an object (light source) via the lens is referred to as an edge intensity distribution, it is possible to grasp the degree of light blur by knowing the edge intensity distribution. Since such a broad object or light source can be considered to be composed of many point-like light sources, the point spread function corresponding to each point light source is accumulated over the optical conjugate position of the focal image plane. Then, the edge intensity distribution can be obtained.
　図９６は、かかるエッジに対する強度分布を一般的な単焦点レンズと回折型多焦点レンズの間で比較した概念図である。図９６（ａ）に示すようなハイライト部とシャドー部が明確に区分けされた光源があるとする。そして、単焦点レンズ、回折型多焦点レンズの点像広がり関数が図９６（ｂ）（ｃ）のような分布をなしているとすると、それぞれのエッジ強度分布は図９６（ｄ）（ｅ）のように示される。一見すると両者でエッジの強度分布に差異はないように見えるが、エッジのシャドー部近傍を拡大すると明確な相違が認められるのである( 図９６（ｆ））。単焦点レンズでは鋭く切れ落ちたエッジの強度分布を示す一方で、回折型多焦点レンズではエッジ近傍のシャドー部においてある種の膨らみのある分布を示す。この膨らみ部はシャドー部へ滲み出た光の強度を表わすもので、これが大きいと光の滲みとして我々の観察されるところとなるのである。 FIG. 96 is a conceptual diagram comparing the intensity distribution for such an edge between a general single focus lens and a diffractive multifocal lens. Assume that there is a light source in which a highlight portion and a shadow portion are clearly divided as shown in FIG. If the point spread function of the single focus lens and the diffractive multifocal lens has a distribution as shown in FIGS. 96B and 96C, the respective edge intensity distributions are shown in FIGS. 96D and 96E. As shown. At first glance, it seems that there is no difference in the edge intensity distribution between the two, but when the vicinity of the shadow portion of the edge is enlarged, a clear difference is recognized (FIG. 96 (f)). The single focus lens shows the intensity distribution of sharply cut edges, while the diffractive multifocal lens shows a distribution with a certain bulge in the shadow portion near the edges. This bulge part represents the intensity of light that has oozed out into the shadow part, and if this is large, it will be observed as light bleed.
　この膨らみは点像広がり関数のサイドバンドの強度や分布の状態によって異なるが、総じてサイドバンドの強度が大きければ膨らみは大きくなる。また、サイドバンドの出現位置が主ピークに近ければ膨らみはエッジ部の近傍で発生することとなる。その結果、物を見た時に物体近傍で靄のようなグレアが認められることになる。また、サイドバンドが主ピークから離れれば、エッジの強度分布はなだらかな棚状の分布を示す傾向にある。もしこのような分布で棚部の強度が大きければ、靄が広がって見えたりする。実際にかかる膨らみのあるエッジ強度分布を示すレンズをコンタクトレンズとして装用した場合、あるいは眼内レンズとして眼の中に挿入した場合、光軸に対してレンズの偏位が生じるとかかるエッジの強度分布はゴーストと呼ばれる二重像となって我々に知覚されることもある。よってかかるエッジの強度分布と実際の見え方の相関はレンズ特性とそれが置かれた状態に依存するため、一律に述べることはできないが、エッジのシャドー部にかけての強度が小さければ小さいほどかかる二重像などの見え方の弊害も低減できるのである。つまり、ブラードビジョンを改善するにはエッジ部の強度分布においてシャドー部領域の強度を低減させることであり、その結果としてブラードビジョンのみならず他のゴーストと称される弊害なども改善できる可能性があるのである。 This bulge varies depending on the intensity and distribution of the sideband of the point spread function, but as a whole, the bulge becomes larger as the sideband intensity is larger. Further, if the appearance position of the side band is close to the main peak, the swelling occurs near the edge portion. As a result, glare such as wrinkles is recognized near the object when the object is viewed. Further, if the sideband is separated from the main peak, the edge intensity distribution tends to show a gentle shelf-like distribution. If the shelf strength is high with this distribution, the wrinkles may appear to spread out. When a lens showing such a bulging edge intensity distribution is actually worn as a contact lens or inserted into the eye as an intraocular lens, the intensity distribution of the edge will occur if the lens is displaced with respect to the optical axis. May be perceived by us as a double image called a ghost. Therefore, since the correlation between the intensity distribution of the edge and the actual appearance depends on the lens characteristics and the state in which it is placed, it cannot be described uniformly. However, the smaller the intensity at the edge shadow portion, the more it takes. It can also reduce the harmful effects of the appearance of multiple images. In other words, to improve the blood vision, it is necessary to reduce the strength of the shadow area in the intensity distribution of the edge. As a result, there is a possibility that not only the blood vision but also other harmful effects called ghosts can be improved. There is.
　なお、かかるブラードビジョンの問題点は眼内レンズ特有のものではなく、コンタクトレンズ、あるいは角膜内挿入インレイ、などに応用される多焦点眼用レンズに等しく発生しうるものである。よって、この課題の解決がかかる分野において強く求められているのである。 It should be noted that the problem of such a blood vision is not unique to an intraocular lens, but can occur equally in a multifocal ophthalmic lens applied to a contact lens or an intracorneal inlay. Therefore, there is a strong demand in the field where this problem can be solved.
　いくつかの先行文献では回折型多焦点眼用レンズのコントラスト感度の低下の問題を取り上げ、その解決案を提示している。例えば特開２０１０－１５２３８８（特許文献２）では、ＭＴＦ（変調伝達関数）を向上させるためにレンズを非球面化する設計方法が開示されている。かかる先行文献では回折構造と併せてレンズを非球面化することによってＭＴＦが向上するとしている。ＭＴＦは空間周波数に対するコントラストの変化を表わすもので、ＭＴＦ値が向上することは各周波数における物体の識別、分解能力を改善せしめることとほぼ同じである。しかし、成書「シミュレーション光学」（牛山ら、東海大学出版会）では、ＭＴＦだけでエッジ部の鮮明さを判断することは危険であることを説明している。一般に点像広がり関数において主ピークが鋭峻な分布をなしているとＭＴＦ値は大きくなる傾向にある。しかし、鋭峻なピークであってもサイドバンドピークの大きさや分布の状態いかんによっては背景シャドー部に光の滲みが生成する、というケースもありうるのである。したがって、ＭＴＦが改善されたことが前述のぼんやりとした見え方の改善となることを保証するものではない。前記先行文献ではコントラスト感度には言及するものの、ブラードビジョンの問題に関しては何も言及しておらず、これを重要問題と認識している証左は何もない。また、ＭＴＦにのみ言及しており、それ以外のエッジの強度分布、さらには光の滲みなどの現象との関連性などの洞察は一切ない。 Some prior literatures address the problem of reduced contrast sensitivity of diffractive multifocal ophthalmic lenses and present solutions. For example, Japanese Patent Application Laid-Open No. 2010-152388 (Patent Document 2) discloses a design method in which a lens is aspherical in order to improve MTF (modulation transfer function). In such prior literature, the MTF is improved by making the lens aspherical together with the diffractive structure. The MTF represents a change in contrast with respect to the spatial frequency. An increase in the MTF value is almost the same as an improvement in the ability to identify and resolve an object at each frequency. However, the book “Simulation Optics” (Ushiyama et al., Tokai University Press) explains that it is dangerous to judge the sharpness of the edge part only by MTF. In general, if the main peak has a sharp distribution in the point spread function, the MTF value tends to increase. However, even if it is a sharp peak, depending on the size and distribution state of the sideband peak, there may be a case where light blur is generated in the background shadow portion. Therefore, the improvement in MTF does not guarantee that the above-described blurry appearance is improved. Although the prior literature mentions contrast sensitivity, it does not mention anything about the problem of blood vision, and there is no evidence to recognize this as an important problem. Further, only the MTF is mentioned, and there is no insight such as the relationship between the intensity distribution of other edges and the phenomenon such as light bleeding.
　また、特開２０１０－１３４２８２（特許文献３）では、かかる問題の原因として回折構造を形成する格子の形状において不連続的に形成された回折格子のレリーフエッジ部での光の散乱がコントラスト低下の原因として、このエッジ部をスムーズに形成するための設計方法及びそれからなる回折レンズの仕様が述べられている。前記したようにブラードビジョンの主原因は点像広がり関数におけるサイドバンドの影響が最も大きい。かかるサイドバンドは他の焦点を形成する光が紛れ込むことによって形成されるものであり、散乱光による寄与は少ないと考えられる。よって該先行文献による方法ではコントラストの改善効果はさほど期待できないと考えられる。また、該文献では光の滲みに関しては何ら触れておらず、また、これの解決を示唆する情報は何も示していない。 Also, in Japanese Patent Laid-Open No. 2010-134282 (Patent Document 3), the cause of such a problem is that light scattering at the relief edge portion of the diffraction grating formed discontinuously in the shape of the grating forming the diffraction structure causes a decrease in contrast. As a cause, a design method for smoothly forming the edge portion and a specification of a diffractive lens including the design method are described. As described above, the main cause of the blood vision is the influence of the sideband in the point spread function. Such a sideband is formed by mixing light forming another focal point, and it is considered that the contribution of scattered light is small. Therefore, it is considered that the contrast improvement effect cannot be expected so much by the method according to the prior document. In addition, the document does not mention anything about the bleeding of light, and does not show any information suggesting the solution.
　また、国際特許公開２０１１／０７５６６８（特許文献４）では、この問題を改善するためにレンズの幾何中心に対してレンズ面を回折構造、屈折領域構造と区分した非対称構造の眼用レンズが提案されている。これら区分された構造において、回折構造領域における光の配分割合などを微調整することによってコントラスト低下を防げるとしている。しかし、該先行文献では光の滲み及びこれを解決する手段に関しては一切言及されていない。一般にレンズは、レンズ中心に対して非対称構造を導入すると点像広がり関数も非対称で歪な分布を示す。また多くのサイドバンドが生成することがある。よってかかる非対称型の構造は、むしろ光の滲みを増悪させ、時として二重像などの好ましからざる効果をもたらすことがある。また、かかる非対称構造の製造は対称構造を製造するよりもずっと困難で時間やコストがかかるという問題点を有する。 In addition, International Patent Publication 2011/075668 (Patent Document 4) proposes an ophthalmic lens having an asymmetric structure in which the lens surface is divided into a diffractive structure and a refractive region structure with respect to the geometric center of the lens in order to improve this problem. ing. In these divided structures, it is possible to prevent a decrease in contrast by finely adjusting the light distribution ratio in the diffraction structure region. However, the prior literature does not mention any light bleeding and means for solving the problem. In general, when an asymmetric structure is introduced with respect to the center of the lens, the point spread function also exhibits an asymmetric and distorted distribution. Many sidebands may also be generated. Thus, such an asymmetric structure may rather exacerbate the light bleed and sometimes lead to undesirable effects such as double images. Also, the manufacture of such an asymmetric structure has the problem that it is much more difficult and time consuming and expensive than manufacturing a symmetrical structure.
　最も簡単に多焦点眼用レンズのコントラスト低下を防ぎ、光の滲みを低減しようとするには、対応する焦点への光の配分量を増やせばよい。例えば遠方視において光の滲みを低減しようとするならば遠方視用の焦点に光の分配量を増やすことである。しかし、特定の焦点に光の配分量を多くすることは他焦点への光の配分量を減らすことになる。たとえば遠方視用焦点用の光の配分量を増やせば遠方視用焦点の点像広がり関数のサイドバンドは減るかもしれないが、他の焦点ではサイドバンドの強度は逆に大きくなる。この結果、光が多く配分された焦点位置では高コントラストでブラードビジョンの少ない見え方を与えるかもしれないが、残りの焦点位置においては見え方の質的な低下は免れない。 ¡The easiest way to prevent the contrast reduction of multifocal ophthalmic lenses and reduce light blur is to increase the amount of light distributed to the corresponding focus. For example, if light blur is to be reduced in far vision, the amount of light distributed to the focal point for far vision is increased. However, increasing the amount of light distributed to a specific focus reduces the amount of light distributed to other focal points. For example, if the amount of light distribution for the far vision focus is increased, the sideband of the point spread function of the far vision focus may be reduced, but the intensity of the sideband is increased at other focal points. As a result, the focus position where a lot of light is distributed may give a view with high contrast and less blurred vision, but the quality of the view is inevitably deteriorated at the remaining focus positions.
　更にまた、特表２００８－５１７７３１（特許文献５）では、回折ゾーンの位相板の高さを変えることによって光の配分量を変えてハロやグレアが知覚されにくい像面の強度分布を得る方法について述べている。かかる先行文献では像面強度分布の裾部をなだらかにするとハロ、グレアが知覚されにくくなるとして、回折ゾーン周辺域の位相板からの光の配分量を減じるようなプロファイルが例として述べられている。かかる方法は前記したように各焦点位置への光の配分量を変えるだけの措置に過ぎず、かかる多焦点レンズの設計においては、どうしても特定の焦点特性のみが重要視された偏った設計となるため、実質的に利用可能な多焦点眼用レンズを提供することはできない。 Furthermore, Japanese Patent Laid-Open No. 2008-517731 (Patent Document 5) discloses a method for obtaining an intensity distribution of an image plane in which halo and glare are hardly perceived by changing the amount of light distribution by changing the height of the phase plate in the diffraction zone. Says. In this prior document, a profile that reduces the amount of light distributed from the phase plate in the vicinity of the diffraction zone is described as an example, assuming that the halo and glare are less likely to be perceived if the skirt of the image surface intensity distribution is smoothed. . As described above, this method is merely a measure for changing the amount of light distributed to each focal position, and the design of such a multifocal lens is inevitably a biased design in which only specific focus characteristics are regarded as important. Therefore, it is not possible to provide a multifocal ophthalmic lens that can be substantially used.
　以上、述べたように先行文献（特許文献２～５）では、コントラストの改善についてはこれを解決する方法をいくつか提案しているものの、光の滲みに対してこれを抑制する方法を具体的に示したものは何も存在していないのである。また、複数の焦点への配分量を、意図した設計値から大きく変更させることなく、目的とする焦点位置でのエッジ強度分布を改善し、その結果としてのブラードビジョンが改善された多焦点眼用レンズの具体例はまだ存在していないのである。 As described above, the prior literatures (Patent Documents 2 to 5) have proposed several methods for solving this with respect to the improvement of contrast, but concrete methods for suppressing this against the blur of light. There is nothing that is shown in. In addition, for the multifocal eye that improves the edge intensity distribution at the target focus position and the resulting blurred vision without significantly changing the amount of distribution to multiple focal points from the intended design value. There are no specific examples of lenses yet.
米国特許第５１４４４８３号明細書US Pat. No. 5,144,483 特開２０１０－１５２３８８号公報JP 2010-152388 A 特開２０１０－１３４２８２号公報JP 2010-134282 A 国際特許公開２０１１／０７５６６８号公報International Patent Publication No. 2011/075668 特表２００８－５１７７３１号公報JP 2008-517731 A
　本発明は、上述の如き多焦点眼用レンズにおいて大きな問題であるブラードビジョンの改善を目的とするものであり、ブラードビジョンの発生機構の解明を為し得たことに基づいて、その結果得られた知見をもとに新規な解決策を見出したものである。そして、このようにして得られた新規な技術思想に基づいて、ブラードビジョンが改善された回折型多焦点眼用レンズを実現すべく、本発明は、回折型多焦点眼用レンズの新規な製造方法と、新規な構造の回折型多焦点眼用レンズとを、それぞれ提供することを解決課題とする。 The present invention aims to improve the blurred vision, which is a major problem in the multifocal ophthalmic lens as described above, and is obtained as a result based on the elucidation of the generation mechanism of the blurred vision. Based on this knowledge, a new solution has been found. Based on the new technical idea thus obtained, in order to realize a diffractive multifocal ophthalmic lens with an improved blood vision, the present invention provides a novel manufacture of a diffractive multifocal ophthalmic lens. It is an object of the present invention to provide a method and a diffractive multifocal ophthalmic lens having a novel structure.
　以下、本発明の説明に先立ち、本発明で用いられる語句などについて以下のように定義する。 Hereinafter, prior to the description of the present invention, terms and the like used in the present invention are defined as follows.
　振幅関数（分布）は、光の波としての特性を数学的に記述した関数（分布）のことであり、具体的には数１で表わされる。 The amplitude function (distribution) is a function (distribution) that mathematically describes the characteristics as a wave of light.
Figure JPOXMLDOC01-appb-M000001
Figure JPOXMLDOC01-appb-M000001
　位相は、数１のφ（ｘ）に相当するもので、光の波としての状態を示すパラメータの一つで、具体的には波の谷と山の位置、あるいは経過時間ごとのかかる位置を定めるものである。また、位相を変えることによって波の進行を早めたり、遅らせたりもする。なお、本発明では位相をφで表記することとし、その単位はラジアンである。例えば光の１波長を２πラジアン、半波長をπラジアンとして表わす。 The phase corresponds to φ (x) in Equation 1, and is one of the parameters indicating the state as a wave of light. Specifically, the position of the valley and the peak of the wave, or the position that takes every elapsed time. It is determined. It also accelerates or delays the progression of the wave by changing the phase. In the present invention, the phase is expressed by φ, and its unit is radians. For example, one wavelength of light is expressed as 2π radians and a half wavelength is expressed as π radians.
　位相変調は、レンズに入射した光に対して何らかの方法でその位相に変化を与えるようなレンズに設けられた構造あるいは方法を総じていう。 Phase modulation generally refers to a structure or method provided in a lens that changes the phase of light incident on the lens in some way.
　位相関数は、数１の指数部またはｃｏｓ関数内の位相の変化を表す関数である。本発明では位相関数の変数は主にレンズの中心から半径方向の位置ｒとし、ｒ地点におけるレンズの位相φを表すものとして用いられ、具体的には図９７に示すようなｒ－φ座標系で表わすこととする。また、位相変調構造が設けられた全域の位相の分布を同座標系で表したものを位相プロファイル（Ｐｒｏｆｉｌｅ）と呼ぶ。なお、φ＝０のｒ軸を基準線とし、φ＝０の地点では入射した光はその位相を変化させることなく射出されることを意味する。そして、この基準線に対してφが正の値を取るとき、光はその位相分だけ進行が遅れ、φが負の値を取るとき、光はその位相分だけ進行が進むことを意味する。実際の眼用レンズにおいては回折構造が付与されていない屈折面がこの基準線（面）に相当する。 The phase function is a function that represents a change in phase within the exponent part of Equation 1 or the cos function. In the present invention, the phase function variable is mainly a position r in the radial direction from the center of the lens, and is used to represent the phase φ of the lens at the point r. Specifically, an r-φ coordinate system as shown in FIG. It will be expressed as Further, a distribution of phases in the entire area where the phase modulation structure is provided is expressed in the same coordinate system as a phase profile. Note that the r axis at φ = 0 is taken as a reference line, and at the point where φ = 0, incident light is emitted without changing its phase. When φ takes a positive value with respect to the reference line, light progresses by the phase, and when φ takes a negative value, the light advances by the phase. In an actual ophthalmic lens, a refracting surface not provided with a diffractive structure corresponds to this reference line (surface).
　光軸は、レンズの回転対称軸で、ここではレンズ中心を貫き物体空間および像側空間へ延長された軸のことをいう。 The optical axis is a rotationally symmetric axis of the lens, and here refers to an axis extending through the center of the lens to the object space and the image side space.
　像面は、レンズに入射した光が射出された像側空間のある地点において光軸と垂直に交わる面のことをいう。 The image plane refers to a plane perpendicular to the optical axis at a certain point in the image side space where the light incident on the lens is emitted.
　０次焦点は、０次回折光の焦点位置をいう。以下、＋１次回折光の焦点位置に対しては＋１次焦点、・・・という。 The 0th order focal point refers to the focal position of the 0th order diffracted light. Hereinafter, the focus position of the + 1st order diffracted light is referred to as the + 1st order focus.
　０次焦点像面は、０次回折光の焦点位置における像面のことをいう。 The 0th-order focal image plane refers to the image plane at the focal position of the 0th-order diffracted light.
　ゾーンは、回折構造における最小の単位としてここでは用いる。例えば一つのブレーズが形成された領域を一つのゾーンと呼ぶ。 The zone is used here as the smallest unit in the diffractive structure. For example, a region where one blaze is formed is called one zone.
　ブレーズは、位相関数の一形態で、主に屋根状の形で位相が変化しているものを指す。本発明では、図９８（ａ）に示すような一つのゾーンにおいて屋根の山と谷の間が直線で変化するものをブレーズの基本とするが、山と谷の間を放物線状の曲線で変化するようにつながったもの（図９８（ｂ））や凹凸形状（方形波状）等も本発明ではブレーズの概念の中に含まれる。また、山と谷の間が正弦波の関数の一部で変化するようにつながれたもの（図９８（ｃ））、さらにはある関数において極値を含まない区間で変化するようにつながれたものもブレーズの概念の中に含まれる。本発明では特に断りがない限り図９８（ａ）に示すように第ｎ番目のゾーンのブレーズにおいて、ゾーンの外径ｒn の位置の位相φn と内径ｒn-1 の位置の位相φn-1 の絶対値が基準面（線）に対して等しくなるように、つまり｜φn ｜= ｜φn-1 ｜となるように設定することを基本とする。なお、ブレーズの位相関数φ（ｒ）は、数２のように表される。 Blaze is a form of phase function, and refers to a phase that changes mainly in the form of a roof. In the present invention, blaze is basically the one in which the distance between the mountain and valley of the roof changes in a straight line in one zone as shown in FIG. 98 (a), but the curve between the mountain and valley changes with a parabolic curve. In the present invention, the concept of blaze is also included in the present invention, such as those connected as shown (FIG. 98 (b)), uneven shape (square wave shape), and the like. Also, the peak and valley are connected so as to change as a part of the function of the sine wave (FIG. 98 (c)), and further, the function is connected so as to change in the section not including the extreme value. Is also included in the concept of blaze. In the n-th zone blaze as particularly shown in FIG. 98 (a) Unless otherwise specified in the present invention, the phase position of the phase phi n and the inner diameter r n-1 position of the outer diameter r n zone phi n Basically, the absolute value of −1 is set to be equal to the reference plane (line), that is, | φ n | = | φ n-1 |. The blaze phase function φ (r) is expressed as shown in Equation 2.
Figure JPOXMLDOC01-appb-M000002
Figure JPOXMLDOC01-appb-M000002
　位相ずれ量は、ある位相関数φ（ｒ）をｒ－φ座標系の基準線（面）に対してφ軸方向にτずらす場合、このτのことを位相ずれ量と定義する。τずらすことによって新たに得られる位相関数φ’（ｒ）との関係は数３の通りである。位相ずれ量の単位はラジアンである。 The phase shift amount is defined as a phase shift amount when a phase function φ (r) is shifted by τ in the φ axis direction with respect to the reference line (plane) of the r−φ coordinate system. The relationship with the phase function φ ′ (r) newly obtained by shifting τ is as shown in Equation 3. The unit of the phase shift amount is radians.
Figure JPOXMLDOC01-appb-M000003
Figure JPOXMLDOC01-appb-M000003
　たとえば、前記ブレーズにおいてブレーズ段差を維持したまま基準面に対するブレーズの位置関係をφ軸方向にずらす場合は、ずらすことによって新たに谷と山になるφ’n とφ’n-1 とずらす前のφn とφn-1 の関係は数４の通りとなる。この位置関係は図９９に示されている。本発明ではこのように位相ずれ量τを導入して新たに設定される関数φ’（ｒ）も位相関数の一形態として用いることができる。 For example, when shifting the position of the blaze relative to the reference surface in the φ-axis direction while maintaining the blaze step in the blaze, it is necessary to shift the φ ′ n and φ ′ n−1 to become valleys and peaks newly by shifting. The relationship between φ n and φ n-1 is as shown in Equation 4. This positional relationship is shown in FIG. In the present invention, the function φ ′ (r) newly set by introducing the phase shift amount τ can also be used as one form of the phase function.
Figure JPOXMLDOC01-appb-M000004
Figure JPOXMLDOC01-appb-M000004
　また、位相ずれ量τを導入した場合のブレーズの位相関数は数２から数５のように表わされる。 Also, the phase function of blaze when the phase shift amount τ is introduced is expressed as in Equation 2 to Equation 5.
Figure JPOXMLDOC01-appb-M000005
Figure JPOXMLDOC01-appb-M000005
　位相定数は、ブレーズ形状の位相関数において数６で定義される定数ｈのことをいう。 The phase constant refers to the constant h defined by Equation 6 in the blaze-shaped phase function.
Figure JPOXMLDOC01-appb-M000006
Figure JPOXMLDOC01-appb-M000006
　レリーフは、位相プロファイルで定められる位相に相当する光路長を反映して具体的にレンズの実形状に変換して得られるレンズの表面に形成される微小な凸凹構造の総称である。なお、位相プロファイルをレリーフ形状に変換する具体的な方法は以下の通りである。 Relief is a general term for minute uneven structures formed on the surface of a lens obtained by specifically converting the lens to the actual shape reflecting the optical path length corresponding to the phase defined by the phase profile. A specific method for converting the phase profile into a relief shape is as follows.
　光はある屈折率を有する媒体に入射するとその屈折率分だけ速度が遅くなる。遅くなった分だけ波長が変化し、結果として位相変化が生ずる。位相プロファイルにおけるプラスの位相は光を遅らせることを意味するので、屈折率の高い領域に光が入射するようにすればプラス位相を付与したことと同じになる。なお、これらプラス、マイナスとは相対的な表現であり、例えば位相が－２πと－πでは同符号であっても後者の方が位相は遅れているので、屈折率の高い領域を設定する。 When light is incident on a medium having a certain refractive index, the speed is reduced by that refractive index. The wavelength changes by the amount of delay, resulting in a phase change. Since a positive phase in the phase profile means that the light is delayed, if the light is incident on a region having a high refractive index, it is the same as the case where the positive phase is given. These plus and minus are relative expressions. For example, even if the phase is −2π and −π, even if the phase is the same sign, the latter is delayed in phase, so a region with a high refractive index is set.
　たとえばブレーズ状の位相関数を有する場合、その実形状のブレーズ段差は、数７で表わされる。かかるレリーフ形状は精密旋盤による切削加工やモールド成形法などでレンズ面に設けることができる。 For example, in the case of having a blazed phase function, the actual blazed level difference is expressed by Equation 7. Such a relief shape can be provided on the lens surface by cutting with a precision lathe or molding.
Figure JPOXMLDOC01-appb-M000007
Figure JPOXMLDOC01-appb-M000007
　強度分布は、レンズ通過後の光の強度をある領域に亘ってプロットしたもので、前記振幅関数の共役絶対値として表わされる。ここでは大別して「光軸上の強度分布」と「像面の強度分布」が用いられる。前者はレンズの位置を基点とし、像側光軸上の光の強度分布をプロットしたもので、光軸上のどの位置に焦点を形成するか、また強度の割合などを調べる際に用いる。一方、像面強度分布はある像面における光の強度分布を示し、本発明では像面の中心から動径偏角がゼロ方向の位置ρにおける強度をプロットしたもので表わすこととする。人の眼においては網膜上で知覚されるのは像面強度分布の情報である。 The intensity distribution is a plot of the intensity of light after passing through the lens over a certain region, and is expressed as a conjugate absolute value of the amplitude function. Here, “intensity distribution on the optical axis” and “intensity distribution on the image plane” are roughly used. The former is a plot of the light intensity distribution on the image side optical axis with the position of the lens as a base point, and is used for examining the position on the optical axis where the focal point is formed and the intensity ratio. On the other hand, the image plane intensity distribution indicates the intensity distribution of light on a certain image plane. In the present invention, the image plane intensity distribution is expressed by plotting the intensity at a position ρ where the radial deviation angle is zero from the center of the image plane. What is perceived on the retina in the human eye is information on the image plane intensity distribution.
　点像広がり関数は、一点から出た光がレンズを通過し焦点位置の像面に形成する強度分布のことをいう。ＰＳＦ（Ｐｏｉｎｔ　Ｓｐｒｅａｄ　Ｆｕｎｃｔｉｏｎ）とも言う。本発明では特に断りがない限り遠方視用焦点位置の像面になす強度分布のことを言う。前述の像面強度分布における「遠方視用焦点位置の像面強度分布」と同義語である。 The point spread function refers to the intensity distribution formed on the image plane at the focal position by the light emitted from one point passing through the lens. It is also called PSF (Point Spread Function). In the present invention, it means the intensity distribution formed on the image plane of the far vision focal position unless otherwise specified. It is synonymous with “image plane intensity distribution at the focal position for far vision” in the above-described image plane intensity distribution.
　エッジ強度分布は、一定の明るさを有する広がりのある光源においてハイライト部とシャドー部の遷移領域がレンズを介して像面に形成する明暗の境の強度の分布を言う。本発明では光の滲みの目安を表わすものとして用いる。本発明では広がりのある光源として、図１（ａ）に示すように物体側空間のｘ軸上に伸びた一次元の有限な線状の光源を想定する。かかる光源がレンズを通過して像面に形成する光の強度分布Ｉ（ρ) は、光源の強度分布をＯ（ｘ）、点像広がり関数をＰＳＦ（ρ）とすると両者のコンボリューション（重畳積分）で表わされる（数８）。 Edge intensity distribution refers to the intensity distribution at the border of light and darkness formed on the image plane by the transition region between the highlight portion and the shadow portion via the lens in a wide light source having a certain brightness. In the present invention, it is used as a measure of light bleeding. In the present invention, a one-dimensional finite linear light source extending on the x-axis of the object-side space is assumed as a broad light source as shown in FIG. The light intensity distribution I (ρ) formed on the image plane by the light source passing through the lens is a convolution (superimposition) between the light source when the intensity distribution of the light source is O (x) and the point spread function is PSF (ρ). (Equation 8).
Figure JPOXMLDOC01-appb-M000008
Figure JPOXMLDOC01-appb-M000008
　光源強度は光源位置に依らず一定でその強度を１とすると、光源の強度分布は数９のようなステップ関数で表わすことができる。ステップ関数を用いると数８は数１０で表わされる。 If the light source intensity is constant regardless of the light source position and the intensity is 1, the intensity distribution of the light source can be expressed by a step function as shown in Equation 9. Using the step function, Equation 8 is expressed by Equation 10.
Figure JPOXMLDOC01-appb-M000009
Figure JPOXMLDOC01-appb-M000009
Figure JPOXMLDOC01-appb-M000010
Figure JPOXMLDOC01-appb-M000010
　数１０からｘ＝Ｌまたは－Ｌ近傍の強度分布を求めることによってエッジの強度分布を把握することができる。本発明では点像広がり関数は数値解析で算出された離散データとして取り扱う関係上、数１０の積分式の代わりに数１１を用いてエッジの強度分布を示すこととする。 By obtaining the intensity distribution in the vicinity of x = L or −L from Equation 10, the edge intensity distribution can be grasped. In the present invention, since the point spread function is handled as discrete data calculated by numerical analysis, Expression 11 is used instead of Expression 10 to indicate the edge intensity distribution.
Figure JPOXMLDOC01-appb-M000011
Figure JPOXMLDOC01-appb-M000011
　かかるエッジ強度を算出する際のコンボリューションの概念図を図１（ａ）～（ｅ）に示した。ここで、（ａ）はｘ軸上に存在する多くの点光源から構成された有限な長さを有する線状光源、（ｂ）はレンズ、（ｃ）は各点光源が像面のρ軸上になす点像広がり関数、（ｄ）は構成点光源の数が増えて対応する点像広がり関数が密集してくる様子、そして（ｅ）は点像広がり関数の合算値としての像面の強度分布を表わしている。なお、（ｅ）中、破線で囲まれた領域をエッジの強度分布とする。 The conceptual diagram of convolution when calculating the edge strength is shown in FIGS. Here, (a) is a linear light source having a finite length composed of many point light sources existing on the x axis, (b) is a lens, and (c) is the ρ axis of each point light source on the image plane. The point spread function formed above, (d) is a state in which the number of constituent point light sources is increased and the corresponding point spread functions are densely packed, and (e) is the sum of the point spread functions. It represents the intensity distribution. In (e), an area surrounded by a broken line is an edge intensity distribution.
　フレネル間隔は、回折レンズのゾーン構成においてある規則に従って定められるゾーン間隔の一つの形態のことをいう。ここでは、第ｎ番目のゾーンの外径をｒn とすると数１２で定められる間隔を有するものをいう。 The Fresnel interval refers to one form of zone interval determined according to a certain rule in the zone configuration of the diffractive lens. Here, when the outer diameter of the nth zone is denoted by rn, it means that having an interval defined by Equation 12.
Figure JPOXMLDOC01-appb-M000012
Figure JPOXMLDOC01-appb-M000012
　一般的には数１２で定められる間隔にすることによって１次回折光の焦点に相当する付加屈折力Ｐadd （０次光を遠用、１次光を近用とした時、近用焦点位置をどこに設定するかの目安となるもの）を設定することができる。なお、フレネル間隔を定める数１２における第１番目のゾーン外径（半径）は通常は数１３で定められるが、任意の値を用いて設定してもよい。本発明にて使用されるフレネル間隔型の回折レンズは、屈折原理を利用したフレネルレンズとは異なるものであり、上記式に従った間隔を有した回折原理を利用したレンズのことをいう。 In general, by setting the interval defined by Equation 12, the additional refractive power P add corresponding to the focal point of the first-order diffracted light (when the zero-order light is used for the distance and the first light is used for the near purpose, the near-focus position is determined. It can be set as a guide for where to set). Note that the first zone outer diameter (radius) in Formula 12 that defines the Fresnel interval is normally determined by Formula 13, but may be set using an arbitrary value. The Fresnel interval type diffractive lens used in the present invention is different from the Fresnel lens using the refraction principle, and refers to a lens using the diffraction principle having an interval according to the above formula.
Figure JPOXMLDOC01-appb-M000013
Figure JPOXMLDOC01-appb-M000013
　続いて、前述の如き課題を解決するために為された本発明の態様を記載する。なお、以下に記載の各態様において採用される構成要素は、可能な限り任意の組み合わせで採用可能である。 Subsequently, aspects of the present invention made to solve the above-described problems will be described. In addition, the component employ | adopted in each aspect as described below is employable by arbitrary combinations as much as possible.
　すなわち、回折型多焦点眼用レンズに関する本発明の第１の態様は、同心円状に複数形成された回折ゾーンが設けられた光学部を備えており、該光学部によって少なくとも二つの焦点が与えられる回折型多焦点眼用レンズにおいて、前記焦点のうちの一つの焦点である第一の焦点における像面上で、該第一の焦点におけるサイドバンド領域の振幅分布を減少せしめてブラードビジョンを抑制する回折光を与えるキャンセル用領域を、前記光学部における明所視の瞳孔径に対応する領域内に設けた回折型多焦点眼用レンズを、特徴とする。 That is, the first aspect of the present invention relating to a diffractive multifocal ophthalmic lens includes an optical part provided with a plurality of concentric diffraction zones, and at least two focal points are provided by the optical part. In the diffractive multifocal ophthalmic lens, the blur vision is suppressed by reducing the amplitude distribution of the sideband region at the first focal point on the image plane at the first focal point which is one of the focal points. The present invention is characterized by a diffractive multifocal ophthalmic lens in which a canceling region that gives diffracted light is provided in a region corresponding to a pupil diameter of photopic vision in the optical unit.
　本態様に従う構造とされた回折型多焦点眼用レンズでは、第一の焦点における像面上で、該第一の焦点を形成する光以外の光による振幅分布を減少せしめる回折ゾーンであるキャンセルゾーンが、レンズにおいて、明所視状態の瞳孔を透過する光線の通過領域内のキャンセル用領域に形成されることとなる。それ故、サイドバンドの大きな原因と考えられる、該第一の焦点を形成する光以外の光による像面上での振幅分布が抑えられ、その結果、かかる第一の焦点における像の見え方の質が向上することとなる。 In the diffractive multifocal ophthalmic lens structured according to this aspect, a cancellation zone that is a diffraction zone that reduces the amplitude distribution of light other than the light that forms the first focus on the image plane at the first focus. However, in the lens, it is formed in a canceling area within the passage area of the light beam that passes through the pupil in the photopic vision state. Therefore, the amplitude distribution on the image plane caused by light other than the light forming the first focal point, which is considered to be a major cause of the sideband, is suppressed, and as a result, the appearance of the image at the first focal point is suppressed. Quality will be improved.
　なお、本態様においてキャンセルゾーンの回折光によって振幅分布を減少せしめる対象光は、前記第一の焦点を形成する光以外の全ての光とされる必要はない。例えば、該第一の焦点以外の単一又は複数の焦点を形成する回折光を対象光としても良いし、該第一の焦点における像面上で単一又は複数の領域に位置する振幅分布を与える回折光を対象としても良い。 In this embodiment, the target light whose amplitude distribution is reduced by the diffracted light in the cancellation zone does not have to be all light other than the light that forms the first focus. For example, diffracted light that forms a single or a plurality of focal points other than the first focal point may be the target light, and an amplitude distribution located in a single or a plurality of regions on the image plane at the first focal point. The diffracted light to be given may be targeted.
　回折型多焦点眼用レンズに関する本発明の第２の態様は、第１の態様に係る回折型多焦点眼用レンズであって、前記第一の焦点が、前記回折ゾーンにおける回折構造の０次回折光によって与えられるものである。 A second aspect of the present invention relating to a diffractive multifocal ophthalmic lens is the diffractive multifocal ophthalmic lens according to the first aspect, wherein the first focus is zero order of the diffractive structure in the diffraction zone. It is given by Origami.
　本態様によれば、前記第一の焦点が、回折型多焦点眼用レンズの主たる焦点形成要因である回折構造の０次回折光によって与えられている。これにより、該第一の焦点を形成する光以外の光すなわちブラードビジョンの原因となり得る光成分を低減することができる。 According to this aspect, the first focus is given by the 0th-order diffracted light of the diffractive structure, which is the main focus forming factor of the diffractive multifocal ophthalmic lens. Thereby, light components other than the light that forms the first focus, that is, light components that can cause a blurred vision can be reduced.
　回折型多焦点眼用レンズに関する本発明の第３の態様は、第１又は２の態様に係る回折型多焦点眼用レンズであって、前記第一の焦点が遠方視用焦点であり、且つ、他の焦点として近方視用焦点を有するものである。 A third aspect of the present invention relating to a diffractive multifocal ophthalmic lens is the diffractive multifocal ophthalmic lens according to the first or second aspect, wherein the first focus is a far vision focus, and The other focus has a near vision focus.
　本態様によれば、特に昼間の遠方視で問題となり易いブラードビジョンの抑制が、一層効果的に発揮される。即ち、遠方視用焦点における像面上における、近方視用焦点を与える回折光の振幅分布がブラードビジョンの主たる原因と考えられることから、この近方視用焦点を与える回折光による遠方視用焦点の像面上の振幅を抑えることで、問題となり易い昼間遠方視でのブラードビジョンを低下させることが可能となる。なお、上記「近方視焦点」は、遠方焦点より近くの距離に位置する焦点であって、例えば二焦点の場合の近方視焦点だけでなく、多焦点の場合の中間視焦点などを含む。 According to this aspect, the suppression of the blood vision, which is likely to be a problem especially in daytime distance vision, is more effectively exhibited. In other words, the amplitude distribution of the diffracted light that gives the near vision focus on the image plane at the far vision focus is considered to be the main cause of the blurred vision. By suppressing the amplitude of the focal point on the image plane, it is possible to reduce the blur vision in daytime far vision, which is problematic. The “near vision focus” is a focus located at a distance closer to the far focus, and includes, for example, not only the near vision focus in the case of two focus but also the intermediate vision focus in the case of multiple focus. .
　回折型多焦点眼用レンズに関する本発明の第４の態様は、第１～３の何れかの態様に係る回折型多焦点眼用レンズであって、前記キャンセル用領域が、前記複数の回折ゾーンのうちで最内周の該回折ゾーンを除く領域に設けられているものである。 A fourth aspect of the present invention relating to a diffractive multifocal ophthalmic lens is the diffractive multifocal ophthalmic lens according to any one of the first to third aspects, wherein the cancel region is the plurality of diffraction zones. Are provided in a region excluding the diffraction zone at the innermost circumference.
　最内周の回折ゾーンは多焦点形成の起点となり、多焦点形成の機能を重点的に担うゾーンであるため、これ以外の領域にキャンセルゾーンを設けることによって多焦点形成能を確実に発現させると同時にブラードビジョンの抑制が可能となるのである。 The innermost diffraction zone is the starting point for multifocal formation, and is the zone that focuses on the multifocal formation function. At the same time, blur vision can be suppressed.
　ところで、上述の本発明の第１～４の何れかの態様に係る回折型多焦点眼用レンズにおいては、レンズ中心から半径で少なくとも０．３ｍｍ以上で且つ２．５ｍｍ以下の範囲内に、前記キャンセル用領域が設けられていることが好適である。 Incidentally, in the diffractive multifocal ophthalmic lens according to any one of the first to fourth aspects of the present invention described above, the radius is at least 0.3 mm or more and 2.5 mm or less from the lens center. It is preferable that a canceling area is provided.
　このような態様では、レンズ中心から半径で少なくとも０．３ｍｍ以上で且つ２．５ｍｍ以下の範囲内に、キャンセル用領域が設けられていることとなる。これにより、キャンセル用領域を光学部の最内周の回折ゾーンを除く領域に確実に設けることができる一方、ブラードビジョンが問題となり易い昼間における瞳孔径も十分にカバーでき、より一層確実にブラードビジョンを抑圧することが可能となる。なお、本発明では、キャンセル用領域を、レンズ中心から２．０ｍｍ未満の範囲内に設けることも好適に採用され得る。 In such an embodiment, the canceling region is provided within a range of at least 0.3 mm and a radius of 2.5 mm or less from the lens center. As a result, the cancellation area can be surely provided in the area excluding the innermost diffraction zone of the optical unit, while the pupil diameter in the daytime when the blurry vision is likely to be a problem can be sufficiently covered, and the blurry vision is more reliably achieved. Can be suppressed. In the present invention, it is also possible to suitably employ the canceling area within a range of less than 2.0 mm from the lens center.
　回折型多焦点眼用レンズに関する本発明の第５の態様は、第１～４の何れかの態様に係る回折型多焦点眼用レンズであって、前記回折ゾーンが、光の位相を変調させうるための位相関数で特徴付けられた回折構造をもって形成されているものである。 A fifth aspect of the present invention relating to a diffractive multifocal ophthalmic lens is the diffractive multifocal ophthalmic lens according to any one of the first to fourth aspects, wherein the diffraction zone modulates the phase of light. It is formed with a diffractive structure characterized by a phase function to obtain.
　本態様によれば、回折ゾーンが、光の位相を変調させうるための位相関数で特徴付けられた回折構造をもって形成されている。これにより、たとえば、光が透過するゾーンと非透過となるゾーンで組み合わせた振幅変調型の回折構造とした場合などと比較して透過光量を低下させることなく、かつ回折構造をより精度よく設計することが出来る等の利点がある。 According to this aspect, the diffraction zone is formed with a diffraction structure characterized by a phase function for modulating the phase of light. As a result, for example, the diffraction structure can be designed more accurately without reducing the amount of transmitted light compared to the case of an amplitude modulation type diffractive structure combined with a light transmitting zone and a non-transmitting zone. There are advantages such as being able to.
　回折型多焦点眼用レンズに関する本発明の第６の態様は、第１～５の何れかの態様に係る回折型多焦点眼用レンズであって、前記回折ゾーンにおける回折構造の少なくとも一部の位相関数が、ブレーズ形状の関数からなるものである。 A sixth aspect of the present invention relating to a diffractive multifocal ophthalmic lens is a diffractive multifocal ophthalmic lens according to any one of the first to fifth aspects, wherein at least part of the diffractive structure in the diffraction zone is provided. The phase function is a blazed function.
　本態様によれば、回折ゾーンの少なくとも一部の位相関数をブレーズ状の関数とすることにより、ブラードビジョンの原因であるサイドバンドピーク群の位置や大きさを特定して設計するための式の簡易化が可能となり、計算機によるシミュレートの簡素化・短時間化が可能となる。また、より精度よく作製することが可能となり、より緻密な設計が出来るようになる。すなわち、よりブラードビジョンを低減できるようになるのである。 According to this aspect, by using at least a part of the phase function of the diffraction zone as a blazed function, a formula for specifying and designing the position and size of the sideband peak group that causes the blurred vision is obtained. Simplification is possible, and simulation by a computer can be simplified and shortened. Further, it becomes possible to manufacture with higher accuracy, and a more precise design can be performed. That is, the blood vision can be further reduced.
　回折型多焦点眼用レンズに関する本発明の第７の態様は、第１～６の何れかの態様に係る回折型多焦点眼用レンズであって、前記回折ゾーンにおける回折構造の位相関数がブレーズ形状の関数からなり、且つ、前記第一の焦点における像面上で、ｉ番目の回折ゾーンとｊ番目の回折ゾーンのそれぞれを通過した光の振幅が互いに強め合う関係にある場合において、ｃ番目の回折ゾーンの位置が、各該回折ゾーンを通過した光が互いに振幅を弱め合う条件としての下記数１４を実質的に満足するように設定されているものである。
Figure JPOXMLDOC01-appb-M000014
 A seventh aspect of the present invention relating to a diffractive multifocal ophthalmic lens is the diffractive multifocal ophthalmic lens according to any one of the first to sixth aspects, wherein the phase function of the diffractive structure in the diffraction zone is blaze. C-th in the case where the amplitude of the light that has passed through each of the i-th diffraction zone and the j-th diffraction zone is intensifying each other on the image plane at the first focal point. The positions of the diffraction zones are set so as to substantially satisfy the following formula 14 as a condition for the light passing through each diffraction zone to weaken the amplitude of each other.
Figure JPOXMLDOC01-appb-M000014
　本態様によれば、ブラードビジョンの原因であるサイドバンドの振幅に最も寄与する、あるいはそれに準ずる振幅を特定し、かかる振幅を構成するゾーンの組合せを抽出し、数１４を含む一連の関係式にてその振幅を低減するキャンセルゾーンを、ｃ番目の回折ゾーンとして所望の位置に配することができる。これにより、サイドバンドが低減し、さらにはコンボリューションした際のエッジの強度分布が減少した回折構造を得ることができるのである。 According to the present aspect, the amplitude that most contributes to or conforms to the amplitude of the sideband that is the cause of the blood vision is identified, the combination of the zones that constitute the amplitude is extracted, and a series of relational expressions including Expression 14 is obtained. Thus, the cancel zone for reducing the amplitude can be arranged at a desired position as the c-th diffraction zone. As a result, it is possible to obtain a diffractive structure in which the sideband is reduced and the edge intensity distribution is reduced when convolved.
　回折型多焦点眼用レンズに関する本発明の第８の態様は、前記回折ゾーンにおける回折構造の少なくとも一部が、フレネル間隔の周期構造を有しているものである。 In an eighth aspect of the present invention relating to a diffractive multifocal lens, at least a part of the diffractive structure in the diffraction zone has a periodic structure with Fresnel spacing.
　本態様によれば、フレネル間隔の周期構造を一部または全体に利用することにより、既知のフレネル間隔による光学特性を活用することができる。なお、フレネル間隔の周期構造は、回折ゾーンの少なくとも一部に設けられていれば良く、例えば等間隔の回折ゾーンなどの非フレネル間隔の周期構造と組み合わせて、フレネル間隔の周期構造を採用することが可能である。 According to this aspect, by utilizing the periodic structure of the Fresnel interval partially or entirely, it is possible to utilize the optical characteristics due to the known Fresnel interval. The periodic structure of the Fresnel interval may be provided in at least a part of the diffraction zone. For example, a periodic structure of the Fresnel interval is adopted in combination with a non-Fresnel interval periodic structure such as an equally spaced diffraction zone. Is possible.
　回折型多焦点眼用レンズに関する本発明の第９の態様は、第１～８の何れかの態様に係る回折型多焦点眼用レンズであって、前記回折ゾーンにおける回折構造の位相関数がブレーズ形状の関数からなり、且つ該回折ゾーンにおける回折構造がフレネル間隔の周期構造とされていると共に、該回折ゾーンにおける回折構造の０次回折光によって与えられた前記第一の焦点における像面上で、ｉ番目の回折ゾーンとｊ番目の回折ゾーンのそれぞれを通過した光の振幅が互いに強め合う関係にある場合において、ｃ番目の回折ゾーンの位置と該ｉ番目の回折ゾーンの位置が、各該回折ゾーンを通過した光が互いに振幅を弱め合う条件としての下記数１５を実質的に満足するように設定されているものである。
Figure JPOXMLDOC01-appb-M000015
 A ninth aspect of the present invention relating to a diffractive multifocal ophthalmic lens is a diffractive multifocal ophthalmic lens according to any one of the first to eighth aspects, wherein the phase function of the diffractive structure in the diffraction zone is blaze. On the image plane at the first focus given by the 0th order diffracted light of the diffractive structure in the diffractive zone, the diffractive structure in the diffractive zone being a periodic structure of Fresnel spacing, When the amplitudes of the light beams that have passed through the i-th diffraction zone and the j-th diffraction zone are intensifying each other, the position of the c-th diffraction zone and the position of the i-th diffraction zone correspond to the respective diffraction It is set so as to substantially satisfy the following formula 15 as a condition for the light passing through the zone to weaken the amplitude.
Figure JPOXMLDOC01-appb-M000015
　本態様によれば、第一の焦点における像面上の特定の動径方向位置において、ｉ番目の回折ゾーンとｊ番目の回折ゾーンとによって発生する大きな振幅に対して低減効果を発揮し得るキャンセルゾーンとしてのｃ番目の回折ゾーンを、数学的に特定して把握することが可能となる。なお、本態様では、第一の焦点を与える回折ゾーンがフレネル間隔の周期構造であれば良く、例えばキャンセルゾーンであるｃ番目の回折ゾーンとｉ番目の回折ゾーンとの間等においては、フレネル間隔の周期構造とされる必要がない。 According to this aspect, at a specific radial direction position on the image plane at the first focal point, a cancellation that can exert a reduction effect on the large amplitude generated by the i-th diffraction zone and the j-th diffraction zone. It becomes possible to mathematically identify and grasp the c-th diffraction zone as a zone. In this aspect, the diffraction zone providing the first focus may be a periodic structure with Fresnel spacing. For example, between the c-th diffraction zone and the i-th diffraction zone, which are cancellation zones, the Fresnel spacing. It is not necessary to have a periodic structure.
　回折型多焦点眼用レンズに関する本発明の第１０の態様は、第１～９の何れかの態様に係る回折型多焦点眼用レンズであって、前記回折ゾーンにおける回折構造の少なくとも一部が、等間隔の周期構造を有しているものである。 A tenth aspect of the present invention relating to a diffractive multifocal ophthalmic lens is the diffractive multifocal ophthalmic lens according to any one of the first to ninth aspects, wherein at least a part of the diffractive structure in the diffraction zone is provided. , Which has a periodic structure with equal intervals.
　本態様によれば、回折ゾーンにおける回折構造の少なくとも一部が、等間隔の周期構造を有している。これにより、ブラードビジョンの原因であるサイドバンドについての定式化がより簡便となり、容易にその位置や大きさを特定してキャンセル用領域を設計することが可能となるのである。 According to this aspect, at least a part of the diffractive structure in the diffractive zone has an equally spaced periodic structure. This makes it easier to formulate the sideband that is the cause of the blood vision, and it is possible to easily specify the position and size and design the cancellation area.
　回折型多焦点眼用レンズに関する本発明の第１１の態様は、第１～１０の何れかの態様に係る回折型多焦点眼用レンズであって、前記回折ゾーンにおける回折構造において、前記キャンセル用領域の回折ゾーンにおけるブレーズ形状の関数の傾きが、該キャンセル用領域以外の領域の回折ゾーンのブレーズ形状の傾きと反対の符号を有しているものである。 An eleventh aspect of the present invention relating to a diffractive multifocal ophthalmic lens is the diffractive multifocal ophthalmic lens according to any one of the first to tenth aspects, wherein the diffractive structure in the diffractive zone has the canceling function. The slope of the function of the blaze shape in the diffraction zone of the region has the opposite sign to the slope of the blaze shape of the diffraction zone in the region other than the cancellation region.
　本態様によれば、キャンセル用領域の回折ゾーンにおけるブレーズ形状の関数の傾きが、該キャンセル用領域以外の領域の回折ゾーンのブレーズ形状の傾きと反対の符号を有している。これにより、キャンセル用領域の回折ゾーンで発生する振幅の正負が逆になる領域がでてくる。この領域をブラードビジョンの原因であるサイドバンドの出現位置に持ってくることにより、サイドバンドの振幅を低減、あるいは打ち消すことが可能となる。 According to this aspect, the slope of the function of the blaze shape in the diffraction zone of the cancel region has the opposite sign to the slope of the blaze shape of the diffraction zone of the region other than the cancel region. As a result, a region where the amplitude of the amplitude generated in the diffraction zone of the cancellation region is reversed appears. By bringing this region to the appearance position of the sideband that is the cause of the blood vision, it is possible to reduce or cancel the amplitude of the sideband.
　回折型多焦点眼用レンズに関する本発明の第１２の態様は、第１～１１の何れかの態様に係る回折型多焦点眼用レンズであって、前記キャンセル用領域の回折ゾーンが、該回折ゾーンにおける位置設定と、該回折ゾーンにおけるブレーズ形状の関数の位相設定と、該回折ゾーンにおけるブレーズ形状の関数の傾き設定との、少なくとも一つを異ならせて設定されているものである。 A twelfth aspect of the present invention relating to a diffractive multifocal ophthalmic lens is the diffractive multifocal ophthalmic lens according to any one of the first to eleventh aspects, wherein the diffractive zone in the cancel region is the diffractive zone. At least one of the position setting in the zone, the phase setting of the function of the blaze shape in the diffraction zone, and the inclination setting of the function of the blaze shape in the diffraction zone is set differently.
　本態様によれば、キャンセル用領域の回折ゾーンと該キャンセル用領域以外の回折ゾーンとが、該回折ゾーンの位置設定と、該回折ゾーンにおけるブレーズ形状の関数の位相設定と、該回折ゾーンにおけるブレーズ形状の関数の傾き設定との、少なくとも一つを異ならせて設定されている。これにより、ブラードビジョンの原因であるサイドバンドをより低減できる条件を見出すことが可能となる。なお、２つあるいは３つすべてを再調整して、ブラードビジョンの原因であるサイドバンドをより低減できる条件を見出すようにしてもよい。なお、キャンセル用領域の各回折ゾーン間でのブレーズの相対的な位置や位相や傾きの調節設定は、回折ゾーンのブレーズ形状を所定の関数をもって表すこととし、かかる関数において、ブレーズの位置と位相と傾きに各関係する特定の定数を変更することによって効率的に行うことが可能である。 According to this aspect, the diffraction zone of the cancellation region and the diffraction zone other than the cancellation region include the position setting of the diffraction zone, the phase setting of the function of the blaze shape in the diffraction zone, and the blaze in the diffraction zone. At least one of the shape function inclination setting and the inclination setting is set differently. This makes it possible to find a condition that can further reduce the sideband that is the cause of the blood vision. Note that two or all three may be readjusted to find a condition that can further reduce the sideband that causes the blurred vision. It should be noted that the relative position, phase, and inclination of the blaze between the diffraction zones in the cancellation area are expressed by a predetermined function representing the blaze shape of the diffraction zone. And can be done efficiently by changing the specific constants related to the slope.
　回折型多焦点眼用レンズに関する本発明の第１３の態様は、第１～１２の何れかの態様に係る回折型多焦点眼用レンズであって、前記回折ゾーンにおける回折構造が、位相に相当する光路長を反映したレリーフ構造によって構成されているものである。 A thirteenth aspect of the present invention relating to a diffractive multifocal ophthalmic lens is a diffractive multifocal ophthalmic lens according to any one of the first to twelfth aspects, wherein the diffractive structure in the diffraction zone corresponds to a phase. The relief structure reflects the optical path length.
　本態様によれば、回折ゾーンにおける回折構造が、位相に相当する光路長を反映したレリーフ構造によって構成されている。これにより、位相関数を正確に実形状の回折構造として構築することができ、かつ精度よく回折構造を製造することができる。その結果、より目的とするブラードビジョンを正確に低減できるのである。 According to this aspect, the diffractive structure in the diffractive zone is constituted by a relief structure reflecting the optical path length corresponding to the phase. As a result, the phase function can be accurately constructed as a real-shaped diffractive structure, and the diffractive structure can be manufactured with high accuracy. As a result, the target blood vision can be accurately reduced.
　また、上述の如き本発明に従う構造とされた回折型多焦点眼用レンズの製造に好適に採用され得る、回折型多焦点眼用レンズの製造方法に関する本発明の第１の態様は、同心円状に複数形成された回折ゾーンが設けられた光学部を備えており、該光学部によって少なくとも二つの焦点が与えられると共に、かかる焦点のうちの一つの焦点である第一の焦点におけるブラードビジョンが抑制された回折型多焦点眼用レンズを製造するに際して、以下（ｉ）～（ｉｖ）の工程を採用する回折型多焦点眼用レンズの製造方法を、特徴とする。
（ｉ）少なくとも二つの焦点が与えられる前記光学部における複数の前記回折ゾーンを設定する基本形状設定工程。
（ｉｉ）該基本形状設定工程で設定した複数の該回折ゾーンによって前記第一の焦点における像面上で与えられる光の振幅分布を求める振幅情報取得工程。
（ｉｉｉ）該振幅情報取得工程で求めた該光の振幅分布において低減対象とするサイドバンドを決定する低減対象決定工程。
（ｉｖ）該低減対象決定工程で決定した該サイドバンドを相殺的に減少せしめる光の振幅分布を前記第一の焦点における像面上で与えるキャンセル用領域を、複数の前記回折ゾーンと共に前記光学部における明所視状態の瞳孔径に対応する領域内に形成するキャンセル用領域形成工程。 In addition, the first aspect of the present invention relating to a method for manufacturing a diffractive multifocal ophthalmic lens that can be suitably employed for manufacturing a diffractive multifocal ophthalmic lens having a structure according to the present invention as described above is a concentric circle. The optical unit is provided with a plurality of diffraction zones, and at least two focal points are provided by the optical unit, and the blur vision at the first focal point which is one of the focal points is suppressed. In producing the diffractive multifocal ophthalmic lens thus produced, a method for producing a diffractive multifocal ophthalmic lens that employs the following steps (i) to (iv) is characterized.
(I) A basic shape setting step for setting a plurality of diffraction zones in the optical unit to which at least two focal points are given.
(Ii) An amplitude information acquisition step of obtaining an amplitude distribution of light provided on the image plane at the first focus by the plurality of diffraction zones set in the basic shape setting step.
(Iii) A reduction target determination step of determining a sideband to be reduced in the amplitude distribution of the light obtained in the amplitude information acquisition step.
(Iv) a cancel region that gives an amplitude distribution of light on the image plane at the first focal point that destructively reduces the sideband determined in the reduction target determination step together with the plurality of diffraction zones; A region forming process for cancellation formed in a region corresponding to the pupil diameter in the photopic vision state in FIG.
　本態様の製造方法に従えば、一つの焦点における像面上でのブラードビジョンの大きな原因と考えられるサイドバンドの振幅分布を抑えるキャンセルゾーンを、明所視状態の瞳孔を透過する光線の通過領域内に形成することで、ブラードビジョンが抑えられて良好な見え方の質を与える回折型多焦点眼用レンズが、実現可能となる。 According to the manufacturing method of this aspect, a cancel zone that suppresses the amplitude distribution of the sideband, which is considered to be a major cause of the blurred vision on the image plane at one focal point, is a passing region of the light beam that passes through the pupil in the photopic vision state. By forming the lens inside, it is possible to realize a diffractive multifocal ophthalmic lens that suppresses the blood vision and gives a good appearance quality.
　なお、本態様において、前記基本形状設定工程における回折ゾーンの設定は、回折型多焦点眼用レンズに要求される複数の焦点を与える回折構造の基本的な位相プロファイルを決定することによって行われ得る。また、低減対象決定工程における低減対象とするサイドバンドの決定は、ブラードビジョンへの影響が大きいサイドバンドが優先的に選択されることとなり、一般に、ピークエッジに近く且つ大きい回折次数が一次又は二次のサイドバンドが選択される。 In this aspect, the setting of the diffraction zone in the basic shape setting step can be performed by determining a basic phase profile of a diffractive structure that provides a plurality of focal points required for a diffractive multifocal ophthalmic lens. . In the determination of the side band to be reduced in the reduction target determining step, a side band having a large influence on the blood vision is preferentially selected. Generally, a diffraction order close to the peak edge and having a large diffraction order is first or second. The next sideband is selected.
　回折型多焦点眼用レンズの製造方法に関する本発明の第２の態様は、前記第１の態様に従って回折型多焦点眼用レンズを製造するに際し、前記低減対象決定工程において低減対象として決定した前記サイドバンドの振幅および領域の振幅データを取得し、かかる振幅データから前記第一の焦点における像面上での光の振幅関数を求めて、かかるサイドバンドの振幅関数に対して相殺的な低減効果を及ぼす光の振幅関数を与えるキャンセル用の回折ゾーンを、前記キャンセル用領域として採用する回折型多焦点眼用レンズの製造方法である。 According to a second aspect of the present invention relating to a method for manufacturing a diffractive multifocal ophthalmic lens, the diffractive multifocal ophthalmic lens according to the first aspect has been determined as a reduction target in the reduction target determination step when manufacturing the diffractive multifocal ophthalmic lens. The sideband amplitude and area amplitude data are obtained, the amplitude function of light on the image plane at the first focus is obtained from the amplitude data, and the reduction effect that is offset against the sideband amplitude function is obtained. This is a method of manufacturing a diffractive multifocal ophthalmic lens that employs a canceling diffraction zone that gives an amplitude function of light that affects the above as the canceling region.
　本態様に従えば、例えば各回折ゾーンによる回折現象を数値解析することにより、低減対象決定工程で決定した該サイドバンドを相殺的に減少させるキャンセル用領域の回折ゾーンを、高速フーリエ変換などのアルゴリズムを用いた演算によって精度良く設定することが可能になる。 According to this aspect, for example, by performing a numerical analysis of the diffraction phenomenon caused by each diffraction zone, an algorithm such as a fast Fourier transform is applied to the diffraction zone in the cancel region that reduces the sideband determined in the reduction target determination step in an offset manner. It becomes possible to set with high precision by calculation using.
　なお、本態様での数値解析に際しては、好適には、０次回折光の焦点像面位置における各回折ゾーンからの振幅関数を表す以下の数１６が基本式として用いられ、かかる基本式を数学的に解析することによって、本態様の数値解析が実行される。
Figure JPOXMLDOC01-appb-M000016
 In the numerical analysis in this aspect, the following equation 16 representing the amplitude function from each diffraction zone at the focal image plane position of the 0th-order diffracted light is preferably used as a basic equation, and this basic equation is mathematically expressed. By performing the analysis, the numerical analysis of this aspect is executed.
Figure JPOXMLDOC01-appb-M000016
　回折型多焦点眼用レンズの製造方法に関する本発明の第３の態様は、前記第１又は第２の態様に従う回折型多焦点眼用レンズの製造方法であって、前記回折ゾーンにおける回折構造の位相関数がブレーズ形状の関数からなり、且つ、前記第一の焦点が該回折ゾーンにおける回折構造の０次回折光によって与えられるものである。 A third aspect of the present invention relating to a method for manufacturing a diffractive multifocal ophthalmic lens is a method for manufacturing a diffractive multifocal ophthalmic lens according to the first or second aspect, wherein the diffractive structure in the diffraction zone is formed. The phase function is a blazed function, and the first focal point is given by the 0th-order diffracted light of the diffractive structure in the diffraction zone.
　本態様に従えば、各ゾーンの位相関数がブレーズ形状の一次関数で表されるものと仮定することにより、例えば後述するように目的とするキャンセルゾーンを数学的な解析結果を利用して、効率的に調節して再設定することが可能になる。 According to this aspect, by assuming that the phase function of each zone is represented by a linear function of a blaze shape, for example, as will be described later, the objective cancellation zone is utilized by using a mathematical analysis result, and the efficiency is improved. It becomes possible to adjust and reset again.
　回折型多焦点眼用レンズの製造方法に関する本発明の第４の態様は、前記第３の態様に従って回折型多焦点眼用レンズを製造するに際し、前記第一の焦点における像面上で、ｉ番目の回折ゾーンとｊ番目の回折ゾーンのそれぞれを通過した光の振幅が互いに強め合う関係にある場合において、ｃ番目の回折ゾーンの位置が、各該回折ゾーンを通過した光が互いに振幅を弱め合う条件としての前記数１４を実質的に満足するように、前記キャンセル用領域の前記回折ゾーンを設定する回折型多焦点眼用レンズの製造方法である。 According to a fourth aspect of the present invention relating to a method for manufacturing a diffractive multifocal ophthalmic lens, when manufacturing a diffractive multifocal ophthalmic lens according to the third aspect, i is formed on the image plane at the first focus. In the case where the amplitudes of the light beams that have passed through each of the th-th diffraction zone and the j-th diffraction zone are intensifying each other, the positions of the c-th diffraction zone are such that the light beams that have passed through the respective diffraction zones weaken the amplitude of each other. This is a method for manufacturing a diffractive multifocal ophthalmic lens in which the diffraction zone of the cancel region is set so as to substantially satisfy Equation 14 as a matching condition.
　本態様によれば、ブラードビジョンの原因であるサイドバンドの振幅に影響が大きい振幅を効率的に特定すると共に、かかる振幅を構成するゾーンの組合せを選定し、更に、その振幅を低減してサイドバンドを抑制し得るゾーンを適切な位置に設定することが効率的に可能とされる。 According to this aspect, the amplitude that has a large influence on the amplitude of the sideband that is the cause of the blood vision is efficiently identified, the combination of the zones that constitute the amplitude is selected, and the amplitude is further reduced to reduce the sideband. It is possible to efficiently set a zone capable of suppressing the band at an appropriate position.
　回折型多焦点眼用レンズの製造方法に関する本発明の第５の態様は、前記第３の態様に従って回折型多焦点眼用レンズを製造するに際し、前記第一の焦点における像面上で、ｉ番目の回折ゾーンとｊ番目の回折ゾーンのそれぞれを通過した光の振幅が互いに強め合う関係にある場合において、ｃ番目の回折ゾーンの位置と該ｉ番目の回折ゾーンの位置が、各該回折ゾーンを通過した光が互いに振幅を弱め合う条件としての前記数１５を実質的に満足するように設定されている回折型多焦点眼用レンズの製造方法である。 According to a fifth aspect of the present invention relating to a method for manufacturing a diffractive multifocal ophthalmic lens, when manufacturing a diffractive multifocal ophthalmic lens according to the third aspect, i In the case where the amplitudes of the light beams that have passed through each of the th-th diffraction zone and the j-th diffraction zone are intensifying each other, the position of the c-th diffraction zone and the position of the i-th diffraction zone correspond to each diffraction zone. Is a method for manufacturing a diffractive multifocal ophthalmic lens that is set so as to substantially satisfy Equation 15 as a condition in which the amplitudes of light passing through each other weaken.
　本態様に従えば、フレネル間隔からなる回折構造において前記数１５を利用してｉ番目の回折ゾーンとｃ番目の回折ゾーンの相対的な位置を変更設定することにより、フレネル間隔に基づく結像特性を維持したまま前記キャンセルゾーンとしてのｃ番目の回折ゾーンを、効率的に設計することができる。 According to this aspect, in the diffractive structure having the Fresnel interval, the imaging characteristic based on the Fresnel interval is set by changing and setting the relative position of the i-th diffraction zone and the c-th diffraction zone using Equation 15. The c-th diffraction zone as the cancellation zone can be efficiently designed while maintaining the above.
　回折型多焦点眼用レンズの製造方法に関する本発明の第６の態様は、前記第３の態様に従って回折型多焦点眼用レンズを製造するに際し、前記ブレーズ形状の関数を位相軸方向にずらして調節して、前記キャンセル用領域の回折ゾーンが前記サイドバンドに対応する振幅を弱め合うように設定する回折型多焦点眼用レンズの製造方法である。 According to a sixth aspect of the present invention relating to a method for manufacturing a diffractive multifocal ophthalmic lens, in manufacturing a diffractive multifocal ophthalmic lens according to the third aspect, the function of the blaze shape is shifted in the phase axis direction. This is a method for manufacturing a diffractive multifocal ophthalmic lens that is adjusted so that the diffraction zone of the cancellation region weakens the amplitude corresponding to the sideband.
　本態様に従えば、ｉ番目の回折ゾーンに対するｃ番目の回折ゾーンの相対的な位相ずれ量を変更設定することにより、前記キャンセルゾーンとしてのｃ番目の回折ゾーンを、効率的に設計することができる。即ち、例えばブレーズ形状の位相関数を定める座標上で、ｉ番目とｃ番目の各回折ゾーンに対応する関数を各レンズ半径位置（ｒ）において、座標上の位相軸方向に所定位相（τ）だけ相対的にずらして調節することにより、本態様における設定が行われ得る。 According to this aspect, the c-th diffraction zone as the cancellation zone can be efficiently designed by changing and setting the relative phase shift amount of the c-th diffraction zone with respect to the i-th diffraction zone. it can. That is, for example, a function corresponding to each of the i-th and c-th diffraction zones on the coordinates defining the blaze-shaped phase function at each lens radius position (r) is a predetermined phase (τ) in the phase axis direction on the coordinates. The setting in this aspect can be performed by adjusting by relatively shifting.
　回折型多焦点眼用レンズの製造方法に関する本発明の第７の態様は、前記第３の態様に従って回折型多焦点眼用レンズを製造するに際し、前記キャンセル用領域の回折ゾーンにおけるブレーズ形状の関数の傾きの符号を、該キャンセル用領域以外の領域の回折ゾーンのブレーズ形状の傾きと反対の符号に設定することにより、前記サイドバンドに対応する振幅を弱め合うように設定する回折型多焦点眼用レンズの製造方法である。 A seventh aspect of the present invention relating to a method for manufacturing a diffractive multifocal ophthalmic lens is the function of the blaze shape in the diffraction zone of the cancel region when manufacturing a diffractive multifocal ophthalmic lens according to the third aspect. The diffractive multifocal eye is set so that the amplitude corresponding to the sideband is weakened by setting the sign of the tilt of the diffractive zone to a sign opposite to that of the blazed shape in the region other than the canceling region. It is a manufacturing method of a lens.
　本態様に従えば、ｉ番目の回折ゾーンに対するｃ番目の回折ゾーンの位相定数を変量することでブレーズの傾きを調節し、前記キャンセルゾーンとしてのｃ番目の回折ゾーンを効率的に設計することができる。 According to this aspect, it is possible to efficiently design the c-th diffraction zone as the cancellation zone by adjusting the blaze slope by varying the phase constant of the c-th diffraction zone with respect to the i-th diffraction zone. it can.
　なお、本発明方法では、上記第４～７の各態様に係る設計手法について、必要に応じて何れか一つを選択して採用する他、それらを適宜に必要数だけ組み合わせて採用することで、キャンセルゾーンとしてのｃ番目の回折ゾーンひいては目的とする回折型多焦点眼用レンズを設計製造することも可能である。 In the method of the present invention, any one of the design methods according to the fourth to seventh aspects described above may be selected and used as necessary, or may be combined in a necessary number as appropriate. It is also possible to design and manufacture the c-th diffraction zone as a cancellation zone, and thus the target diffractive multifocal ophthalmic lens.
　すなわち、回折型多焦点眼用レンズの製造方法に関する本発明の第８の態様は、製造方法に関する前記第４又は５の態様に従う前記回折ゾーンの位置の調節と、製造方法に関する前記第６の態様に従う該回折ゾーンの位相ずれ量τの調節と、製造方法に関する前記第７の態様に従う該回折ゾーンの前記ブレーズ形状の傾きの調節との、少なくとも二つを組み合わせて調節することにより、前記サイドバンドに対応する振幅を弱め合うように設定する回折型多焦点眼用レンズの製造方法である。 That is, the eighth aspect of the present invention related to the method for manufacturing a diffractive multifocal ophthalmic lens is the sixth aspect related to the adjustment of the position of the diffraction zone according to the fourth or fifth aspect related to the manufacturing method and the manufacturing method. Adjusting the phase shift amount τ of the diffraction zone according to the method and adjusting the tilt of the blazed shape of the diffraction zone according to the seventh aspect of the manufacturing method in combination with at least two. Is a method for manufacturing a diffractive multifocal ophthalmic lens in which the amplitude corresponding to is set so as to weaken.
エッジ強度を算出する際のコンボリューションの概念図。The conceptual diagram of the convolution at the time of calculating edge strength. 本発明のキャンセル機構の概念図。The conceptual diagram of the cancellation mechanism of this invention. 本発明の第一の実施形態としてのコンタクトレンズを示す裏面モデル図。The back surface model figure which shows the contact lens as 1st embodiment of this invention. 図３のＩＶ－ＩＶ断面に相当する、同コンタクトレンズの断面モデル図。FIG. 4 is a cross-sectional model diagram of the contact lens corresponding to the IV-IV cross section of FIG. 3. 図３に示すコンタクトレンズの裏面に形成されたレリーフ形状を説明するための断面モデル図。FIG. 4 is a cross-sectional model diagram for explaining a relief shape formed on the back surface of the contact lens shown in FIG. 3. 本発明の第一の実施形態（実線）と比較例１（破線）の位相プロファイル。The phase profile of 1st embodiment (solid line) of this invention and the comparative example 1 (dashed line). 比較例１（ａ）と本実施形態（ｂ）における光軸上の強度分布のシミュレーション結果。The simulation result of the intensity distribution on the optical axis in Comparative Example 1 (a) and the present embodiment (b). 本実施形態（実線）と比較例１（破線）の０次回折光の焦点位置における点像広がり関数のシミュレーション結果。The simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and the comparative example 1 (broken line). 本実施形態（実線）と比較例１（破線）の０次回折光の焦点位置におけるエッジ強度分布のシミュレーション結果。The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and Comparative Example 1 (broken line). 本発明の第二の実施形態（実線）と比較例２（破線）の位相プロファイル。The phase profile of 2nd embodiment (solid line) of this invention, and the comparative example 2 (dashed line). 比較例２（ａ）と本実施形態（ｂ）における光軸上の強度分布のシミュレーション結果。The simulation result of the intensity distribution on the optical axis in Comparative Example 2 (a) and this embodiment (b). 本実施形態（実線）と比較例２（破線）の０次回折光の焦点位置における点像広がり関数のシミュレーション結果。The simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and the comparative example 2 (broken line). 本実施形態（実線）と比較例２（破線）の０次回折光の焦点位置におけるエッジ強度分布のシミュレーション結果。The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and Comparative Example 2 (broken line). 本発明の第二の実施形態の変形例１（実線）と比較例２の変形例１（破線）の位相プロファイル。The phase profile of the modification 1 (solid line) of the second embodiment of the present invention and the modification 1 (broken line) of the comparative example 2. 比較例２の変形例１（ａ）と本実施形態（ｂ）における光軸上の強度分布のシミュレーション結果。The simulation result of the intensity distribution on the optical axis in the modification 1 (a) of the comparative example 2 and this embodiment (b). 本実施形態（実線）と比較例２の変形例１（破線）の０次回折光の焦点位置における点像広がり関数のシミュレーション結果。The simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and the modification 1 of the comparative example 2 (broken line). 本実施形態（実線）と比較例２の変形例１（破線）の０次回折光の焦点位置におけるエッジ強度分布のシミュレーション結果。The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and the modification 1 (broken line) of the comparative example 2. 本発明の第二の実施形態（実線）と比較例２の変形例２（破線）の位相プロファイル。The phase profile of 2nd embodiment (solid line) of this invention and the modification 2 (broken line) of the comparative example 2. FIG. 比較例２の変形例２における光軸上の強度分布のシミュレーション結果。The simulation result of the intensity distribution on the optical axis in the modification 2 of the comparative example 2. FIG. 本実施形態（実線）と比較例２の変形例２（破線）の０次回折光の焦点位置におけるエッジ強度分布のシミュレーション結果。The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and the modification 2 of the comparative example 2 (broken line). 比較例２の変形例２における第３ゾーンまでの光軸上の強度分布のシミュレーション結果。The simulation result of the intensity distribution on the optical axis to the 3rd zone in the modification 2 of the comparative example 2. FIG. 本発明の第三の実施形態（実線）と比較例２（破線）の位相プロファイル。The phase profile of 3rd embodiment (solid line) and comparative example 2 (broken line) of this invention. 本実施形態における光軸上の強度分布のシミュレーション結果。The simulation result of the intensity distribution on the optical axis in this embodiment. 本実施形態（実線）と比較例２（破線）の０次回折光の焦点位置における点像広がり関数のシミュレーション結果。The simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and the comparative example 2 (broken line). 本実施形態（実線）と比較例２（破線）の０次回折光の焦点位置におけるエッジ強度分布のシミュレーション結果。The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and Comparative Example 2 (broken line). 本発明の第四の実施形態（実線）と比較例４（破線）の位相プロファイル。The phase profile of 4th embodiment (solid line) of this invention, and the comparative example 4 (broken line). 比較例４（ａ）と本実施形態（ｂ）における光軸上の強度分布のシミュレーション結果。The simulation result of the intensity distribution on the optical axis in Comparative Example 4 (a) and this embodiment (b). 本実施形態（実線）と比較例４（破線）の０次回折光の焦点位置における点像広がり関数のシミュレーション結果。The simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and the comparative example 4 (broken line). 本実施形態（実線）と比較例４（破線）の０次回折光の焦点位置におけるエッジ強度分布のシミュレーション結果。The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and Comparative Example 4 (broken line). 本実施形態の等間隔領域（ａ）および第３ゾーン（ｂ）における振幅関数のシミュレーション結果。The simulation result of the amplitude function in the equidistant area | region (a) and 3rd zone (b) of this embodiment. 本発明の第五の実施形態（実線）と比較例５（破線）の位相プロファイル。The phase profile of 5th embodiment (solid line) and the comparative example 5 (broken line) of this invention. 比較例５（ａ）と本実施形態（ｂ）における光軸上の強度分布のシミュレーション結果。The simulation result of the intensity distribution on the optical axis in the comparative example 5 (a) and this embodiment (b). 本実施形態（実線）と比較例５（破線）の０次回折光の焦点位置における点像広がり関数のシミュレーション結果。The simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and the comparative example 5 (broken line). 本実施形態（実線）と比較例５（破線）の０次回折光の焦点位置におけるエッジ強度分布のシミュレーション結果。The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and Comparative Example 5 (broken line). 本発明の第六の実施形態（実線）と比較例６（破線）の位相プロファイル。The phase profile of 6th embodiment (solid line) of this invention and the comparative example 6 (broken line). 比較例６（ａ）と本実施形態（ｂ）における光軸上の強度分布のシミュレーション結果。The simulation result of the intensity distribution on the optical axis in Comparative Example 6 (a) and the present embodiment (b). 本実施形態（実線）と比較例６（破線）の０次回折光の焦点位置における点像広がり関数のシミュレーション結果。The simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and the comparative example 6 (broken line). 本実施形態（実線）と比較例６（破線）の０次回折光の焦点位置におけるエッジ強度分布のシミュレーション結果。The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and Comparative Example 6 (broken line). 比較例７（ａ）と本発明の第七の実施形態（ｂ）の位相プロファイル。The phase profile of the comparative example 7 (a) and the seventh embodiment (b) of the present invention. 比較例７（ａ）と本実施形態（ｂ）における光軸上の強度分布のシミュレーション結果。The simulation result of the intensity distribution on the optical axis in the comparative example 7 (a) and this embodiment (b). 本実施形態（実線）と比較例７（破線）の０次回折光の焦点位置における点像広がり関数のシミュレーション結果。The simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and the comparative example 7 (broken line). 本実施形態（実線）と比較例７（破線）の０次回折光の焦点位置におけるエッジ強度分布のシミュレーション結果。The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and Comparative Example 7 (broken line). 本発明の第八の実施形態（実線）と比較例８（破線）の位相プロファイル。The phase profile of 8th embodiment (solid line) and the comparative example 8 (broken line) of this invention. 比較例８（ａ）と本実施形態（ｂ）における光軸上の強度分布のシミュレーション結果。The simulation result of the intensity distribution on the optical axis in the comparative example 8 (a) and this embodiment (b). 本実施形態（実線）と比較例８（破線）の０次回折光の焦点位置における点像広がり関数のシミュレーション結果。The simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and the comparative example 8 (broken line). 本実施形態（実線）と比較例８（破線）の０次回折光の焦点位置におけるエッジ強度分布のシミュレーション結果。The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and Comparative Example 8 (broken line). 本発明の第九の実施形態（実線）と比較例９（破線）の位相プロファイル。The phase profile of 9th embodiment (solid line) and comparative example 9 (broken line) of this invention. 比較例９（ａ）と本実施形態（ｂ）における光軸上の強度分布のシミュレーション結果。The simulation result of the intensity distribution on the optical axis in Comparative Example 9 (a) and this embodiment (b). 本実施形態（実線）と比較例９（破線）の０次回折光の焦点位置における点像広がり関数のシミュレーション結果。The simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and the comparative example 9 (broken line). 本実施形態（実線）と比較例９（破線）の０次回折光の焦点位置におけるエッジ強度分布のシミュレーション結果。The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and Comparative Example 9 (broken line). 本発明の第十の実施形態（実線）と比較例１０（破線）の位相プロファイル。The phase profile of the tenth embodiment (solid line) of the present invention and comparative example 10 (broken line). 比較例１０（ａ）と本実施形態（ｂ）における光軸上の強度分布のシミュレーション結果。The simulation result of the intensity distribution on the optical axis in Comparative Example 10 (a) and this embodiment (b). 本実施形態（実線）と比較例１０（破線）の０次回折光の焦点位置における点像広がり関数のシミュレーション結果。The simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and the comparative example 10 (broken line). 本実施形態（実線）と比較例１０（破線）の０次回折光の焦点位置におけるエッジ強度分布のシミュレーション結果。The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and Comparative Example 10 (broken line). 本実施形態における次数ｑr が整数の場合（ａ）と整数±０．５の場合（ｂ）の振幅関数のシミュレーション結果。The simulation result of the amplitude function in the case where the order q r in the present embodiment is an integer (a) and in the case of an integer ± 0.5 (b). 本発明の第十一の実施形態（実線）と第四の実施形態（破線）の位相プロファイル。The phase profile of 11th embodiment (solid line) and 4th embodiment (broken line) of this invention. 本実施形態における光軸上の強度分布のシミュレーション結果。The simulation result of the intensity distribution on the optical axis in this embodiment. 本実施形態（実線）と第四の実施形態（破線）の０次回折光の焦点位置における点像広がり関数のシミュレーション結果。The simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and 4th embodiment (broken line). 本実施形態（実線）と第四の実施形態（○）と比較例４（破線）の０次回折光の焦点位置におけるエッジ強度分布のシミュレーション結果。The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line), 4th embodiment ((circle)), and the comparative example 4 (dashed line). 本発明の第十二の実施形態（実線）と比較例１２（破線）の位相プロファイル。The phase profile of 12th embodiment (solid line) of this invention, and the comparative example 12 (dashed line). 比較例１２（ａ）と本実施形態（ｂ）における光軸上の強度分布のシミュレーション結果。The simulation result of the intensity distribution on the optical axis in Comparative Example 12 (a) and this embodiment (b). 本実施形態（実線）と比較例１２（破線）の０次回折光の焦点位置における点像広がり関数のシミュレーション結果。The simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and Comparative Example 12 (broken line). 本実施形態（実線）と比較例１２（破線）の０次回折光の焦点位置におけるエッジ強度分布のシミュレーション結果。The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and Comparative Example 12 (broken line). 位相ずれ量τ＝０（ａ）、－０．５π（ｂ）および０．５π（ｃ）における振幅関数のシミュレーション結果。Simulation results of amplitude functions at phase shift amounts τ = 0 (a), −0.5π (b), and 0.5π (c). 本実施形態における位相ずれ量τ付与前（ａ）と付与後（ｂ）の振幅関数のシミュレーション結果。The simulation result of the amplitude function before (a) and after provision (b) of phase shift amount τ in this embodiment. 本発明の第十三の実施形態（実線）と比較例１２（破線）の位相プロファイル。The phase profile of 13th embodiment (solid line) of this invention, and the comparative example 12 (dashed line). 比較例１２（ａ）と本実施形態（ｂ）における光軸上の強度分布のシミュレーション結果。The simulation result of the intensity distribution on the optical axis in Comparative Example 12 (a) and this embodiment (b). 本実施形態（実線）と比較例１２（破線）の０次回折光の焦点位置における点像広がり関数のシミュレーション結果。The simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and Comparative Example 12 (broken line). 本実施形態（実線）と比較例１２（破線）の０次回折光の焦点位置におけるエッジ強度分布のシミュレーション結果。The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and Comparative Example 12 (broken line). 比較例１４（ａ）と本発明の第十四の実施形態（ｂ）の位相プロファイル。The phase profile of the comparative example 14 (a) and 14th embodiment (b) of this invention. 比較例１４（ａ）と本実施形態（ｂ）における光軸上の強度分布のシミュレーション結果。The simulation result of the intensity distribution on the optical axis in Comparative Example 14 (a) and this embodiment (b). 本実施形態（実線）と比較例１４（破線）の０次回折光の焦点位置における点像広がり関数のシミュレーション結果。The simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and Comparative Example 14 (broken line). 本実施形態（実線）と比較例１４（破線）の０次回折光の焦点位置におけるエッジ強度分布のシミュレーション結果。The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and Comparative Example 14 (broken line). 位相定数ｈ＝０．５（ａ）と－０．５（ｂ）の場合の振幅関数のシミュレーション結果。Simulation results of the amplitude function when the phase constant h = 0.5 (a) and −0.5 (b). 比較例１５（ａ）と本発明の第十五の実施形態（ｂ）の位相プロファイル。The phase profile of the comparative example 15 (a) and 15th embodiment (b) of this invention. 比較例１５（ａ）と本実施形態（ｂ）における光軸上の強度分布のシミュレーション結果。The simulation result of the intensity distribution on the optical axis in the comparative example 15 (a) and this embodiment (b). 本実施形態（実線）と比較例１５（破線）の０次回折光の焦点位置における点像広がり関数のシミュレーション結果。The simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and Comparative Example 15 (broken line). 本実施形態（実線）と比較例１５（破線）の０次回折光の焦点位置におけるエッジ強度分布のシミュレーション結果。The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and Comparative Example 15 (broken line). 本発明の第十六の実施形態（実線）と第二の実施形態（破線）の位相プロファイル。The phase profile of 16th embodiment (solid line) and 2nd embodiment (broken line) of this invention. 第二の実施形態（ａ）と本実施形態（ｂ）における光軸上の強度分布のシミュレーション結果。The simulation result of intensity distribution on the optical axis in the second embodiment (a) and the present embodiment (b). 本実施形態（実線）と第二の実施形態（破線）の０次回折光の焦点位置における点像広がり関数のシミュレーション結果。The simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and 2nd embodiment (broken line). 本実施形態（実線）と第二の実施形態（破線）の０次回折光の焦点位置におけるエッジ強度分布のシミュレーション結果。The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and 2nd embodiment (broken line). 本発明の第十七の実施形態（実線）と第四の実施形態（破線）の位相プロファイル。The phase profile of 17th embodiment (solid line) and 4th embodiment (broken line) of this invention. 第四の実施形態（ａ）と本実施形態（ｂ）における光軸上の強度分布のシミュレーション結果。The simulation result of intensity distribution on the optical axis in the fourth embodiment (a) and the present embodiment (b). 本実施形態（実線）と第四の実施形態（破線）の０次回折光の焦点位置における点像広がり関数のシミュレーション結果。The simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and 4th embodiment (broken line). 本実施形態（実線）と第四の実施形態（破線）の０次回折光の焦点位置におけるエッジ強度分布のシミュレーション結果。The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and 4th embodiment (broken line). 本発明の第十八の実施形態（実線）と第十五の実施形態（破線）の位相プロファイル。The phase profiles of the eighteenth embodiment (solid line) and the fifteenth embodiment (dashed line) of the present invention. 第十五の実施形態（ａ）と本実施形態（ｂ）における光軸上の強度分布のシミュレーション結果。The simulation result of intensity distribution on the optical axis in the fifteenth embodiment (a) and the present embodiment (b). 本実施形態（実線）と第十五の実施形態（破線）の０次回折光の焦点位置における点像広がり関数のシミュレーション結果。The simulation result of the point spread function in the focus position of the 0th-order diffracted light of this embodiment (solid line) and 15th embodiment (broken line). 本実施形態（実線）と第十五の実施形態（破線）の０次回折光の焦点位置におけるエッジ強度分布のシミュレーション結果。The simulation result of edge intensity distribution in the focus position of the 0th-order diffracted light of this embodiment (solid line) and 15th embodiment (broken line). 比較例５（ａ）と第５の実施形態（ｂ）における蛍光灯のエッジ部の実写写真。The real photography of the edge part of the fluorescent lamp in the comparative example 5 (a) and 5th Embodiment (b). 本実施形態（実線）と比較例５（破線）の０次回折光の焦点位置におけるエッジ部の強度分布測定結果。The intensity distribution measurement result of the edge part in the focus position of the 0th-order diffracted light of this embodiment (solid line) and the comparative example 5 (broken line). 一般的な回折多焦点レンズ（ａ）と単焦点レンズ（ｂ）を通して撮影された解像度チャート。The resolution chart image | photographed through the general diffraction multifocal lens (a) and the single focus lens (b). 回折多焦点レンズにおけるブラードビジョンの発生に関する説明図。Explanatory drawing about generation | occurrence | production of the blood vision in a diffractive multifocal lens. 回折多焦点レンズにおけるブラードビジョンの発生機構のモデルの説明図（Ｉ）。Explanatory drawing (I) of the model of the generation mechanism of the blood vision in a diffractive multifocal lens. 回折多焦点レンズにおけるブラードビジョンの発生機構のモデルの説明図（ＩＩ）。Explanatory drawing (II) of the model of the generation mechanism of the blood vision in a diffractive multifocal lens. 位相プロファイルを説明する概念図。The conceptual diagram explaining a phase profile. ブレーズ形状の位相プロファイルを説明する図。The figure explaining the blaze-shaped phase profile. 位相関数に位相ずれ量τを付与した場合の位相関数説明図。FIG. 6 is an explanatory diagram of a phase function when a phase shift amount τ is added to the phase function.
　本発明ではまずブラードビジョン改善を目的としてかかる現象の機構を説明し、かかる機構に基づくブラードビジョン改善の方法を説明する。その後、かかる方法から見出された新たな結像特性について説明し、それが近年必要性を増している多焦点レンズへ応用可能であることを説明する。そして、かかる方法や特性を具体的な実施例に基づき説明する。 In the present invention, the mechanism of such a phenomenon is first described for the purpose of improving the blood vision, and a method for improving the blood vision based on such a mechanism is described. Then, the new imaging characteristics found from such a method will be described, and it will be explained that it can be applied to multifocal lenses that have recently become increasingly necessary. Such methods and characteristics will be described based on specific examples.
　光の滲みは前記したように、点像広がり関数と光源の強度分布との間のコンボリューションによって示される像面の動径方向に広がるエッジ部の光の強度分布である。よってこの滲みの原因となる光の強度分布を低減させるには、その基となる点像広がり関数のサイドバンドのピーク強度を、滲みが目立たないようなレベルにまで低減させることによって達成できる。 As described above, the blur of light is the light intensity distribution at the edge portion extending in the radial direction of the image plane indicated by the convolution between the point spread function and the light source intensity distribution. Therefore, reducing the intensity distribution of the light that causes the bleeding can be achieved by reducing the peak intensity of the sideband of the point spread function that is the basis to a level at which the bleeding is not noticeable.
　ブラードビジョンと称される光の滲みは、快晴時の屋外において、あるいは室内などの標準的な明るさにおける明所視といわれる明るい環境下（照度でおよそ１００～１０００００ルクス）で遠方を目視した時に知覚されやすいことから、かかる明所視状態での人の瞳孔径内の回折ゾーン領域に、遠方視用の焦点像面におけるサイドバンドのピーク強度が低減するような回折構造を設定することが望ましい。明所視状態での人の瞳孔径（半径）の範囲は、個人差、性別、人種差、年齢差などによって差があり一律に定めることは難しいが、本発明では、統計情報にある程度の余裕を加えて最小約０．７５ｍｍから最大で２．５ｍｍの範囲にあると考えることができる。したがってサイドバンドのピーク強度が低減するような回折構造もかかる範囲を考慮して、明所視状態での瞳孔内となるように設定されることが望ましい。 The blur of light called “Blood Vision” is observed outdoors when the weather is fine, or when you look far away in a bright environment (approximately 100 to 100000 lux in illuminance), which is said to be a photopic vision at standard brightness such as indoors. Since it is easily perceived, it is desirable to set a diffractive structure that reduces the peak intensity of the sideband in the focal image plane for far vision in the diffraction zone region within the pupil diameter of a person in such a photopic state. . The range of the pupil diameter (radius) of a person in the photopic state varies depending on individual differences, gender, race differences, age differences, etc., and is difficult to determine uniformly. And a minimum of about 0.75 mm to a maximum of 2.5 mm. Therefore, it is desirable that the diffractive structure in which the sideband peak intensity is reduced is set so as to be within the pupil in the photopic state in consideration of such a range.
　今、特定の屈折面を有するレンズに複数の焦点を生成するための回折ゾーンが設定されているとする。遠方視用の焦点がこの回折構造における０次回折光で設定されているとすると、第ｎ番目のゾーンの位相関数がφ（ｒ）とされた時にかかる領域から射出される光が０次焦点像面に形成する振幅関数Ｅ（ρ）は、下式数１７で表わされる。 Suppose now that a diffraction zone for generating a plurality of focal points is set in a lens having a specific refractive surface. If the focal point for far vision is set by the 0th-order diffracted light in this diffractive structure, the light emitted from this region when the phase function of the nth zone is φ (r) is the 0th-order focused image. The amplitude function E (ρ) formed on the surface is expressed by the following equation (17).
Figure JPOXMLDOC01-appb-M000017
Figure JPOXMLDOC01-appb-M000017
　一般に回折型多焦点レンズではレンズ中心に対して対称な形の位相プロファイルを取り扱うので、θ＝０の動径方向からの振幅関数を議論するだけで十分に事足りる。この場合の振幅関数は、前記数１６で表わされる。 In general, a diffractive multifocal lens handles a phase profile that is symmetrical with respect to the lens center, so it is sufficient to discuss the amplitude function from the radial direction of θ = 0. The amplitude function in this case is expressed by the above equation (16).
　今、このゾーン以外の領域からの振幅分布において光の滲みの原因となるサイドバンドの振幅を減少せしめる振幅関数をＡ（ρ）とすると、かかる領域からの振幅関数Ｅ（ρ）がＡ（ρ）を含むような振幅分布を与えれば、図２に示すようにお互い打ち消しあって光の滲みの成因となる振幅を低減することが可能となる。すなわち、かかる振幅分布を与えるような位相関数φ（ｒ）を有するゾーンあるいは領域を設定することができれば、かかる光の滲みを低減することが可能となるのである。 Now, let A (ρ) be an amplitude function that reduces the amplitude of the sideband that causes the bleeding of light in the amplitude distribution from a region other than this zone, the amplitude function E (ρ) from this region is A (ρ 2), it is possible to cancel out each other and reduce the amplitude that causes light bleeding as shown in FIG. That is, if it is possible to set a zone or a region having a phase function φ (r) that gives such an amplitude distribution, it is possible to reduce such bleeding of light.
　実際の回折レンズにおいて、前記数１６を数学的に解析することは困難であるため、しかるべき近似、数値解析、あるいは数値フィッティング法などによって位相関数を見積もる必要がある。かかる数値解析などによって位相関数を求めるためには専用のアルゴリズムやプログラムを用いて行う。その手順の一例として後述する本発明の第一の実施形態の場合について以下に示す。
（１）基本形状設定工程として、回折レンズの複数の回折ゾーンを設計する。
（２）振幅情報取得工程として、設計した回折レンズの振幅分布を求める。
（３）低減対象決定工程として、上記振幅情報取得工程で求めた振幅分布において、低減すべき対象のサイドバンドの振幅とその領域を定める。
（４）その領域の振幅データをサンプリングして振幅関数とする。
（５）専用のアルゴリズム、プログラムを用いて数１６を解析する。
（６）キャンセル用領域形成工程として、（３）で決定したサイドバンドを相殺的に減少せしめる光の振幅分布を第一の焦点における像面上で与えるキャンセル用領域の位相関数を見積もる。 In an actual diffractive lens, it is difficult to mathematically analyze the equation (16). Therefore, it is necessary to estimate the phase function by appropriate approximation, numerical analysis, or numerical fitting method. In order to obtain the phase function by such numerical analysis, a dedicated algorithm or program is used. As an example of the procedure, the case of the first embodiment of the present invention described later will be described below.
(1) As a basic shape setting step, a plurality of diffraction zones of the diffractive lens are designed.
(2) As an amplitude information acquisition step, an amplitude distribution of the designed diffractive lens is obtained.
(3) As the reduction target determination step, the amplitude of the side band to be reduced and its region are determined in the amplitude distribution obtained in the amplitude information acquisition step.
(4) The amplitude data in that region is sampled to obtain an amplitude function.
(5) Analyze Equation 16 using a dedicated algorithm and program.
(6) As a canceling region forming step, a phase function of a canceling region that gives an amplitude distribution of light on the image plane at the first focal point, which reduces the sideband determined in (3) in an offset manner, is estimated.
　手順（１）は、例えば後述する本発明の第一の実施形態の場合で説明すると、付加屈折力Ｐadd ＝２（Ｄｉｏｐｔｅｒ），波長λ＝５４６ｎｍとして、前記数１２を用いて各回折ゾーンの半径を計算する。なお、計算する範囲は、ブラードビジョンが知覚されることの多い日中の標準的な明るさにおける人の眼の平均的な瞳孔径を勘案して回折構造の最外径（半径）が１．５～３．５ｍｍの範囲とする。また、各回折ゾーンはブレーズ形状の位相関数を持つものとし、前記数６で定義される位相定数ｈ＝０．５とする。なお、実形状としてのブレーズ段差は、前記数７により求められる。 For example, the procedure (1) will be described in the case of the first embodiment of the present invention to be described later. With the additional refractive power P add = 2 (Diopter) and the wavelength λ = 546 nm, Calculate the radius. Note that the outermost diameter (radius) of the diffractive structure is 1 in consideration of the average pupil diameter of the human eye at standard brightness during the daytime when blood vision is often perceived. The range is 5 to 3.5 mm. Each diffraction zone has a blazed phase function, and the phase constant h defined by Equation 6 is 0.5. In addition, the blaze level difference as an actual shape is obtained by the above formula 7.
　手順（２）は、回折レンズを設計するための専用のシミュレーションソフト、たとえば本発明に用いた回折計算シミュレーション方法や市販の波動光学設計・解析ソフトウェア（商品名：Ｖｉｒｔｕａｌ　Ｌａｂ（Ｌｉｇｈｔ　Ｔｒａｎｓ社製））などを用いることによって振幅分布を算出することができる。具体的には、例えば後述する本発明の第一の実施形態の場合で説明すると、位相関数がブレーズ形状の線形一次式で表わされることから、手順（１）で求めた回折ゾーン半径を前記の数２または数５に代入して各回折ゾーンの位相関数を具体的に求め、かかる位相関数を前記数１６に代入して、各回折ゾーンごとの振幅を算出する。光の強度分布は、回折ゾーンごとの振幅を合算し、その共役絶対値として算出する。 Step (2) is a dedicated simulation software for designing a diffractive lens, for example, a diffraction calculation simulation method used in the present invention or a commercially available wave optical design / analysis software (trade name: Virtual Lab (manufactured by Light Trans)) Etc. can be used to calculate the amplitude distribution. Specifically, for example, in the case of the first embodiment of the present invention to be described later, since the phase function is represented by a blazed linear linear equation, the diffraction zone radius obtained in step (1) is set to the above-described diffraction zone radius. The phase function of each diffraction zone is specifically obtained by substituting into Equation 2 or Equation 5, and the amplitude for each diffraction zone is calculated by substituting this phase function into Equation 16. The intensity distribution of light is calculated as the absolute value of its conjugate by adding the amplitudes for each diffraction zone.
　手順（３）で光の滲みの状態を想定して、これを打ち消すためのサイドバンドの領域を特定する。特にサイドバンド分布の中でも周辺領域に存在する比較的強度の大きなサイドバンドは広がりのある滲みとして知覚されやすいので、かかる滲みの範囲が狭くなるようにサイドバンドピークを特定するのが望ましい。 In step (3), assume the state of light blur and specify the sideband area for canceling this. In particular, sidebands with relatively high intensity existing in the peripheral region in the sideband distribution are easily perceived as spreading blurs, and therefore it is desirable to specify the sideband peak so that the range of such blurring is narrowed.
　手順（４）（５）（６）に係る具体的な計算方法としては、前記数１６がフーリエ変換の形式として表わされているので、手順（３）で特定したサイドバンドを打ち消すような振幅Ａ（ρ）を含む振幅関数を数１６のＥ（ρ）へ代入し、たとえば高速フーリエ変換などのアルゴリズムを用いることによって、キャンセル用領域の位相関数φ（ｒ）を見積もることができる。なお、かかる打ち消すための光の振幅を射出するためのゾーンの位相関数は、所望の割合で設計された遠方、近方、あるいは中間領域を含む各焦点位置の光の配分比に大きな変化を与えない範囲で決定されるのが望ましい。 As a specific calculation method according to the procedures (4), (5), and (6), since the equation 16 is expressed as a Fourier transform format, the amplitude cancels the sideband specified in the procedure (3). By substituting the amplitude function including A (ρ) into E (ρ) in Expression 16 and using an algorithm such as fast Fourier transform, the phase function φ (r) in the cancellation region can be estimated. It should be noted that the phase function of the zone for emitting the amplitude of the light for canceling gives a large change to the light distribution ratio at each focal position including a far, near, or intermediate region designed at a desired ratio. It is desirable that it is determined within a range.
　かかる数値解析以外に、ゾーンの位相関数がブレーズ形状の関数で表わされる場合は、以下の理論式に基づきサイドバンドを低減できる条件を簡単に見積もることもできる。位相関数がブレーズ形状の線形一次式で表わされる場合、前記数１６は下式数１８で表わされる。数１８は、振幅関数がＳｉｎｃ関数を包絡線として周期的に変化するｃｏｓ関数で表わされることを示している。つまり、Ｓｉｎｃ関数が大局的な周期分布を支配して表す一方、ｃｏｓ関数が細部の微小な周期変化を支配して表すものと考えられる。複数のゾーン間で振幅がどの地点で強め合ったり弱め合うかの位相情報は、Ｓｉｎｃ関数の極（正負の領域）が同一の領域においてはｃｏｓ関数間の挙動に支配される。今、任意のｉ番目とｊ番目の二つのゾーンにおいて位相ずれ量τがτ＝０で、それぞれのゾーンの振幅関数のうちＳｉｎｃ関数の極が同じであるとした場合、下式数１９で定められる像面上のρe 地点で両ゾーンからの光の振幅が強め合う。 In addition to such numerical analysis, when the phase function of the zone is represented by a blazed shape function, the conditions for reducing the sideband can be easily estimated based on the following theoretical formula. When the phase function is expressed by a blazed linear linear equation, the above equation 16 is expressed by the following equation 18. Equation 18 shows that the amplitude function is represented by a cos function that periodically changes with the Sinc function as an envelope. That is, it is considered that the Sinc function dominates and represents the global periodic distribution, while the cosine function dominates and represents a minute period change in detail. The phase information indicating at which point the amplitude increases or decreases between a plurality of zones is governed by the behavior between the cos functions in the region where the poles (positive and negative regions) of the Sinc function are the same. If the phase shift amount τ is τ = 0 in any two i-th and j-th zones, and the poles of the Sinc function are the same among the amplitude functions of each zone, The amplitude of light from both zones strengthens at the point ρ e on the image plane.
Figure JPOXMLDOC01-appb-M000018
Figure JPOXMLDOC01-appb-M000018
Figure JPOXMLDOC01-appb-M000019
Figure JPOXMLDOC01-appb-M000019
　一方、かかる２つのゾーンから選ばれた一つのゾーン（たとえばｒi ～ｒi-1 ）と、これらゾーンとは異なるゾーン（ｒc ～ｒc-1 ）において、振幅が弱めあう地点ρr は、下式数２０で表わされる。 On the other hand, in one zone selected from these two zones (for example, r i to r i-1 ) and a zone (r c to r c-1 ) different from these zones, the point ρ r where the amplitude weakens is Is expressed by the following equation (20).
Figure JPOXMLDOC01-appb-M000020
Figure JPOXMLDOC01-appb-M000020
　ここで、ρe とρr が同一地点にあれば、かかる異なるゾーン（ｒc ～ｒc-1 ）は、該位置にて前記二つのゾーン（ｒi ～ｒi-1 とｒj ～ｒj-1 ）によって強め合った振幅を特定し、弱め合うための波を選択的に送り出せるようになる。つまり、ρe ＝ρr より、前記数１４の関係式が得られる。 Here, if ρ e and ρ r are at the same point, the different zones (r c to r c-1 ) are the two zones (r i to r i-1 and r j to r at that position). j-1 ) identifies the strengthened amplitude and selectively sends out the wave for destructing. That is, the relational expression (14) is obtained from ρ e = ρ r .
　サイドバンドの振幅に最も寄与する、あるいはそれに準ずる振幅を特定し、かかる振幅を構成するゾーンの組合せを抽出し、前記数１９，数２０，数１４の一連の関係式にてその振幅を低減するゾーンを所望の位置に配することによってサイドバンドが低減し、ひいてはコンボリューションした際のエッジの強度分布が減少した回折構造を得ることができるのである。 The amplitude that most contributes to or conforms to the amplitude of the sideband is identified, the combination of zones constituting the amplitude is extracted, and the amplitude is reduced by the series of relational expressions of Equations 19, 20, and 14. By arranging the zone at a desired position, it is possible to obtain a diffractive structure in which sidebands are reduced and, consequently, the intensity distribution of the edge when convolved is reduced.
　今、これらゾーンがフレネル間隔の回折構造を有しており、ゾーンｒc ～ｒc-1 、ゾーンｒi ～ｒi-1 、ｒj ～ｒj-1 のそれぞれの第１ゾーン半径をＲ1 ，Ｒ2 ，Ｒ2 とすると、前記数１４は前記数１２を用いて前記数１５のように表わすことができる。 Now, these zones have diffractive structures with Fresnel spacing, and the first zone radii of the zones r c to r c-1 , zones r i to r i-1 , r j to r j-1 are defined as R 1, when R 2, R 2 to the number 14 can be represented as the number 15 with the number 12.
　かかる関係式の数１５を用いてエッジの強度分布が改善された具体例について、以下に示す。なお、本発明で用いられる計算シミュレーションの方法、条件、出力データは、以下に示す通りである。 A specific example in which the edge intensity distribution is improved by using the number 15 of the relational expression is shown below. The calculation simulation method, conditions, and output data used in the present invention are as follows.
　計算ソフトは、スカラー回折理論と呼ばれる該分野にて知られた理論から導出される回折積分式に基づいて各ゾーンからの振幅分布や強度分布を計算できるものを用いた。かかる計算ソフトを用いて光軸上の強度分布、像面上の強度分布（または点像広がり関数）を計算した。計算に際しては、光源は遠方に存在する点光源として設定し、レンズには同位相の平行光が入射するとして計算した。また、物体側空間および像側空間の媒体は真空、レンズは収差が存在しない理想レンズ（レンズから出た光は射出位置に関わらず全て同一の焦点に結像する）として計算した。また計算は、波長＝５４６ｎｍ、レンズの０次回折光の屈折力（ベースとなる屈折力）＝７Ｄ（Ｄｉｏｐｔｅｒ）、で行った。 The calculation software used was that which can calculate the amplitude distribution and intensity distribution from each zone based on a diffraction integral formula derived from a theory known in the field called scalar diffraction theory. Using such calculation software, the intensity distribution on the optical axis and the intensity distribution on the image plane (or point spread function) were calculated. In the calculation, the light source was set as a point light source existing in the distance, and the parallel light of the same phase was incident on the lens. Further, the calculation was performed on the assumption that the medium in the object-side space and the image-side space was a vacuum, and the lens was an ideal lens with no aberration (all the light emitted from the lens forms an image at the same focal point regardless of the exit position). The calculation was performed at a wavelength of 546 nm and the refractive power of the 0th-order diffracted light of the lens (refractive power as a base) = 7D (Diopter).
　光軸上の強度分布は、レンズを基点とした光軸上の距離に対する強度をプロットした。また、点像広がり関数は、像面の動径角度がゼロの方向において像面中心から半径方向の距離に対する強度をプロットした。ちなみにρ＝０の地点が主ピークの最大強度位置になっている。振幅関数は、前記数１８で表わされるものを用い、点像広がり関数と同様に像面の中心から半径方向の距離に対する振幅値をプロットしたもので示す。 The intensity distribution on the optical axis was plotted with respect to the distance on the optical axis with the lens as the base point. In the point spread function, the intensity with respect to the distance in the radial direction from the center of the image plane was plotted in the direction where the radial angle of the image plane was zero. Incidentally, the point where ρ = 0 is the maximum intensity position of the main peak. As the amplitude function, the one represented by Equation 18 is used, and the amplitude function is plotted by plotting the amplitude value with respect to the radial distance from the center of the image plane in the same manner as the point spread function.
　エッジ強度分布は、前記シミュレーション計算から得られた点像広がり関数の数値データを前記数１１に基づき像面動径方向に亘ってＮΔεずつ平行移動してずらし、積算範囲全域に亘って合算したものをかかる強度分布とした。なお、ここではＭ＝２５０、Δε＝０．００３ｍｍとして計算した。 The edge intensity distribution is obtained by translating the numerical data of the point spread function obtained from the simulation calculation by shifting NΔε in the radial direction of the image plane based on the formula 11, and adding up the entire integration range. Was defined as such an intensity distribution. Here, calculation was performed assuming that M = 250 and Δε = 0.003 mm.
　計算対象のゾーン範囲は、ブラードビジョンが知覚されることの多い日中の標準的な明るさにおける人の眼の平均的な瞳孔径を勘案してレンズの回折ゾーンの最大径（半径）がほぼ１．５～２．５ｍｍ内に入るような範囲とし、特に断りがない限り各表に示されるゾーン全域を計算対象とした。また、各実施例と比較例との対比においては計算対象の開口径がほぼ同じになるように計算対象のゾーン範囲を設定した。また、特に断りがない限り、点像広がり関数及びエッジ強度分布図の縦軸は、算出される強度の絶対値で表示し、各実施形態とその比較例との対比においては強度値のスケールは一定とした。 The zone range to be calculated is approximately the maximum diameter (radius) of the diffraction zone of the lens, taking into account the average pupil diameter of the human eye at normal daytime brightness, where blood vision is often perceived. The range was within 1.5 to 2.5 mm, and the entire zone shown in each table was subject to calculation unless otherwise specified. In addition, in the comparison between each example and the comparative example, the zone range to be calculated is set so that the aperture diameters to be calculated are substantially the same. Further, unless otherwise specified, the vertical axis of the point spread function and the edge intensity distribution diagram is displayed as an absolute value of the calculated intensity, and the intensity value scale in comparison between each embodiment and the comparative example is Constant.
　なお、本発明のシミュレーション計算では０次回折光の焦点位置を７（Ｄｉｏｐｔｅｒ）( 焦点距離：ｆ＝１４２．８ｍｍに相当) に設定して行っているため、像面座標の横軸の値はかかる焦点位置に限定したものである点に注意する必要がある。異なる焦点距離に変更した場合の像面の位置は、下式数２１を用いて換算すればよい。 In the simulation calculation of the present invention, since the focal position of the 0th-order diffracted light is set to 7 (Diopter) (focal length: equivalent to f = 142.8 mm), the value of the horizontal axis of the image plane coordinates is required. It should be noted that this is limited to the focal position. What is necessary is just to convert the position of the image surface at the time of changing into a different focal distance using the following Formula 21.
Figure JPOXMLDOC01-appb-M000021
Figure JPOXMLDOC01-appb-M000021
　たとえば焦点距離が１６．６ｍｍ（眼光学系を一つの理想的なレンズとした場合の焦点距離）の場合の像面位置ρ’は、本実施例における像面位置をρとするとρ’＝（１６．６／１４２．８）×ρ＝０．１１６×ρとして換算した値に相当する。 For example, when the focal length is 16.6 mm (focal length when the eye optical system is one ideal lens), the image plane position ρ ′ is ρ ′ = ( 16.6 / 142.8) × ρ = 0.116 × ρ.
　引き続き、本発明を更に具体的に明らかにするために、本発明の実施形態について、図面を参照しつつ、詳細に説明する。 Subsequently, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.
　先ず、図３に、本発明における回折型多焦点眼用レンズに係る、第一の実施形態としてのコンタクトレンズである眼用レンズ１０の光学部１２の裏面図をモデル的に示すと共に、図４に、同眼用レンズ１０の光学部１２の断面図をモデル的に示す。 First, FIG. 3 schematically shows a rear view of the optical unit 12 of the ophthalmic lens 10 that is a contact lens according to the first embodiment of the diffractive multifocal ophthalmic lens of the present invention. Next, a cross-sectional view of the optical unit 12 of the same-eye lens 10 is schematically shown.
　眼用レンズ１０は、中央の大きな領域が光学部１２とされており、光学部１２の外周側には公知の周辺部とエッジ部が形成されている。また、光学部１２は、全体として略球冠形状の凸面を有する光学部前面１４と、全体として略球冠形状の凹面を有する光学部後面１６をもって形成されている。そして、眼用レンズ１０の光学部１２は、レンズを近視矯正用とする場合は全体として、中心部が僅かに薄肉とされた略お椀形状とされており、遠視矯正用とする場合は中心部が僅かに膨らんだ略お椀形状とされ、幾何中心軸としてのレンズ中心軸１８を回転中心軸とする回転体形状とされている。このような眼用レンズ１０は、眼球の角膜上に直接装着される。従って、眼用レンズ１０の光学部１２の径は直径で、概ね４～１０ｍｍで形成されていることが望ましい。 The ophthalmic lens 10 has a central large area as an optical part 12, and a known peripheral part and edge part are formed on the outer peripheral side of the optical part 12. The optical part 12 is formed with an optical part front surface 14 having a substantially spherical crown-shaped convex surface as a whole and an optical part rear surface 16 having a substantially spherical crown-shaped concave surface as a whole. The optical portion 12 of the ophthalmic lens 10 has a generally bowl-like shape with a slightly thin central portion when the lens is used for correcting myopia, and the central portion when used for correcting hyperopia. Is formed into a substantially bowl shape with a slightly swollen shape, and a rotating body shape having a lens center axis 18 as a geometric center axis as a rotation center axis. Such an ophthalmic lens 10 is mounted directly on the cornea of the eyeball. Therefore, it is desirable that the optical part 12 of the ophthalmic lens 10 has a diameter of approximately 4 to 10 mm.
　眼用レンズ１０の光学部１２は、その光学部前面１４および光学部後面１６が屈折面とされている。そして、これら光学部前面１４および光学部後面１６による屈折光（０次回折光）に対して第一の焦点が設定されており、本実施形態では、遠方視用焦点が設定されている。 The optical unit 12 of the ophthalmic lens 10 has an optical unit front surface 14 and an optical unit rear surface 16 as refractive surfaces. The first focal point is set for the refracted light (0th-order diffracted light) by the optical unit front surface 14 and the optical unit rear surface 16, and in this embodiment, the far vision focal point is set.
　なお、眼用レンズ１０の形成材料としては、光透過性等の光学特性を備えた各種の重合性モノマーからなる従来公知の樹脂材料やゲル状の合成高分子化合物 (ハイドロゲル) 等が好適に採用され、具体的には、ポリメチルメタクリレート（ＰＭＭＡ）やポリヒドロキシエチルメタアクリレート（Ｐｏｌｙ－ＨＥＭＡ）等が例示される。 As a material for forming the ophthalmic lens 10, a conventionally known resin material made of various polymerizable monomers having optical properties such as light transmittance, a gel-like synthetic polymer compound (hydrogel) and the like are preferably used. Specifically, polymethyl methacrylate (PMMA), polyhydroxyethyl methacrylate (Poly-HEMA) and the like are exemplified.
　そして、特に本実施形態における光学部後面１６には、回折構造２０が形成されている。回折構造２０は、レンズ中心軸１８を中心として同心円状に複数形成され、レンズ周方向に連続して円環状で延びる、径方向の起伏形状であるレリーフ２１を含んで構成されている。そして、本実施形態では、この回折構造２０による回折＋１次光により、遠方視用焦点よりも小さな焦点距離を有する焦点（近方視用焦点）が設定されている。なお、個々の回折構造２０は前述のように、ゾーン（回折ゾーン）もしくは輪帯と呼ばれており、光の位相を変調させうるための位相関数で特徴づけられている。 In particular, the diffractive structure 20 is formed on the rear surface 16 of the optical part in the present embodiment. A plurality of diffractive structures 20 are concentrically formed around the lens central axis 18 and include reliefs 21 that are undulated in the radial direction and extend in an annular shape continuously in the circumferential direction of the lens. In the present embodiment, the diffracted + first-order light from the diffractive structure 20 sets a focal point (near vision focus) having a smaller focal length than the far vision focus. As described above, each diffractive structure 20 is called a zone (diffraction zone) or an annular zone, and is characterized by a phase function that can modulate the phase of light.
　図５（ａ）に、光学部後面１６におけるレリーフ２１の径方向の拡大断面図を示す。なお、図５においては、理解を容易とするために、レリーフ２１の大きさを誇張して示している。図５（ａ）に示すように、レリーフ２１の形状は、眼用レンズ１０のもともとの光学部後面１６の形状を反映して、右上がりの階段状の形状を呈している。眼用レンズ光学部の前面及び後面が単一の屈折力を有するように設定されている場合は、光学部後面１６は、前記定義にて説明したｒ－φ座標（図９７）における基準線と解して相違ない。また、図５（ａ）において、レリーフ２１を境として下方の領域はコンタクトレンズの基材からなっており、上方の領域は外部の媒体となっている。理解を容易にするため、今後は眼用レンズ１０のもともとの光学部後面１６の形状を除いた状態で、即ち、図５（ｂ）に示すように、光学部後面１６を径方向で直線的なｘ座標軸としてレリーフ２１の形状の検討を進めることにする。 FIG. 5A shows an enlarged sectional view in the radial direction of the relief 21 on the rear surface 16 of the optical part. In FIG. 5, the size of the relief 21 is exaggerated for easy understanding. As shown in FIG. 5A, the shape of the relief 21 has a stepped shape that rises to the right, reflecting the original shape of the rear surface 16 of the optical part of the ophthalmic lens 10. When the front surface and the rear surface of the ophthalmic lens optical unit are set so as to have a single refractive power, the optical unit rear surface 16 corresponds to the reference line in the r-φ coordinate (FIG. 97) described in the above definition. There is no difference. Further, in FIG. 5A, the lower area from the relief 21 is a contact lens base material, and the upper area is an external medium. In order to facilitate understanding, in the future, the shape of the original optical unit rear surface 16 of the ophthalmic lens 10 is removed, that is, as shown in FIG. 5B, the optical unit rear surface 16 is linear in the radial direction. The study of the shape of the relief 21 will be promoted as a proper x coordinate axis.
　図５（ｂ）に示すように、レリーフ２１は、レンズ中心軸１８を中心として同心円状に延びると共に、眼用レンズ１０の外方（図４乃至５中、上方）に向けて突出する稜線２２と、眼用レンズ１０の内方（図４乃至５中、下方）に向けて突出する谷線２４を有する起伏形状とされている。 As shown in FIG. 5B, the relief 21 extends concentrically around the lens central axis 18 and protrudes outward (upward in FIGS. 4 to 5) of the ophthalmic lens 10. And an undulating shape having a valley line 24 projecting inward (downward in FIGS. 4 to 5) of the ophthalmic lens 10.
　なお、以下の説明において、格子ピッチとは、稜線２２と谷線２４の間の径方向幅寸法をいう。また、ゾーンとは、稜線２２と谷線２４の間をいい、各ゾーンには、中央のゾーンを１として、ゾーン方向外方に向けて２，３，…のゾーン番号が割り振られる。また、ゾーン半径とは、各ゾーンの外周半径、換言すれば、各ゾーンにおいて同心円の中心（本実施形態においては、レンズ中心軸１８）に対して外側に位置する稜線２２又は谷線２４の同心円の中心からの半径をいう。従って、格子ピッチは各ゾーンの径方向幅寸法であり、所定ゾーンの格子ピッチは、該ゾーンのゾーン半径と、該ゾーンよりもゾーン番号が１つ小さいゾーンのゾーン半径との差となる。ここではコンタクトレンズの具体例とともにレリーフ構造からなる回折構造２０について説明したが、以降の説明に際してはレリーフ設計の基となる位相関数または位相プロファイルにて回折構造２０を説明することとする。よって今後、特に断りがない限り回折構造２０としての位相プロファイルを図９７に示すｒ－φ座標系で表すこととする。 In the following description, the lattice pitch refers to the radial width dimension between the ridge line 22 and the valley line 24. Further, the zone is defined between the ridge line 22 and the valley line 24, and each zone is assigned zone numbers 2, 3,... Further, the zone radius is the outer peripheral radius of each zone, in other words, the concentric circles of the ridge line 22 or the valley line 24 positioned outside the center of the concentric circle (in this embodiment, the lens central axis 18) in each zone. The radius from the center. Therefore, the lattice pitch is the radial width dimension of each zone, and the lattice pitch of a predetermined zone is the difference between the zone radius of the zone and the zone radius of a zone having a zone number one smaller than the zone. Here, the diffractive structure 20 having a relief structure is described together with a specific example of a contact lens. However, in the following description, the diffractive structure 20 will be described using a phase function or a phase profile that is a basis of a relief design. Therefore, in the future, unless otherwise specified, the phase profile as the diffractive structure 20 will be represented by the r-φ coordinate system shown in FIG.
　図６に、本発明の第一の実施形態としての各ゾーンがブレーズ形状の位相関数から構成された位相プロファイル２６と、比較例１としてのフレネルゾーンプレート（位相プロファイル２８）の形状の拡大断面図を示す。なお、本実施形態の位相プロファイル２６の詳細を下記表１に、また比較例の位相プロファイル２８の詳細を下記表２に、示す。 FIG. 6 is an enlarged cross-sectional view of the phase profile 26 in which each zone according to the first embodiment of the present invention is configured by a blazed phase function, and the shape of a Fresnel zone plate (phase profile 28) as a comparative example 1. Indicates. Details of the phase profile 26 of the present embodiment are shown in Table 1 below, and details of the phase profile 28 of the comparative example are shown in Table 2 below.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　比較例１は、近方視用の焦点位置を定める付加屈折力Ｐadd が遠方視用の焦点に対して２（Ｄｉｏｐｔｅｒ）となるようなフレネル間隔で構成され、また図７（ａ）に示すように遠方視用と近方視用の光の強度がほぼ等しくなるように各ゾーンの位相定数がｈ＝０．５の一定とされたものである。比較例１の遠方視用焦点における点像広がり関数の強度分布を図８の破線で示した。この強度分布図は主ピークの周辺を拡大して示したものである。以降の点像広がり関数の強度分布図においても同じく拡大図で示すこととする。この強度分布からエッジ強度分布を算出すると図９の破線のようになることが分かった。比較例１の回折レンズではかかるエッジ強度分布に基づく光の滲みが観察されることが予想される。 Comparative Example 1 is configured with a Fresnel interval such that the additional refractive power P add for determining the near vision focus position is 2 (Diopter) with respect to the far vision focus, and is shown in FIG. Thus, the phase constant of each zone is made constant at h = 0.5 so that the intensities of the far vision light and the near vision light are substantially equal. The intensity distribution of the point spread function at the far vision focus of Comparative Example 1 is indicated by a broken line in FIG. This intensity distribution is an enlarged view around the main peak. In the subsequent intensity distribution diagrams of the point spread function, they are also shown in an enlarged view. It was found that when the edge intensity distribution is calculated from this intensity distribution, the broken line in FIG. 9 is obtained. In the diffractive lens of Comparative Example 1, it is expected that bleeding of light based on such edge intensity distribution is observed.
　一方、本実施形態は、第１ゾーンと第２ゾーンの位置と間隔は比較例１と同じで、第２ゾーンを数１４のｃ番目のゾーンとし、第３ゾーン以降のゾーンの位置と間隔を関連の数式を用いて再設定したものである。すなわち、本実施形態では、第２ゾーンがキャンセル用領域として設定されており、キャンセル用領域の回折ゾーンとキャンセル用領域以外の回折ゾーンとが、回折ゾーンにおける位置設定を異ならせて設定されている。具体的には本実施形態の第４ゾーンと第５ゾーンは数１４におけるｉ番目とｊ番目のゾーンに対応するとし、両者の間で次数ｑe ＝１で振幅が強め合う位置が、第２ゾーンとｉ番目のゾーン間の次数ｑr ＝２で振幅が弱め合う位置と一致するように第４ゾーンと第５ゾーンの位置と間隔を再設定したものである。また、数１５より第３ゾーンを除く全てのゾーンが、付加屈折力Ｐadd が２（Ｄｉｏｐｔｅｒ）のフレネル間隔となるように定められている。本実施形態は比較例１の第２ゾーンまで同じであるが、第４ゾーンと第５ゾーンは数１４に基づく位置関係を維持しつつフレネル間隔を形成するために第２ゾーンと第４ゾーンの間にギャップが生じることとなる。本実施形態ではこのギャップも構成ゾーンの一つと見なし、第３ゾーンとして取り扱っている。以降の実施形態においてもかかるギャップが生じたものは同じく構成ゾーンの一つとして取り扱うことにする。 On the other hand, in the present embodiment, the positions and intervals of the first zone and the second zone are the same as those in Comparative Example 1, and the second zone is the c-th zone of Formula 14, and the positions and intervals of the zones after the third zone are set as follows. It is reset using related mathematical formulas. That is, in the present embodiment, the second zone is set as a canceling area, and the diffraction zone in the canceling area and the diffraction zone other than the canceling area are set with different position settings in the diffraction zone. . Specifically, it is assumed that the fourth zone and the fifth zone of the present embodiment correspond to the i-th and j-th zones in Equation 14, and the position where the amplitude intensifies with the order q e = 1 between them is the second zone. The positions and intervals of the fourth zone and the fifth zone are reset so as to coincide with the position where the amplitude is weakened at the order q r = 2 between the zone and the i-th zone. Further, according to Equation 15, all zones except the third zone are determined so that the additional refractive power P add is a Fresnel interval of 2 (Diopter). The present embodiment is the same up to the second zone of Comparative Example 1, but the fourth zone and the fifth zone have the positional relationship based on Equation 14 and the second zone and the fourth zone are formed in order to form the Fresnel interval. A gap will occur between them. In this embodiment, this gap is also considered as one of the constituent zones and is handled as the third zone. In the following embodiments, the case where such a gap occurs is also treated as one of the constituent zones.
　本実施形態の第６ゾーンまでを含む開口の光軸上の強度分布を図７（ｂ）に示す。本実施形態では第３ゾーンの間隔は若干狭くなるが、光軸上の強度分布は比較例１（図７（ａ））と比較して変化はなく、かかる再設定操作によって遠近への光の分配にほとんど影響を与えていないことが分かる。図８の実線で示された点像広がり関数は、ρが約０．３～０．３６ｍｍの領域のサイドバンドが明らかに減少した分布を示し、コンボリューションの結果としてのエッジ強度分布（図９の実線）においても強度が減少していることが分かる。 FIG. 7B shows the intensity distribution on the optical axis of the aperture including up to the sixth zone of the present embodiment. In the present embodiment, the interval between the third zones is slightly narrowed, but the intensity distribution on the optical axis is not changed as compared with Comparative Example 1 (FIG. 7A), and the reset operation makes it possible to transmit light to the near and far. It can be seen that there is little impact on distribution. The point spread function indicated by the solid line in FIG. 8 shows a distribution in which the side band in the region where ρ is about 0.3 to 0.36 mm is clearly reduced, and the edge intensity distribution (FIG. 9) as a result of convolution. It can be seen that the intensity also decreases at the solid line.
　なお、本実施形態におけるエッジの強度分布の低減量は僅かに見えるかもしれないが、ここに示したエッジ強度分布は一次元の線状光源でのシミュレーション結果であり、光源が二次元的な面状の広がりを持つ場合、この差はさらに拡大されることに注意すべきである。つまり実際に物を見る時には対象物体の多くは二次元的な広がりを持っており、かかるシミュレーション結果で僅かな差であっても二次元の物体に対するこの改善度合いは増強され明確な滲みの低減となるのである。以上のことから、本実施形態では遠近の強度比に変化を与えることなくエッジ強度を低減できうる位相プロファイルとなっていることが分かる。 Although the reduction amount of the edge intensity distribution in this embodiment may seem slight, the edge intensity distribution shown here is a simulation result with a one-dimensional linear light source, and the light source is a two-dimensional surface. It should be noted that this difference is further magnified when having a shape spread. In other words, when actually looking at an object, many of the target objects have a two-dimensional extent, and even if there is a slight difference in the simulation results, this improvement degree for a two-dimensional object is enhanced and clear blurring is reduced. It becomes. From the above, it can be seen that the present embodiment has a phase profile that can reduce the edge intensity without changing the near / far intensity ratio.
　以上、本発明の一実施形態について詳述してきたが、これはあくまでも例示であって、本発明は、かかる実施形態における具体的な記載によって、何等、限定的に解釈されるものではない。以下に、本発明において好適に採用され得るその他の態様を幾つか示すが、本発明が以下の態様に限定されることを示すものではないことが理解されるべきである。なお、以下の説明において、前述の実施形態と実質的に同様の部材および部位については、前述の実施形態と同様の符号を付することによって、詳細な説明を省略する。 As mentioned above, although one embodiment of the present invention has been described in detail, this is merely an example, and the present invention is not construed as being limited by the specific description in the embodiment. Several other embodiments that can be suitably employed in the present invention are shown below, but it should be understood that the present invention is not limited to the following embodiments. In the following description, members and parts that are substantially the same as those of the above-described embodiment are denoted by the same reference numerals as those of the above-described embodiment, and detailed description thereof is omitted.
　図１０に、本発明の第二の実施形態としての位相プロファイル３０と、比較例２としての位相プロファイル３２を示す。なお、本実施形態の位相プロファイル３０の詳細を表３に、また比較例２の位相プロファイル３２の詳細を表４に、示す。 FIG. 10 shows a phase profile 30 as a second embodiment of the present invention and a phase profile 32 as a comparative example 2. Details of the phase profile 30 of the present embodiment are shown in Table 3, and details of the phase profile 32 of Comparative Example 2 are shown in Table 4.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
　比較例２は、前記比較例１の計算対象の開口径を拡大し、第６ゾーンまで計算対象としたもので、位相定数及び付加屈折力は比較例１と同じである。比較例２の光軸上の強度分布、点像広がり関数、エッジ強度分布を図１１（ａ）、図１２の破線、図１３の破線、にそれぞれ示す。 In Comparative Example 2, the aperture diameter of the calculation target of Comparative Example 1 is enlarged and the calculation target is up to the sixth zone, and the phase constant and the additional refractive power are the same as those of Comparative Example 1. The intensity distribution, the point spread function, and the edge intensity distribution on the optical axis of Comparative Example 2 are shown in FIG. 11A, the broken line in FIG. 12, and the broken line in FIG.
　本実施形態は、第１ゾーンから第３ゾーンの位置と間隔は比較例２と同じで、第３ゾーンを数１４のｃ番目のゾーンとし、第４ゾーン以降のゾーンの位置と間隔を関連の数式を用いて再設定したものである。すなわち、本実施形態では、第３ゾーンがキャンセル用領域として設定されている。具体的には、本実施形態の第５ゾーンと第７ゾーンは数１４におけるｉ番目とｊ番目のゾーンに対応するとし、両者の間で次数ｑe ＝２で振幅が強め合う位置が、第３ゾーンとｉ番目のゾーン間の次数ｑr ＝２で振幅が弱め合う位置と一致するように第５ゾーンと第７ゾーンの位置と間隔が再設定されたものである。また、数１５より第４ゾーンを除く全てのゾーンが、付加屈折力Ｐadd が２（Ｄｉｏｐｔｅｒ）のフレネル間隔となるように定められている。本実施形態は比較例２の第３ゾーンまで同じであるが、第５以降のゾーンを、フレネル間隔を保持しつつ振幅が打ち消されるように再設定した都合上、第３ゾーンと第５ゾーン間にはギャップが生じている。本実施例ではこのギャップを第４ゾーンとみなし、構成ゾーンの一つとしている。結果として第４ゾーンの間隔が少し狭くなった形になっているが、かかる位相プロファイルにおける光軸上の強度分布（図１１（ｂ））は比較例２（図１１（ａ））と比べてほとんど差異がなく遠近の光の配分割合を崩していないことが分かる。にもかかわらず点像広がり関数（図１２の実線）はρが０．３６～０．４４ｍｍの範囲のサイドバンドが明確に減少しており、コンボリューションの結果としてのエッジの強度も図１３の実線に示すように低減されていることが分かる。 In this embodiment, the position and interval from the first zone to the third zone are the same as in Comparative Example 2, the third zone is the c-th zone of Formula 14, and the positions and intervals of the zones after the fourth zone are related. It is reset using mathematical formulas. That is, in the present embodiment, the third zone is set as a canceling area. Specifically, the fifth zone and the seventh zone of the present embodiment correspond to the i-th and j-th zones in Formula 14, and the positions where the amplitudes intensify with the order q e = 2 between them are The positions and intervals of the fifth zone and the seventh zone are reset so as to coincide with the position where the amplitude is weakened with the order q r = 2 between the third zone and the i-th zone. In addition, from Formula 15, all zones except the fourth zone are determined such that the additional refractive power P add is a Fresnel interval of 2 (Diopter). This embodiment is the same up to the third zone of Comparative Example 2, but for the convenience of resetting the fifth and subsequent zones so that the amplitude is canceled while maintaining the Fresnel interval, it is between the third zone and the fifth zone. There is a gap. In this embodiment, this gap is regarded as the fourth zone and is one of the constituent zones. As a result, the interval between the fourth zones is slightly narrowed, but the intensity distribution on the optical axis in such a phase profile (FIG. 11 (b)) is compared with Comparative Example 2 (FIG. 11 (a)). It can be seen that there is almost no difference and the distribution ratio of near and far light is not disturbed. Nevertheless, in the point spread function (solid line in FIG. 12), the sideband in the range of ρ from 0.36 to 0.44 mm is clearly reduced, and the edge intensity as a result of the convolution is also shown in FIG. As shown by the solid line, it can be seen that it is reduced.
　このように標準的なフレネル間隔から構成される従来からの回折型多焦点眼用レンズにおいて、かかる方法によってゾーン位置と間隔を僅かに再編成するだけで光の滲みが低減された回折多焦点眼用レンズを得ることができるのである。 In such a conventional diffractive multifocal ophthalmic lens composed of standard Fresnel intervals, a diffractive multifocal eye in which light blur is reduced by slightly rearranging zone positions and intervals by such a method. A lens can be obtained.
　図１４に、本発明の第二の実施形態の変形例１としての位相プロファイル３４と、比較例２の変形例１としての位相プロファイル３６を示す。なお、本実施形態の位相プロファイル３４の詳細を下記表５に、また比較例２の変形例１の位相プロファイル３６の詳細を下記表６に、示す。本実施形態では、第３ゾーンがキャンセル用領域として設定されている。 FIG. 14 shows a phase profile 34 as Modification 1 of the second embodiment of the present invention and a phase profile 36 as Modification 1 of Comparative Example 2. Details of the phase profile 34 of the present embodiment are shown in Table 5 below, and details of the phase profile 36 of Modification 1 of Comparative Example 2 are shown in Table 6 below. In the present embodiment, the third zone is set as a cancellation area.
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006
　本実施形態では、第二の実施形態における間隔の狭い第４ゾーンにブレーズ構造を設けることによる製造上の困難さを、屈折領域に代替することによって回避しつつエッジ強度分布が低減されうることを示す例である。本実施形態の光軸上の強度分布、点像広がり関数、エッジ強度分布を、図１５（ｂ）、図１６の実線、図１７の実線、にそれぞれ示す。第４ゾーンを屈折領域としても第二の実施形態と同様にエッジ強度の減少効果は維持されていることが分かる。このようにギャップとして生じる第４ゾーンは、回折構造２０中で占める割合が低いため、この例で示すような屈折領域、あるいは別の製造しやすい回折構造２０としても、影響は少ないのである。このような設定は第二の実施形態に対してだけでなく、他の例においても等しく適用できるものである。なお、比較例２の変形例１は、本実施形態の光軸上の遠方と近方の強度比と合致させるために比較例２における第４ゾーンの位相定数（ｈ）を０．４５で設定し直したものである。 In the present embodiment, it is possible to reduce the edge strength distribution while avoiding the manufacturing difficulty by providing the blaze structure in the fourth zone having a narrow interval in the second embodiment by substituting the refractive region. It is an example to show. The intensity distribution, point spread function, and edge intensity distribution on the optical axis of this embodiment are shown in FIG. 15B, the solid line in FIG. 16, and the solid line in FIG. It can be seen that even when the fourth zone is a refractive region, the effect of reducing the edge strength is maintained as in the second embodiment. The fourth zone generated as a gap in this way has a low ratio in the diffractive structure 20, and therefore, even a refracting region as shown in this example or another easily manufactured diffractive structure 20 has little influence. Such a setting is equally applicable not only to the second embodiment but also to other examples. In Modification 1 of Comparative Example 2, the phase constant (h) of the fourth zone in Comparative Example 2 is set to 0.45 in order to match the far and near intensity ratio on the optical axis of this embodiment. It has been reworked.
　図１８に、前述の本発明の第二の実施形態としての位相プロファイル３０と、比較例２の変形例２としての位相プロファイル３８を示す。なお、比較例２の変形例２の位相プロファイル３８の詳細を表７に、示す。 FIG. 18 shows the phase profile 30 as the second embodiment of the present invention and the phase profile 38 as the second modification of the second comparative example. Table 7 shows details of the phase profile 38 of the second modification of the second comparative example.
Figure JPOXMLDOC01-appb-T000007
Figure JPOXMLDOC01-appb-T000007
　比較例２の変形例２は、比較例２の位相定数（ｈ）を変更して第二の実施形態と同程度のエッジ強度分布を得るようにしたものである。具体的には、第１ゾーンから第３ゾーンの位相定数（ｈ）を０．６とすると共に、第４ゾーンから第６ゾーンの位相定数（ｈ）を０．４とした。これにより、第二の実施形態とほぼ同程度のエッジ強度分布を達成できており（図２０）、また光軸上の強度分布もほぼ同じものが得られていることが分かる（図１９）。 Modification 2 of Comparative Example 2 is obtained by changing the phase constant (h) of Comparative Example 2 so as to obtain an edge intensity distribution similar to that of the second embodiment. Specifically, the phase constant (h) from the first zone to the third zone was set to 0.6, and the phase constant (h) from the fourth zone to the sixth zone was set to 0.4. Thereby, it can be seen that the edge intensity distribution of almost the same degree as in the second embodiment can be achieved (FIG. 20), and the intensity distribution on the optical axis is substantially the same (FIG. 19).
　以上の結果からは、従来の回折構造（比較例２）でも位相定数（ｈ）の調整だけで第二の実施形態と同様のエッジ低減効果が得られるように見えるが、比較例２の変形例２では第１ゾーンから第３ゾーンまでの位相定数（ｈ）を０．６とし、近方への光の配分を増すような設定となっている。このゾーン範囲に相当する開口径での光軸上の強度分布は図２１に示すように近方側の強度が大きく、遠方側の強度が小さくなるという遠近の強度のバランスが崩れたものとなってしまう。したがってかかるゾーン範囲に該当する環境下、たとえば日中の屋外などのかなりの明るさがあり瞳孔が小さくなっている状況下では、遠方を見る時にその見え方が損なわれることが予想される。このように従来の回折構造（比較例２）では、遠近あるいは遠方と他焦点位置間の光の配分割合を変更してエッジ強度分布を低減せしめるしかなかったのに対して、本発明では数１４に基づきゾーン間の配置を再設定するという簡単な操作で、目的とする遠近の光の配分割合を大きく変えることなくエッジの強度を低減させることができ、光の滲みを抑えることができるのである。 From the above results, it seems that the edge reduction effect similar to that of the second embodiment can be obtained only by adjusting the phase constant (h) even in the conventional diffraction structure (Comparative Example 2). 2, the phase constant (h) from the first zone to the third zone is set to 0.6 so that the distribution of light in the vicinity is increased. As shown in FIG. 21, the intensity distribution on the optical axis at the aperture diameter corresponding to this zone range is such that the near-intensity balance is broken, with the near-side intensity being large and the far-side intensity being small. End up. Therefore, in an environment corresponding to such a zone range, for example, in a situation where there is considerable brightness such as outdoors in the daytime and the pupil is small, it is expected that the appearance will be impaired when looking far away. As described above, in the conventional diffractive structure (Comparative Example 2), the edge intensity distribution must be reduced by changing the light distribution ratio between the near and far distances and the other focal positions. With the simple operation of resetting the arrangement between zones based on the above, it is possible to reduce the intensity of the edge without greatly changing the target distribution ratio of near and near light, and to suppress the bleeding of light. .
　なお、位相定数（ｈ）を変更して各焦点への光の配分を調整する方法は、本発明の方法においてもエッジ強度の低減を図りつつ、各焦点位置における見え方のバランスを取る上で有用であるため、かかる位相定数（ｈ）の変更を併用することは一向に構わない。 The method of adjusting the distribution of light to each focus by changing the phase constant (h) is to reduce the edge intensity and balance the appearance at each focus position in the method of the present invention. Since it is useful, it is possible to use such a change of the phase constant (h) in combination.
　図２２に、本発明の第三の実施形態としての位相プロファイル４０と、比較例２としての位相プロファイル３２を示す。なお、本実施形態の位相プロファイル４０の詳細を、下記表８に示す。 FIG. 22 shows a phase profile 40 as a third embodiment of the present invention and a phase profile 32 as a comparative example 2. Details of the phase profile 40 of the present embodiment are shown in Table 8 below.
Figure JPOXMLDOC01-appb-T000008
Figure JPOXMLDOC01-appb-T000008
　本実施形態は、比較例２の第４ゾーンから第６ゾーンの位置と間隔はそのまま変えずに、第１ゾーンから第３ゾーンの位置と間隔を関連の数式を用いて再設定したものである。具体的には、本実施形態における第５ゾーンと第６ゾーンを数１４のｉ番目とｊ番目のゾーンとし、両者の間で次数ｑe ＝１で振幅が強め合う位置が、ｃ番目ゾーンとした第３ゾーンと、ｉ番目のゾーン間の次数ｑr ＝２で振幅が弱め合う位置と一致するように、第１ゾーンから第３ゾーンのゾーンの位置と間隔が再設定されたものである。すなわち、本実施形態では、第３ゾーンがキャンセル用領域として設定されている。なお、ゾーンの再設定に際して付加屈折力Ｐadd は２（Ｄｉｏｐｔｅｒ）のままとした。第一または第二の実施形態では中央近傍のゾーンを固定し、それより外側のゾーンをずらした形態となっているのに対して、第三の実施形態では周辺のゾーンの位置と間隔を固定し、それより内側のゾーンをずらした形態になっている。このように周辺の開口径を先に定める必要がある場合の設計に際して、本実施形態の設定は有用となり得る。 In this embodiment, the positions and intervals of the first zone to the third zone are reset using related mathematical formulas without changing the positions and intervals of the fourth zone to the sixth zone of Comparative Example 2 as they are. . Specifically, the fifth zone and the sixth zone in the present embodiment are the i-th and j-th zones of Expression 14, and the position where the amplitude is intensified with order q e = 1 between them is the c-th zone. The position and the interval of the zone from the first zone to the third zone are reset so that the third zone and the position where the amplitude is weakened at the order q r = 2 between the i-th zone and the third zone. . That is, in the present embodiment, the third zone is set as a canceling area. Note that the additional refractive power P add was kept at 2 (Diopter) when the zone was reset. In the first or second embodiment, the zone near the center is fixed and the outer zone is shifted, whereas in the third embodiment, the positions and intervals of the surrounding zones are fixed. However, the inner zone is shifted. Thus, the setting of this embodiment can be useful in designing when it is necessary to determine the peripheral opening diameter first.
　本実施形態の光軸上の強度分布を図２３に示す。本実施例では、第３ゾーンを含む内側のゾーンもフレネル間隔となるように第１ゾーンの半径が、比較例１，２や第一および第二の実施形態より小さくなっている。このように通常のフレネル間隔とは第１ゾーンの半径が異なり且つ第４ゾーン如きギャップが存在するものの、遠方と近方のそれぞれの焦点位置に比較例２（図１１（ａ））と同等の明確なピークが形成されるようになっていることが分かる。従って、かかる再設定操作によって当初設定した各焦点位置での光の配分にほとんど影響を与えないことが分かる。 FIG. 23 shows the intensity distribution on the optical axis of this embodiment. In the present example, the radius of the first zone is smaller than those of Comparative Examples 1 and 2 and the first and second embodiments so that the inner zone including the third zone also has the Fresnel interval. Thus, although the radius of the first zone is different from the normal Fresnel interval and there is a gap as in the fourth zone, it is equivalent to the comparative example 2 (FIG. 11 (a)) at the far and near focal positions. It can be seen that a clear peak is formed. Therefore, it can be seen that the light distribution at each focal position initially set by the resetting operation has little influence.
　本実施形態の点像広がり関数を図２４の実線に示す。この図より、ρ＝０．３９～０．４２ｍｍのサイドバンドのピーク強度が減っていることが分かる。かかる位置は第５ゾーンと第６ゾーン間の干渉の結果発現するピークで、本実施例のゾーン位置の再設定によって選択的に低減されたことが分かる。この場合のエッジ強度分布を図２５に示した。この図から比較例２（破線）と比べるとエッジ強度の膨らみが低減されていることが分かる。 The point spread function of this embodiment is shown by a solid line in FIG. From this figure, it can be seen that the peak intensity of the side band of ρ = 0.39 to 0.42 mm is reduced. Such a position is a peak that appears as a result of the interference between the fifth zone and the sixth zone, and it can be seen that the position was selectively reduced by resetting the zone position of this embodiment. The edge intensity distribution in this case is shown in FIG. From this figure, it can be seen that the swelling of the edge strength is reduced as compared with Comparative Example 2 (broken line).
　なお、本実施形態ではエッジ近傍のρ＝０．９５ｍｍ付近で比較例２よりもふくらみが増すエッジ強度分布（図２５）となっているが、これは点像広がり関数においてρ＝０．２３～０．２７ｍｍ付近のサイドバンド強度が増えた（図２４）ことが原因である。このようにエッジの周辺部の強度を低減できる一方で、場合によってはこれより内側で強度が若干増すこともある。しかし、この強度が増した領域とエッジの境との領域範囲が、人が物を識別する際の眼の分解能の最少単位内に入っていれば、この領域内でのエッジ強度が大きくなっても人はそれを識別できず、光の滲みとして知覚されることはなくなる。よってエッジに非常に近い領域の強度分布に関してはさほど注意を払う必要はないのである。 In the present embodiment, an edge intensity distribution (FIG. 25) in which the bulge is larger than that in Comparative Example 2 near ρ = 0.95 mm in the vicinity of the edge, which is ρ = 0.23 to in the point spread function. This is because the sideband strength around 0.27 mm increased (FIG. 24). Thus, while the strength of the peripheral portion of the edge can be reduced, in some cases, the strength may slightly increase inside the edge. However, if the area range between the increased intensity area and the edge boundary is within the minimum unit of eye resolution when a person identifies an object, the edge intensity in this area increases. However, humans cannot recognize it and it will not be perceived as a blur of light. Therefore, it is not necessary to pay much attention to the intensity distribution in the region very close to the edge.
　かかる位相プロファイルを有する回折レンズでは、光の滲みが低減されると同時に第１ゾーンの半径が小さく設定されていることから、小開口径内に多焦点機能を十分に発現するに必要な回折ゾーン領域を設置し得るという点から、加齢と伴に瞳孔径が小さくなった高齢者向けのコンタクトレンズ、あるいは白内障手術後に眼内に挿入される眼内レンズとして有用なものとなる。 In the diffractive lens having such a phase profile, since the blur of light is reduced and the radius of the first zone is set to be small, the diffractive zone necessary for sufficiently expressing the multifocal function within a small aperture diameter From the point that an area can be set, it is useful as a contact lens for elderly people whose pupil diameter has decreased with aging, or an intraocular lens inserted into the eye after cataract surgery.
　本発明では、フレネル間隔以外の間隔を有する回折構造２０においても同様に数１９，数２０，数１４が適用できる。たとえばゾーンの間隔が互いに等しい等間隔の領域を有する回折構造２０も多焦点を形成することができるので、回折型多焦点眼用レンズとして有用である。このような等間隔領域を有する回折構造２０に対してのエッジ強度の低減例について以下に示す。まず、等間隔ゾーンが隣接している領域の振幅分布の低減例について説明する。 In the present invention, Equations 19, 20, and 14 can be similarly applied to the diffraction structure 20 having an interval other than the Fresnel interval. For example, the diffractive structure 20 having equally spaced regions with equal zone intervals can also form multifocals, which is useful as a diffractive multifocal ophthalmic lens. An example of reducing the edge strength for the diffractive structure 20 having such equally spaced regions will be described below. First, an example of reducing the amplitude distribution in the region where the equally spaced zones are adjacent will be described.
　図２６に、本発明の第四の実施形態としての位相プロファイル４２と、比較例４としての位相プロファイル４４を示す。なお、本実施形態の位相プロファイル４２の詳細を下記表９に、また比較例４の位相プロファイル４４の詳細を下記表１０に、示す。 FIG. 26 shows a phase profile 42 as a fourth embodiment of the present invention and a phase profile 44 as a comparative example 4. Details of the phase profile 42 of the present embodiment are shown in Table 9 below, and details of the phase profile 44 of Comparative Example 4 are shown in Table 10 below.
Figure JPOXMLDOC01-appb-T000009
Figure JPOXMLDOC01-appb-T000009
Figure JPOXMLDOC01-appb-T000010
Figure JPOXMLDOC01-appb-T000010
　比較例４は、中央の第１ゾーンから第４ゾーンまでが付加屈折力Ｐadd が２（Ｄｉｏｐｔｅｒ）となるようなフレネル間隔から構成され、その周辺の第５ゾーンと第６ゾーンの間隔が、Δｒ＝０．２７５ｍｍの等間隔領域となっているものである。比較例４の第６ゾーンまでを含む開口の光軸上の強度分布を図２７（ａ）に示す。等間隔領域を含む回折レンズでは設定された付加屈折力に対応する焦点以外に、等間隔領域から射出される光によって中間領域にも焦点生成可能なピークを形成するという特徴を有する。かかる特性は、パソコンモニターを見るなどの中間領域の対象物も併せて視認できる多焦点眼用レンズとして有効なものである。 Comparative Example 4 is composed of a Fresnel interval such that the additional refractive power P add is 2 (Diopter) from the central first zone to the fourth zone, and the interval between the surrounding fifth zone and the sixth zone is This is an equally spaced region of Δr = 0.275 mm. The intensity distribution on the optical axis of the aperture including up to the sixth zone of Comparative Example 4 is shown in FIG. In addition to the focal point corresponding to the set additional refractive power, the diffractive lens including the equidistant region has a characteristic that a peak capable of generating a focal point is formed also in the intermediate region by light emitted from the equidistant region. Such a characteristic is effective as a multifocal ophthalmic lens that can also visually recognize an object in an intermediate region such as when looking at a personal computer monitor.
　しかし、かかるレンズの点像広がり関数は、図２８の破線に示すようにρ＝０．３ｍｍ付近に強度の大きな急峻なピークが形成される。これは、等間隔領域からの光の振幅は像面の特定の位置で選択的に強め合うという特徴に由来するものである。比較例４のこのピークの出現位置は、第５ゾーンと第６ゾーンの間隔Δｒ＝０．２７５ｍｍとして計算されるｑe ＝１における強め合った振幅の出現位置と一致している。かかる点像広がり関数のコンボリューションによるエッジ強度分布を図２９の破線に示した。この図に示すようにこのような急峻なピークを有する場合、そのコンボリューションとしてのエッジ強度分布は瘤状のふくらみのある分布となる。かかるエッジ強度分布によれば像の近傍で強い光の滲みが発生することが予想される。 However, in the point spread function of such a lens, a sharp peak with a large intensity is formed in the vicinity of ρ = 0.3 mm as shown by the broken line in FIG. This is due to the feature that the amplitude of light from the equally spaced region selectively strengthens at a specific position on the image plane. The appearance position of this peak in Comparative Example 4 coincides with the appearance position of the strengthened amplitude at q e = 1 calculated as the distance Δr = 0.275 mm between the fifth zone and the sixth zone. The broken line in FIG. 29 shows the edge intensity distribution by the convolution of the point spread function. As shown in this figure, when having such a steep peak, the edge intensity distribution as the convolution is a distribution having a swell-like bulge. According to such edge intensity distribution, it is expected that strong light blur occurs in the vicinity of the image.
　本実施形態は、第１ゾーンから第３ゾーンまでは比較例４と同じとし、第３ゾーンを数１４のｃ番目のゾーンとし、かかる数式に基づき第５ゾーンと第６ゾーンの等間隔領域の配置をΔｒ＝０．２７５ｍｍを維持しつつ再設定したものである。すなわち、本実施形態では、第３ゾーンがキャンセル用領域として設定されている。なお、等間隔領域の強め合う地点の次数はｑe ＝１とし、かかる次数の強め合う振幅を打ち消すための第３ゾーンの次数は、ｑr ＝２とした。 In the present embodiment, the first zone to the third zone are the same as those in the comparative example 4, the third zone is the c-th zone of Formula 14, and the equidistant region between the fifth zone and the sixth zone is calculated based on this formula. The arrangement was reset while maintaining Δr = 0.275 mm. That is, in the present embodiment, the third zone is set as a canceling area. Note that the order of the points in the equally spaced region is q e = 1, and the order of the third zone for canceling the strengthening amplitude of the order is q r = 2.
　本実施形態の第６ゾーンまでを含む開口径を対象とした光軸上の強度分布を図２７（ｂ）に示す。近方のみならず中間にも焦点形成用ピークが生成しており、かつ各焦点位置の強度比は比較例４（図２７（ａ））とほとんど変わっていないことが分かる。これよりかかるゾーンの再設定を行うことによる各焦点への光の配分にほとんど影響がないことが分かる。本実施形態の点像広がり関数を図２８（実線）に示す。図よりρ＝０．３ｍｍの急峻なピークがほぼ半分程度まで強度が減じられていることが分かる。かかる点像広がり関数のコンボリューションに基づくエッジ強度分布を図２９（実線）に示す。これより比較例４で認められた瘤状の膨らみがなくなっていることが分かる。なお、本実施形態では比較例４よりも遠方への光の配分割合が少し減っており、その影響でエッジ強度の低減割合が少し大きくなっているが、最大強度で規格化した相対的なエッジ強度分布（図示せず）においても明確に瘤状の出っ張りが削減されていることから、かかる構造によって光の滲みがかなり低減されることが分かる。 FIG. 27 (b) shows the intensity distribution on the optical axis for the aperture diameter including up to the sixth zone of the present embodiment. It can be seen that focus forming peaks are generated not only in the vicinity but also in the middle, and the intensity ratio of each focus position is almost the same as that of Comparative Example 4 (FIG. 27A). From this, it can be seen that there is almost no influence on the light distribution to each focal point by performing the resetting of the zone. The point spread function of this embodiment is shown in FIG. 28 (solid line). From the figure, it can be seen that the steep peak at ρ = 0.3 mm is reduced to about half. An edge intensity distribution based on the convolution of the point spread function is shown in FIG. 29 (solid line). From this, it can be seen that the nodular bulge observed in Comparative Example 4 disappears. In this embodiment, the distribution ratio of light farther than that of Comparative Example 4 is slightly reduced, and the edge intensity reduction ratio is slightly increased due to the influence. However, the relative edge normalized by the maximum intensity is used. In the intensity distribution (not shown), since the bump-like protrusion is clearly reduced, it can be seen that such a structure significantly reduces light bleeding.
　本実施形態は、第３ゾーンの位置は比較例４と同じで固定し、等間隔領域の振幅が強め合う地点でこれを打ち消す波を送り出すように数式を用いて等間隔領域の位置を設定したものである。この関係を前記数１８の振幅関数に基づいて図示したのが図３０である。第５ゾーンと第６ゾーンからの振幅関数はρ＝０．２９ｍｍ付近で位相が一致し振幅が強め合っていることが分かる（図３０（ａ）矢印）。第３ゾーンからの振幅は第５ゾーンと第６ゾーンからの振幅が強め合う地点でちょうど逆位相になっていることが図３０（ｂ）から良く分かる。かかる配置は僅かに位置をずらしただけの処置となっているが、かかる再設定だけも大きなエッジ強度の低減効果をもたらしうることが分かる。 In this embodiment, the position of the third zone is fixed as in Comparative Example 4, and the position of the equidistant region is set using a mathematical formula so as to send out a wave that cancels this at a point where the amplitude of the equidistant region strengthens. Is. FIG. 30 shows this relationship based on the amplitude function of Equation (18). It can be seen that the amplitude functions from the fifth zone and the sixth zone are in phase and intensified in the vicinity of ρ = 0.29 mm (arrows in FIG. 30 (a)). It can be clearly seen from FIG. 30 (b) that the amplitude from the third zone is exactly opposite in phase at the point where the amplitudes from the fifth zone and the sixth zone reinforce. Although such an arrangement is a treatment that is slightly shifted, it can be seen that such resetting alone can also bring about a great edge strength reduction effect.
　図３１に、本発明の第五の実施形態としての位相プロファイル４６と、比較例５としての位相プロファイル４８を示す。なお、本実施形態の位相プロファイル４６の詳細を表１１に、また比較例５の位相プロファイル４８の詳細を表１２に、示す。 FIG. 31 shows a phase profile 46 as a fifth embodiment of the present invention and a phase profile 48 as a comparative example 5. Details of the phase profile 46 of this embodiment are shown in Table 11, and details of the phase profile 48 of Comparative Example 5 are shown in Table 12.
Figure JPOXMLDOC01-appb-T000011
Figure JPOXMLDOC01-appb-T000011
Figure JPOXMLDOC01-appb-T000012
Figure JPOXMLDOC01-appb-T000012
　比較例５は、中央の第１ゾーンから第３ゾーンまでが付加屈折力Ｐadd が２（Ｄｉｏｐｔｅｒ）となるようなフレネル間隔から構成され、その周辺の第４ゾーンと第５ゾーンの間隔が、Δｒ＝０．３５ｍｍの等間隔領域となっている位相プロファイルについて示したものである。比較例５の第５ゾーンまでを含む開口の光軸上の強度分布を図３２（ａ）に示す。比較例５も近方ピーク以外に等間隔領域を含むことによる中間領域焦点形成ピークが出現することが分かる。比較例５では、等間隔領域がΔｒ＝０．３５ｍｍで構成されており、かかる間隔のｑe ＝１で強め合う時の振幅位置はρ＝０．２２３ｍｍとなる。比較例５の点像広がり関数（図３３破線）において果たしてρ＝０．２２～０．２６ｍｍにおいて急峻なピークが生成していることが分かる。かかる場合のエッジ強度は図３４（破線）のようになり、ピークが像面中心に近づいた分、エッジ強度分布も膨らみのある位置がよりエッジの近くに近づくことが分かる。かかるエッジ強度分布から比較例４と同様に像のエッジ近傍で光の滲みが大きくなることが予想される。 In Comparative Example 5, the first zone to the third zone in the center are configured with a Fresnel interval such that the additional refractive power P add is 2 (Diopter), and the interval between the surrounding fourth zone and the fifth zone is It shows a phase profile that is an equally spaced region of Δr = 0.35 mm. The intensity distribution on the optical axis of the aperture including up to the fifth zone of Comparative Example 5 is shown in FIG. It can be seen that Comparative Example 5 also has an intermediate region focal point formation peak due to the equidistant region other than the near peak. In Comparative Example 5, the equally-spaced region is configured with Δr = 0.35 mm, and the amplitude position when strengthening at the interval q e = 1 is ρ = 0.223 mm. It can be seen that in the point spread function of Comparative Example 5 (broken line in FIG. 33), a sharp peak is generated at ρ = 0.22 to 0.26 mm. The edge intensity in such a case is as shown in FIG. 34 (broken line), and it can be seen that the position where the edge intensity distribution swells closer to the edge as the peak approaches the center of the image plane. From this edge intensity distribution, it is expected that the blur of light increases near the edge of the image as in Comparative Example 4.
　本実施形態では、第２ゾーンまでは比較例５と同じで、第２ゾーンを数１４のｃ番目のゾーンとし、数式に基づき第４ゾーンと第５ゾーンの配置を間隔Δｒ＝０．３５ｍｍを維持しつつ再設定したものである。すなわち、本実施形態では、第２ゾーンがキャンセル用領域として設定されており、キャンセル用領域の回折ゾーンとキャンセル用領域以外の回折ゾーンとが、回折ゾーンにおける位置設定を異ならせて設定されている。なお、第４ゾーンと第５ゾーンの強め合う地点の次数は、ｑe ＝１とし、かかる強め合う振幅を打ち消すための第２ゾーンの次数は、ｑr ＝２とした。なお、本実施形態においては比較例５との間で各焦点の強度比を合わせるために表１１に示すように位相定数を若干変更した。 In the present embodiment, up to the second zone is the same as Comparative Example 5, and the second zone is the c-th zone of Formula 14, and the arrangement of the fourth zone and the fifth zone is set to an interval Δr = 0.35 mm based on the formula. It has been reset while maintaining. That is, in the present embodiment, the second zone is set as a canceling area, and the diffraction zone in the canceling area and the diffraction zone other than the canceling area are set with different position settings in the diffraction zone. . In addition, the order of the points where the fourth zone and the fifth zone are strengthened is q e = 1, and the order of the second zone for canceling the strengthening amplitude is q r = 2. In this embodiment, the phase constant is slightly changed as shown in Table 11 in order to match the intensity ratio of each focal point with Comparative Example 5.
　本実施形態では第３ゾーンの間隔を少し圧縮するように間隔を狭めた以外は比較例と全く同じ間隔となっている。本実施形態の第５ゾーンまでを含む開口径での光軸上強度分布を図３２（ｂ）に示す。これより実施例５においても比較例５と同様の強度比となっていることが分かる。 In this embodiment, the interval is exactly the same as that of the comparative example except that the interval is narrowed so that the interval of the third zone is slightly compressed. FIG. 32B shows the intensity distribution on the optical axis at the aperture diameter including up to the fifth zone of the present embodiment. Thus, it can be seen that the intensity ratio in Example 5 is the same as that in Comparative Example 5.
　本実施形態の点像広がり関数（図３３実線）においては、ρ＝０．１７～０．１９ｍｍにかけてのピーク強度が少し増大する結果となったが、目的とするρ＝０．２２～０．２６ｍｍ付近の急峻なピークの強度が有意に低下していることが分かる。総合的にはこの場合のエッジ強度分布は図３４（実線）に示す通り、エッジ近傍の膨らみをえぐるように強度が低下していることが分かる。よって本実施形態においても光の滲みが相当低減されることが分かる。 In the point spread function (solid line in FIG. 33) of the present embodiment, the peak intensity slightly increased from ρ = 0.17 to 0.19 mm, but the target ρ = 0.22-0. It can be seen that the intensity of the steep peak around 26 mm is significantly reduced. Overall, it can be seen that the strength of the edge intensity distribution in this case decreases as shown by the solid line in FIG. Therefore, it can be seen that light blur is considerably reduced also in this embodiment.
　図３５に、本発明の第六の実施形態としての位相プロファイル５０と、比較例６としての位相プロファイル５２を示す。なお、本実施形態の位相プロファイル５０の詳細を表１３に、また比較例６の位相プロファイル５２の詳細を表１４に、示す。 FIG. 35 shows a phase profile 50 as a sixth embodiment of the present invention and a phase profile 52 as a comparative example 6. Details of the phase profile 50 of the present embodiment are shown in Table 13, and details of the phase profile 52 of Comparative Example 6 are shown in Table 14.
Figure JPOXMLDOC01-appb-T000013
Figure JPOXMLDOC01-appb-T000013
Figure JPOXMLDOC01-appb-T000014
Figure JPOXMLDOC01-appb-T000014
　比較例６は、中央の第１ゾーンから第３ゾーンまでが付加屈折力Ｐadd が２．５（Ｄｉｏｐｔｅｒ）となるようなフレネル間隔から構成され、その周辺の第４ゾーンと第５ゾーンの間隔が、Δｒ＝０．３ｍｍの等間隔領域となっている位相プロファイルについて示したものである。比較例６の第５ゾーンまでを含む開口の光軸上の強度分布を図３６（ａ）に示す。比較例６も近方ピーク以外に等間隔領域を含むことによる中間領域焦点形成ピークが出現することが分かる。なお、付加屈折力Ｐadd が２．５（Ｄｉｏｐｔｅｒ）としたことによって近方用の焦点位置がこれまでの実施例よりもよりレンズ側に近づいていることが分かる。比較例６では、等間隔領域がΔｒ＝０．３ｍｍで構成されており、かかる間隔のｑe ＝１で強め合う時の振幅位置はρ＝０．２６ｍｍと計算される。比較例６の点像広がり関数（図３７破線）において果たしてρ＝０．２６～０．２９ｍｍにおいて急峻なピークが生成していることが分かる。かかる場合のエッジ強度は図３８（破線）のようになり、膨らみのある強度分布を示すことが分かる。かかるエッジ強度分布から像のエッジ近傍で光の滲みが大きくなることが予想される。 In Comparative Example 6, the first zone to the third zone in the center are configured with a Fresnel interval such that the additional refractive power P add is 2.5 (Diopter), and the interval between the surrounding fourth zone and the fifth zone Shows the phase profile in the equally spaced region of Δr = 0.3 mm. The intensity distribution on the optical axis of the aperture including up to the fifth zone of Comparative Example 6 is shown in FIG. It can be seen that Comparative Example 6 also shows an intermediate region focus formation peak due to the inclusion of equally spaced regions in addition to the near peak. In addition, it can be seen that the near focus position is closer to the lens side than in the previous embodiments by setting the additional refractive power P add to 2.5 (Diopter). In Comparative Example 6, the equally-spaced region is configured with Δr = 0.3 mm, and the amplitude position at the time of strengthening when q e = 1 of the space is calculated as ρ = 0.26 mm. In the point spread function of Comparative Example 6 (broken line in FIG. 37), it can be seen that a steep peak is generated at ρ = 0.26 to 0.29 mm. The edge intensity in such a case is as shown in FIG. 38 (broken line), and it can be seen that the intensity distribution is swollen. From this edge intensity distribution, it is expected that the blur of light increases in the vicinity of the edge of the image.
　本実施形態では、第２ゾーンまでの間隔は比較例６と同じで、第２ゾーンを数１４のｃ番目のゾーンとし、数式に基づき第４ゾーンと第５ゾーンの配置を再設定したものである。すなわち、本実施形態では、第２ゾーンがキャンセル用領域として設定されている。なお、等間隔領域の強め合う地点の次数はｑe ＝１とし、かかる次数の強め合う振幅を打ち消すための第２ゾーンの次数は、ｑr ＝２とした。なお、本実施形態においても比較例６との間で遠近の強度比を合わせるために表１３に示すように位相定数を若干変更した。 In the present embodiment, the interval to the second zone is the same as that in Comparative Example 6, and the second zone is set as the c-th zone of Expression 14, and the arrangement of the fourth zone and the fifth zone is reset based on the mathematical formula. is there. That is, in the present embodiment, the second zone is set as a canceling area. In addition, the order of the points where the equidistant regions are strengthened is q e = 1, and the order of the second zone for canceling the strengthening amplitude of the orders is q r = 2. In this embodiment as well, the phase constant was slightly changed as shown in Table 13 in order to match the perspective intensity ratio with Comparative Example 6.
　本実施形態でも第３ゾーンの間隔を少し圧縮するように狭めた以外は比較例６と全く同じ間隔となっている。実施例６の第５ゾーンまでを含む開口径での光軸上強度分布を図３６（ｂ）に示す。これよりゾーンの再設定を行っても各焦点位置の強度比にほとんど影響がないことが分かる。 In this embodiment, the interval is exactly the same as that of Comparative Example 6 except that the interval of the third zone is narrowed to be slightly compressed. FIG. 36B shows the intensity distribution on the optical axis at the aperture diameter including up to the fifth zone in Example 6. It can be seen from this that even if the zone is reset, the intensity ratio of each focal position has almost no influence.
　一方、図３７（実線）に示す点像広がり関数においては、ρ＝０．２６～０．２９ｍｍにかけての急峻なピークの強度が半分以下に低減されていることが分かる。この場合のエッジ強度分布は、図３８（実線）に示す通りでエッジ近傍の膨らみがへこみ、強度が明らかに低下していることが分かる。本実施形態においても、このようにゾーンの配置を僅かに変えるだけで所定の遠近の配分割合にほとんど影響を与えることなく光の滲みを相当低減できることが分かる。 On the other hand, in the point spread function shown in FIG. 37 (solid line), it can be seen that the intensity of the steep peak from ρ = 0.26 to 0.29 mm is reduced to half or less. In the edge intensity distribution in this case, as shown in FIG. 38 (solid line), it can be seen that the bulge in the vicinity of the edge is dented and the intensity is clearly reduced. Also in the present embodiment, it can be seen that light blur can be considerably reduced with little influence on the distribution ratio of the predetermined perspective by simply changing the arrangement of the zones in this way.
　図３９に、比較例７としての位相プロファイル５４と、本発明の第七の実施形態としての位相プロファイル５６を示す。なお、本実施形態の位相プロファイル５６の詳細を表１５に、また比較例７の位相プロファイル５４の詳細を表１６に、示す。 FIG. 39 shows a phase profile 54 as a comparative example 7 and a phase profile 56 as a seventh embodiment of the present invention. Details of the phase profile 56 of the present embodiment are shown in Table 15, and details of the phase profile 54 of Comparative Example 7 are shown in Table 16.
Figure JPOXMLDOC01-appb-T000015
Figure JPOXMLDOC01-appb-T000015
Figure JPOXMLDOC01-appb-T000016
Figure JPOXMLDOC01-appb-T000016
　比較例７は、中央の第１ゾーンから第３ゾーンまでが付加屈折力Ｐadd が２（Ｄｉｏｐｔｅｒ）となるようなフレネル間隔から構成され、その周辺の第４ゾーンから第６ゾーンの間隔が、順番に０．３５ｍｍ、０．２ｍｍ、０．３５ｍｍとなっており、Δｒ＝０．３５ｍｍの等間隔ゾーンが隣接しないように設定されている。図４０（ａ）に、第６ゾーンまでを含んだ開口径を対象とした光軸上の強度分布を示した。かかるプロファイルではΔｒ＝０．３５ｍｍの等間隔ゾーンが間隔の異なるゾーンを隔てて配されているが、等間隔の特性である近方から中間領域にかけて複数の独立したピークが出現するという強度分布を示す。比較例７では、第４ゾーンと第６ゾーンが第５ゾーンによって隣接せずに配されており、かかる位置関係で振幅が強め合う地点は次数ｑe ＝２でρ＝０．２８４ｍｍとなる。一方、間隔が０．３５ｍｍと０．２ｍｍのゾーン間での強め合う地点は、次数ｑe ＝１でρ＝０．２８４ｍｍとなり、同じ地点で振幅が強め合うプロファイルとなっている。このように特定の地点で振幅が強め合うことから、果たして図４１（破線）に示す点像広がり関数においてもρ＝０．２６～０．２９ｍｍの位置で急峻なピークが出現することが分かる。かかる場合のエッジ強度分布は図４２（破線）に示す通りで、階段状の膨らみのある強度分布となることが分かる。かかる強度分布から像の近傍に強度な光の滲みが生じる可能性がある。 In Comparative Example 7, the first zone to the third zone in the center are configured by a Fresnel interval such that the additional refractive power P add is 2 (Diopter), and the interval from the surrounding fourth zone to the sixth zone is In order, they are 0.35 mm, 0.2 mm, and 0.35 mm, and the equally spaced zones of Δr = 0.35 mm are set not to be adjacent to each other. FIG. 40A shows the intensity distribution on the optical axis for the aperture diameter including up to the sixth zone. In such a profile, evenly spaced zones with Δr = 0.35 mm are arranged with differently spaced zones, but the intensity distribution that a plurality of independent peaks appear from the near to the middle region, which is a property of equally spaced. Show. In Comparative Example 7, the fourth zone and the sixth zone are arranged without being adjacent to each other by the fifth zone, and the point where the amplitudes are strengthened by such a positional relationship is the order q e = 2 and ρ = 0.284 mm. On the other hand, the points where the intervals between the zones of 0.35 mm and 0.2 mm strengthen each other are the order q e = 1 and ρ = 0.284 mm, and the profile is such that the amplitudes are strengthened at the same point. Since the amplitude intensifies at a specific point in this way, it can be seen that a steep peak appears at a position of ρ = 0.26 to 0.29 mm even in the point spread function shown in FIG. 41 (broken line). The edge intensity distribution in such a case is as shown in FIG. 42 (broken line), and it can be seen that the intensity distribution has a stepped bulge. From such an intensity distribution, there is a possibility that intense light bleeding occurs in the vicinity of the image.
　本実施形態は、第２ゾーンまでの間隔は比較例７と同じで、第２ゾーンを数１４のｃ番目のゾーン、等間隔領域の第４ゾーンと第６ゾーンをそれぞれｉ番目、ｊ番目のゾーンとし第４ゾーンと第６ゾーン間の次数ｑe ＝２で振幅が強め合う地点が、第２とｉ番目のソーン間の次数ｑr ＝２で振幅が弱め合う地点と一致するように等間隔領域の位置を再設定したものである。すなわち、本実施形態では、第２ゾーンがキャンセル用領域として設定されている。 In the present embodiment, the interval to the second zone is the same as that of Comparative Example 7, the second zone is the c-th zone of Equation 14, the fourth zone and the sixth zone of the equally spaced region are the i-th and j-th zones, respectively. The zone where the amplitude is strengthened at the order q e = 2 between the fourth zone and the sixth zone and the point where the amplitude is weakened at the order q r = 2 between the second and i th zones, etc. The position of the interval area is reset. That is, in the present embodiment, the second zone is set as a canceling area.
　本実施形態では、第３ゾーンが圧縮されて間隔が狭くなった以外は比較例７と同じ間隔となっている。本実施形態の第６ゾーンまでを含む開口径を対象とした光軸上の強度分布を図４０（ｂ）に示す。比較例７と比較すると、ピークの数が減るなどやや異なる強度分布を示すが、多焦点を形成しうるものであることが分かる。このプロファイルの点像広がり関数を図４１（実線）に示す。ρ＝０．２６～０．２９ｍｍのピークが激減していることが分かる。この時のエッジ強度分布は図４２（実線）に示す通りで、比較例７で認められた出っ張りが、まるで氷河によって削られたカール地形のような分布にまで減少していることが分かる。よってこのようにゾーンを再設定することによって光の滲みを相当低減できることが分かる。 In the present embodiment, the interval is the same as that of Comparative Example 7 except that the third zone is compressed and the interval is narrowed. FIG. 40B shows an intensity distribution on the optical axis for the aperture diameter including up to the sixth zone of the present embodiment. Compared with Comparative Example 7, it shows a slightly different intensity distribution, such as a reduced number of peaks, but it can be seen that multifocals can be formed. The point spread function of this profile is shown in FIG. 41 (solid line). It can be seen that the peak at ρ = 0.26 to 0.29 mm is drastically reduced. The edge intensity distribution at this time is as shown in FIG. 42 (solid line), and it can be seen that the protrusion recognized in Comparative Example 7 is reduced to a distribution like a curl topography cut by a glacier. Therefore, it can be seen that the blurring of light can be considerably reduced by resetting the zones in this way.
　図４３に本発明の第八の実施形態としての位相プロファイル５８と、比較例８としての位相プロファイル６０を示す。なお、本実施形態の位相プロファイル５８の詳細を表１７に、また比較例８の位相プロファイル６０の詳細を表１８に、示す。 FIG. 43 shows a phase profile 58 as an eighth embodiment of the present invention and a phase profile 60 as a comparative example 8. Details of the phase profile 58 of the present embodiment are shown in Table 17, and details of the phase profile 60 of Comparative Example 8 are shown in Table 18.
Figure JPOXMLDOC01-appb-T000017
Figure JPOXMLDOC01-appb-T000017
Figure JPOXMLDOC01-appb-T000018
Figure JPOXMLDOC01-appb-T000018
　比較例８は、中央の第１ゾーンから第３ゾーンまでが付加屈折力Ｐadd が２（Ｄｉｏｐｔｅｒ）となるようなフレネル間隔から構成され、その周辺の第４ゾーンから第７ゾーンにおいて第４ゾーンと第６ゾーンがΔｒ＝０．２５ｍｍで、第５ゾーンと第７ゾーンがΔｒ＝０．３ｍｍの等間隔領域がお互いを隔てて交互に配されたプロファイルとなったものである。比較例８の光軸上の強度分布を図４４（ａ）に示す。この場合も隣接はしていないが等間隔領域が存在するため、近方から中間領域にかけて複数の焦点を形成しうるピークが存在することが分かる。比較例８の点像広がり関数（図４５破線）は、ρ＝０．２７～０．２９ｍｍの領域において強度の大きな急峻なピークが生成していることが分かる。かかる等間隔ゾーンが交互に配された領域ではρ＝０．２８４ｍｍの地点で振幅が集中して強め合うことが事前の計算で分かっている。よって、かかる強め合った振幅が該当のρ地点で急峻なピークとなって現れているのである。エッジ強度分布は図４６（破線）に示すように出っ張りのある膨らみの非常に大きな強度分布となることが分かる。かかる強度分布から像の周囲に強度の光の滲みが生じる可能性がある。 In Comparative Example 8, the first zone to the third zone in the center are configured by a Fresnel interval such that the additional refractive power P add is 2 (Diopter), and the fourth zone from the fourth zone to the seventh zone is the fourth zone. And the sixth zone is Δr = 0.25 mm, and the fifth zone and the seventh zone have a profile in which equidistant regions of Δr = 0.3 mm are alternately arranged apart from each other. The intensity distribution on the optical axis of Comparative Example 8 is shown in FIG. In this case as well, although not adjacent to each other, there are equidistant regions, and it can be seen that there are peaks that can form a plurality of focal points from the near region to the intermediate region. It can be seen that the point spread function (broken line in FIG. 45) of Comparative Example 8 generates a sharp peak with a large intensity in the region of ρ = 0.27 to 0.29 mm. It is known from prior calculations that the amplitudes are concentrated and strengthened at a point of ρ = 0.284 mm in a region where such equally spaced zones are alternately arranged. Therefore, the strengthened amplitude appears as a steep peak at the corresponding ρ point. As shown in FIG. 46 (broken line), it can be seen that the edge intensity distribution is an intensity distribution with a very large bulge. From such an intensity distribution, there is a possibility that an intense light blur will occur around the image.
　本実施形態は、第２ゾーンまでの間隔は比較例８と同じで、第２ゾーンを数１４のｃ番目のゾーンとし、数式に基づき等間隔領域の配置を計算した。この際、ｉ番目のゾーンを第４ゾーン、ｊ番目ゾーンを第６ゾーンとし、両ゾーン間で次数ｑe ＝２で振幅が強め合う位置が、第２ゾーンとｉ番目のゾーン間の次数ｑr ＝２で振幅が弱め合う地点と一致するように等間隔領域の位置を再設定した。すなわち、本実施形態では、第２ゾーンがキャンセル用領域として設定されている。 In the present embodiment, the interval to the second zone is the same as that in Comparative Example 8, and the second zone is set as the c-th zone of Formula 14, and the arrangement of equally spaced regions is calculated based on the mathematical formula. At this time, the i-th zone is the fourth zone, the j-th zone is the sixth zone, and the position where the amplitude intensifies between both zones with order q e = 2 is the order q between the second zone and the i-th zone. The position of the equally spaced region was reset so that it coincided with the point where the amplitude was weakened at r = 2. That is, in the present embodiment, the second zone is set as a canceling area.
　本実施形態では、第３ゾーンが圧縮されて間隔が狭くなった以外、残りのゾーンの間隔は比較例８と同じ間隔となっている。本実施形態の第７ゾーンまでを含む開口径を対象とした光軸上の強度分布を図４４（ｂ）に示す。比較例８と比較して近方視用焦点用のピークの強度が多少小さくなっているが、比較例８と似た多焦点を形成しうる強度分布を示すことが分かる。本実施形態の点像広がり関数を図４５（実線）に示す。ρ＝０．２４ｍｍ付近に再設定による新たなピークの出現があるものの、その外周に存在していたρ＝０．２６～０．２９ｍｍの二峰のピークが激減していることが分かる。この時のエッジ強度分布は図４６（実線）に示す通りで、出っ張りのある領域の強度が減少しなだらかな分布となっていることが分かる。よって、かかる位相プロファイルの回折レンズでは光の滲みが抑制できることが分かる。 In the present embodiment, the intervals of the remaining zones are the same as those in the comparative example 8, except that the third zone is compressed and the interval is narrowed. FIG. 44B shows the intensity distribution on the optical axis for the aperture diameter including up to the seventh zone of the present embodiment. Although the intensity of the near vision focus peak is slightly smaller than that of Comparative Example 8, it can be seen that the intensity distribution is similar to that of Comparative Example 8 and can form multiple focal points. The point spread function of this embodiment is shown in FIG. 45 (solid line). Although a new peak appears due to resetting in the vicinity of ρ = 0.24 mm, it can be seen that the two peaks of ρ = 0.26 to 0.29 mm existing on the outer periphery are drastically reduced. The edge intensity distribution at this time is as shown in FIG. 46 (solid line), and it can be seen that the intensity of the protruding area decreases and becomes a gentle distribution. Therefore, it can be seen that the diffractive lens having such a phase profile can suppress the bleeding of light.
　図４７に、本発明の第九の実施形態としての位相プロファイル６２と、比較例９としての位相プロファイル６４を示す。なお、本実施形態の位相プロファイル６２の詳細を表１９に、また比較例９の位相プロファイル６４の詳細を表２０に、示す。 FIG. 47 shows a phase profile 62 as a ninth embodiment of the present invention and a phase profile 64 as a comparative example 9. Details of the phase profile 62 of this embodiment are shown in Table 19, and details of the phase profile 64 of Comparative Example 9 are shown in Table 20.
Figure JPOXMLDOC01-appb-T000019
Figure JPOXMLDOC01-appb-T000019
Figure JPOXMLDOC01-appb-T000020
Figure JPOXMLDOC01-appb-T000020
　比較例９は、第１ゾーンから第４ゾーンまでがΔｒ＝０．２７５ｍｍの等間隔から構成された等間隔領域で、その周辺の第５ゾーンと第６ゾーンは付加屈折力Ｐadd が２（Ｄｉｏｐｔｅｒ）となるようなフレネル間隔から成っており、該フレネル間隔は、第４ゾーンの半径を数１２のフレネル間隔を定める際の第１ゾーン半径ｒ1 として計算して定められたものである。比較例９は、これまでの比較例４～８と異なり、中央に等間隔領域が存在し、その周辺にフレネル間隔が配されるという逆の配置になったものである。図４８（ａ）に第６ゾーンまでを含む開口径を対象とした光軸上の強度分布を示す。比較例９では、近方と遠方視用焦点位置に明確な二つのピークが生成し、回折型多焦点眼用レンズとして有用なプロファイルであることが分かる。しかし、図４９（破線）に示された点像広がり関数では、Δｒ＝０．２７５ｍｍの等間隔領域による振幅の特異的な干渉作用によってρ＝０．２８～０．３３ｍｍの領域に亘って強度の大きな二つのピークが生成する。かかる点像広がり関数からなるエッジ強度分布は、図５０（破線）の通りで、階段状の大きな出っ張りのある分布を示すことが分かる。このような強度分布では像の近傍で強度の大きな光の滲みが発生する可能性がある。 In Comparative Example 9, the first zone to the fourth zone are equally spaced regions having equal spacing of Δr = 0.275 mm, and the additional refractive power P add is 2 (5) and the sixth zone around it. The fresnel interval is determined by calculating the radius of the fourth zone as the first zone radius r 1 when the Fresnel interval of Formula 12 is determined. Unlike the comparative examples 4 to 8 so far, the comparative example 9 has a reverse arrangement in which an equally-spaced region exists in the center and a fresnel interval is arranged in the periphery thereof. FIG. 48A shows the intensity distribution on the optical axis for the aperture diameter including up to the sixth zone. In Comparative Example 9, two distinct peaks are generated at the near and far vision focal positions, and it can be seen that the profile is useful as a diffractive multifocal ophthalmic lens. However, in the point spread function shown in FIG. 49 (broken line), the intensity over the region of ρ = 0.28 to 0.33 mm is caused by the specific interference action of the amplitude by the equally spaced region of Δr = 0.275 mm. Two large peaks are generated. The edge intensity distribution made up of such a point spread function is shown in FIG. 50 (broken line) and shows a distribution with a large stepped protrusion. In such an intensity distribution, there is a possibility that light blur having a high intensity occurs in the vicinity of the image.
　本実施形態は、第４ゾーンまでの間隔は比較例９と同じで、第３、第４及び第６ゾーンを数１４のｊ、ｉ、ｃ番目のゾーンとし、第５ゾーンの外径を第一半径とするフレネル間隔となるように第５ゾーンと第６ゾーンの位置を再設定したものである。すなわち、本実施形態では、第６ゾーンがキャンセル用領域として設定されている。なお、かかる例では再設定するフレネル間隔が等間隔領域の外側周辺にある関係上、数１４中の打ち消す対象の振幅の出現位置のρ値の符号をこれまでの計算例とは逆にして計算した。なお、計算に際して打ち消す振幅の次数は、ｑe ＝１及びｑr ＝２とした。本実施形態の第６ゾーンまでを含む開口径を対象とした光軸上の強度分布を図４８（ｂ）に示す。比較例９とほぼ同じ強度分布を示し、かかる再設定操作を施しても遠近への光の配分に影響がほとんどないことが分かる。一方、点像広がり関数は、図４９（実線）に示す通りで、比較例９で認められたρ＝０．２８～０．３３ｍｍの強度の大きなピークが明らかに減少していることが分かる。この場合のエッジ強度分布は、図５０（実線）に示す通りで、階段状に突出していた箇所がなだらかになっていることが分かる。かかるエッジ強度分布から、実施例９においても光の滲みが大幅に抑制されることが分かる。 In the present embodiment, the distance to the fourth zone is the same as that in Comparative Example 9, and the third, fourth, and sixth zones are the j, i, and cth zones of Equation 14, and the outer diameter of the fifth zone is the first. The positions of the fifth zone and the sixth zone are reset so that the Fresnel interval becomes one radius. That is, in the present embodiment, the sixth zone is set as a canceling area. In this example, since the Fresnel interval to be reset is around the outside of the equidistant region, the calculation is performed by reversing the sign of the ρ value of the appearance position of the amplitude to be canceled in Equation 14 from the previous calculation examples. did. Note that the order of amplitude to be canceled in the calculation is q e = 1 and q r = 2. FIG. 48B shows the intensity distribution on the optical axis for the aperture diameter including up to the sixth zone of the present embodiment. The intensity distribution is almost the same as that of Comparative Example 9, and it can be seen that even if such a resetting operation is performed, there is almost no influence on the light distribution to the near and far. On the other hand, in the point spread function, as shown in FIG. 49 (solid line), it can be seen that the strong peak of ρ = 0.28 to 0.33 mm observed in Comparative Example 9 is clearly reduced. The edge intensity distribution in this case is as shown in FIG. 50 (solid line), and it can be seen that the portion protruding in a staircase shape is gentle. From this edge intensity distribution, it can be seen that even in Example 9, bleeding of light is significantly suppressed.
　図５１に、本発明の第十の実施形態としての位相プロファイル６６と、比較例１０としての位相プロファイル６８を示す。なお、本実施形態の位相プロファイル６６の詳細を表２１に、また比較例１０の位相プロファイル６８の詳細を表２２に、示す。 51 shows a phase profile 66 as the tenth embodiment of the present invention and a phase profile 68 as the comparative example 10. FIG. Details of the phase profile 66 of this embodiment are shown in Table 21, and details of the phase profile 68 of Comparative Example 10 are shown in Table 22.
Figure JPOXMLDOC01-appb-T000021
Figure JPOXMLDOC01-appb-T000021
Figure JPOXMLDOC01-appb-T000022
Figure JPOXMLDOC01-appb-T000022
　比較例１０は、第四から第九の実施形態において示されたフレネル間隔と等間隔領域から構成された回折構造２０においてフレネル間隔の領域を等間隔領域に代え、中央の第１ゾーンと第２ゾーンの間隔が０．４ｍｍ、周辺の第３ゾーンから第６ゾーンまでの間隔が０．２ｍｍの異なる等間隔領域で構成された回折構造２０の位相プロファイルについて示したものである。比較例１０ではこれまでのようなフレネル間隔が併用されずに全域、間隔は異なるが等間隔領域から構成された回折構造２０の例を示すものである。比較例１０の第６ゾーンまでを含む開口の光軸上の強度分布を図５２（ａ）に示す。比較例１０においても明確に遠方と近方それぞれの焦点位置でピークが生成しており、回折型多焦点眼用レンズとして有用なものであることが分かる。しかし、比較例１０の点像広がり関数（図５３破線）において周辺部のρ＝０．３８ｍｍ付近に強度の大きなピークが生成しており、かかるピークの影響でエッジ強度分布はρ＝１から１．１５ｍｍの周辺付近に膨らみのある形態となる。このサイドバンドピークはΔｒ＝０．２ｍｍの等間隔領域間において次数ｑe ＝１で干渉し強め合う振幅に由来するものであり、このように像面中心から離れた地点にピークが生成すると周辺のエッジ強度が大きくなるため、光の滲みの範囲が拡大することが予想される。 In Comparative Example 10, in the diffractive structure 20 composed of the Fresnel interval and the equidistant region shown in the fourth to ninth embodiments, the Fresnel interval region is replaced with the equidistant region, and the central first zone and the second zone are changed. This shows the phase profile of the diffractive structure 20 composed of different equidistant regions with a zone interval of 0.4 mm and a distance from the surrounding third zone to the sixth zone of 0.2 mm. The comparative example 10 shows an example of the diffractive structure 20 that is formed of equidistant regions although the whole area and the interval are different without using the Fresnel interval as before. The intensity distribution on the optical axis of the aperture including up to the sixth zone of Comparative Example 10 is shown in FIG. Also in Comparative Example 10, it is clear that peaks are generated at the far and near focal positions, which is useful as a diffractive multifocal ophthalmic lens. However, in the point spread function (broken line in FIG. 53) of Comparative Example 10, a large intensity peak is generated in the vicinity of ρ = 0.38 mm, and the edge intensity distribution is changed from ρ = 1 to 1 due to the influence of the peak. .Swelling around 15mm. This sideband peak originates from an amplitude that interferes and strengthens with an order q e = 1 between equally spaced regions of Δr = 0.2 mm, and when a peak is generated at a point away from the center of the image plane as described above, Since the edge strength of the light increases, the range of light bleeding is expected to expand.
　本実施形態は、第２ゾーンまでの間隔は比較例１０と同じで、第２ゾーンを数１４のｃ番目のゾーンとし、Δｒ＝０．２ｍｍの等間隔領域の強め合う振幅を、第２ゾーンとｉ番目ゾーンとした第４ゾーンとの間で次数ｑr ＝２．５の振幅で打ち消すことができるように、Δｒ＝０．２ｍｍの等間隔領域の位置を再設定したものである。すなわち、本実施形態では、第２ゾーンがキャンセル用領域として設定されている。 In the present embodiment, the distance to the second zone is the same as that of Comparative Example 10, and the second zone is the c-th zone of Formula 14, and the reinforcing amplitude of the equally-spaced region of Δr = 0.2 mm is set to the second zone. The position of the equally-spaced region of Δr = 0.2 mm is reset so that it can be canceled with an amplitude of order q r = 2.5 between the first zone and the fourth zone as the i-th zone. That is, in the present embodiment, the second zone is set as a canceling area.
　本実施例では、これまでの実施例とは異なり、打ち消すための振幅を決定する際の次数をｑr ＝２．５という実数で設定した例である。かかる実数値で設定した理由は、図５５（ａ）に示すようにｑr ＝２に代表される整数で設定すると第２ゾーンとこれによって再設定されるΔｒ＝０．２ｍｍの領域の振幅が逆に強め合ってしまうからである。本実施形態ではΔｒ＝０．２ｍｍの等間隔領域において振幅が強め合う地点は、Δｒ＝０．４ｍｍのゾーンの振幅分布において、前記数１８の振幅関数のＳｉｎｃ関数の極が正負反対の関係になる領域にかかる。よって、同一極においては打ち消すための次数の条件が、かかる例では逆に強め合うように作用するのである。このようにＳｉｎｃ関数の極が同一ではない場合は、ｑr は整数で設定せずに半波長分の位相差を付与できるようにｑr ＝整数値±０．５で設定する必要があるのである。このようにｑr ＝２．５としてΔｒ＝０．２ｍｍの領域の位置を再設定した場合の振幅分布の関係を図５５（ｂ）に示す。半波長分の次数で設定することによってΔｒ＝０．２ｍｍの等間隔領域の振幅が第２ゾーンの振幅とちょうど逆になることが分かる。 Unlike the previous embodiments, this embodiment is an example in which the order for determining the amplitude for canceling is set as a real number q r = 2.5. As shown in FIG. 55 (a), the reason for setting with such real values is that the amplitude of the second zone and the region of Δr = 0.2 mm reset by this is set by an integer typified by q r = 2. On the contrary, they will strengthen each other. In the present embodiment, the points where the amplitudes intensify in the equally spaced region of Δr = 0.2 mm are in the amplitude distribution of the zone of Δr = 0.4 mm, and the poles of the Sinc function of the amplitude function of Equation 18 are opposite to each other. Take on the area that will be. Therefore, the order condition for canceling out at the same pole acts to reinforce in this example. Thus, when the poles of the Sinc function are not the same, q r is not set as an integer, and it is necessary to set q r = integer value ± 0.5 so that a half-wave phase difference can be given. is there. FIG. 55B shows the relationship of the amplitude distribution when q r = 2.5 and the position of Δr = 0.2 mm is reset. It can be seen that the amplitude of the equally-spaced region of Δr = 0.2 mm is just opposite to the amplitude of the second zone by setting the order of half wavelengths.
　本実施形態では、Δｒ＝０．４ｍｍの領域とΔｒ＝０．２ｍｍの等間隔領域の間に間隔が０．１ｍｍのゾーンが新たに追加された形になり、全体のゾーン位置が比較例１０より０．１ｍｍ周辺へ移動している。その結果、全ゾーンを含む開口からの光軸上の強度分布（図５２（ｂ））において各焦点位置のピーク強度が比較例１０よりも大きくなっている。しかし、各焦点位置のピークの相対的な比率は比較例１０とほぼ同じで、かかる再設定操作が光軸上の強度分布に大きな影響を与えていないことが分かる。本実施形態の点像広がり関数を図５３（実線）に示す。図から分かるように本実施形態では比較例１０で認められたρ＝０．３８ｍｍ付近のピークが明確に低減しており、かかる再設定によって選択的にサイドバンドを低減しうることが分かる。また、エッジ強度分布（図５４）も明確に強度が減っており、光の滲みが抑制できることが分かる。なお、本実施形態及び比較例１０では遠方視用焦点位置のピーク強度に明確な相違があるため、点像広がり関数とエッジ強度分布は、それぞれの最大強度で規格化した相対強度で表示した。 In the present embodiment, a zone having an interval of 0.1 mm is newly added between a region of Δr = 0.4 mm and an equally spaced region of Δr = 0.2 mm, and the entire zone position is the comparative example 10. It has moved to around 0.1 mm. As a result, in the intensity distribution on the optical axis from the aperture including all zones (FIG. 52 (b)), the peak intensity at each focal position is larger than in Comparative Example 10. However, the relative ratio of the peaks at the respective focal positions is substantially the same as in Comparative Example 10, and it can be seen that such resetting operation does not significantly affect the intensity distribution on the optical axis. The point spread function of this embodiment is shown in FIG. 53 (solid line). As can be seen from the figure, in the present embodiment, the peak around ρ = 0.38 mm recognized in Comparative Example 10 is clearly reduced, and it can be seen that the sideband can be selectively reduced by such resetting. Further, the edge intensity distribution (FIG. 54) also clearly decreases in intensity, and it can be seen that light bleeding can be suppressed. In this embodiment and Comparative Example 10, since there is a clear difference in the peak intensity at the far vision focal position, the point spread function and the edge intensity distribution are displayed as relative intensities normalized by their maximum intensity.
　以上が、一連の関係式を用いてゾーンの位置を再設定するだけの簡単な操作で、回折型多焦点眼用レンズが有する各焦点への光の配分挙動にほとんど影響を与えずに点像広がり関数のサイドバンドを低減し、その結果として光の滲みが抑制された回折レンズを設計する方法とそれより得られる回折レンズの仕様について説明した。 The above is a simple operation that simply resets the position of the zone using a series of relational expressions, and has a point image with little effect on the light distribution behavior to each focal point of the diffractive multifocal ophthalmic lens. A method for designing a diffractive lens in which the sideband of the spread function is reduced and, as a result, light bleeding is suppressed, and the specifications of the diffractive lens obtained thereby are described.
　なお、かかるゾーン間の位置の再設定に際して、数２０で定められるρr を数１９で定められるρe に必ずしも完全に一致させる必要はない。なぜならば、ρr 値をρe 値から少しずらすことによって目的とする振幅の低減を可能としつつ同時に他の振幅の増減も制御し、全体的なエッジ強度のバランスを取ることが可能な場合があるからである。この場合、数２０のρr を僅かに変量して位置の再設定を行ってもよいし、ρr を直接変量せずとも数１４のｑr を変量して再設定してもよい。さらには数１４から計算されるゾーンの位置を直接ずらして設定してもよい。かかるゾーンの位置を数１４の計算値から少しずらしてエッジ強度分布を制御する場合の例を次に示す。 When resetting the position between the zones, it is not always necessary to completely match ρ r defined by Equation 20 with ρ e defined by Equation 19. Because it is possible to reduce the target amplitude by slightly shifting the ρ r value from the ρ e value, while controlling the increase and decrease of other amplitudes at the same time, it is possible to balance the overall edge strength. Because there is. In this case, the position may be reset by slightly changing ρ r in Expression 20, or may be reset by changing q r in Expression 14 without directly changing ρ r . Further, the position of the zone calculated from Equation 14 may be set by directly shifting. An example in which the edge intensity distribution is controlled by slightly shifting the position of the zone from the calculated value of Equation 14 is shown below.
　図５６に、本発明の第十一の実施形態としての位相プロファイル７０と、第四の実施形態の位相プロファイル４２を示す。なお、本実施形態の位相プロファイル７０の詳細を表２３に、第四の実施形態の位相プロファイル４２の詳細を表９に、示す。本実施形態では、第３ゾーンがキャンセル用領域として設定されている。 FIG. 56 shows a phase profile 70 according to the eleventh embodiment of the present invention and a phase profile 42 according to the fourth embodiment. Details of the phase profile 70 of the present embodiment are shown in Table 23, and details of the phase profile 42 of the fourth embodiment are shown in Table 9. In the present embodiment, the third zone is set as a cancellation area.
Figure JPOXMLDOC01-appb-T000023
Figure JPOXMLDOC01-appb-T000023
　本実施形態は、第四の実施形態における第５ゾーンと第６ゾーンの位置をわずかにずらして第四の実施形態で達成されたエッジ強度の低減を維持しつつさらにエッジ強度を減少せしめる例として示すものである。具体的には本実施形態では、第四の実施形態における第５ゾーンと第６ゾーンの位置を、ゾーン間隔はΔｒ＝０．２７５ｍｍで維持しつつ全体に内側へ０．０３ｍｍずらした位相プロファイルとなっている。かかる位相プロファイルを第四の実施形態と対比して図５６（実線：本実施形態、破線：第四の実施形態）に表示した。かかるプロファイル図より、ずらした量は僅かであることが分かる。 This embodiment is an example in which the edge strength is further reduced while maintaining the reduction in edge strength achieved in the fourth embodiment by slightly shifting the positions of the fifth zone and the sixth zone in the fourth embodiment. It is shown. Specifically, in this embodiment, the positions of the fifth zone and the sixth zone in the fourth embodiment are maintained at a zone interval of Δr = 0.275 mm, and the phase profile is shifted 0.03 mm inward as a whole. It has become. Such a phase profile is shown in FIG. 56 (solid line: this embodiment, broken line: fourth embodiment) in contrast to the fourth embodiment. From this profile diagram, it can be seen that the amount of displacement is small.
　本実施形態の第６ゾーンまで含む開口の光軸上の強度分布を図５７に示す。図より、第５ゾーンと第６ゾーンを全体的に内側へ０．０３ｍｍずらしてもその移動量はわずかであるため、図２７（ａ）の比較例４及び図２７（ｂ）の第四の実施形態の光軸上の強度分布と比較して各焦点位置のピークの強度分布に大きな変化はないことが分かる。本実施形態の点像広がり関数を第四の実施形態と対比して図５８に示した。第四の実施形態と比較するとρ＝０．２５ｍｍ付近のピーク強度が少し大きくなるものの、ρ＝０．３～０．３５ｍｍの範囲のピーク強度はさらに低減されていることが分かる。かかるサイドバンド強度のさらなる低減によってエッジ強度（図５９実線）もρ＝１から１．０５ｍｍ付近の強度がさらに低減され、第四の実施形態にて示された光の滲みの低減効果がさらに向上していることが分かる。 FIG. 57 shows the intensity distribution on the optical axis of the aperture including up to the sixth zone of the present embodiment. From the figure, since the moving amount is small even if the fifth zone and the sixth zone are shifted inward by 0.03 mm as a whole, the fourth example of FIG. 27A and the fourth example of FIG. It can be seen that there is no significant change in the intensity distribution of the peak at each focal position as compared to the intensity distribution on the optical axis of the embodiment. The point spread function of this embodiment is shown in FIG. 58 in comparison with the fourth embodiment. Although the peak intensity in the vicinity of ρ = 0.25 mm is slightly increased as compared with the fourth embodiment, it can be seen that the peak intensity in the range of ρ = 0.3 to 0.35 mm is further reduced. By further reducing the sideband intensity, the edge intensity (solid line in FIG. 59) is further reduced in the vicinity of ρ = 1 to 1.05 mm, and the light bleeding reduction effect shown in the fourth embodiment is further improved. You can see that
　本実施形態では第四の実施形態の第５ゾーンと第６ゾーンを０．０３ｍｍ内側へ変位させたが、かかる変位量は、数２０のρr において、ρr ＝０．３０６ｍｍとして計算される場合のゾーン位置の変位量に相当する（ずらさない場合はρr ＝０．２８４ｍｍとして計算される）。よって、ゾーン位置を直接ずらして微調整しても良いが、数２０を用いて各ゾーンの振幅の干渉状態などを勘案してρr を変量してゾーンの位置を変更してもよい。 Although in this embodiment by displacing the fifth zone and the sixth zone of the fourth embodiment to 0.03mm inner, such displacement is in the number 20 of the [rho r, it is calculated as ρ r = 0.306mm This corresponds to the displacement amount of the zone position in the case (in the case of not shifting, it is calculated as ρ r = 0.284 mm). Therefore, the zone position may be directly shifted and finely adjusted. However, the position of the zone may be changed by changing ρ r in consideration of the interference state of the amplitude of each zone using Equation 20.
　かかる例から分かるように、数１４から再設定されるゾーンの位置は、計算値をそのまま用いてもよいし、かかる式をゾーン位置関係の第一段階の見積もり値として利用し、さらにバランスがとれたエッジ強度分布となるようにこの前後で微調整して設定してもよいのである。 As can be seen from such an example, the calculated position may be used as it is for the zone position to be reset from the equation (14), or such a formula can be used as an estimated value for the first stage of the zone position relationship for further balancing. Alternatively, fine adjustment may be made before and after this so as to obtain an edge intensity distribution.
　次に、前記ゾーン位置を再設定する方法以外のエッジ強度を低減し得る方法について説明する。前記した０次回折光の焦点像面における振幅を表わす前記数１８のうち、ｃｏｓ関数内に含まれる位相ずれ量τは、これを変えることによって、ｃｏｓ関数の位相を変えることができる。いままで述べた実施形態および比較例は全て位相ずれ量τ＝０の位相プロファイルのものであったが、次にいくつかの実施形態に基づきこの位相ずれ量τを変えることによってもサイドバンドのピークの低減が可能で、その結果としてエッジ強度を低減しうることを示す。 Next, a method that can reduce the edge strength other than the method of resetting the zone position will be described. The phase shift amount τ included in the cos function in the equation 18 representing the amplitude of the 0th-order diffracted light on the focal image plane can be changed to change the phase of the cos function. All of the embodiments and comparative examples described so far have the phase profile of the phase shift amount τ = 0. Next, the sideband peak can be changed by changing the phase shift amount τ based on some embodiments. It is shown that the edge strength can be reduced as a result.
　図６０に、本発明の第十二の実施形態としての位相プロファイル７２と、比較例１２の位相プロファイル７４を示す。なお、本実施形態の位相プロファイル７２の詳細を表２４に、比較例１２の位相プロファイル７４の詳細を表２５に、示す。 FIG. 60 shows a phase profile 72 as a twelfth embodiment of the present invention and a phase profile 74 of Comparative Example 12. Details of the phase profile 72 of the present embodiment are shown in Table 24, and details of the phase profile 74 of Comparative Example 12 are shown in Table 25.
Figure JPOXMLDOC01-appb-T000024
Figure JPOXMLDOC01-appb-T000024
Figure JPOXMLDOC01-appb-T000025
Figure JPOXMLDOC01-appb-T000025
　比較例１２は、中央の第1 ゾーンから第２ゾーンまでが付加屈折力Ｐadd が２（Ｄｉｏｐｔｅｒ）となるようなフレネル間隔から構成され、その周辺の３ゾーンから第５ゾーンまでがΔｒ＝０．３５ｍｍの等間隔で構成された回折多焦点眼用レンズの位相プロファイルである。比較例１２の位相プロファイルを図６０の破線で示した。また、このプロファイルの光軸上の強度分布を図６１（ａ）に示す。かかる位相プロファイルでは、等間隔領域の存在によって遠近のみならず中間領域にも焦点生成用のピークが形成され、多焦点眼用レンズとして有用なものであることが分かる。しかし、図６２（破線）に示された点像広がり関数はρ＝０．２２ｍｍ付近に等間隔領域に起因する急峻なピークが生成し、そのエッジ強度分布は膨らみのあるものとなり、光の滲みが発生する可能性があることが分かる。 In Comparative Example 12, the first zone to the second zone in the center are configured by a Fresnel interval such that the additional refractive power P add is 2 (Diopter), and Δr = 0 from the surrounding three zones to the fifth zone This is a phase profile of a diffractive multifocal ophthalmic lens constructed at equal intervals of 35 mm. The phase profile of Comparative Example 12 is indicated by a broken line in FIG. Moreover, the intensity distribution on the optical axis of this profile is shown in FIG. In such a phase profile, it can be seen that the focus generation peak is formed not only in the perspective but also in the intermediate region due to the presence of the equidistant region, which is useful as a multifocal ophthalmic lens. However, in the point spread function shown in FIG. 62 (broken line), a steep peak due to the equidistant region is generated in the vicinity of ρ = 0.22 mm, and the edge intensity distribution becomes swelled, and light blurs. It can be seen that this may occur.
　本実施形態は、表２４及び図６０（実線）に示すようにゾーン間隔は比較例１２と全く同じであるが、第３ゾーンのブレーズに対してτ＝－０．１π、第５ゾーンのブレーズに対してτ＝－０．３πの位相ずれ量を与えたものである。本実施形態の光軸上の強度分布は、図６１（ｂ）に示す通りで比較例１２とほぼ同じ強度分布を示し、かかる位相ずれ量τを導入することによる各焦点への光の配分にほとんど影響がないことが分かる。点像広がり関数（図６２実線）は、比較例１２で認められたρ＝０．２２ｍｍ付近のピークの強度が減少していることが分かる。そしてエッジ強度分布（図６３実線）も、かかる点像広がり関数の変化を反映し、比較例１２で認められた膨らみがへこみ、強度が低減していることが分かる。よって本実施形態は光の滲みが低減したものとなることが分かる。 In this embodiment, as shown in Table 24 and FIG. 60 (solid line), the zone interval is exactly the same as in Comparative Example 12, but τ = −0.1π with respect to the third zone blaze, and the fifth zone blaze. Is given a phase shift amount of τ = −0.3π. The intensity distribution on the optical axis of the present embodiment is substantially the same as that of the comparative example 12 as shown in FIG. 61B, and distribution of light to each focal point by introducing such a phase shift amount τ. It turns out that there is almost no influence. The point spread function (solid line in FIG. 62) shows that the peak intensity around ρ = 0.22 mm observed in Comparative Example 12 is reduced. The edge intensity distribution (solid line in FIG. 63) also reflects the change in the point spread function, and it can be seen that the bulge observed in Comparative Example 12 is dented and the intensity is reduced. Therefore, it can be seen that the present embodiment reduces light bleeding.
　かかる位相ずれ量τを変量することによるサイドバンドの低減効果についてさらに詳細に説明する。前記数１８より、τは直接ｃｏｓ関数の位相を変調できることが分かる。図６４に示すように、位相ずれ量τを導入するとその振幅関数の位相が変化し、波が進んだり、遅れたりして振幅位置をシフトさせることができる。本実施形態の数１８に基づく振幅関数の挙動を図６５にそれぞれ示す（第１ゾーンの振幅関数は表示せず）。位相ずれ量τを付与する前（図６５（ａ））と位相ずれ量τを付与した後（図６５（ｂ））を比較すると、位相ずれ量τに対してτが付与されたゾーンすなわちキャンセル用領域の回折ゾーンの振幅が僅かにシフトしていることが分かる。かかる例では位相ずれ量τは僅かであるが、それにも関わらずゾーン全体の相互干渉の結果としてサイドバンドピークが低減されることが分かる。 The sideband reduction effect by varying the phase shift amount τ will be described in more detail. From Equation 18, it can be seen that τ can directly modulate the phase of the cos function. As shown in FIG. 64, when the phase shift amount τ is introduced, the phase of the amplitude function is changed, and the amplitude position can be shifted as the wave advances or delays. The behavior of the amplitude function based on Equation 18 of this embodiment is shown in FIG. 65 (the amplitude function of the first zone is not displayed). Comparing before adding the phase shift amount τ (FIG. 65 (a)) and after applying the phase shift amount τ (FIG. 65 (b)), a zone in which τ is applied to the phase shift amount τ, that is, cancellation. It can be seen that the amplitude of the diffraction zone in the working area is slightly shifted. In such an example, although the phase shift amount τ is small, it can be seen that the sideband peak is reduced as a result of the mutual interference of the entire zone.
　位相ずれ量τは、どのゾーンに導入しても構わず、また、一か所のみならず複数の箇所に設定しても良い。また、位相ずれ量τはマイナスのずれのみならずプラスのずれを付与してもよい。また、複数のゾーンに設定する場合は正負の符号がそれぞれ異なっていてもよいし、同じであってもよい。かかる位相ずれ量τの値、また付与するゾーンに関しては目的とする振幅を打ち消す、あるいは低減できるように設定すればよい。なお、望ましくは設定したプロファイルの各焦点位置への光の配分挙動に影響を与えないように設定するのが望ましい。さらに別の実施例にてかかる位相ずれ量τを用いたエッジ強度の低減例について説明する。 The phase shift amount τ may be introduced in any zone, and may be set not only in one place but also in a plurality of places. Further, the phase shift amount τ may be given a positive shift as well as a negative shift. Moreover, when setting to a some zone, a positive / negative code | symbol may differ, respectively, and may be the same. The value of the phase shift amount τ and the zone to be applied may be set so that the target amplitude can be canceled or reduced. Desirably, it is desirable to set so as not to affect the light distribution behavior to each focal position of the set profile. Further, another example of edge strength reduction using the phase shift amount τ will be described.
　図６６に、本発明の第十三の実施形態としての位相プロファイル７６と、比較例１３の位相プロファイル７８を示す。なお、本実施形態の位相プロファイル７６の詳細を表２６に、比較例１３の位相プロファイル７８の詳細を表２７に、示す。 66 shows a phase profile 76 as a thirteenth embodiment of the present invention and a phase profile 78 of Comparative Example 13. FIG. Details of the phase profile 76 of this embodiment are shown in Table 26, and details of the phase profile 78 of Comparative Example 13 are shown in Table 27.
Figure JPOXMLDOC01-appb-T000026
Figure JPOXMLDOC01-appb-T000026
Figure JPOXMLDOC01-appb-T000027
Figure JPOXMLDOC01-appb-T000027
　比較例１３は、中央の第１ゾーンから第３ゾーンまでが付加屈折力Ｐadd が２（Ｄｉｏｐｔｅｒ）となるようなフレネル間隔から構成され、その周辺の４ゾーンから第６ゾーンまでがΔｒ＝０．３ｍｍの等間隔で構成された回折多焦点眼用レンズの位相プロファイルである。比較例１３の位相プロファイルを図６６の破線で示した。かかるプロファイルの光軸上の強度分布を図６７（ａ）に示す。かかる位相プロファイルでは、等間隔領域の存在によって遠近のみならず中間領域にも焦点生成用のピークが形成され、多焦点眼用レンズとして有用なものであることが分かる。しかし、図６８（破線）に示された点像広がり関数はρ＝０．２６ｍｍ付近に等間隔領域に起因する急峻なピークが生成し、そのエッジ強度分布（図６９破線）は膨らみのあるものとなり、光の滲みが発生する可能性があることが分かる。 In Comparative Example 13, the first zone to the third zone in the center are configured by a Fresnel interval such that the additional refractive power P add is 2 (Diopter), and Δr = 0 from the surrounding four zones to the sixth zone. FIG. 3 is a phase profile of a diffractive multifocal ophthalmic lens configured at an equal interval of 3 mm. The phase profile of Comparative Example 13 is indicated by a broken line in FIG. The intensity distribution on the optical axis of such a profile is shown in FIG. In such a phase profile, it can be seen that the focus generation peak is formed not only in the perspective but also in the intermediate region due to the presence of the equidistant region, which is useful as a multifocal ophthalmic lens. However, the point spread function shown in FIG. 68 (broken line) generates a steep peak due to the equidistant region in the vicinity of ρ = 0.26 mm, and the edge intensity distribution (broken line in FIG. 69) is swollen. Thus, it can be seen that light bleeding may occur.
　本実施形態は、表２６及び図６６（実線）に示すようにゾーン間隔は比較例１３と全く同じであるが、第４ゾーンのブレーズに対して＝－０．２π、第６ゾーンのブレーズに対してτ＝－０．３πの位相ずれ量を与えたものである。本実施形態の光軸上の強度分布は、図６７（ｂ）に示す通りで比較例１３とほぼ同じ強度分布を示し、かかる位相ずれ量τを導入することによる各焦点への光の配分にはほとんど影響がないことが分かる。点像広がり関数（図６８実線）は、比較例１３で認められたρ＝０．２６ｍｍ付近のピークの強度が減少していることが分かる。そしてエッジ強度分布（図６９実線）も、かかる点像広がり関数の変化を反映し、比較例１３で認められた膨らみがへこみ、強度が低減していることが分かる。よって本実施形態は光の滲みが低減したものとなることが分かる。 In this embodiment, as shown in Table 26 and FIG. 66 (solid line), the zone interval is exactly the same as that of Comparative Example 13, but it is −0.2π with respect to the blaze of the fourth zone, and the blaze of the sixth zone. On the other hand, a phase shift amount of τ = −0.3π is given. The intensity distribution on the optical axis of the present embodiment is substantially the same as that of Comparative Example 13 as shown in FIG. 67B, and the distribution of light to each focal point by introducing such a phase shift amount τ. Can be seen to have little effect. The point spread function (solid line in FIG. 68) shows that the intensity of the peak around ρ = 0.26 mm observed in Comparative Example 13 is reduced. The edge intensity distribution (solid line in FIG. 69) also reflects the change in the point spread function, and it can be seen that the bulge observed in Comparative Example 13 is dented and the intensity is reduced. Therefore, it can be seen that the present embodiment reduces light bleeding.
　なお、かかる実施形態では、エッジ近傍のρ＝０．８ｍｍ付近で比較例１３よりもふくらみが増すエッジ強度分布となっているが、かかる領域は第四の実施形態と同様にエッジに近いため光の滲みとして知覚されにくいことが予想される。よって、かかる領域の強度の増加にさほど注意を払う必要はないのである。以上よりゾーン位置を再設定する以外に位相ずれ量τを変量するだけでもエッジ強度分布を低減することができ、光の滲みを抑制できることを示した。 In this embodiment, the edge intensity distribution is larger than the comparative example 13 in the vicinity of ρ = 0.8 mm in the vicinity of the edge. However, since this region is close to the edge as in the fourth embodiment, the light intensity is increased. It is expected to be difficult to perceive as bleeding. Therefore, it is not necessary to pay much attention to the increase in the intensity of such a region. From the above, it was shown that the edge intensity distribution can be reduced only by changing the phase shift amount τ in addition to resetting the zone position, and light bleeding can be suppressed.
　さらに別の方法にて同様のエッジ強度の低減効果を上げる例について説明する。前記数１８は、ｃｏｓ関数とＳｉｎｃ関数の積になっており、これまではｃｏｓ関数の挙動に着目した制御の方法について説明してきた。次にＳｉｎｃ関数の挙動を利用した制御の方法について説明する。 An example of increasing the edge strength reduction effect by another method will be described. Equation 18 is a product of the cos function and the sinc function, and the control method focusing on the behavior of the cos function has been described so far. Next, a control method using the behavior of the Sinc function will be described.
　図７０ (ａ) に比較例１４の位相プロファイル８０を、図７０（ｂ）に本発明の第十四の実施形態としての位相プロファイル８２を示す。なお、本実施形態の位相プロファイル８２の詳細を表２８に、比較例１４の位相プロファイル８０の詳細を表２９に、示す。 FIG. 70 (a) shows the phase profile 80 of Comparative Example 14, and FIG. 70 (b) shows the phase profile 82 as the fourteenth embodiment of the present invention. Details of the phase profile 82 of this embodiment are shown in Table 28, and details of the phase profile 80 of Comparative Example 14 are shown in Table 29.
Figure JPOXMLDOC01-appb-T000028
Figure JPOXMLDOC01-appb-T000028
Figure JPOXMLDOC01-appb-T000029
Figure JPOXMLDOC01-appb-T000029
　比較例１４は、中央の第１ゾーンから第２ゾーンまでが付加屈折力Ｐadd が２（Ｄｉｏｐｔｅｒ）となるようなフレネル間隔から構成され、その周辺の第３ゾーンから第５ゾーンまでがΔｒ＝０．３ｍｍの等間隔で構成された回折多焦点眼用レンズの位相プロファイルである。なお、表２９及び図７０（ａ）に示すように第４ゾーンの位相定数はｈ＝０とし、ここのみ屈折領域としたものである。かかるプロファイルの光軸上の強度分布を図７１（ａ）に示す。等間隔領域の存在によって遠近のみならず中間領域にも焦点生成用のピークが形成されている。なお、第４ゾーンが屈折領域となっているため、相対的に遠方の強度割合が増している。かかるプロファイルは遠方視を重視した多焦点眼用レンズとして有用なものである。かかるプロファイルの点像広がり関数を図７２（破線）に示す。この場合、等間隔領域が存在することによってρ＝０．２６ｍｍ付近に急峻なピークが存在する。この広がり関数に基づくエッジ強度は図７３（破線）の通りで、膨らみのある強度分布となる。よってかかるプロファイルにおいても光の滲みが発生する可能性がある。 In Comparative Example 14, the first zone to the second zone in the center are configured by a Fresnel interval such that the additional refractive power P add is 2 (Diopter), and the third zone to the fifth zone in the vicinity thereof are Δr = It is a phase profile of a diffractive multifocal ophthalmic lens configured at equal intervals of 0.3 mm. As shown in Table 29 and FIG. 70 (a), the phase constant of the fourth zone is h = 0, and only this is the refractive region. The intensity distribution on the optical axis of such a profile is shown in FIG. Due to the existence of the equidistant region, peaks for focus generation are formed not only in the perspective but also in the intermediate region. Since the fourth zone is a refracting region, the far-intensity ratio is relatively increased. Such a profile is useful as a multifocal ophthalmic lens focusing on far vision. A point spread function of such a profile is shown in FIG. 72 (broken line). In this case, a steep peak exists in the vicinity of ρ = 0.26 mm due to the existence of equally spaced regions. The edge intensity based on the spread function is as shown in FIG. 73 (broken line), and the intensity distribution has a bulge. Therefore, even in such a profile, light bleeding may occur.
　本実施形態は、比較例１４における第４のゾーンの位相定数（ｈ）を－０．２としたブレーズ構造を導入したものである。本実施形態のプロファイルを図７０（ｂ）に示す。位相定数（ｈ）が－０．２で設定されたブレーズは図に示すようにその他のゾーンのブレーズと反対の傾きを有するものとなる。すなわち、本実施形態では、第４ゾーンがキャンセル用領域として設定されており、キャンセル用領域の回折ゾーンが、回折ゾーンにおけるブレーズ形状の傾きの符号をキャンセル用領域以外の回折ゾーンに対して異ならせて設定されている。このプロファイルの光軸上の強度分布、点像広がり関数を図７１（ｂ）、図７２（実線）にそれぞれ示した。光軸上の強度分布は、比較例１４とほとんど変わらず、かかる反対向きのブレーズを導入しても各焦点への光の配分挙動にはほとんど影響がないことが分かる。一方、点像広がり関数は、ρ＝０．２６ｍｍのピークが強度にして３割程度減少していることが分かる。また、エッジ強度分布（図７３実線）においては比較例で膨らみのあった部分の強度が減少しており、よって光の滲みが抑制されることが分かる。 This embodiment introduces a blaze structure in which the phase constant (h) of the fourth zone in Comparative Example 14 is −0.2. FIG. 70B shows the profile of this embodiment. As shown in the figure, the blaze set with the phase constant (h) of −0.2 has a slope opposite to the blaze of the other zones. In other words, in the present embodiment, the fourth zone is set as the canceling region, and the diffraction zone in the canceling region has a sign of the inclination of the blaze shape in the diffraction zone different from that in the diffraction zone other than the canceling region. Is set. The intensity distribution and the point spread function on the optical axis of this profile are shown in FIG. 71 (b) and FIG. 72 (solid line), respectively. It can be seen that the intensity distribution on the optical axis is almost the same as that of Comparative Example 14, and that even if such a blaze in the opposite direction is introduced, the light distribution behavior to each focal point is hardly affected. On the other hand, in the point spread function, it can be seen that the peak at ρ = 0.26 mm is reduced by about 30% in intensity. In addition, in the edge intensity distribution (solid line in FIG. 73), it can be seen that the intensity of the bulging portion in the comparative example is reduced, and thus the bleeding of light is suppressed.
　かかるブレーズの傾き、つまり位相定数（ｈ）を変量することによる効果は以下のように説明できる。ブレーズの傾き、つまり位相定数（ｈ）を変えると、この変化はｃｏｓ関数の位相に変化は与えないが、Ｓｉｎｃ関数の位相に変化を与える。この関係を図７４に示す。ここでは本実施形態の第４ゾーンのみを取り上げ、ｈ＝０．５の場合（図７４（ａ））、ｈ＝－０．５の場合（図７４（ｂ））で比較したものである。位相定数を変えるとＳｉｎｃ関数全体が像面のρ軸方向にシフトし、その結果、Ｓｉｎｃ関数の位相が変化することが分かる。そして、ある地点では変量前ではＳｉｎｃの極が正であった領域が変量後では極が負になることがある。一方、位相定数（ｈ）を変量してもｃｏｓ関数の位相には変化がないので、Ｓｉｎｃ関数の極が正負反対になった領域では、かかる極の反転によって振幅関数全体の振幅の正負が逆になる領域がでてくる。この領域がたとえば光の滲みのような有害なサイドバンドの出現位置に相当していれば、かかる方法によってもサイドバンドの振幅を低減、あるいは打ち消すことが可能となる。位相定数（ｈ）の変量範囲は、目的とするサイドバンドの位置や強度を勘案して定めればよく、特に限定する必要はない。 The effect of changing the slope of the blaze, that is, the phase constant (h) can be explained as follows. When the inclination of the blaze, that is, the phase constant (h) is changed, this change does not change the phase of the cos function, but changes the phase of the Sinc function. This relationship is shown in FIG. Here, only the fourth zone of this embodiment is taken up, and the comparison is made in the case of h = 0.5 (FIG. 74 (a)) and the case of h = −0.5 (FIG. 74 (b)). It can be seen that when the phase constant is changed, the entire Sinc function is shifted in the ρ-axis direction of the image plane, and as a result, the phase of the Sinc function changes. At a certain point, a region where the Sinc pole was positive before the variable may be negative after the variable. On the other hand, since the phase of the cos function does not change even when the phase constant (h) is varied, in the region where the poles of the Sinc function are opposite to each other, the polarity of the amplitude function as a whole is reversed by the inversion of the poles. The area that will become. If this region corresponds to the appearance position of a harmful sideband such as a blur of light, the amplitude of the sideband can be reduced or canceled by this method. The variable range of the phase constant (h) may be determined in consideration of the position and strength of the target sideband, and is not particularly limited.
　図７５（ａ）に、比較例１５の位相プロファイル８４を、図７５（ｂ）に本発明の第十五の実施形態としての位相プロファイル８６を示す。なお、本実施形態の位相プロファイル８６の詳細を表３０に、比較例１５の位相プロファイル８４の詳細を表３１に、示す。 75 (a) shows the phase profile 84 of Comparative Example 15, and FIG. 75 (b) shows the phase profile 86 as the fifteenth embodiment of the present invention. Details of the phase profile 86 of the present embodiment are shown in Table 30, and details of the phase profile 84 of Comparative Example 15 are shown in Table 31.
Figure JPOXMLDOC01-appb-T000030
Figure JPOXMLDOC01-appb-T000030
Figure JPOXMLDOC01-appb-T000031
Figure JPOXMLDOC01-appb-T000031
　比較例１５は、中央の第１ゾーンから第３ゾーンまでが付加屈折力Ｐadd が２（Ｄｉｏｐｔｅｒ）となるようなフレネル間隔から構成され、その周辺の第４ゾーンから第６ゾーンまでがΔｒ＝０．３ｍｍの等間隔で構成された回折多焦点眼用レンズの位相プロファイルである。なお、表３１及び図７５（ａ）に示すように第５ゾーンの位相定数（ｈ）は０とし、ここのみ屈折領域としたものである。かかるプロファイルの光軸上の強度分布を図７６（ａ）に示す。等間隔領域の存在によって遠近のみならず中間領域にも焦点生成用のピークが形成されている。よってこのプロファイルを有する回折レンズは多焦点眼用レンズとして有用なものであることが分かる。かかるプロファイルの点像広がり関数を図７７（破線）に示す。この場合、等間隔領域が存在することによってρ＝０．２６ｍｍ付近に急峻なピークが存在する。この広がり関数に基づくエッジ強度は図７８（破線）の通りで、膨らみのある強度分布となる。よってかかるプロファイルにおいても光の滲みが発生する可能性がある。 In the comparative example 15, the center first zone to the third zone are configured with Fresnel intervals such that the addition refractive power P add is 2 (Diopter), and the surrounding fourth zone to sixth zone is Δr = It is a phase profile of a diffractive multifocal ophthalmic lens configured at equal intervals of 0.3 mm. As shown in Table 31 and FIG. 75 (a), the phase constant (h) of the fifth zone is 0, and only this is the refractive region. The intensity distribution on the optical axis of such a profile is shown in FIG. Due to the existence of the equidistant region, peaks for focus generation are formed not only in the perspective but also in the intermediate region. Therefore, it can be seen that the diffractive lens having this profile is useful as a multifocal ophthalmic lens. The point spread function of such a profile is shown in FIG. 77 (broken line). In this case, a steep peak exists in the vicinity of ρ = 0.26 mm due to the existence of equally spaced regions. The edge intensity based on the spread function is as shown in FIG. 78 (broken line), and the intensity distribution has a bulge. Therefore, even in such a profile, light bleeding may occur.
　本実施形態は、比較例１５における第５のゾーンにおいて位相定数ｈ＝－０．２としたブレーズ構造を導入したものである。本実施形態のプロファイルを図７５（ｂ）に示す。位相定数がｈ＝－０．２で設定されたブレーズは本実施形態と同様にその他のゾーンのブレーズと反対の傾きを有するものとなる。このプロファイルの光軸上の強度分布、点像広がり関数を図７６（ｂ）、図７７（実線）にそれぞれ示した。光軸上の強度分布は、比較例１５とほとんど変わらず、かかる反対向きのブレーズを導入しても各焦点への光の配分にほとんど影響がないことが分かる。一方、点像広がり関数は、ρ＝０．２６ｍｍのピークが強度にして２～３割程度減少していることが分かる。また、エッジ強度分布（図７８実線）においては比較例で膨らみのあった部分の強度が減少しており、よって光の滲みが抑制されていることが分かる。 In the present embodiment, a blazed structure having a phase constant h = −0.2 is introduced in the fifth zone in Comparative Example 15. The profile of this embodiment is shown in FIG. A blaze set with a phase constant of h = −0.2 has a slope opposite to that of blazes in other zones as in the present embodiment. The intensity distribution on the optical axis and the point spread function of this profile are shown in FIG. 76 (b) and FIG. 77 (solid line), respectively. It can be seen that the intensity distribution on the optical axis is almost the same as that of Comparative Example 15, and that the introduction of blaze in the opposite direction has little influence on the distribution of light to each focal point. On the other hand, in the point spread function, it can be seen that the peak at ρ = 0.26 mm decreases in intensity by about 20 to 30%. In addition, in the edge intensity distribution (solid line in FIG. 78), it can be seen that the intensity of the bulging portion in the comparative example is reduced, and thus the bleeding of light is suppressed.
　以上説明したサイドバンド強度を低減し、エッジ強度を減らし光の滲みを抑制する方法は、これら方法を単独で用いても良いし、これら方法を組合せて用いても良い。次に各方法を組合せた例について説明する。 As described above, the method for reducing the sideband intensity, reducing the edge intensity, and suppressing the bleeding of light may be used alone or in combination. Next, an example in which each method is combined will be described.
　図７９に、本発明の第十六の実施形態としての位相プロファイル８８と、第二の実施形態の位相プロファイル３０を示す。なお、本実施形態の位相プロファイル８８の詳細を表３２に、第二の実施形態の位相プロファイル３０の詳細を表３に、示す。 79 shows a phase profile 88 according to the sixteenth embodiment of the present invention and a phase profile 30 according to the second embodiment. Details of the phase profile 88 of the present embodiment are shown in Table 32, and details of the phase profile 30 of the second embodiment are shown in Table 3.
Figure JPOXMLDOC01-appb-T000032
Figure JPOXMLDOC01-appb-T000032
　比較例１６は第二の実施形態のことで、第二の実施形態において、方法の組合せによってさらに光の滲みが抑制されることを示すために、ここでは比較例として用いた。本実施形態は、第二の実施形態で示されたゾーン位置の再設定による方法に加えて位相ずれ量を第５ゾーンにτ＝－０．１５π、第７ゾーンにτ＝－０．１π、それぞれ導入したものである。図７９に示すように、導入した位相ずれ量にそれぞれ対応してブレーズの位置がφ方向にシフトしたプロファイルとなっている。かかるプロファイルの光軸上の強度分布を図８０（ｂ）に示す。位相ずれ量を導入しても光軸上の強度分布にほとんど変化はなく、かかる操作によって遠近への光の配分に影響がないことが分かる。点像広がり関数を図８１（実線）に示す。第二の実施形態で低減されたρ＝０．２６ｍｍ付近のピークが、位相ずれ量の導入を併用することによってさらに低減されていることが分かる。この場合のエッジ強度分布（図８２実線）は、ρ＝０．９～１ｍｍの領域の強度がさらに低減されたものとなり、より光の滲みが抑制されることが分かる。 Comparative Example 16 is the second embodiment, and in the second embodiment, it is used here as a comparative example to show that the bleeding of light is further suppressed by a combination of methods. In this embodiment, in addition to the method by resetting the zone position shown in the second embodiment, the phase shift amount is set to τ = −0.15π in the fifth zone, τ = −0.1π in the seventh zone, Each was introduced. As shown in FIG. 79, the profile is such that the position of the blaze is shifted in the φ direction corresponding to the introduced phase shift amount. The intensity distribution on the optical axis of such a profile is shown in FIG. Even if the amount of phase shift is introduced, the intensity distribution on the optical axis hardly changes, and it can be seen that this operation does not affect the light distribution to the near and far. The point spread function is shown in FIG. 81 (solid line). It can be seen that the peak in the vicinity of ρ = 0.26 mm reduced in the second embodiment is further reduced by using the introduction of the phase shift amount together. In this case, the edge intensity distribution (solid line in FIG. 82) shows that the intensity in the region of ρ = 0.9 to 1 mm is further reduced, and it is understood that the bleeding of light is further suppressed.
　図８３に、本発明の第十七の実施形態としての位相プロファイル９０と、第四の実施形態の位相プロファイル４２を示す。なお、本実施形態の位相プロファイル９０の詳細を表３３に、第四の実施形態の位相プロファイル３０の詳細を表９に、示す。 FIG. 83 shows the phase profile 90 as the seventeenth embodiment of the present invention and the phase profile 42 of the fourth embodiment. Details of the phase profile 90 of the present embodiment are shown in Table 33, and details of the phase profile 30 of the fourth embodiment are shown in Table 9.
Figure JPOXMLDOC01-appb-T000033
Figure JPOXMLDOC01-appb-T000033
　比較例１７は第四の実施形態のことで、第四の実施形態において、方法の組合せによってさらに光の滲みが抑制されることを示すために、ここでは比較例として用いた。本実施形態は、第四の実施形態で示されたゾーン位置の再設定による方法に加えて第６ゾーンに位相ずれ量、τ＝－０．１５πを導入したものである。図８３に示すように、導入した位相ずれ量に対応してブレーズの位置がφ方向にシフトしたプロファイルとなっている。かかるプロファイルの光軸上の強度分布を比較例１７（図８４（ａ））と対比させて図８４（ｂ）に示す。位相ずれ量を導入しても光軸上の強度分布にほとんど変化はなく、かかる操作によって各焦点への光の配分に影響がないことが分かる。点像広がり関数を図８５（実線）に示す。第四の実施形態で低減されたρ＝０．２２ｍｍ付近のピークが、位相ずれ量の導入を併用することによってさらに低減されていることが分かる。このサイドバンドの低減によってエッジ強度分布（図８６実線）は、ρ＝０．８５～０．９７ｍｍの領域の強度がさらに低減されたものとなり、光の滲みがより抑制されることが分かる。このような組合せによるさらなる低減効果は他の方法の組合せによっても同様に発現される。 Comparative Example 17 is the fourth embodiment, and in the fourth embodiment, it is used here as a comparative example in order to show that the bleeding of light is further suppressed by the combination of methods. In this embodiment, in addition to the method by resetting the zone position shown in the fourth embodiment, a phase shift amount τ = −0.15π is introduced into the sixth zone. As shown in FIG. 83, the profile is such that the position of the blaze is shifted in the φ direction corresponding to the introduced phase shift amount. The intensity distribution of the profile on the optical axis is shown in FIG. 84B in comparison with Comparative Example 17 (FIG. 84A). Even if the amount of phase shift is introduced, the intensity distribution on the optical axis hardly changes, and it can be seen that this operation does not affect the distribution of light to each focal point. The point spread function is shown in FIG. 85 (solid line). It can be seen that the peak in the vicinity of ρ = 0.22 mm reduced in the fourth embodiment is further reduced by using the introduction of the phase shift amount together. It can be seen that the edge intensity distribution (solid line in FIG. 86) is obtained by further reducing the intensity of the region where ρ = 0.85 to 0.97 mm by the reduction of the side band, and the bleeding of light is further suppressed. The further reduction effect by such a combination is similarly expressed by the combination of other methods.
　図８７に、本発明の第十八の実施形態としての位相プロファイル９２と、第十五の実施形態の位相プロファイル８６を示す。なお、本実施形態の位相プロファイル９２の詳細を表３４に、第十五の実施形態の位相プロファイル３０の詳細を表３０に、示す。 FIG. 87 shows a phase profile 92 according to the eighteenth embodiment of the present invention and a phase profile 86 according to the fifteenth embodiment. Details of the phase profile 92 of the present embodiment are shown in Table 34, and details of the phase profile 30 of the fifteenth embodiment are shown in Table 30.
Figure JPOXMLDOC01-appb-T000034
Figure JPOXMLDOC01-appb-T000034
　比較例１８は第十五の実施形態のことで、第十五の実施形態において、方法の組合せによってさらに光の滲みが抑制されることを示すために、ここでは比較例として用いた。本実施形態は、第十五の実施形態で示されたブレーズの傾きを変える方法に加えて第４ゾーンに位相ずれ量、τ＝－０．１５πを導入したものである。図８７に示すように導入した位相ずれ量に対応してブレーズの位置がφ方向にシフトしたプロファイルとなっている。かかるプロファイルの光軸上の強度分布を比較例１８（図８８（ａ））と対比させて図８８（ｂ）に示す。位相ずれ量を導入しても光軸上の強度分布にほとんど変化はなく、かかる操作によって各焦点への光の配分に影響がないことが分かる。点像広がり関数を図８９（実線）に示す。比較例１８と対比するとサイドバンド強度の大幅な低減はないものの全体のピークが均等に減少していることが分かる。エッジ強度分布（図９０実線）は、ρ＝０．８４～０．９ｍｍの領域の強度がさらに低減されたものとなっている。よってかかる方法の組合せによって光の滲みがより抑制されることが分かる。 Comparative Example 18 is the fifteenth embodiment, and in the fifteenth embodiment, it is used here as a comparative example to show that light bleeding is further suppressed by a combination of methods. In this embodiment, in addition to the method of changing the blaze inclination shown in the fifteenth embodiment, a phase shift amount τ = −0.15π is introduced into the fourth zone. As shown in FIG. 87, the profile is such that the position of the blaze is shifted in the φ direction corresponding to the phase shift amount introduced. The intensity distribution of the profile on the optical axis is shown in FIG. 88 (b) in comparison with Comparative Example 18 (FIG. 88 (a)). Even if the amount of phase shift is introduced, the intensity distribution on the optical axis hardly changes, and it can be seen that this operation does not affect the distribution of light to each focal point. The point spread function is shown in FIG. 89 (solid line). When compared with Comparative Example 18, it can be seen that although the sideband intensity is not significantly reduced, the entire peak is uniformly reduced. In the edge intensity distribution (solid line in FIG. 90), the intensity in the region of ρ = 0.84 to 0.9 mm is further reduced. Therefore, it can be seen that the bleeding of light is further suppressed by the combination of such methods.
　第十六～十八の実施形態に示したように各方法の組合せによってさらに効果的にエッジ強度を低減でき、その結果として光の滲みが大幅に改善された回折多焦点眼用レンズを得ることができる。なお、前記第十六及び十七の実施形態では、第３ゾーンをキャンセル用領域と認定できるが、位相ずれ量τの変量法によるエッジ強度の低減作用としてみると第５及び第７ゾーンがキャンセル用領域に該当するとも認められる。このように本発明方法では、特定の又は一つのゾーンをキャンセル用領域として限定的に解釈される必要はない。 As shown in the sixteenth to eighteenth embodiments, the edge intensity can be more effectively reduced by the combination of the respective methods, and as a result, a diffractive multifocal ophthalmic lens with greatly improved light bleeding can be obtained. Can do. In the sixteenth and seventeenth embodiments, the third zone can be recognized as a canceling area, but the fifth and seventh zones are canceled when viewed as a reduction effect of the edge strength by the variation method of the phase shift amount τ. It is recognized that it falls under the business domain. Thus, in the method of the present invention, it is not necessary to interpret a specific or one zone as a canceling area in a limited manner.
　以上説明した方法に関して実際にコンタクトレンズを作製し、ブラードビジョンの改善効果を検証した。コンタクトレンズ素材は、２－ヒドロキシエチルメタクリレートを主成分とする含水率約３７．５％の含水性ソフトコンタクトレンズで、レンズ直径：１４ｍｍ、光学部直径：８ｍｍ、ベースカーブ：８．５ｍｍの規格にて、レンズ基材の屈折率を１．４３８、媒体の屈折率を１．３３５とし、波長を５４６ｎｍとして実施例５及び比較例５の位相プロファイルをレリーフ構造に変換し、かかるレリーフをレンズ後面に設けたコンタクトレンズを作製した。試作したコンタクトレンズを、生理食塩水を満たしたガラスセル内に浸漬し、そのセルをカメラレンズの前に設置して室内の蛍光灯を撮影し、蛍光灯のエッジ部の光の強度分布について調べた。 For the method described above, contact lenses were actually manufactured and the improvement effect of the blood vision was verified. The contact lens material is a hydrous soft contact lens containing 2-hydroxyethyl methacrylate as the main component and a water content of about 37.5%. The lens diameter is 14 mm, the optical part diameter is 8 mm, and the base curve is 8.5 mm. Then, the refractive index of the lens substrate is 1.438, the refractive index of the medium is 1.335, the wavelength is 546 nm, the phase profiles of Example 5 and Comparative Example 5 are converted into a relief structure, and such a relief is formed on the rear surface of the lens. The provided contact lens was produced. The prototype contact lens is immersed in a glass cell filled with physiological saline, the cell is placed in front of the camera lens, and an indoor fluorescent lamp is photographed. The light intensity distribution at the edge of the fluorescent lamp is examined. It was.
　図９１（ａ）は、比較例５の位相プロファイルを有するコンタクトレンズを通して撮影された蛍光灯のエッジ部の写真である。この図に示すような範囲で光の滲みが認められる。図９１（ｂ）は、実施例５の位相プロファイルを有するコンタクトレンズを通して撮影された蛍光灯のエッジ部の写真で、比較例５と比べるとエッジ部の光の滲みが低減されていることが分かる。かかる実写データにおいて計測されたエッジ部の強度分布（図９２）は、図３４の理論的に求められたエッジ強度分布と似たものとなっており、シミュレーション通りの結果が得られていることが分かる。 FIG. 91 (a) is a photograph of an edge portion of a fluorescent lamp taken through a contact lens having a phase profile of Comparative Example 5. Light blur is observed in the range shown in this figure. FIG. 91B is a photograph of the edge portion of the fluorescent lamp taken through the contact lens having the phase profile of Example 5, and it can be seen that the blur of light at the edge portion is reduced as compared with Comparative Example 5. . The intensity distribution (FIG. 92) of the edge portion measured in the actual photograph data is similar to the theoretically obtained edge intensity distribution of FIG. 34, and the result as simulated is obtained. I understand.
　以上述べたように各焦点位置への光の配分割合をほとんど変えることなく点像広がり関数におけるサイドバンドの強度を低減することができ、またエッジの強度も低減することが可能で、その結果として光の滲みが抑制された回折型の多焦点眼用レンズを得ることができるのである。 As described above, the sideband intensity in the point spread function can be reduced with little change in the light distribution ratio to each focal position, and the edge intensity can also be reduced. Thus, a diffractive multifocal ophthalmic lens in which light bleeding is suppressed can be obtained.
　また、前記各実施形態などで示された回折構造２０は目的とする眼用レンズ１０の前面、または後面のどちらかに設定されてもよい。あるいはレンズの内部に設置されていてもよい。また、例えば特開２００１－４２１１２号公報等に記載のように、屈折率が異なる二つの材質からなる積層面に、本発明にかかる回折構造２０を形成することも可能である。 Further, the diffractive structure 20 shown in each of the above embodiments may be set on either the front surface or the rear surface of the target ophthalmic lens 10. Or you may install in the inside of a lens. Further, as described in, for example, Japanese Patent Application Laid-Open No. 2001-42112, the diffractive structure 20 according to the present invention can be formed on a laminated surface made of two materials having different refractive indexes.
　また、本発明の適用可能な焦点位置は特に遠方視用焦点に限定されるものではなく、これ以外の、たとえば近方視用焦点、あるいは中間視用焦点など他の焦点位置においてもこれらが０次回折光で形成される場合は本発明の方法が等しく適用できる。 Further, the focus position to which the present invention can be applied is not particularly limited to the far vision focus, and other focus positions such as the near vision focus or the intermediate vision focus are 0. The method of the present invention is equally applicable when formed with the next diffracted light.
　なお、本発明における眼用レンズ１０としてはコンタクトレンズ、眼鏡、眼内レンズなどが具体的な対象となる。さらには角膜実質内に埋植して視力を矯正する角膜挿入レンズ、あるいは人工角膜などにも適用可能である。またコンタクトレンズにおいては硬質性の酸素透過性ハードコンタクトレンズ、含水または非含性のソフトコンタクトレンズ、さらにはシリコーン成分を含有した酸素透過性の含水または非含水性のソフトコンタクトレンズなどに好適に用いることができる。また、眼内レンズにおいても硬質性の眼内レンズや、折り畳んで眼内に挿入可能な軟質眼内レンズなど、いずれの眼内レンズにも好適に用いることができる。本発明に基づく眼内レンズにおいては従来からの回折型の多焦点眼内レンズで指摘されているブラードビジョン，ワクシービジョンあるいはワセリンビジョンの問題を解消しうる。 The ophthalmic lens 10 according to the present invention specifically includes contact lenses, glasses, intraocular lenses, and the like. Furthermore, the present invention can be applied to a corneal insertion lens that is implanted in the corneal stroma and corrects visual acuity, or an artificial cornea. In contact lenses, it is preferably used for hard oxygen-permeable hard contact lenses, water-containing or non-water-containing soft contact lenses, and oxygen-permeable water-containing or non-water-containing soft contact lenses containing a silicone component. be able to. In addition, the intraocular lens can be suitably used for any intraocular lens such as a hard intraocular lens or a soft intraocular lens that can be folded and inserted into the eye. In the intraocular lens based on this invention, the problem of the blood vision, waxy vision, or petroleum jelly vision pointed out by the conventional diffractive multifocal intraocular lens can be solved.
　以上、前記各実施形態を用いて説明してきたように、等間隔領域を含む回折構造２０を設計する場合の等間隔領域の構成形態としては、回折構造２０全域が単一の格子ピッチ（Δｒ）からなる等間隔領域で構成されるもの、異なる格子ピッチ（Δｒ）の等間隔領域が複数存在して構成されるもの、あるいは単一の格子ピッチ（Δｒ）のゾーンが一定間隔おきに配された繰り返し周期構造で構成されるもの、または異なる格子ピッチ（Δｒ）のゾーンが交互に配された繰り返し周期構造で構成されるもの、さらには単一の格子ピッチ（Δｒ）のゾーンが不定間隔おきに複数設けられるもの、などが含まれる。また、等間隔領域が他の規則に従う間隔を有する領域と組み合わさって構成されるものも本発明の態様の中に含まれ、たとえば等間隔領域とフレネル間隔を有する領域との組み合わせなどは本発明の好ましい態様の一つである。即ち、等間隔領域を構成するゾーン間に、それ以外のゾーン（等間隔領域を構成しないゾーン）が介在されている構成であっても良く、また、等間隔領域を構成するゾーン間に介在する他のゾーンの数や大きさ等は、要求される光学特性等に応じて、等間隔領域を構成する各ゾーン間において一定としても良いし互いに異ならせても良い。このように等間隔領域を含む回折構造２０の構成形態は、かかる例以外にも様々な順列、組み合わせが考えられるので、決して上記例に限定されるものではない。かかる格子ピッチ（Δｒ）や位相定数ｈや位相ずれ量（τ）、あるいは等間隔領域の構成形態を適宜選択、組み合わせることによって、ブラードビジョンが低減され、かつ、遠近あるいは遠中近の適切な位置に人の生理学的な見え方の要求度に応じた焦点形成が実現できるような回折多焦点レンズを設計することができる。 As described above with reference to each of the above embodiments, as a configuration form of the equidistant region when designing the diffractive structure 20 including the equidistant region, the entire diffraction structure 20 has a single grating pitch (Δr). Are composed of equidistant regions consisting of, composed of a plurality of equidistant regions with different lattice pitches (Δr), or zones of a single lattice pitch (Δr) are arranged at regular intervals. Those composed of a repetitive periodic structure, those composed of a repetitive periodic structure in which zones of different lattice pitches (Δr) are alternately arranged, and further, zones of a single lattice pitch (Δr) are arranged at irregular intervals. The thing provided with two or more is included. In addition, a configuration in which the equally spaced region is configured in combination with a region having an interval according to another rule is also included in the aspect of the present invention. For example, a combination of an equally spaced region and a region having a Fresnel interval is included in the present invention. This is one of the preferred embodiments. That is, another zone (a zone that does not constitute the equidistant region) may be interposed between the zones that constitute the equidistant region, or may be intervened between the zones that constitute the equidistant region. The number, size, etc. of other zones may be constant among the zones constituting the equally spaced region or may be different from each other according to the required optical characteristics. In this way, the configuration form of the diffractive structure 20 including the equidistant regions is not limited to the above example because various permutations and combinations other than the above example are conceivable. By appropriately selecting and combining the lattice pitch (Δr), the phase constant h, the phase shift amount (τ), or the configuration of the equidistant region, the blood vision is reduced, and an appropriate position in the near or near middle In addition, it is possible to design a diffractive multifocal lens that can realize focus formation in accordance with the degree of demand for human physiological appearance.
１０：眼用レンズ、１２：光学部、２０：回折構造、２６，４２，７２，８２：位相プロファイル 10: ophthalmic lens, 12: optical unit, 20: diffractive structure, 26, 42, 72, 82: phase profile

Claims (21)

  1. 　同心円状に複数形成された回折ゾーンが設けられた光学部を備えており、該光学部によって少なくとも二つの焦点が与えられる回折型多焦点眼用レンズにおいて、
    　前記焦点のうちの一つの焦点である第一の焦点における像面上で、該第一の焦点におけるサイドバンド領域の振幅分布を減少せしめてブラードビジョンを抑制する回折光を与えるキャンセル用領域を、前記光学部における明所視の瞳孔径に対応する領域内に設けたことを特徴とする回折型多焦点眼用レンズ。     In a diffractive multifocal ophthalmic lens comprising an optical unit provided with a plurality of concentric diffraction zones and having at least two focal points provided by the optical unit,
    On the image plane at the first focal point, which is one of the focal points, a canceling region that provides diffracted light that reduces the amplitude distribution of the sideband region at the first focal point and suppresses the blur vision, A diffractive multifocal ophthalmic lens, which is provided in a region corresponding to a pupil diameter of photopic vision in the optical unit.
  2. 　前記第一の焦点が、前記回折ゾーンにおける回折構造の０次回折光によって与えられることを特徴とする請求項１に記載の回折型多焦点眼用レンズ。 2. The diffractive multifocal ophthalmic lens according to claim 1, wherein the first focal point is given by zero-order diffracted light of a diffractive structure in the diffraction zone.
  3. 　前記第一の焦点が遠方視用焦点であり、且つ、他の焦点として近方視用焦点を有する請求項１又は２に記載の回折型多焦点眼用レンズ。 3. The diffractive multifocal ophthalmic lens according to claim 1, wherein the first focus is a far vision focus, and the other focus has a near vision focus.
  4. 　前記キャンセル用領域が、前記複数の回折ゾーンのうちで最内周の該回折ゾーンを除く領域に設けられている請求項１～３の何れか一項に記載の回折型多焦点眼用レンズ。 The diffractive multifocal ophthalmic lens according to any one of claims 1 to 3, wherein the cancel region is provided in a region excluding the innermost periphery of the plurality of diffraction zones.
  5. 　前記回折ゾーンが、光の位相を変調させうるための位相関数で特徴付けられた回折構造をもって形成されている請求項１～４の何れか一項に記載の回折型多焦点眼用レンズ。 The diffractive multifocal ophthalmic lens according to any one of claims 1 to 4, wherein the diffraction zone is formed with a diffractive structure characterized by a phase function for modulating the phase of light.
  6. 　前記回折ゾーンにおける回折構造の少なくとも一部の位相関数が、ブレーズ形状の関数からなる請求項１～５の何れか一項に記載の回折型多焦点眼用レンズ。 6. The diffractive multifocal ophthalmic lens according to claim 1, wherein the phase function of at least a part of the diffractive structure in the diffraction zone is a blazed shape function.
  7. 　前記回折ゾーンにおける回折構造の位相関数がブレーズ形状の関数からなり、且つ、前記第一の焦点における像面上で、ｉ番目の回折ゾーンとｊ番目の回折ゾーンのそれぞれを通過した光の振幅が互いに強め合う関係にある場合において、ｃ番目の回折ゾーンの位置が、各該回折ゾーンを通過した光が互いに振幅を弱め合う条件としての下記［数１］を実質的に満足するように設定されている請求項１～６の何れか一項に記載の回折型多焦点眼用レンズ。
    Figure JPOXMLDOC01-appb-M000022
         The phase function of the diffractive structure in the diffraction zone is a blazed shape function, and the amplitude of the light that has passed through each of the i-th diffraction zone and the j-th diffraction zone on the image plane at the first focus is In the case where they are in a mutually intensifying relationship, the position of the c-th diffraction zone is set so as to substantially satisfy the following [Equation 1] as a condition in which the light passing through each diffraction zone weakens the amplitude of each other. The diffractive multifocal ophthalmic lens according to any one of claims 1 to 6.
    Figure JPOXMLDOC01-appb-M000022
  8. 　前記回折ゾーンにおける回折構造の少なくとも一部が、フレネル間隔の周期構造を有している請求項１～７の何れか一項に記載の回折型多焦点眼用レンズ。 The diffractive multifocal ophthalmic lens according to any one of claims 1 to 7, wherein at least a part of the diffractive structure in the diffractive zone has a periodic structure with a Fresnel interval.
  9. 　前記回折ゾーンにおける回折構造の位相関数がブレーズ形状の関数からなり、且つ該回折ゾーンにおける回折構造がフレネル間隔の周期構造とされていると共に、該回折ゾーンにおける回折構造の０次回折光によって与えられた前記第一の焦点における像面上で、ｉ番目の回折ゾーンとｊ番目の回折ゾーンのそれぞれを通過した光の振幅が互いに強め合う関係にある場合において、ｃ番目の回折ゾーンの位置と該ｉ番目の回折ゾーンの位置が、各該回折ゾーンを通過した光が互いに振幅を弱め合う条件としての下記［数２］を実質的に満足するように設定されている請求項１～８の何れか一項に記載の回折型多焦点眼用レンズ。
    Figure JPOXMLDOC01-appb-M000023
         The phase function of the diffractive structure in the diffractive zone is a blazed shape function, and the diffractive structure in the diffractive zone is a periodic structure with Fresnel spacing, and is given by the 0th-order diffracted light of the diffractive structure in the diffractive zone. In the case where the amplitudes of the light beams that have passed through the i-th diffraction zone and the j-th diffraction zone are intensifying each other on the image plane at the first focal point, the position of the c-th diffraction zone and the i-th diffraction zone 9. The position of the first diffraction zone is set so as to substantially satisfy the following [Equation 2] as a condition in which light passing through each diffraction zone weakens the amplitude of each other: The diffractive multifocal lens according to one item.
    Figure JPOXMLDOC01-appb-M000023
  10. 　前記回折ゾーンにおける回折構造の少なくとも一部が、等間隔の周期構造を有している請求項１～９の何れか一項に記載の回折型多焦点眼用レンズ。 The diffractive multifocal ophthalmic lens according to any one of claims 1 to 9, wherein at least a part of the diffractive structure in the diffractive zone has a periodically spaced structure.
  11. 　前記回折ゾーンにおける回折構造において、前記キャンセル用領域の回折ゾーンにおけるブレーズ形状の関数の傾きが、該キャンセル用領域以外の領域の回折ゾーンのブレーズ形状の傾きと反対の符号を有している請求項１～１０の何れか一項に記載の回折型多焦点眼用レンズ。 In the diffractive structure in the diffraction zone, the inclination of the function of the blazed shape in the diffraction zone of the cancellation region has a sign opposite to the inclination of the blazed shape of the diffraction zone in the region other than the cancellation region. 11. The diffractive multifocal lens according to any one of 1 to 10.
  12. 　前記キャンセル用領域の回折ゾーンと該キャンセル用領域以外の回折ゾーンとが、該回折ゾーンにおける位置設定と、該回折ゾーンにおけるブレーズ形状の関数の位相設定と、該回折ゾーンにおけるブレーズ形状の関数の傾き設定との、少なくとも一つを異ならせて設定されている請求項１～１１の何れか一項に記載の回折型多焦点眼用レンズ。 The diffraction zone of the cancellation region and the diffraction zone other than the cancellation region are positioned in the diffraction zone, the phase setting of the function of the blaze shape in the diffraction zone, and the slope of the function of the blaze shape in the diffraction zone The diffractive multifocal ophthalmic lens according to any one of claims 1 to 11, wherein the diffractive multifocal ophthalmic lens is set differently from at least one of the setting.
  13. 　前記回折ゾーンにおける回折構造が、位相に相当する光路長を反映したレリーフ構造によって構成されている請求項１～１２の何れか一項に記載の回折型多焦点眼用レンズ。 The diffractive multifocal ophthalmic lens according to any one of claims 1 to 12, wherein the diffractive structure in the diffraction zone is constituted by a relief structure reflecting an optical path length corresponding to a phase.
  14. 　同心円状に複数形成された回折ゾーンが設けられた光学部を備えており、該光学部によって少なくとも二つの焦点が与えられると共に、かかる焦点のうちの一つの焦点である第一の焦点におけるブラードビジョンが抑制された回折型多焦点眼用レンズを製造するに際して、
    （ｉ）少なくとも二つの焦点が与えられる前記光学部における複数の前記回折ゾーンを設定する基本形状設定工程と、
    （ｉｉ）該基本形状設定工程で設定した複数の該回折ゾーンによって前記第一の焦点における像面上で与えられる光の振幅分布を求める振幅情報取得工程と、
    （ｉｉｉ）該振幅情報取得工程で求めた該光の振幅分布において低減対象とするサイドバンドを決定する低減対象決定工程と、
    （ｉｖ）該低減対象決定工程で決定した該サイドバンドを相殺的に減少せしめる光の振幅分布を前記第一の焦点における像面上で与えるキャンセル用領域を、複数の前記回折ゾーンと共に前記光学部における明所視状態の瞳孔径に対応する領域内に形成するキャンセル用領域形成工程と
    を、含むことを特徴とする回折型多焦点眼用レンズの製造方法。     An optical unit provided with a plurality of concentrically formed diffraction zones is provided, and at least two focal points are provided by the optical unit, and a blood vision in a first focal point which is one of the focal points When manufacturing a diffractive multifocal ophthalmic lens with suppressed
    (I) a basic shape setting step of setting a plurality of the diffraction zones in the optical unit to which at least two focal points are given;
    (Ii) an amplitude information acquisition step for obtaining an amplitude distribution of light provided on the image plane at the first focus by the plurality of diffraction zones set in the basic shape setting step;
    (Iii) a reduction target determination step for determining a sideband to be reduced in the amplitude distribution of the light obtained in the amplitude information acquisition step;
    (Iv) a cancel region that gives an amplitude distribution of light on the image plane at the first focal point that destructively reduces the sideband determined in the reduction target determination step together with the plurality of diffraction zones; And a cancel region forming step formed in a region corresponding to the pupil diameter of the photopic vision state in the method for manufacturing a diffractive multifocal ophthalmic lens.
  15. 　前記低減対象決定工程において低減対象として決定した前記サイドバンドの振幅および領域の振幅データを取得し、かかる振幅データから前記第一の焦点における像面上での光の振幅関数を求めて、かかるサイドバンドの振幅関数に対して相殺的な低減効果を及ぼす光の振幅関数を与えるキャンセル用の回折ゾーンを、前記キャンセル用領域として採用する請求項１４に記載の回折型多焦点眼用レンズの製造方法。 The sideband amplitude and area amplitude data determined as the reduction target in the reduction target determination step are acquired, and the amplitude function of light on the image plane at the first focal point is obtained from the amplitude data, and the side The method for manufacturing a diffractive multifocal ophthalmic lens according to claim 14, wherein a canceling diffraction zone that gives an amplitude function of light that exerts a canceling effect on a band amplitude function is adopted as the canceling region. .
  16. 　前記回折ゾーンにおける回折構造の位相関数がブレーズ形状の関数からなり、且つ、前記第一の焦点が該回折ゾーンにおける回折構造の０次回折光によって与えられる請求項１４又は１５に記載の回折型多焦点眼用レンズの製造方法。 The diffractive multifocal according to claim 14 or 15, wherein a phase function of a diffractive structure in the diffractive zone is a function of a blazed shape, and the first focal point is provided by a zero-order diffracted light of the diffractive structure in the diffractive zone. A method for producing an ophthalmic lens.
  17. 　前記第一の焦点における像面上で、ｉ番目の回折ゾーンとｊ番目の回折ゾーンのそれぞれを通過した光の振幅が互いに強め合う関係にある場合において、ｃ番目の回折ゾーンの位置が、各該回折ゾーンを通過した光が互いに振幅を弱め合う条件としての下記［数３］を実質的に満足するように、前記キャンセル用領域の前記回折ゾーンを設定する請求項１６に記載の回折型多焦点眼用レンズの製造方法。
    Figure JPOXMLDOC01-appb-M000024
         On the image plane at the first focus, when the amplitudes of the light beams that have passed through the i-th diffraction zone and the j-th diffraction zone are intensifying each other, the position of the c-th diffraction zone is 17. The diffractive multi-channel according to claim 16, wherein the diffractive zone in the cancel region is set so as to substantially satisfy the following [Equation 3] as a condition in which the light passing through the diffractive zone weakens the amplitude. A method for manufacturing a lens for a focal eye.
    Figure JPOXMLDOC01-appb-M000024
  18. 　前記第一の焦点における像面上で、ｉ番目の回折ゾーンとｊ番目の回折ゾーンのそれぞれを通過した光の振幅が互いに強め合う関係にある場合において、ｃ番目の回折ゾーンの位置と該ｉ番目の回折ゾーンの位置が、各該回折ゾーンを通過した光が互いに振幅を弱め合う条件としての下記［数４］を実質的に満足するように設定されている請求項１６に記載の回折型多焦点眼用レンズの製造方法。
    Figure JPOXMLDOC01-appb-M000025
         In the case where the amplitudes of the light beams that have passed through the i-th diffraction zone and the j-th diffraction zone are intensifying each other on the image plane at the first focal point, the position of the c-th diffraction zone and the i-th diffraction zone The diffraction pattern according to claim 16, wherein the position of the second diffraction zone is set so as to substantially satisfy the following [Equation 4] as a condition for the lights passing through the diffraction zones to weaken the amplitude of each other. A method for producing a multifocal ophthalmic lens.
    Figure JPOXMLDOC01-appb-M000025
  19. 　前記ブレーズ形状の関数を位相軸方向にずらして調節して、前記キャンセル用領域の回折ゾーンが前記サイドバンドに対応する振幅を弱め合うように設定する請求項１６に記載の回折型多焦点眼用レンズの製造方法。 17. The diffractive multifocal ophthalmic eye according to claim 16, wherein the function of the blaze shape is adjusted by shifting in the phase axis direction so that the diffraction zone of the cancellation region weakens the amplitude corresponding to the sideband. Lens manufacturing method.
  20. 　前記キャンセル用領域の回折ゾーンにおけるブレーズ形状の関数の傾きの符号を、該キャンセル用領域以外の領域の回折ゾーンのブレーズ形状の傾きと反対の符号に設定することにより、前記サイドバンドに対応する振幅を弱め合うように設定する請求項１６に記載の回折型多焦点眼用レンズの製造方法。 By setting the sign of the slope of the function of the blaze shape in the diffraction zone of the cancellation area to the sign opposite to the slope of the blaze shape of the diffraction zone of the area other than the cancellation area, the amplitude corresponding to the sideband The method for producing a diffractive multifocal ophthalmic lens according to claim 16, wherein the diffractive multifocal ophthalmic lens is set so as to weaken each other.
  21. 　請求項１７又は１８に従う前記回折ゾーンの位置の調節と、請求項１９に従う該回折ゾーンの位相軸方向のずれ量の調節と、請求項２０に従う該回折ゾーンの前記ブレーズ形状の傾きの調節との、少なくとも二つを組み合わせて調節することにより、前記サイドバンドに対応する振幅を弱め合うように設定する請求項１６に記載の回折型多焦点眼用レンズの製造方法。 The adjustment of the position of the diffraction zone according to claim 17 or 18, the adjustment of the shift amount in the phase axis direction of the diffraction zone according to claim 19, and the adjustment of the inclination of the blazed shape of the diffraction zone according to claim 20. The method for manufacturing a diffractive multifocal ophthalmic lens according to claim 16, wherein the amplitude corresponding to the sideband is set to be weakened by adjusting at least two in combination.
PCT/JP2012/008031 2012-12-14 2012-12-14 Diffractive multifocal ophthalmic lens and production method thereof WO2014091528A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/JP2012/008031 WO2014091528A1 (en) 2012-12-14 2012-12-14 Diffractive multifocal ophthalmic lens and production method thereof
JP2014525250A JP5993950B2 (en) 2012-12-14 2012-12-14 Diffractive multifocal ophthalmic lens and manufacturing method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2012/008031 WO2014091528A1 (en) 2012-12-14 2012-12-14 Diffractive multifocal ophthalmic lens and production method thereof

Publications (1)

Publication Number Publication Date
WO2014091528A1 true WO2014091528A1 (en) 2014-06-19

Family

ID=50933857

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2012/008031 WO2014091528A1 (en) 2012-12-14 2012-12-14 Diffractive multifocal ophthalmic lens and production method thereof

Country Status (2)

Country Link
JP (1) JP5993950B2 (en)
WO (1) WO2014091528A1 (en)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104765088A (en) * 2015-04-24 2015-07-08 中国工程物理研究院激光聚变研究中心 Linear variable-area wave zone plate with feature of long focal length
WO2017056305A1 (en) * 2015-10-01 2017-04-06 株式会社メニコン Diffractive multi-focal ocular lens and method for manufacturing diffractive multi-focal ocular lens
WO2017138099A1 (en) * 2016-02-09 2017-08-17 株式会社メニコン Diffractive multifocal lens for eye and method for manufacturing diffractive multifocal lens for eye
PL426072A1 (en) * 2015-10-02 2019-02-25 Rayner Intraocular Lenses Limited Multi-focus optical lens and method for producing it
CN112198574A (en) * 2019-09-27 2021-01-08 东莞东阳光医疗智能器件研发有限公司 Diffractive optical element, ophthalmic lens and intraocular lens
US11022815B2 (en) 2012-08-31 2021-06-01 Amo Groningen B.V. Multi-ring lens, systems and methods for extended depth of focus
US11156853B2 (en) 2017-06-28 2021-10-26 Amo Groningen B.V. Extended range and related intraocular lenses for presbyopia treatment
US11262598B2 (en) 2017-06-28 2022-03-01 Amo Groningen, B.V. Diffractive lenses and related intraocular lenses for presbyopia treatment
US11327210B2 (en) 2017-06-30 2022-05-10 Amo Groningen B.V. Non-repeating echelettes and related intraocular lenses for presbyopia treatment
US11497599B2 (en) 2017-03-17 2022-11-15 Amo Groningen B.V. Diffractive intraocular lenses for extended range of vision
US11523897B2 (en) 2017-06-23 2022-12-13 Amo Groningen B.V. Intraocular lenses for presbyopia treatment
US11844689B2 (en) 2019-12-30 2023-12-19 Amo Groningen B.V. Achromatic lenses and lenses having diffractive profiles with irregular width for vision treatment

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010134282A (en) * 2008-12-05 2010-06-17 Hoya Corp Diffractive multifocal lens

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2378319B1 (en) * 2009-01-06 2023-04-05 Menicon Co., Ltd. Diffractive lens manufacturing method
DE102010018436B4 (en) * 2010-04-27 2017-02-09 Carl Zeiss Meditec Ag Multifocal eye lens

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010134282A (en) * 2008-12-05 2010-06-17 Hoya Corp Diffractive multifocal lens

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11022815B2 (en) 2012-08-31 2021-06-01 Amo Groningen B.V. Multi-ring lens, systems and methods for extended depth of focus
CN104765088A (en) * 2015-04-24 2015-07-08 中国工程物理研究院激光聚变研究中心 Linear variable-area wave zone plate with feature of long focal length
WO2017056305A1 (en) * 2015-10-01 2017-04-06 株式会社メニコン Diffractive multi-focal ocular lens and method for manufacturing diffractive multi-focal ocular lens
JPWO2017056305A1 (en) * 2015-10-01 2018-07-19 株式会社メニコン Diffractive multifocal ophthalmic lens and method of manufacturing diffractive multifocal ophthalmic lens
US10564448B2 (en) 2015-10-01 2020-02-18 Menicon Co., Ltd. Diffractive multi-focal ophthalmic lens and method for manufacturing diffractive multi-focal ophthalmic lens
PL426072A1 (en) * 2015-10-02 2019-02-25 Rayner Intraocular Lenses Limited Multi-focus optical lens and method for producing it
WO2017138099A1 (en) * 2016-02-09 2017-08-17 株式会社メニコン Diffractive multifocal lens for eye and method for manufacturing diffractive multifocal lens for eye
JPWO2017138099A1 (en) * 2016-02-09 2018-08-02 株式会社メニコン Ophthalmic diffractive multifocal lens and manufacturing method of ophthalmic diffractive multifocal lens
EP3415980A4 (en) * 2016-02-09 2019-11-13 Menicon Co., Ltd. Diffractive multifocal lens for eye and method for manufacturing diffractive multifocal lens for eye
US11009723B2 (en) 2016-02-09 2021-05-18 Menicon Co., Ltd. Ophthalmic diffractive multi-focal lens and method for manufacturing ophthalmic diffractive multi-focal lens
US11497599B2 (en) 2017-03-17 2022-11-15 Amo Groningen B.V. Diffractive intraocular lenses for extended range of vision
US11523897B2 (en) 2017-06-23 2022-12-13 Amo Groningen B.V. Intraocular lenses for presbyopia treatment
US11262598B2 (en) 2017-06-28 2022-03-01 Amo Groningen, B.V. Diffractive lenses and related intraocular lenses for presbyopia treatment
US11156853B2 (en) 2017-06-28 2021-10-26 Amo Groningen B.V. Extended range and related intraocular lenses for presbyopia treatment
US11573433B2 (en) 2017-06-28 2023-02-07 Amo Groningen B.V. Extended range and related intraocular lenses for presbyopia treatment
US11914229B2 (en) 2017-06-28 2024-02-27 Amo Groningen B.V. Diffractive lenses and related intraocular lenses for presbyopia treatment
US11327210B2 (en) 2017-06-30 2022-05-10 Amo Groningen B.V. Non-repeating echelettes and related intraocular lenses for presbyopia treatment
CN112198574A (en) * 2019-09-27 2021-01-08 东莞东阳光医疗智能器件研发有限公司 Diffractive optical element, ophthalmic lens and intraocular lens
US11844689B2 (en) 2019-12-30 2023-12-19 Amo Groningen B.V. Achromatic lenses and lenses having diffractive profiles with irregular width for vision treatment

Also Published As

Publication number Publication date
JPWO2014091528A1 (en) 2017-01-05
JP5993950B2 (en) 2016-09-21

Similar Documents

Publication Publication Date Title
JP5993950B2 (en) Diffractive multifocal ophthalmic lens and manufacturing method thereof
JP5916770B2 (en) Multifocal ophthalmic lens and manufacturing method thereof
JP6698671B2 (en) Diffractive multifocal ophthalmic lens and method of manufacturing diffractive multifocal ophthalmic lens
JP6161404B2 (en) Diffractive multifocal ophthalmic lens and manufacturing method thereof
JP5848368B2 (en) Diffractive multifocal ophthalmic lens and manufacturing method thereof
AU2007213725B8 (en) Pseudo-accomodative IOL having multiple diffractive patterns
Ravikumar et al. Chromatic aberration and polychromatic image quality with diffractive multifocal intraocular lenses
WO2016021075A1 (en) Diffractive multi-focal lens and method for manufacturing diffractive multi-focal lens
JP2023052663A (en) ophthalmic multifocal diffractive lens
EP3415980B1 (en) Diffractive multifocal lens for eye and method for manufacturing diffractive multifocal lens for eye
WO2013118177A1 (en) Diffraction-type multifocal eye lens and manufacturing method therefor
EP3179294A1 (en) Method for producing diffractive multifocal ophthalmic lens and diffractive multifocal ophthalmic lens
WO2013093916A1 (en) Optical lens with halo reduction
JP2023509811A (en) New generation ophthalmic multifocal lens
RU2804912C1 (en) Ophthalmic multifocal lens and a method of its manufacturing
Trindade et al. Optical parameters and charts
WO2022039682A1 (en) A zonal diffractive ocular lens
WO2022039683A1 (en) A zonal diffractive ocular lens
Ravikumar Effect of optical aberrations on image quality and visual performance

Legal Events

Date Code Title Description
ENP Entry into the national phase

Ref document number: 2014525250

Country of ref document: JP

Kind code of ref document: A

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12890011

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12890011

Country of ref document: EP

Kind code of ref document: A1