WO2019022078A1 - Illumination device - Google Patents

Illumination device Download PDF

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Publication number
WO2019022078A1
WO2019022078A1 PCT/JP2018/027715 JP2018027715W WO2019022078A1 WO 2019022078 A1 WO2019022078 A1 WO 2019022078A1 JP 2018027715 W JP2018027715 W JP 2018027715W WO 2019022078 A1 WO2019022078 A1 WO 2019022078A1
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WO
WIPO (PCT)
Prior art keywords
light
diffractive optical
lens
optical element
projection
Prior art date
Application number
PCT/JP2018/027715
Other languages
French (fr)
Japanese (ja)
Inventor
牧夫 倉重
俊平 西尾
Original Assignee
大日本印刷株式会社
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 大日本印刷株式会社 filed Critical 大日本印刷株式会社
Priority to JP2019500523A priority Critical patent/JP6508580B1/en
Priority to CN201880046183.7A priority patent/CN110869666B/en
Publication of WO2019022078A1 publication Critical patent/WO2019022078A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
    • F21S41/10—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source
    • F21S41/14—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source characterised by the type of light source
    • F21S41/16—Laser light sources
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S8/00—Lighting devices intended for fixed installation
    • F21S8/08—Lighting devices intended for fixed installation with a standard
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V9/00—Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/18—Diffraction gratings

Definitions

  • the present disclosure relates to a lighting device.
  • an illumination apparatus including a light source and a hologram element is known.
  • the hologram element diffracts the light from the light source, it can project light in a specific direction to illuminate a projection surface such as a road surface.
  • the projection plane can be divided into a plurality of regions by illuminating the projection plane with a plurality of linear patterns extending in a plurality of directions.
  • the embodiment of the present disclosure is made in consideration of the above points, and aims to provide a lighting device capable of projecting light in a plurality of directions.
  • a lighting device is A light source for emitting light, A diffractive optical element that diffracts the light emitted from the light source; And a projection optical system that reflects or refracts the light diffracted by the diffractive optical element and directs it to a projection surface.
  • the projection optical system directs one part of the first-order diffracted light diffracted by the diffractive optical element and the other part in different directions.
  • the diffractive optical element includes: a first element diffractive optical element that diffracts a part of the light emitted from the light source; and a second element diffractive optical element that diffracts another part of the light emitted from the light source.
  • the projection optical system includes: first diffracted light which is first order diffracted light diffracted by the first element diffractive optical element; and second diffracted light which is first order diffracted light diffracted by the second element diffractive optical element; May be directed in different directions.
  • the projection optical system may be a reflective element or a prism.
  • the projection optical system includes a half mirror that reflects a part of first-order diffracted light diffracted by the diffractive optical element and transmits another part; And a reflective element for reflecting another part of the transmitted first-order diffracted light.
  • the projection optical system may be a projection diffractive optical element that diffracts light diffracted by the diffractive optical element.
  • the diffractive optical element includes: a first element diffractive optical element that diffracts a part of the light emitted from the light source; and a second element diffractive optical element that diffracts another part of the light emitted from the light source.
  • the projection diffractive optical element is a first projection element diffractive optical element that diffracts first diffraction light, which is first-order diffraction light that is diffracted by the first element diffractive optical element, and directs the first diffraction light in a first direction; And a second projection element diffractive optical element for diffracting second diffracted light, which is first-order diffracted light diffracted by the two-element diffractive optical element, and directing it to a second direction different from the first direction; It is also good.
  • the illumination device may further include a collimator lens disposed between the light source along the optical path from the light source to the diffractive optical element and the diffractive optical element.
  • the projection optical system changes the traveling direction of a part of first-order diffracted light diffracted by the diffractive optical element by an angle exceeding 90 °, and the diffractive optical system The traveling direction of another portion of the first-order diffracted light diffracted by the element may be changed at an angle of more than 90 °.
  • the lighting device according to an embodiment of the present disclosure may be housed in a tubular housing.
  • the housing may be rotatably disposed.
  • the lighting device according to an embodiment of the present disclosure may be rotatably supported.
  • the projection optical system may be rotatably supported.
  • the diffractive optical element may be rotatably supported.
  • a lighting device is: A first lens disposed between the diffractive optical element along the optical path from the diffractive optical element to the projection optical system and the projection optical system, wherein a focal distance of the first lens from the diffractive optical element A first lens spaced apart by A second lens disposed between the first lens along the optical path from the first lens to the projection optical system and the projection optical system, wherein a focal distance of the first lens to the first lens And a second lens disposed spaced apart by the sum of the focal length of the second lens and the second lens, A zero-order light mask disposed between the first lens and the second lens along the optical path from the first lens to the second lens, for blocking zero-order light in the diffractive optical element; It may further be provided.
  • a lighting device is: A first lens disposed between the diffractive optical element along the optical path from the diffractive optical element to the projection optical system and the projection optical system, wherein a focal distance of the first lens from the diffractive optical element A first lens spaced apart by A second lens disposed between the first lens along the optical path from the first lens to the projection optical system and the projection optical system, wherein a focal distance of the first lens to the first lens And a second lens disposed spaced apart by the sum of the focal length of the second lens and the second lens, A high-order diffracted light mask disposed between the first lens and the second lens along the optical path from the first lens to the second lens, which blocks high-order diffracted light from the diffractive optical element; It may further be provided.
  • the projection optical system reflects or refracts a part and another part of the first-order diffracted light diffracted by the diffractive optical element, and directs them to a first illuminated area and a second illuminated area of the projection surface, respectively.
  • the first illuminated area and the second illuminated area may extend along a straight line as a whole. Furthermore, in this case, the first illuminated area and the second illuminated area may extend in a straight line.
  • FIG. 1 is a view for explaining a first embodiment according to the present disclosure, and is a perspective view showing a lighting device.
  • FIG. 2 is a schematic diagram which shows an example of a structure of the illuminating device of FIG.
  • FIG. 3 is a view for explaining a modification of the lighting device shown in FIG. 2, which is based on the length of the area illuminated by the lighting device shown in FIG. 2 and the lighting device projecting light in a single direction It is a figure which shows the length of the area
  • FIG. 4 is a view showing another modified example of the illumination device shown in FIG.
  • FIG. 5 is a figure which shows the further another modification of the illuminating device shown in FIG. FIG.
  • FIG. 6 is a figure which shows the further another modification of the illuminating device shown in FIG.
  • FIG. 7 is a view showing still another modified example of the illumination device shown in FIG.
  • FIG. 8 is a view corresponding to FIG. 2 and showing still another modification of the illumination device shown in FIG.
  • FIG. 9 is a view showing a change of the illuminated area illuminated by the illumination device shown in FIG. 8, and a view of the illumination device and the projection plane shown in FIG. 8 from above.
  • FIG. 10 is a view corresponding to FIG. 2 and showing still another modification of the illumination device shown in FIG.
  • FIG. 11 is a view corresponding to FIG. 2 and showing still another modification of the illumination device shown in FIG.
  • FIG. 12 is a diagram corresponding to FIG. 2, and is a schematic diagram illustrating an example of a configuration of a lighting device according to a second embodiment of the present disclosure.
  • FIG. 1 is a perspective view showing an example of the illumination device 10 according to the first embodiment.
  • FIG. 2 is a schematic diagram which shows an example of a structure of the illuminating device 10 shown in FIG.
  • the illumination device 10 is installed on the ground or floor, and illuminates two different illumination areas Z1 and Z2 with the installation plane as a projection plane S. More specifically, the lighting apparatus 10 projects light in two different directions, and illuminates the first illuminated area Z1 and the second illuminated area Z2 in a linear pattern.
  • Such an illumination device 10 can be used, for example, when partitioning the projection plane S. That is, the illuminating device 10 can show the boundary line of the area
  • the illuminating device 10 may illuminate the to-be-illuminated area
  • the illuminating device 10 may illuminate the to-be-illuminated area
  • the illumination device 10 is diffracted by the light source 15 that emits light, the diffractive optical element 40 that diffracts the light emitted from the light source 15, and the diffractive optical element 40 And a projection optical system 50 for reflecting or refracting light and directing it to the projection surface S.
  • the illumination device 10 further includes a shaping optical system 30 including a collimating lens 32 between the light source 15 and the diffractive optical element 40.
  • the lighting device 10 is housed in a cylindrical housing 60 so as to be able to stand on the projection surface S.
  • the housing 60 in the housing 60, the light source 15, the diffractive optical element 40, and the projection optical system 50 are aligned in a direction substantially perpendicular to the projection surface S.
  • the housing 60 is provided with an opening 61 for transmitting light reflected or refracted by the projection optical system 50.
  • each component of the illuminating device 10 will be described in order.
  • the light source 15 can use various types of light sources.
  • a light source emitting coherent light for example, a laser light source can be used as the light source 15.
  • the coherent light emitted from the light source 15 is excellent in straightness, and is suitable as light for illuminating the illumination regions Z1 and Z2 with high accuracy.
  • the lighting device 10 has a single light source 15, but may have a plurality of light sources 15.
  • the shaping optical system 30 is disposed between the light source 15 along the optical path from the light source 15 to the diffractive optical element 40 and the diffractive optical element 40.
  • the shaping optical system 30 shapes the light emitted from the light source 15.
  • the shaping optical system 30 shapes the shape of the cross section orthogonal to the optical axis x of the light emitted from the light source 15 and the three-dimensional shape of the light flux of the light.
  • the shaping optical system 30 shapes the light emitted from the light source 15 into a spread parallel light flux.
  • the shaping optical system 30 has a lens 31 and a collimating lens 32 in the order along the optical path of the light emitted from the light source 15.
  • the lens 31 shapes the light emitted from the light source 15 into a divergent light beam.
  • the collimating lens 32 reshapes the divergent light flux generated by the lens 31 into a parallel light flux.
  • a plurality of shaping optical systems may be provided corresponding to each of the plurality of light sources.
  • the diffractive optical element 40 is an element that exerts a diffractive action on the light emitted from the light source 15.
  • the illustrated diffractive optical element 40 diffracts the light from the light source 15 and directs it to the projection optical system 50.
  • the diffractive optical element 40 includes a first element diffractive optical element 41 and a second element diffractive optical element 42.
  • the first element diffractive optical element 41 diffracts a part of the light from the collimating lens 32 and directs it to the projection optical system 50.
  • the second element diffractive optical element 42 diffracts another part of the light from the collimating lens 32 and directs it to the projection optical system 50.
  • each element diffractive optical element 41, 42 is configured as a hologram recording medium on which an interference fringe pattern is recorded.
  • the traveling direction of the light diffracted by each element diffractive optical element 41, 42 in other words, the traveling direction of the light diffused by each element diffractive optical element 41, 42, is controlled can do.
  • Each element diffractive optical element 41 and 42 can be produced, for example, using scattered light from a real scattering plate as object light. More specifically, when the hologram photosensitive material that is the base of the element diffractive optical elements 41 and 42 is irradiated with the reference light and the object light that are coherent light having interference with each other, interference fringes due to the interference of these lights are The element diffractive optical elements 41 and 42 are manufactured by forming the hologram photosensitive material.
  • the reference light laser light which is coherent light is used.
  • the object light for example, scattered light from an isotropic scattering plate which can be obtained inexpensively is used.
  • the element diffractive optical elements 41 and 42 are formed by irradiating the element diffractive optical elements 41 and 42 with laser light so that the optical paths of the reference beams used when producing the element diffractive optical elements 41 and 42 are reversed.
  • a reproduction image of the scattering plate is generated at the arrangement position of the scattering plate which is the source of the object light used in fabrication. If the scattering plate which is the source of the object light used when producing the element diffractive optical elements 41 and 42 performs uniform surface scattering, the reproduced image of the scattering plate obtained by the element diffractive optical elements 41 and 42 Even, it will be a uniform surface illumination.
  • the wavelength and incident direction of the planned reproduction illumination light, and reproduction It is possible to design using a computer based on the shape, position, etc. of the image to be done.
  • the element diffractive optical elements 41 and 42 obtained in this manner are also called computer generated holograms (CGH).
  • Fourier transform holograms may be formed by computer synthesis in which diffusion angle characteristics at respective points on the element diffractive optical elements 41 and 42 are the same.
  • a specific form of the element diffractive optical elements 41 and 42 may be a volume type hologram recording medium using a photopolymer, or a volume type hologram recording medium of a type recording using a photosensitive medium containing a silver salt material. It may be a hologram recording medium of relief type (emboss type).
  • the element diffractive optical elements 41 and 42 may be transmissive or reflective.
  • a plurality of diffractive optical elements may be provided corresponding to each of the plurality of light sources.
  • the projection optical system 50 reflects or refracts the light diffracted by the diffractive optical element 40 to direct it to the projection surface S (in the illustrated example, the installation surface). More specifically, the projection optical system 50 is diffracted by the first-order diffracted light (hereinafter also referred to as “first diffracted light”) L11 diffracted by the first element diffractive optical element 41 and the second element diffractive optical element 42.
  • first diffracted light hereinafter also referred to as “second diffracted light” L12 is directed in different directions.
  • second-order or higher-order diffracted light is a diffracted light as the diffracted light in addition to the first-order diffracted lights L11 and L12. It occurs.
  • the projection optical system 50 directs at least first-order diffracted lights L11 and L12 of the diffracted lights entering the projection optical system 50 in directions different from each other.
  • the projection optical system 50 is a reflective element having a reflective surface that reflects light.
  • the projection optical system 50 is made of a material having a high reflectance, such as metal, at least on its reflection surface.
  • at least the reflection surface of the projection optical system 50 is made of silver and has a specular reflection function.
  • the projection optical system 50 has different directions of the first diffracted light L11 diffracted by the first element diffractive optical element 41 and the second diffracted light L12 diffracted by the second element diffractive optical element 42.
  • the projection optical system 50 is configured as a so-called polygon mirror having a plurality of reflecting surfaces. More specifically, the projection optical system 50 has a triangular prism shape as a whole, and two of its three side surfaces form a reflecting surface. Then, one of the two reflecting surfaces is the first reflecting surface 51 on which the first diffracted light L11 is incident, and directs the first diffracted light L11 in the first direction.
  • the other reflecting surface is the second reflecting surface 52 on which the second diffracted light L12 is incident, and directs the second diffracted light L12 in a second direction different from the first direction.
  • the projection optical system 50 capable of directing the first diffracted light L11 and the second diffracted light L12 in different directions, various types such as a concave mirror, a convex mirror, a plane mirror, a prism, etc. can be adopted besides the polygon mirror. It is.
  • the direction of the first reflection surface 51 changes the traveling direction of the first diffracted light L11 at an angle exceeding 90 °, and the first diffracted light L11 is converted to the first object on the projection surface S. It is set to be directed to the illumination area Z1.
  • the direction of the second reflection surface 52 changes the traveling direction of the second diffracted light L12 at an angle exceeding 90 °, and the second diffracted light L12 is directed to the second illumination region Z2 on the projection surface S. It is set to.
  • the light emitted from the light source 15 first enters the shaping optical system 30.
  • the shaping optical system 30 magnifies the light emitted from the light source 15. That is, the shaping optical system 30 shapes the light from the light source 15 so that the area occupied by the light is expanded in the cross section orthogonal to the optical axis x.
  • the shaping optical system 30 includes a lens 31 and a collimating lens 32. As shown in FIG. 2, the lens 31 of the shaping optical system 30 diverges the light emitted from the light source 15 and converts it into a divergent light beam. Then, the collimating lens 32 of the shaping optical system 30 collimates the divergent light flux into a parallel light flux.
  • the light shaped by the shaping optical system 30 then travels to the diffractive optical element 40.
  • the element diffractive optical elements 41 and 42 of the diffractive optical element 40 record interference fringes corresponding to the central wavelength of the light emitted from the light source 15, and the light incident from a certain direction has high efficiency in the desired direction. It can be diffracted.
  • the first element diffractive optical element 41 diffracts part of the light emitted from the light source 15 and diffuses the diffracted light toward the projection optical system 50.
  • the second element diffractive optical element 42 diffracts another part of the light emitted from the light source 15 and diffuses the diffracted light toward the projection optical system 50.
  • the light incident on the reflection surfaces 51 and 52 of the projection optical system 50 is reflected to change its traveling direction.
  • the first diffracted light L11 incident on the first reflection surface 51 is reflected to change its traveling direction at an angle of more than 90 °.
  • the first diffracted light L11 reflected by the first reflection surface 51 passes through the opening 61 provided in the cylindrical casing 60, and is incident on the first illumination area Z1 on the projection surface S.
  • the second diffracted light L12 incident on the second reflection surface 52 is reflected to change its traveling direction at an angle of more than 90 °.
  • the second diffracted light L12 reflected by the second reflection surface 52 travels in a direction different from that of the first diffracted light L11 reflected by the first reflection surface 51.
  • the second diffracted light L12 passes through the opening 61 provided in the cylindrical casing 60, and is incident on the second illumination area Z2 different from the first illumination area Z1 on the projection surface S.
  • the first illuminated area Z1 and the second illuminated area Z2 are illuminated in a line pattern extending in different directions from the illumination device 10.
  • the illumination device 10 includes the light source 15 for emitting light, the diffractive optical element 40 for diffracting the light emitted from the light source 15, and the light diffracted by the diffractive optical element 40. And a projection optical system 50 for reflecting or refracting the light toward the projection surface S. Then, the projection optical system 50 directs one portion L11 of the first-order diffracted light diffracted by the diffractive optical element 40 and the other portion L12 in different directions.
  • Such an illumination device 10 can project light in a plurality of directions to illuminate a plurality of illumination target areas Z1 and Z2.
  • the diffractive optical element 40 diffracts the first element diffractive optical element 41 that diffracts part of the light emitted from the light source 15 and the other part of the light emitted from the light source 15 And a second element diffractive optical element 42.
  • the projection optical system 50 includes a first diffracted light L11 which is a first-order diffracted light diffracted by the first element diffractive optical element 41 and a second diffracted light which is a first-order diffracted light diffracted by the second element diffractive optical element 42.
  • the light L12 is directed in different directions. According to such an illumination device 10, it is easy to illuminate each of the plurality of illumination regions Z1 and Z2 with a desired pattern with high accuracy.
  • the projection optical system 50 is a reflective element or a prism. In this case, it is easy to realize the projection optical system 50 that reflects or refracts the first diffracted light L11 and the second diffracted light L12 and directs them in different directions.
  • the collimator lens 32 disposed between the light source 15 along the optical path from the light source 15 to the diffractive optical element 40 and the diffractive optical element 40 is further provided.
  • the collimated light is incident on the diffractive optical element 40, so that it is easy to diffract the first diffracted light L11 and the second diffracted light L12 in the desired direction with high accuracy by the diffractive optical element 40.
  • the projection optical system 50 changes the traveling direction of the part L11 of the first-order diffracted light diffracted by the diffractive optical element 40 by an angle exceeding 90 °, and the diffractive optical element 40 The traveling direction of the other part L12 of the diffracted first-order diffracted light is changed at an angle of more than 90 °.
  • the illumination device 10 can illuminate the installation plane as the projection plane S.
  • the lighting device 10 is accommodated in a cylindrical case 60.
  • the illumination device 10 illuminates the first illuminated area Z1 and the second illuminated area Z2 extending in a straight line.
  • the areas illuminated with good clarity and bright pattern (therefore clean) by the light L11 illuminating the illuminated area Z1 and the light L12 illuminating the illuminated area Z2 are respectively points E11 shown in FIG. From the point E12 to the point E22. Therefore, the lighting apparatus 10 can be used to illuminate a region of length L10 from the point E12 on one side of the lighting apparatus 10 to the point E22 on the other side in a clear and bright pattern with good visibility.
  • the region illuminated with good visibility in a clear and bright pattern by the light L500 illuminating the light is a region of length L500 ranging from the point E51 to the point E52 shown in FIG.
  • the lighting device 10 can be used to illuminate a region of length L10 from the point E12 on one side of the lighting device 10 to the point E22 on the other side with a clear and bright pattern with good visibility.
  • the illumination device 500 can illuminate with a clear and bright pattern with high visibility only in the region of length L500 extending from the point E51 on one side of the illumination device 500 to the point E52.
  • the length L10 is significantly longer than the length L500. That is, the illumination device 10 can be used to illuminate longer regions in a clear and bright pattern with high visibility as compared to the illumination device 500.
  • the lighting device 10 in the case of illuminating a region having a length L10 longer than the above-mentioned length L500, if the lighting device 10 is disposed at the middle point of the region and light is projected from the middle point, the lighting device within the region It is possible to illuminate in a clear and bright pattern with good visibility to the points E12 and E22 farthest from 10.
  • the illumination device 10 illuminates the first illuminated area Z1 and the second illuminated area Z2 extending in a straight line.
  • the present invention is not limited to this. That is, the first illuminated area Z1 and the second illuminated area Z2 may not extend in a straight line.
  • the first illuminated area Z1 and the second illuminated area Z2 may extend in directions crossing each other, for example, an area Z1b and an area Z2a shown in FIG. 9 described later. Even in this case, if the first illuminated area Z1 and the second illuminated area Z2 extend along a straight line as a whole, the first illuminated area Z1 and the second illuminated area Z2 extend in a straight line. The same effect as in the case of
  • the projection optical system 50 reflects or refracts a part L11 and a part L12 of the first-order diffracted light diffracted by the diffractive optical element 40 to form the projection surface S respectively.
  • the light is directed to the first illuminated area Z1 and the second illuminated area Z2.
  • the first illuminated area Z1 and the second illuminated area Z2 extend along a straight line as a whole. Particularly in the illustrated example, the first illuminated area Z1 and the second illuminated area Z2 extend in a straight line.
  • the lighting device 10 can illuminate a region with a length L10 ranging from the point E12 on one side of the lighting device 10 to the point E22 on the other side with a clear and bright pattern with good visibility (therefore clean)
  • the illumination device 500 that illuminates only a single direction with a light source that emits light of a radiant flux similar to that of the light source 15 of the illumination device 10 illuminates in a clear and bright pattern with good visibility It is significantly longer than the possible region length L500.
  • the diffractive optical element 40 has the two element diffractive optical elements 41 and 42 and the illumination device 10 illuminates the two illumination areas Z1 and Z2. It is not limited to.
  • the diffractive optical element may have three or more element diffractive optical elements.
  • the lighting device may project light in three or more directions to illuminate three or more illuminated areas.
  • the illuminating device 100 shown in FIG. 4 projects light in three directions to illuminate the three illumination regions Z1, Z2, and Z3.
  • the diffractive optical element 140 has three element diffractive optical elements 41, 42 and 43, and the projection optical system 150 has three reflective surfaces 51, 52 and 53. There is.
  • the other configuration is substantially the same as the illumination device 10 shown in FIG. In FIG. 3, the casing 60 is omitted to facilitate understanding.
  • the diffractive optical element 140 has a third element diffractive optical element 43 in addition to the first element diffractive optical element 41 and the second element diffractive optical element 42. Similar to the other element diffractive optical elements 41 and 42, the third element diffractive optical element 43 is configured as, for example, a hologram recording medium on which an interference fringe pattern is recorded.
  • the first element diffractive optical element 41 diffracts part of the light from the collimator lens 32 and directs it to the projection optical system 150.
  • the second element diffractive optical element 42 diffracts another part of the light and directs it to the projection optical system 150.
  • the third element diffractive optical element 43 diffracts another portion of the light and directs it to the projection optical system 150.
  • the projection optical system 150 has a third reflection surface 53 in addition to the first reflection surface 51 and the second reflection surface 52.
  • the projection optical system 150 has a triangular pyramid shape. And three surfaces other than the bottom have a reflective function, and have constituted the reflective surfaces 51, 52, and 53, respectively.
  • the third reflection surface 53 is a first-order diffracted light (hereinafter also referred to as “third diffracted light”) L13 diffracted by the third element diffractive optical element 43, whichever of the first diffracted light L11 and the second diffracted light L12. Also turn in a different third direction.
  • the third reflection surface 53 changes the traveling direction of the third diffracted light L13 at an angle exceeding 90 °, and directs the third diffracted light L13 to the third illuminated region Z3 on the projection surface S.
  • various shapes such as conical shape, are employable besides pyramid shape.
  • ⁇ Modification 3> In the first embodiment described above, the case where the illumination device 10 is installed on the projection surface S has been described. However, for example, when it is desired to make the illumination device 10 appear smaller, a portion of the illumination device 10 may be disposed below the projection surface S, ie, in the ground or floor, as shown in FIG. Moreover, when making a water surface into the projection surface S, the one part of the illuminating device 10 may be arrange
  • ⁇ Modification 4> In the first embodiment described above, the case where the lighting device 10 is installed on the ground or floor has been described, but is not limited thereto.
  • the lighting device 10 can be used in various fields, for example, as a lighting device for moving objects such as cars and ships.
  • the lighting device 10 is installed in the vehicle C, and projects light in two directions, the front lower right of the vehicle C and the front lower left of the vehicle C. Then, the lighting device 10 illuminates the first illuminated area Z1 located on the right front of the vehicle C and the second illuminated area Z2 located on the left front.
  • the lighting device 10 is installed in the vehicle C, and light is provided in two directions which are both in front of and below the vehicle C but have different angles with respect to the ground or floor which is the projection surface S. Project Then, the lighting device 10 illuminates the near-field illuminated region of the vehicle C and the far-field illuminated region.
  • the illumination device 10 shown in FIGS. 6 and 7 has a light source 15, a shaping optical system 30, a diffractive optical element 40 including a plurality of element diffractive optical elements, and projection optics, as in the illumination device described above. And a system 50.
  • the projection optical system 50 is formed of a prism. This prism inclines with respect to the first prism surface 51a that changes the optical path of the first diffracted light L11 by refraction, and the first prism surface 51a, and refracts the optical path of the second diffracted light L12 by refracting the optical path of the first diffracted light L11. And a second prism surface 52a directed in a direction different from the light path.
  • the projection optical system may be a projection diffractive optical element that exerts a diffractive action on the first-order diffracted light diffracted by the diffractive optical element 40.
  • the illumination device 200 shown in FIG. 8 differs from the illumination device 10 shown in FIG. 2 in that the projection optical system is a projection diffractive optical element 250.
  • the projection diffractive optical element 250 is configured as a hologram recording medium on which an interference fringe pattern is recorded. By adjusting the interference fringe pattern variously, it is possible to control the traveling direction of the light diffracted by the projection diffractive optical element 250, in other words, the traveling direction of the light diffused by the projection diffractive optical element 250. .
  • the projection diffractive optical element 250 can be manufactured in the same manner as the element diffractive optical elements 41 and 42 of the diffractive optical element 40.
  • the projection diffractive optical element 250 includes a first projection diffraction region 251 on which the first diffracted light L11 that is first-order diffracted light diffracted by the first element diffractive optical element 41 is incident; And a second projection diffraction region 252 on which the second diffracted light L12 that is the first-order diffracted light diffracted by the element diffractive optical element 42 is incident. Then, the projection diffractive optical element 250 directs the first diffracted light L11 from the first element diffractive optical element 41 in a direction according to the diffraction characteristic of the first projection diffraction region 251. Further, the projection diffractive optical element 250 directs the second diffracted light L12 from the second element diffractive optical element 42 in a direction according to the diffraction characteristic of the second projection diffraction area 252.
  • the first projection diffraction region 251 diffracts the first diffracted light L11 from the first element diffractive optical element 41 and directs it to the first illuminated region Z1.
  • the second projection diffraction area 252 diffracts the second diffracted light L12 from the second element diffractive optical element 42 and directs it to the second illumination area Z2.
  • the illuminated areas Z1 and Z2 illuminated by the illumination device 200 become areas according to the diffraction characteristics of the projection diffractive optical element 250. Therefore, by replacing the projection diffractive optical element 250 with another projection diffractive optical element having a diffraction characteristic different from that of the projection diffractive optical element 250, the illuminated regions Z1 and Z2 are illuminated by the illumination device 200. For example, the illumination areas Z1a and Z2a shown in FIG. 9 can be changed to illumination areas Z1b and Z2b.
  • the projection optical system 250 is a projection diffractive optical element that diffracts the lights L11 and L12 diffracted by the diffractive optical element 40.
  • the projection diffractive optical element 250 by replacing the projection diffractive optical element 250 with another projection diffractive optical element having a diffraction characteristic different from that of the projection diffractive optical element 250, the illuminated area Z1, which is illuminated by the illumination device 200. Z2 can be changed.
  • the portion of the first projection diffraction region 251 of the projection diffractive optical element 250 and the portion of the second projection diffraction region 252 are configured separately. More specifically, the projection diffractive optical element 250 includes the first projection element diffractive optical element 253 on which the first-order diffracted light diffracted by the first element diffractive optical element 41 is incident, and the second element diffractive optical element 42. And a second projection element diffractive optical element 254 on which the diffracted first-order diffracted light is incident.
  • the first projection element diffractive optical element 253 diffracts the first diffracted light L11, which is the first-order diffracted light from the first element diffractive optical element 41, and more specifically the first illuminated light in the first direction. Aim at area Z1.
  • the second projection element diffractive optical element 254 diffracts the second diffracted light L12, which is the first-order diffracted light from the second element diffractive optical element 42, to a second direction different from the first direction. More specifically, the light is directed to the second illuminated area Z2.
  • one of the first and second projection element diffractive optical elements 253 and 254 is different from the projection element diffractive optical elements 253 and 254.
  • one of the first and second illuminated areas Z1 and Z2 is switched from the illuminated area Z1a shown in FIG. 9 to the illuminated area Z1b, for example, Alternatively, the illumination area Z2a can be changed to the illumination area Z2b.
  • the diffractive optical element 40 includes the first element diffractive optical element 41 that diffracts a part of the light emitted from the light source 15 and the other part of the light emitted from the light source 15 And a second element diffractive optical element 41 that diffracts.
  • the projection diffractive optical element 250 diffracts the first diffracted light L11 which is the first-order diffracted light diffracted by the first element diffractive optical element 41 and directs it in the first direction.
  • any one of the first and second projection element diffractive optical elements 253 and 254 is replaced with another projection element diffractive optical element having diffraction characteristics different from those of the projection element diffractive optical elements 253 and 254.
  • only one of the first and second illumination areas Z1 and Z2 can be changed.
  • the diffractive optical element 40 includes a plurality of element diffractive optical elements has been described in the first embodiment and the first to sixth modifications described above, the present invention is not limited to this.
  • the diffractive optical element 40 may be composed of a single element diffractive optical element.
  • the illumination device 300 shown in FIG. 11 is different from the illumination device shown in FIG. 2 in that the diffractive optical element 40 is configured of a single element diffractive optical element. Further, the projection optical system 350 is different in that it includes a half mirror 351 and a reflecting element 352.
  • the diffractive optical element 40 diffracts all of the light emitted from the light source 15.
  • the half mirror 351 and the reflection element 352 of the projection optical system 350 are disposed on the optical path of the first-order diffracted light L1 diffracted by the diffractive optical element 40.
  • the half mirror 351 is disposed between the diffractive optical element 40 and the reflective element 352 along the optical path from the diffractive optical element 40 to the reflective element 352.
  • the half mirror 351 reflects a portion L11 of the first-order diffracted light L1 diffracted by the diffractive optical element 340, directs it in the first direction, and transmits the other portion L12.
  • the reflective element 352 reflects the other part L12 of the first order diffracted light L1 transmitted through the half mirror 351 and directs it in the second direction.
  • the light L11 reflected by the half mirror 351 is directed to the first illuminated area Z1
  • the light L12 reflected by the reflecting element 352 is directed to the second illuminated area Z2.
  • the diffractive optical element 40 is configured of a single element diffractive optical element, but is not limited thereto. Similar to the example shown in FIG. 2, the diffractive optical element 40 may include a plurality of element diffractive optical elements 41 and 42.
  • the projection optical system 350 includes the half mirror 351 that reflects a part L11 of the first-order diffracted light L1 diffracted by the diffractive optical element 40 and transmits the other part L12. And a reflective element 352 for reflecting another portion L12 of the first-order diffracted light L1 transmitted through the mirror 351.
  • the projection optical system 350 directs one portion L11 of the first-order diffracted light L1 diffracted by the diffractive optical element 40 and the other portion L12 in different directions. Therefore, the lighting device 300 can project light in a plurality of directions to illuminate the plurality of illumination target areas Z1 and Z2.
  • the housing 60 containing the lighting devices 10, 100, 200, and 300 is rotatably disposed by mounting the housing 60 on a rotatable pedestal or the like, and the lighting device 10, 100, 200, The illumination area may be moved by Z1, Z2, and Z3 by rotating along with 300.
  • the illumination devices 10, 100, 200, and 300 in the housing 60 are rotatably supported, and the illumination devices 10, 100, 200, and 300 are rotated to move the illumination regions Z1, Z2, and Z3.
  • the illumination regions Z1, Z2, and Z3 may be moved by rotatably supporting the diffractive optical elements 40 and 140 and rotating the diffractive optical elements 40 and 140.
  • the projection optical systems 50, 150, 250, and 350 may be rotatably supported, and the projection optical systems 50, 150, 250, and 350 may be rotated to move the illumination regions Z1, Z2, and Z3.
  • the diffractive optical elements 40 and 140 and the projection optical systems 50, 150, 250, and 350 are rotatably supported, and the projection optical systems 50, 150, 250, and 350 are rotated together with the diffractive optical elements 40 and 140.
  • the illumination areas Z1, Z2, and Z3 may be moved.
  • a part of light from the light source is transmitted through the diffractive optical element without being diffracted by the diffractive optical element, and becomes so-called zero-order light. If such zero-order light is reflected or refracted by the projection optical system, it may cause safety problems such as penetration into the eyes of the observer.
  • zero-order light is incident on the illuminated area, abnormal areas such as a dotted area, a linear area, and a planar area where the brightness (brightness) rises sharply compared to the surroundings are the illuminated area It will occur inside.
  • an element diffractive optical element such as a hologram element
  • second-order or higher-order diffracted light is generated as the diffracted light in addition to the first-order diffracted light.
  • the high-order diffracted light is reflected or refracted by the projection optical system, it may cause safety problems such as penetration into the eyes of the observer.
  • the high-order diffracted light is projected onto the projection plane, a region other than the region to be illuminated is also illuminated, which may cause problems such as difficulty in recognizing the region to be illuminated.
  • the illumination device 400 of the second embodiment will be described in more detail.
  • the illumination device 400 shown in FIG. 12 is different from the illumination device 10 shown in FIG. 1 in that the first lens 71, the second lens 72, the zeroth-order light mask 81, and the diffractive optical element 40 and the projection optical system 50.
  • the only difference is that the high-order diffraction light mask 82 is disposed, and the other configuration is substantially the same as the illumination device 10 shown in FIGS. 1 and 2.
  • the first lens 71 and the second lens 72 are disposed between the diffractive optical element 40 and the projection optical system 50 along the optical path from the diffractive optical element 40 to the projection optical system 50. More specifically, the diffractive optical element 40, the projection optical system 50, the first lens 71, and the second lens 72 are disposed as follows.
  • the first lens 71 is separated between the diffractive optical element 40 and the projection optical system 50 along the optical path from the diffractive optical element 40 to the projection optical system 50 by the focal distance f1 of the first lens 71 from the diffractive optical element 40 It is arranged.
  • the second lens 72 is disposed between the first lens 71 and the projection optical system 50 along the optical path from the first lens 71 to the projection optical system 50.
  • the second lens 72 is spaced from the first lens 71 by the sum of the focal length f1 of the first lens 71 and the focal length f2 of the second lens 72.
  • the distance between the second lens 72 and the projection optical system 50 is not particularly limited. In the example shown in FIG.
  • the second lens 72 is disposed apart from the incident position of the first diffracted light L11 and the second diffracted light L12 in the projection optical system 50 by the focal distance f2 of the second lens 72.
  • the distance between the second lens 72 and the projection optical system 50 may be larger or smaller than the focal length f2.
  • the 4f optical system is formed by the first lens 71, the second lens 72, and the diffractive optical element 40.
  • the first lens 71 sets the zeroth-order light L01 transmitted through the first element diffractive optical element 41 and the zeroth-order light L02 transmitted through the second element diffractive optical element 42 to a point a on the focal plane P of the first lens 71. Turn. The first lens 71 also advances the 0th-order light L01 that has passed through the first lens 71 in the traveling direction of the first-order diffracted light (first diffracted light) L11 and the high-order diffracted light L21 of the first element diffractive optical element 41. Change the direction parallel to the direction.
  • the first lens 71 also advances the 0th-order light L02 that has passed through the first lens 71 in the direction of travel of the first-order diffracted light (second diffracted light) L12 and the high-order diffracted light L22 at the second element diffractive optical element 42. Change the direction parallel to the direction.
  • the incident positions of the zero-order light L01, L02, the first-order diffracted lights L11, L12 and the high-order diffracted lights L21, L22 on the focal plane P are the area around point a and point a, respectively. , It will be summarized in the outer region of the peripheral region.
  • the second lens 72 directs, to the projection optical system 50, light which has passed through a region between a zero-order light mask 81 and a high-order diffracted light mask 82 described later, that is, first diffracted light L11 and second diffracted light L12. Focus.
  • the zero-order light mask 81 is disposed between the first lens 71 and the second lens 72 along the optical path from the first lens 71 to the second lens 72.
  • the zero-order light mask 81 is disposed on the focal plane P of the first lens 71 at a distance from the first lens 71 by the focal length f 1 of the first lens 71.
  • the 0th-order light mask 81 overlaps with the position a of the focal plane P where the 0th-order light L01, L02 is incident, but is disposed at a position not overlapping with the 1st-order diffracted light L11, L12 and the high-order diffracted light L21, L22. Be done.
  • the 0th-order light mask 81 can block only the 0th-order lights L01 and L02 among the diffracted lights in the diffractive optical element 40.
  • the high-order diffracted light mask 82 is also disposed on the same plane as the zero-order light mask 81. That is, the high-order diffraction light mask 82 is disposed between the first lens 71 and the second lens 72 along the optical path from the first lens 71 to the second lens 72. The high-order diffracted light mask 82 is disposed on the focal plane P of the first lens 71 at a distance from the first lens 71 by the focal length f 1 of the first lens 71.
  • the high-order diffracted light mask 82 overlaps the position where the high-order diffracted light L21, L22 on the focal plane P is incident, but is disposed at a position not overlapping the position where the zero-order diffracted light L01, L02 and the first-order diffracted light L11, L12 are incident. Ru.
  • the high-order diffracted light mask 82 can block only the high-order diffracted lights L21 and L22 among the diffracted lights in the diffractive optical element 40.
  • the zero-order light mask 81 and the high-order diffracted light mask 82 are plate-like members that absorb the zero-order lights L01 and L02 and the high-order diffracted lights L21 and L22, respectively.
  • the zero-order light mask 81 and the high-order diffracted light mask 82 may direct the zero-order lights L01 and L02 and the high-order diffracted lights L21 and L22 to other than the projection optical system 50, respectively.
  • the light emitted from the light source 15 first enters the shaping optical system 30.
  • the shaping optical system 30 magnifies the light emitted from the light source 15.
  • the light shaped by the shaping optical system 30 then travels to the diffractive optical element 40.
  • the first element diffractive optical element 41 diffracts part of the light emitted from the light source 15.
  • the second element diffractive optical element 42 diffracts another part of the light emitted from the light source 15.
  • the light diffracted by the diffractive optical element 40 then travels to the first lens 71. Further, the zeroth-order lights L 01 and L 02 transmitted through the element diffractive optical elements 41 and 42 also travel to the first lens 71.
  • the first lens 71 directs zero-order light L01 and L02 to a point a on the focal plane P of the first lens 71.
  • the first-order diffracted light L11 and the high-order diffracted light L21 from the first element diffractive optical element 41 are directed in a direction parallel to the traveling direction of the zero-order light L01.
  • the first-order diffracted light L12 and the high-order diffracted light L22 in the second element diffractive optical element 42 are directed in the direction parallel to the traveling direction of the zero-order light L02.
  • zero-order light L 01 and L 02 are incident on the zero-order light mask 81.
  • the high-order diffracted lights L21 and L22 enter the high-order diffracted light mask 82.
  • the first-order diffracted lights (first and second diffracted lights) L11 and L12 pass through the region between the zero-order light mask 81 and the high-order diffracted light mask 82, and the second traveling direction is maintained. The light is incident on the lens 72.
  • the first diffracted light L11 and the second diffracted light L12 incident on the second lens 72 are condensed toward a point on the first reflection surface 51 of the projection optical system 50 and a point on the second reflection surface 52, respectively. .
  • the first diffracted light L11 incident on the first reflection surface 51 is reflected to change its traveling direction at an angle of more than 90 °. Then, the first diffracted light L11 reflected by the first reflection surface 51 passes through the opening 61 provided in the cylindrical casing 60, and is incident on the first illumination area Z1 on the projection surface S. In addition, the second diffracted light L12 incident on the second reflection surface 52 is reflected to change its traveling direction at an angle of more than 90 °. At this time, the second diffracted light L12 reflected by the second reflection surface 52 travels in a direction different from that of the first diffracted light L11 reflected by the first reflection surface 51.
  • the second diffracted light L12 reflected by the second reflection surface 52 passes through the opening 61 provided in the cylindrical casing 60, and the second diffracted light L12 is different from the first illumination area Z1 on the projection surface S.
  • the light is incident on the illuminated area Z2.
  • the illumination device 400 is disposed between the diffractive optical element 40 and the projection optical system 50 along the optical path from the diffractive optical element 40 to the projection optical system 50.
  • the first lens 71 is a single lens 71 and is separated from the diffractive optical element 40 by the focal length f1 of the first lens 71, and the first along the optical path from the first lens 71 to the projection optical system 50
  • the second lens 72 is disposed between the lens 71 and the projection optical system 50, and is separated from the first lens 71 by the sum of the focal length f1 of the first lens 71 and the focal length f2 of the second lens 72.
  • the second lens 72 disposed between the first lens 71 and the second lens 72 along the optical path from the first lens 71 to the second lens 72, and the zeroth-order light by the diffractive optical element 40 0th order to shut off L01 and L02 Further comprising a mask 81, a.
  • an illumination device 400 it is possible to prevent the zeroth-order light L01 and L02 transmitted through the diffractive optical element 40 from being reflected or refracted by the projection optical system 50.
  • the 0th-order light L01 and L02 enter the eyes of the observer and cause a safety problem, or the 0th-order light enters the area to be illuminated, and the brightness (brightness) is abrupt compared to the surroundings.
  • the rising abnormal area is prevented from occurring in the illuminated area.
  • the first lens 71 is disposed apart from the diffractive optical element 40 by the above-described distance, zero-order light L01, L02, first-order diffracted light L11, L12 and high-order diffracted light L21, The path of L22 is adjusted, and it is easy to arrange the zero-order light mask 81 so as to block only the zero-order lights L01 and L02.
  • the second lens 72 is disposed apart from the first lens 71 by the above-described distance, the characteristics of the first diffracted light L11 and the second diffracted light L12 that have passed through the first lens 71 and the second lens 72 Can be determined according to the characteristics of the first diffracted light L11 and the second diffracted light L12 in the diffractive optical element 40. As a result, it is possible to illuminate the illuminated areas Z1 and Z2 with a desired pattern according to the diffraction characteristics of the diffractive optical element 40 (for example, the interference fringe pattern recorded in the element diffractive optical elements 41 and 42).
  • the illumination device 400 is disposed between the diffractive optical element 40 and the projection optical system 50 along the optical path from the diffractive optical element 40 to the projection optical system 50.
  • the first lens 71 is a first lens 71 disposed apart from the diffractive optical element 40 by the focal distance f1 of the first lens 71, and along the optical path from the first lens 71 to the projection optical system 50.
  • the second lens 72 is disposed between the first lens 71 and the projection optical system 50, and is the sum of the focal distance f1 of the first lens 71 to the first lens 71 and the focal distance f2 of the second lens 72.
  • Next-order diffracted light L21 and L22 And higher-order diffracted light mask 82 further comprising a.
  • an illumination device 400 it is possible to prevent the high-order diffracted lights L21 and L22 in the diffractive optical element 40 from being reflected or refracted by the projection optical system 50.
  • the high-order diffracted lights L21 and L22 enter the eyes of the observer and cause a safety problem, or the high-order diffracted lights L21 and L22 are projected on the projection surface S and the areas other than the illuminated areas Z1 and Z2 are also illuminated.
  • the illumination regions Z1 and Z2 from being difficult to recognize.
  • the first lens 71 is disposed apart from the diffractive optical element 40 by the above-described distance, zero-order light L01, L02, first-order diffracted light L11, L12 and high-order diffracted light L21, The path of L22 is adjusted, and it is easy to arrange the high-order diffracted light mask 82 so as to block only the high-order diffracted lights L21 and L22.
  • the second lens 72 is disposed apart from the first lens 71 by the above-described distance, the characteristics of the first diffracted light L11 and the second diffracted light L12 that have passed through the first lens 71 and the second lens 72 Can be determined according to the characteristics of the first diffracted light L11 and the second diffracted light L12 in the diffractive optical element 40.

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Abstract

An illumination device (10) comprises: a light source (15) that emits light; a diffraction optical element (40) that diffracts the light emitted from the light source (15); and a projection optical system (50) that reflects or refracts the light diffracted by the diffraction optical system (40) and directs such light to a projection surface S. The projection optical system (50) directs some rays of primary diffraction light diffracted by the diffraction optical element (40) and some other rays of the of primary diffraction light in different directions.

Description

照明装置Lighting device
　本開示は、照明装置に関する。 The present disclosure relates to a lighting device.
　例えば、特許文献１に開示されているように、光源とホログラム素子とを含んだ照明装置が知られている。特許文献１に開示された車両用照明装置は、ホログラム素子が光源からの光を回折することで、特定の方向へ光を投射して、路面などの投影面を照明することができる。 For example, as disclosed in Patent Document 1, an illumination apparatus including a light source and a hologram element is known. In the vehicle lighting device disclosed in Patent Document 1, when the hologram element diffracts the light from the light source, it can project light in a specific direction to illuminate a projection surface such as a road surface.
特開２０１２－１４６６２１号公報JP 2012-146621
　ところで、照明装置を用いて照明を行う場合、複数の方向に光を投射して複数の照明を同時に行いたい場合がある。複数の方向へ光を投射することができれば、例えば、複数の方向に延びる複数の線状のパターンで投影面を照明することによって、当該投影面を複数の領域に区画することができる。 By the way, when illuminating using an illuminating device, it may be desired to project light to a plurality of directions and to perform a plurality of illuminations simultaneously. If light can be projected in a plurality of directions, for example, the projection plane can be divided into a plurality of regions by illuminating the projection plane with a plurality of linear patterns extending in a plurality of directions.
　本開示の実施形態は、以上の点を考慮してなされたものであり、複数の方向に光を投射することが可能な照明装置を提供することを目的とする。 The embodiment of the present disclosure is made in consideration of the above points, and aims to provide a lighting device capable of projecting light in a plurality of directions.
　本開示の実施形態による照明装置は、
　光を射出する光源と、
　前記光源から射出した前記光を回折する回折光学素子と、
　前記回折光学素子によって回折された光を反射または屈折させて投影面に向ける投射光学系と、を備え、
　前記投射光学系は、前記回折光学素子で回折された１次回折光の一部と他の一部とを異なる方向に向ける。 A lighting device according to an embodiment of the present disclosure is
A light source for emitting light,
A diffractive optical element that diffracts the light emitted from the light source;
And a projection optical system that reflects or refracts the light diffracted by the diffractive optical element and directs it to a projection surface.
The projection optical system directs one part of the first-order diffracted light diffracted by the diffractive optical element and the other part in different directions.
　本開示の実施形態による照明装置において、
　前記回折光学素子は、前記光源から射出した前記光の一部を回折する第１要素回折光学素子と、前記光源から射出した前記光の他の一部を回折する第２要素回折光学素子と、を有し、
　前記投射光学系は、前記第１要素回折光学素子で回折された１次回折光である第１回折光と、前記第２要素回折光学素子で回折された１次回折光である第２回折光と、を異なる方向に向けてもよい。 In a lighting device according to an embodiment of the present disclosure,
The diffractive optical element includes: a first element diffractive optical element that diffracts a part of the light emitted from the light source; and a second element diffractive optical element that diffracts another part of the light emitted from the light source. Have
The projection optical system includes: first diffracted light which is first order diffracted light diffracted by the first element diffractive optical element; and second diffracted light which is first order diffracted light diffracted by the second element diffractive optical element; May be directed in different directions.
　本開示の実施形態による照明装置において、前記投射光学系は、反射素子またはプリズムであってもよい。 In the illumination device according to an embodiment of the present disclosure, the projection optical system may be a reflective element or a prism.
　また、本開示の実施形態による照明装置において、前記投射光学系は、前記回折光学素子で回折された１次回折光の一部を反射させ他の一部を透過させるハーフミラーと、前記ハーフミラーを透過した前記１次回折光の他の一部を反射する反射素子と、を含んでいてもよい。 Further, in the illumination device according to the embodiment of the present disclosure, the projection optical system includes a half mirror that reflects a part of first-order diffracted light diffracted by the diffractive optical element and transmits another part; And a reflective element for reflecting another part of the transmitted first-order diffracted light.
　また、本開示の実施形態による照明装置において、前記投射光学系は、前記回折光学素子によって回折された光を回折する投射用回折光学素子であってもよい。 Further, in the illumination device according to the embodiment of the present disclosure, the projection optical system may be a projection diffractive optical element that diffracts light diffracted by the diffractive optical element.
　また、本開示の実施形態による照明装置において、
　前記回折光学素子は、前記光源から射出した前記光の一部を回折する第１要素回折光学素子と、前記光源から射出した前記光の他の一部を回折する第２要素回折光学素子と、を有し、
　前記投射用回折光学素子は、前記第１要素回折光学素子で回折された１次回折光である第１回折光を回折して第１の方向に向ける第１投射用要素回折光学素子と、前記第２要素回折光学素子で回折された１次回折光である第２回折光を回折して前記第１の方向とは異なる第２の方向に向ける第２投射用要素回折光学素子と、有していてもよい。 In addition, in the lighting device according to an embodiment of the present disclosure,
The diffractive optical element includes: a first element diffractive optical element that diffracts a part of the light emitted from the light source; and a second element diffractive optical element that diffracts another part of the light emitted from the light source. Have
The projection diffractive optical element is a first projection element diffractive optical element that diffracts first diffraction light, which is first-order diffraction light that is diffracted by the first element diffractive optical element, and directs the first diffraction light in a first direction; And a second projection element diffractive optical element for diffracting second diffracted light, which is first-order diffracted light diffracted by the two-element diffractive optical element, and directing it to a second direction different from the first direction; It is also good.
　また、本開示の実施形態による照明装置は、前記光源から前記回折光学素子までの光路に沿った前記光源と前記回折光学素子との間に配置されたコリメートレンズを更に備えていてもよい。 In addition, the illumination device according to an embodiment of the present disclosure may further include a collimator lens disposed between the light source along the optical path from the light source to the diffractive optical element and the diffractive optical element.
　また、本開示の実施形態による照明装置において、前記投射光学系は、前記回折光学素子で回折された１次回折光の一部の進行方向を９０°を超える角度で変化させ、且つ、前記回折光学素子で回折された１次回折光の他の一部の進行方向を９０°を超える角度で変化させてもよい。 In the illumination device according to an embodiment of the present disclosure, the projection optical system changes the traveling direction of a part of first-order diffracted light diffracted by the diffractive optical element by an angle exceeding 90 °, and the diffractive optical system The traveling direction of another portion of the first-order diffracted light diffracted by the element may be changed at an angle of more than 90 °.
　また、本開示の実施形態による照明装置は、筒状の筐体内に収容されていてもよい。 In addition, the lighting device according to an embodiment of the present disclosure may be housed in a tubular housing.
　この場合、前記筐体は、回転可能に配置されていてもよい。 In this case, the housing may be rotatably disposed.
　また、本開示の実施形態による照明装置は、回転可能に支持されていてもよい。 Also, the lighting device according to an embodiment of the present disclosure may be rotatably supported.
　また、本開示の実施形態による照明装置において、前記投射光学系は、回転可能に支持されていてもよい。 In addition, in the lighting device according to an embodiment of the present disclosure, the projection optical system may be rotatably supported.
　また、本開示の実施形態による照明装置において、前記回折光学素子は、回転可能に支持されていてもよい。 In addition, in the illumination device according to the embodiment of the present disclosure, the diffractive optical element may be rotatably supported.
　また、本開示の実施形態による照明装置は、
　前記回折光学素子から前記投射光学系までの光路に沿った前記回折光学素子と前記投射光学系との間に配置された第１レンズであって、前記回折光学素子から当該第１レンズの焦点距離だけ離間して配置された第１レンズと、
　前記第１レンズから前記投射光学系までの光路に沿った前記第１レンズと前記投射光学系との間に配置された第２レンズであって、前記第１レンズから前記第１レンズの焦点距離と当該第２レンズの焦点距離との和だけ離間して配置された第２レンズと、
　前記第１レンズから前記第２レンズまでの光路に沿った前記第１レンズと前記第２レンズとの間に配置され、前記回折光学素子での０次光を遮断する０次光マスクと、を更に備えていてもよい。 In addition, a lighting device according to an embodiment of the present disclosure is:
A first lens disposed between the diffractive optical element along the optical path from the diffractive optical element to the projection optical system and the projection optical system, wherein a focal distance of the first lens from the diffractive optical element A first lens spaced apart by
A second lens disposed between the first lens along the optical path from the first lens to the projection optical system and the projection optical system, wherein a focal distance of the first lens to the first lens And a second lens disposed spaced apart by the sum of the focal length of the second lens and the second lens,
A zero-order light mask disposed between the first lens and the second lens along the optical path from the first lens to the second lens, for blocking zero-order light in the diffractive optical element; It may further be provided.
　また、本開示の実施形態による照明装置は、
　前記回折光学素子から前記投射光学系までの光路に沿った前記回折光学素子と前記投射光学系との間に配置された第１レンズであって、前記回折光学素子から当該第１レンズの焦点距離だけ離間して配置された第１レンズと、
　前記第１レンズから前記投射光学系までの光路に沿った前記第１レンズと前記投射光学系との間に配置された第２レンズであって、前記第１レンズから前記第１レンズの焦点距離と当該第２レンズの焦点距離との和だけ離間して配置された第２レンズと、
　前記第１レンズから前記第２レンズまでの光路に沿った前記第１レンズと前記第２レンズとの間に配置され、前記回折光学素子での高次回折光を遮断する高次回折光マスクと、を更に備えていてもよい。 In addition, a lighting device according to an embodiment of the present disclosure is:
A first lens disposed between the diffractive optical element along the optical path from the diffractive optical element to the projection optical system and the projection optical system, wherein a focal distance of the first lens from the diffractive optical element A first lens spaced apart by
A second lens disposed between the first lens along the optical path from the first lens to the projection optical system and the projection optical system, wherein a focal distance of the first lens to the first lens And a second lens disposed spaced apart by the sum of the focal length of the second lens and the second lens,
A high-order diffracted light mask disposed between the first lens and the second lens along the optical path from the first lens to the second lens, which blocks high-order diffracted light from the diffractive optical element; It may further be provided.
　また、本開示の実施形態による照明装置において、
　前記投射光学系は、前記回折光学素子で回折された１次回折光の一部および他の一部を反射または屈折させて、それぞれ前記投影面の第１被照明領域および第２被照明領域に向け、
　前記第１被照明領域および前記第２被照明領域は、全体として直線に沿って延びていても良い。さらに、この場合、前記第１被照明領域および前記第２被照明領域は、一直線上に延びてもよい。 In addition, in the lighting device according to an embodiment of the present disclosure,
The projection optical system reflects or refracts a part and another part of the first-order diffracted light diffracted by the diffractive optical element, and directs them to a first illuminated area and a second illuminated area of the projection surface, respectively. ,
The first illuminated area and the second illuminated area may extend along a straight line as a whole. Furthermore, in this case, the first illuminated area and the second illuminated area may extend in a straight line.
　本開示によれば、複数の方向に光を投射することが可能な照明装置を提供することができる。 According to the present disclosure, it is possible to provide a lighting device capable of projecting light in a plurality of directions.
図１は、本開示による第１の実施形態を説明するための図であって、照明装置を示す斜視図である。FIG. 1 is a view for explaining a first embodiment according to the present disclosure, and is a perspective view showing a lighting device. 図２は、図１の照明装置の構成の一例を示す模式図である。FIG. 2: is a schematic diagram which shows an example of a structure of the illuminating device of FIG. 図３は、図２に示す照明装置の変形例を説明するための図であって、図２に示す照明装置によって照明される領域の長さと、単一の方向に光を投射する照明装置によって照明される領域の長さと、を示す図である。FIG. 3 is a view for explaining a modification of the lighting device shown in FIG. 2, which is based on the length of the area illuminated by the lighting device shown in FIG. 2 and the lighting device projecting light in a single direction It is a figure which shows the length of the area | region to be illuminated. 図４は、図２に示す照明装置の他の変形例を示す図である。FIG. 4 is a view showing another modified example of the illumination device shown in FIG. 図５は、図２に示す照明装置のさらに他の変形例を示す図である。FIG. 5 is a figure which shows the further another modification of the illuminating device shown in FIG. 図６は、図２に示す照明装置のさらに他の変形例を示す図である。FIG. 6 is a figure which shows the further another modification of the illuminating device shown in FIG. 図７は、図２に示す照明装置のさらに他の変形例を示す図である。FIG. 7 is a view showing still another modified example of the illumination device shown in FIG. 図８は、図２に対応する図であって、図２に示す照明装置のさらに他の変形例を示す図である。FIG. 8 is a view corresponding to FIG. 2 and showing still another modification of the illumination device shown in FIG. 図９は、図８に示す照明装置によって照明される被照明領域の変化を示す図であって、図８に示す照明装置および投影面を上方から見た図である。FIG. 9 is a view showing a change of the illuminated area illuminated by the illumination device shown in FIG. 8, and a view of the illumination device and the projection plane shown in FIG. 8 from above. 図１０は、図２に対応する図であって、図２に示す照明装置のさらに他の変形例を示す図である。FIG. 10 is a view corresponding to FIG. 2 and showing still another modification of the illumination device shown in FIG. 図１１は、図２に対応する図であって、図２に示す照明装置のさらに他の変形例を示す図である。FIG. 11 is a view corresponding to FIG. 2 and showing still another modification of the illumination device shown in FIG. 図１２は、図２に対応する図であって、本開示による第２の実施形態における照明装置の構成の一例を示す模式図である。FIG. 12 is a diagram corresponding to FIG. 2, and is a schematic diagram illustrating an example of a configuration of a lighting device according to a second embodiment of the present disclosure.
　以下、図面を参照して本開示の実施の形態について説明する。なお、本件明細書に添付する図面においては、図示と理解のしやすさの便宜上、適宜縮尺および縦横の寸法比等を、実物のそれらから変更し誇張してある。 Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings attached to the present specification, for the sake of easy illustration and understanding, the scale, the dimensional ratio in the vertical and horizontal directions, etc. are appropriately changed from those of the actual one and exaggerated.
　また、本明細書において用いる、形状や幾何学的条件並びにそれらの程度を特定する、例えば、「平行」、「直交」、「同一」等の用語や、長さや角度の値等については、厳密な意味に縛られることなく、同様の機能を期待し得る程度の範囲を含めて解釈することとする。 In addition, as used herein, the terms such as “parallel”, “orthogonal”, “identical”, values of length and angle, etc., which specify the shape and geometric conditions and their degree, etc. It shall be interpreted including the range which can expect the same function without being restricted by the meaning.
　＜第１の実施形態＞
　まず、図１および図２を参照して、第１の実施形態について説明する。 First Embodiment
First, the first embodiment will be described with reference to FIGS. 1 and 2.
　図１は、第１の実施形態に係る照明装置１０の一例を示す斜視図である。図２は、図１に示す照明装置１０の構成の一例を示す模式図である。 FIG. 1 is a perspective view showing an example of the illumination device 10 according to the first embodiment. FIG. 2: is a schematic diagram which shows an example of a structure of the illuminating device 10 shown in FIG.
　図１に示すように、照明装置１０は、地面または床面に設置され、設置面を投影面Ｓとして、互いに異なる２つの被照明領域Ｚ１，Ｚ２を照明する。より具体的には、照明装置１０は、互いに異なる２方向に光を投射して、第１被照明領域Ｚ１および第２被照明領域Ｚ２をライン状のパターンで照明する。このような照明装置１０は、例えば、投影面Ｓを区画する際等に用いることができる。すなわち、照明装置１０は、区画される領域の境界線をライン状の被照明領域Ｚ１，Ｚ２で示すことができる。なお、照明装置１０は、被照明領域Ｚ１，Ｚ２をライン状以外の任意のパターンで照明してよく、例えば図形や文字のパターンで照明してもよい。また、照明装置１０は、被照明領域Ｚ１，Ｚ２を互いに異なるパターンで照明してもよい。 As shown in FIG. 1, the illumination device 10 is installed on the ground or floor, and illuminates two different illumination areas Z1 and Z2 with the installation plane as a projection plane S. More specifically, the lighting apparatus 10 projects light in two different directions, and illuminates the first illuminated area Z1 and the second illuminated area Z2 in a linear pattern. Such an illumination device 10 can be used, for example, when partitioning the projection plane S. That is, the illuminating device 10 can show the boundary line of the area | region divided | segmented by line-shaped illumination area Z1, Z2. In addition, the illuminating device 10 may illuminate the to-be-illuminated area | regions Z1 and Z2 with arbitrary patterns other than a linear form, for example, may illuminate with the pattern of a figure or a character. Moreover, the illuminating device 10 may illuminate the to-be-illuminated area | regions Z1 and Z2 with a mutually different pattern.
　図２に示すように、第１の実施形態において、照明装置１０は、光を射出する光源１５と、光源１５から射出した光を回折する回折光学素子４０と、回折光学素子４０によって回折された光を反射または屈折させて投影面Ｓに向ける投射光学系５０と、を備えている。また、図２に示す例においては、照明装置１０は、光源１５と回折光学素子４０との間にコリメートレンズ３２を含む整形光学系３０を更に備えている。 As shown in FIG. 2, in the first embodiment, the illumination device 10 is diffracted by the light source 15 that emits light, the diffractive optical element 40 that diffracts the light emitted from the light source 15, and the diffractive optical element 40 And a projection optical system 50 for reflecting or refracting light and directing it to the projection surface S. Further, in the example shown in FIG. 2, the illumination device 10 further includes a shaping optical system 30 including a collimating lens 32 between the light source 15 and the diffractive optical element 40.
　図１および図２から理解されるように、照明装置１０は、筒状の筐体６０内に収容されており、投影面Ｓ上で自立することができるようになっている。図示の例では、筐体６０内において、光源１５、回折光学素子４０および投射光学系５０は、投影面Ｓに対し、概ね垂直方向に整列している。筐体６０には、投射光学系５０で反射または屈折された光を透過させる開口６１が設けられている。以下、照明装置１０の各構成要素について順に説明していく。 As understood from FIG. 1 and FIG. 2, the lighting device 10 is housed in a cylindrical housing 60 so as to be able to stand on the projection surface S. In the illustrated example, in the housing 60, the light source 15, the diffractive optical element 40, and the projection optical system 50 are aligned in a direction substantially perpendicular to the projection surface S. The housing 60 is provided with an opening 61 for transmitting light reflected or refracted by the projection optical system 50. Hereinafter, each component of the illuminating device 10 will be described in order.
　光源１５は、種々の型式の光源を用いることができる。一例として、コヒーレント光を射出する光源、例えばレーザー光源を、光源１５として用いることができる。光源１５から射出するコヒーレント光は、直進性に優れ、被照明領域Ｚ１，Ｚ２を高精度に照明するための光として好適である。図２に示す例では、照明装置１０は、単一の光源１５を有しているが、複数の光源１５を有していてもよい。 The light source 15 can use various types of light sources. As an example, a light source emitting coherent light, for example, a laser light source can be used as the light source 15. The coherent light emitted from the light source 15 is excellent in straightness, and is suitable as light for illuminating the illumination regions Z1 and Z2 with high accuracy. In the example shown in FIG. 2, the lighting device 10 has a single light source 15, but may have a plurality of light sources 15.
　次に、整形光学系３０について説明する。整形光学系３０は、光源１５から回折光学素子４０までの光路に沿った光源１５と回折光学素子４０との間に配置されている。整形光学系３０は、光源１５から射出した光を整形する。言い換えると、整形光学系３０は、光源１５から射出した光の光軸ｘに直交する断面での形状や、当該光の光束の立体的な形状を整形する。図示された例において、整形光学系３０は、光源１５から射出した光を拡幅した平行光束に整形する。図２に示すように、整形光学系３０は、光源１５から射出した光の光路に沿った順で、レンズ３１およびコリメートレンズ３２を有している。レンズ３１は、光源１５から射出した光を発散光束に整形する。コリメートレンズ３２は、レンズ３１で生成された発散光束を、平行光束に整形し直す。なお、照明装置１０が複数の光源を有する場合、複数の光源のそれぞれに対応して、複数の整形光学系を設けてもよい。 Next, the shaping optical system 30 will be described. The shaping optical system 30 is disposed between the light source 15 along the optical path from the light source 15 to the diffractive optical element 40 and the diffractive optical element 40. The shaping optical system 30 shapes the light emitted from the light source 15. In other words, the shaping optical system 30 shapes the shape of the cross section orthogonal to the optical axis x of the light emitted from the light source 15 and the three-dimensional shape of the light flux of the light. In the illustrated example, the shaping optical system 30 shapes the light emitted from the light source 15 into a spread parallel light flux. As shown in FIG. 2, the shaping optical system 30 has a lens 31 and a collimating lens 32 in the order along the optical path of the light emitted from the light source 15. The lens 31 shapes the light emitted from the light source 15 into a divergent light beam. The collimating lens 32 reshapes the divergent light flux generated by the lens 31 into a parallel light flux. When the illumination device 10 has a plurality of light sources, a plurality of shaping optical systems may be provided corresponding to each of the plurality of light sources.
　次に、回折光学素子４０について説明する。回折光学素子４０は、光源１５から射出した光に対して回折作用を及ぼす素子である。図示された回折光学素子４０は、光源１５からの光を回折して、投射光学系５０に向ける。 Next, the diffractive optical element 40 will be described. The diffractive optical element 40 is an element that exerts a diffractive action on the light emitted from the light source 15. The illustrated diffractive optical element 40 diffracts the light from the light source 15 and directs it to the projection optical system 50.
　図示された例において、回折光学素子４０は、第１要素回折光学素子４１と第２要素回折光学素子４２とを有している。第１要素回折光学素子４１は、コリメートレンズ３２からの光の一部を回折して投射光学系５０に向ける。また、第２要素回折光学素子４２は、コリメートレンズ３２からの光の他の一部を回折して、投射光学系５０に向ける。 In the illustrated example, the diffractive optical element 40 includes a first element diffractive optical element 41 and a second element diffractive optical element 42. The first element diffractive optical element 41 diffracts a part of the light from the collimating lens 32 and directs it to the projection optical system 50. Further, the second element diffractive optical element 42 diffracts another part of the light from the collimating lens 32 and directs it to the projection optical system 50.
　一例として、各要素回折光学素子４１，４２は、干渉縞パターンを記録されたホログラム記録媒体として構成される。干渉縞パターンを種々に調整することで、各要素回折光学素子４１，４２で回折される光の進行方向、言い換えると、各要素回折光学素子４１，４２で拡散される光の進行方向を、制御することができる。 As an example, each element diffractive optical element 41, 42 is configured as a hologram recording medium on which an interference fringe pattern is recorded. By adjusting the interference fringe pattern variously, the traveling direction of the light diffracted by each element diffractive optical element 41, 42, in other words, the traveling direction of the light diffused by each element diffractive optical element 41, 42, is controlled can do.
　各要素回折光学素子４１，４２は、例えば実物の散乱板からの散乱光を物体光として用いて作製することができる。より具体的には、要素回折光学素子４１，４２の母体であるホログラム感光材料に、互いに干渉性を有するコヒーレント光からなる参照光と物体光とを照射すると、これらの光の干渉による干渉縞がホログラム感光材料に形成されて、要素回折光学素子４１，４２が作製される。参照光としては、コヒーレント光であるレーザー光が用いられ、物体光としては、例えば安価に入手可能な等方散乱板からの散乱光が用いられる。 Each element diffractive optical element 41 and 42 can be produced, for example, using scattered light from a real scattering plate as object light. More specifically, when the hologram photosensitive material that is the base of the element diffractive optical elements 41 and 42 is irradiated with the reference light and the object light that are coherent light having interference with each other, interference fringes due to the interference of these lights are The element diffractive optical elements 41 and 42 are manufactured by forming the hologram photosensitive material. As the reference light, laser light which is coherent light is used. As the object light, for example, scattered light from an isotropic scattering plate which can be obtained inexpensively is used.
　要素回折光学素子４１，４２を作製する際に用いた参照光の光路を逆向きに進むよう要素回折光学素子４１，４２に向けてレーザー光を照射することで、要素回折光学素子４１，４２を作製する際に用いた物体光の元となる散乱板の配置位置に、散乱板の再生像が生成される。要素回折光学素子４１，４２を作製する際に用いられた物体光の元となる散乱板が均一的な面散乱をしていれば、要素回折光学素子４１，４２により得られる散乱板の再生像も、均一な面照明となる。 The element diffractive optical elements 41 and 42 are formed by irradiating the element diffractive optical elements 41 and 42 with laser light so that the optical paths of the reference beams used when producing the element diffractive optical elements 41 and 42 are reversed. A reproduction image of the scattering plate is generated at the arrangement position of the scattering plate which is the source of the object light used in fabrication. If the scattering plate which is the source of the object light used when producing the element diffractive optical elements 41 and 42 performs uniform surface scattering, the reproduced image of the scattering plate obtained by the element diffractive optical elements 41 and 42 Even, it will be a uniform surface illumination.
　また、要素回折光学素子４１，４２に形成される複雑な干渉縞のパターンは、現実の物体光と参照光を用いて形成する代わりに、予定した再生照明光の波長や入射方向、並びに、再生されるべき像の形状や位置等に基づき計算機を用いて設計することが可能である。このようにして得られた要素回折光学素子４１，４２は、計算機合成ホログラム（ＣＧＨ：Computer Generated Hologram）とも呼ばれる。 Also, instead of forming complex interference fringe patterns formed on the element diffractive optical elements 41 and 42 using actual object light and reference light, the wavelength and incident direction of the planned reproduction illumination light, and reproduction, It is possible to design using a computer based on the shape, position, etc. of the image to be done. The element diffractive optical elements 41 and 42 obtained in this manner are also called computer generated holograms (CGH).
　また、要素回折光学素子４１，４２上の各点における拡散角度特性が同じであるフーリエ変換ホログラムを計算機合成により形成してもよい。 In addition, Fourier transform holograms may be formed by computer synthesis in which diffusion angle characteristics at respective points on the element diffractive optical elements 41 and 42 are the same.
　要素回折光学素子４１，４２の具体的な形態としては、フォトポリマーを用いた体積型ホログラム記録媒体でもよいし、銀塩材料を含む感光媒体を利用して記録するタイプの体積型ホログラム記録媒体でもよいし、レリーフ型（エンボス型）のホログラム記録媒体でもよい。また、要素回折光学素子４１，４２は、透過型であってもよいし、反射型であってもよい。 A specific form of the element diffractive optical elements 41 and 42 may be a volume type hologram recording medium using a photopolymer, or a volume type hologram recording medium of a type recording using a photosensitive medium containing a silver salt material. It may be a hologram recording medium of relief type (emboss type). The element diffractive optical elements 41 and 42 may be transmissive or reflective.
　なお、照明装置１０が複数の光源を有する場合、複数の光源のそれぞれに対応して、複数の回折光学素子を設けてもよい。 When the illumination device 10 has a plurality of light sources, a plurality of diffractive optical elements may be provided corresponding to each of the plurality of light sources.
　投射光学系５０は、回折光学素子４０によって回折された光を反射または屈折させて投影面Ｓ（図示の例では設置面）に向ける。より詳細には、投射光学系５０は、第１要素回折光学素子４１で回折された１次回折光（以下、「第１回折光」とも称する。）Ｌ１１と第２要素回折光学素子４２で回折された１次回折光（以下、「第２回折光」とも称する。）Ｌ１２とを、異なる方向に向ける。なお、ホログラム素子のような要素回折光学素子４１，４２では、回折光として、１次回折光Ｌ１１，Ｌ１２以外に２次以上の高次の回折光（以下、「高次回折光」とも称する。）が生じる。投射光学系５０は、投射光学系５０に入射する回折光のうち、少なくとも１次回折光Ｌ１１，Ｌ１２を、互いに異なる方向に向ける。 The projection optical system 50 reflects or refracts the light diffracted by the diffractive optical element 40 to direct it to the projection surface S (in the illustrated example, the installation surface). More specifically, the projection optical system 50 is diffracted by the first-order diffracted light (hereinafter also referred to as "first diffracted light") L11 diffracted by the first element diffractive optical element 41 and the second element diffractive optical element 42. The first-order diffracted light (hereinafter also referred to as “second diffracted light”) L12 is directed in different directions. In the element diffractive optical elements 41 and 42 such as hologram elements, second-order or higher-order diffracted light (hereinafter also referred to as "high-order diffracted light") is a diffracted light as the diffracted light in addition to the first-order diffracted lights L11 and L12. It occurs. The projection optical system 50 directs at least first-order diffracted lights L11 and L12 of the diffracted lights entering the projection optical system 50 in directions different from each other.
　図示の例では、投射光学系５０は光を反射する反射面を有する反射素子である。投射光学系５０は、少なくともその反射面を例えば金属等の高い反射率を有する材料から構成されている。とりわけ、図示の例では、投射光学系５０は、少なくともその反射面が銀で構成されて鏡面反射機能を有している。 In the illustrated example, the projection optical system 50 is a reflective element having a reflective surface that reflects light. The projection optical system 50 is made of a material having a high reflectance, such as metal, at least on its reflection surface. In particular, in the illustrated example, at least the reflection surface of the projection optical system 50 is made of silver and has a specular reflection function.
　上述のように、投射光学系５０は、第１要素回折光学素子４１で回折された第１回折光Ｌ１１と、第２要素回折光学素子４２で回折された第２回折光Ｌ１２とを、異なる方向に向ける。図２に示す例においては、投射光学系５０は、複数の反射面を有するいわゆる多面鏡として構成されている。より具体的には、投射光学系５０は、全体として三角柱の形状を有しており、その３つの側面のうちの２つが反射面をなしている。そして、２つの反射面のうちの１つは、第１回折光Ｌ１１が入射する第１反射面５１であり、第１回折光Ｌ１１を第１の方向に向ける。また、他の反射面は、第２回折光Ｌ１２が入射する第２反射面５２であり、第２回折光Ｌ１２を第１の方向とは異なる第２の方向に向ける。なお、第１回折光Ｌ１１および第２回折光Ｌ１２を異なる方向に向けることが可能な投射光学系５０としては、多面鏡以外にも、凹面鏡や凸面鏡、平面鏡、プリズム等、種々のものが採用可能である。 As described above, the projection optical system 50 has different directions of the first diffracted light L11 diffracted by the first element diffractive optical element 41 and the second diffracted light L12 diffracted by the second element diffractive optical element 42. Turn to. In the example shown in FIG. 2, the projection optical system 50 is configured as a so-called polygon mirror having a plurality of reflecting surfaces. More specifically, the projection optical system 50 has a triangular prism shape as a whole, and two of its three side surfaces form a reflecting surface. Then, one of the two reflecting surfaces is the first reflecting surface 51 on which the first diffracted light L11 is incident, and directs the first diffracted light L11 in the first direction. The other reflecting surface is the second reflecting surface 52 on which the second diffracted light L12 is incident, and directs the second diffracted light L12 in a second direction different from the first direction. In addition, as the projection optical system 50 capable of directing the first diffracted light L11 and the second diffracted light L12 in different directions, various types such as a concave mirror, a convex mirror, a plane mirror, a prism, etc. can be adopted besides the polygon mirror. It is.
　図２に示す例においては、第１反射面５１の向きは、第１回折光Ｌ１１の進行方向を９０°を超える角度で変化させ、第１回折光Ｌ１１を、投影面Ｓ上の第１被照明領域Ｚ１に向けるように設定されている。また、第２反射面５２の向きは、第２回折光Ｌ１２の進行方向を９０°を超える角度で変化させ、第２回折光Ｌ１２を、投影面Ｓ上の第２被照明領域Ｚ２に向けるように設定されている。 In the example shown in FIG. 2, the direction of the first reflection surface 51 changes the traveling direction of the first diffracted light L11 at an angle exceeding 90 °, and the first diffracted light L11 is converted to the first object on the projection surface S. It is set to be directed to the illumination area Z1. In addition, the direction of the second reflection surface 52 changes the traveling direction of the second diffracted light L12 at an angle exceeding 90 °, and the second diffracted light L12 is directed to the second illumination region Z2 on the projection surface S. It is set to.
　次に、以上に説明した構成からなる照明装置１０の作用について説明する。 Next, the operation of the lighting device 10 configured as described above will be described.
　光源１５から射出した光は、まず、整形光学系３０に入射する。整形光学系３０では、光源１５から射出した光を拡大する。すなわち、光軸ｘに直交する断面において光が占める領域が広がるよう、整形光学系３０は光源１５からの光を整形する。図示された例において、整形光学系３０は、レンズ３１およびコリメートレンズ３２を有している。図２に示すように、整形光学系３０のレンズ３１は、光源１５から射出した光を発散させて発散光束に変換する。そして、整形光学系３０のコリメートレンズ３２は、発散光束を平行光束へとコリメートする。 The light emitted from the light source 15 first enters the shaping optical system 30. The shaping optical system 30 magnifies the light emitted from the light source 15. That is, the shaping optical system 30 shapes the light from the light source 15 so that the area occupied by the light is expanded in the cross section orthogonal to the optical axis x. In the illustrated example, the shaping optical system 30 includes a lens 31 and a collimating lens 32. As shown in FIG. 2, the lens 31 of the shaping optical system 30 diverges the light emitted from the light source 15 and converts it into a divergent light beam. Then, the collimating lens 32 of the shaping optical system 30 collimates the divergent light flux into a parallel light flux.
　整形光学系３０で整形された光は、次に、回折光学素子４０へと向かう。回折光学素子４０の各要素回折光学素子４１，４２は、光源１５から射出する光の中心波長に対応した干渉縞を記録しており、一定の方向から入射する光を所望の方向に高効率で回折することができる。図示された例において、第１要素回折光学素子４１は、光源１５から射出した光の一部を回折し、回折光を投射光学系５０に向けて拡散させる。また、第２要素回折光学素子４２は、光源１５から射出した光の他の一部を回折し、回折光を投射光学系５０に向けて拡散させる。 The light shaped by the shaping optical system 30 then travels to the diffractive optical element 40. The element diffractive optical elements 41 and 42 of the diffractive optical element 40 record interference fringes corresponding to the central wavelength of the light emitted from the light source 15, and the light incident from a certain direction has high efficiency in the desired direction. It can be diffracted. In the illustrated example, the first element diffractive optical element 41 diffracts part of the light emitted from the light source 15 and diffuses the diffracted light toward the projection optical system 50. Also, the second element diffractive optical element 42 diffracts another part of the light emitted from the light source 15 and diffuses the diffracted light toward the projection optical system 50.
　投射光学系５０の反射面５１，５２に入射した光は、反射して、その進行方向を変える。とりわけ、第１反射面５１に入射した第１回折光Ｌ１１は、反射して、その進行方向を９０°を超える角度で変える。そして、第１反射面５１で反射した第１回折光Ｌ１１は、筒状の筐体６０に設けられた開口６１を通過して、投影面Ｓ上の第１被照明領域Ｚ１に入射する。また、第２反射面５２に入射した第２回折光Ｌ１２は、反射して、その進行方向を９０°を超える角度で変える。第２反射面５２で反射した第２回折光Ｌ１２は、第１反射面５１で反射した第１回折光Ｌ１１とは異なる方向に向かう。そして、第２回折光Ｌ１２は、筒状の筐体６０に設けられた開口６１を通過して、投影面Ｓ上の第１被照明領域Ｚ１とは異なる第２被照明領域Ｚ２に入射する。図示の例においては、第１被照明領域Ｚ１及び第２被照明領域Ｚ２は、照明装置１０から異なる方向に延びるライン状のパターンで照明される。 The light incident on the reflection surfaces 51 and 52 of the projection optical system 50 is reflected to change its traveling direction. In particular, the first diffracted light L11 incident on the first reflection surface 51 is reflected to change its traveling direction at an angle of more than 90 °. Then, the first diffracted light L11 reflected by the first reflection surface 51 passes through the opening 61 provided in the cylindrical casing 60, and is incident on the first illumination area Z1 on the projection surface S. In addition, the second diffracted light L12 incident on the second reflection surface 52 is reflected to change its traveling direction at an angle of more than 90 °. The second diffracted light L12 reflected by the second reflection surface 52 travels in a direction different from that of the first diffracted light L11 reflected by the first reflection surface 51. Then, the second diffracted light L12 passes through the opening 61 provided in the cylindrical casing 60, and is incident on the second illumination area Z2 different from the first illumination area Z1 on the projection surface S. In the illustrated example, the first illuminated area Z1 and the second illuminated area Z2 are illuminated in a line pattern extending in different directions from the illumination device 10.
　以上のような第１の実施形態によれば、照明装置１０は、光を射出する光源１５と、光源１５から射出した光を回折する回折光学素子４０と、回折光学素子４０によって回折された光を反射または屈折させて投影面Ｓに向ける投射光学系５０と、を備えている。そして、投射光学系５０は、回折光学素子４０で回折された１次回折光の一部Ｌ１１と他の一部Ｌ１２とを異なる方向に向ける。 According to the first embodiment as described above, the illumination device 10 includes the light source 15 for emitting light, the diffractive optical element 40 for diffracting the light emitted from the light source 15, and the light diffracted by the diffractive optical element 40. And a projection optical system 50 for reflecting or refracting the light toward the projection surface S. Then, the projection optical system 50 directs one portion L11 of the first-order diffracted light diffracted by the diffractive optical element 40 and the other portion L12 in different directions.
　このような照明装置１０は、複数方向に光を投射して複数の被照明領域Ｚ１，Ｚ２を照明することができる。 Such an illumination device 10 can project light in a plurality of directions to illuminate a plurality of illumination target areas Z1 and Z2.
　また、第１の実施形態において、回折光学素子４０は、光源１５から射出した光の一部を回折する第１要素回折光学素子４１と、光源１５から射出した光の他の一部を回折する第２要素回折光学素子４２と、を有している。そして、投射光学系５０は、第１要素回折光学素子４１で回折された１次回折光である第１回折光Ｌ１１と、第２要素回折光学素子４２で回折された１次回折光である第２回折光Ｌ１２と、を異なる方向に向ける。このような照明装置１０によれば、複数の被照明領域Ｚ１，Ｚ２の各々を所望のパターンで高精度に照明することが容易である。 In the first embodiment, the diffractive optical element 40 diffracts the first element diffractive optical element 41 that diffracts part of the light emitted from the light source 15 and the other part of the light emitted from the light source 15 And a second element diffractive optical element 42. Then, the projection optical system 50 includes a first diffracted light L11 which is a first-order diffracted light diffracted by the first element diffractive optical element 41 and a second diffracted light which is a first-order diffracted light diffracted by the second element diffractive optical element 42. The light L12 is directed in different directions. According to such an illumination device 10, it is easy to illuminate each of the plurality of illumination regions Z1 and Z2 with a desired pattern with high accuracy.
　また、第１の実施形態において、投射光学系５０は、反射素子またはプリズムである。この場合、第１回折光Ｌ１１と第２回折光Ｌ１２とを反射または屈折させて異なる方向に向ける投射光学系５０を実現することが容易である。 In the first embodiment, the projection optical system 50 is a reflective element or a prism. In this case, it is easy to realize the projection optical system 50 that reflects or refracts the first diffracted light L11 and the second diffracted light L12 and directs them in different directions.
　また、第１の実施形態において、光源１５から回折光学素子４０までの光路に沿った光源１５と回折光学素子４０との間に配置されたコリメートレンズ３２を更に備える。これにより、平行化された光が回折光学素子４０に入射するので、回折光学素子４０で第１回折光Ｌ１１および第２回折光Ｌ１２を所望の方向に高精度に回折させることが容易である。 Further, in the first embodiment, the collimator lens 32 disposed between the light source 15 along the optical path from the light source 15 to the diffractive optical element 40 and the diffractive optical element 40 is further provided. Thus, the collimated light is incident on the diffractive optical element 40, so that it is easy to diffract the first diffracted light L11 and the second diffracted light L12 in the desired direction with high accuracy by the diffractive optical element 40.
　また、第１の実施形態において、投射光学系５０は、回折光学素子４０で回折された１次回折光の一部Ｌ１１の進行方向を９０°を超える角度で変化させ、且つ、回折光学素子４０で回折された１次回折光の他の一部Ｌ１２の進行方向を９０°を超える角度で変化させる。この場合、例えば図１および図２に示すように、照明装置１０は、その設置面を投影面Ｓとして照明することができる。 In the first embodiment, the projection optical system 50 changes the traveling direction of the part L11 of the first-order diffracted light diffracted by the diffractive optical element 40 by an angle exceeding 90 °, and the diffractive optical element 40 The traveling direction of the other part L12 of the diffracted first-order diffracted light is changed at an angle of more than 90 °. In this case, for example, as shown in FIG. 1 and FIG. 2, the illumination device 10 can illuminate the installation plane as the projection plane S.
　また、第１の実施形態において、照明装置１０は、筒状の筐体６０内に収容されている。この場合、照明装置１０を、投影面Ｓにおいて自立させることが容易である。さらには、後述する図４に示すように、その一部を地中や床下、水中に設置することが容易である。 Further, in the first embodiment, the lighting device 10 is accommodated in a cylindrical case 60. In this case, it is easy for the lighting device 10 to stand on the projection surface S. Furthermore, as shown in FIG. 4 described later, it is easy to install a part thereof in the ground, under the floor, or in water.
　なお、上述してきた第１の実施形態に対して様々な変更を加えることが可能である。以下、図面を参照しながら、いくつかの変形例について説明する。以下の説明および以下の説明で用いる図面では、上述した第１の実施形態と同様に構成され得る部分について、上述の第１の実施形態における対応する部分に対して用いた符号と同一の符号を用いることとし、重複する説明を省略する。 Note that various modifications can be made to the first embodiment described above. Hereinafter, some modifications will be described with reference to the drawings. In the following description and the drawings used in the following description, for the parts that can be configured in the same manner as the first embodiment described above, the same reference numerals as the reference numerals used for the corresponding parts in the first embodiment described above are used. It shall be used and the duplicate explanation is omitted.
　＜変形例１＞
　上述した第１の実施の形態において、例えば、照明装置１０で、一直線上に延びる第１被照明領域Ｚ１および第２被照明領域Ｚ２を照明する場合について考える。この場合、被照明領域Ｚ１，Ｚ２内において、照明装置１０に近いほど明瞭で明るいパターン照明となり視認性が良く、照明装置１０から遠いほど投影パターンがボケて暗く照明され視認性が悪くなることを考慮すると、被照明領域Ｚ１を照明する光Ｌ１１および被照明領域Ｚ２を照明する光Ｌ１２によって明瞭且つ明るいパターンで視認性良く（したがって綺麗に）照明される領域は、それぞれ、図３に示す地点Ｅ１１から地点Ｅ１２および地点Ｅ２１から地点Ｅ２２に亘る領域である。したがって、照明装置１０は、照明装置１０の一側の地点Ｅ１２から他側の地点Ｅ２２に亘る長さＬ１０の領域を、明瞭且つ明るいパターンで視認性良く照明するのに用いることができる。 <Modification 1>
In the first embodiment described above, for example, it is assumed that the illumination device 10 illuminates the first illuminated area Z1 and the second illuminated area Z2 extending in a straight line. In this case, in the illuminated areas Z1 and Z2, the closer to the illumination device 10, the clearer and brighter the pattern illumination becomes and the visibility is good. The farther the distance from the illumination device 10, the more the projection pattern is blurred and the darker illumination deteriorates the visibility. In consideration of this, the areas illuminated with good clarity and bright pattern (therefore clean) by the light L11 illuminating the illuminated area Z1 and the light L12 illuminating the illuminated area Z2 are respectively points E11 shown in FIG. From the point E12 to the point E22. Therefore, the lighting apparatus 10 can be used to illuminate a region of length L10 from the point E12 on one side of the lighting apparatus 10 to the point E22 on the other side in a clear and bright pattern with good visibility.
　これに対し、照明装置１０の光源１５と同程度の放射束の光を射出する光源を用いて単一の方向にのみ光を投射する照明装置５００で被照明領域Ｚ５００を照明する場合、被照明領域Ｚ５００内において、照明装置５００に近いほど明瞭で明るいパターン照明となり視認性が良く、照明装置５００から遠いほど投影パターンがボケて暗く照明され視認性が悪くなることを考慮すると、被照明領域Ｚ５００を照明する光Ｌ５００によって明瞭且つ明るいパターンで視認性良く照明される領域は、図３に示す地点Ｅ５１から地点Ｅ５２に亘る長さＬ５００の領域である。 On the other hand, in the case of illuminating the illuminated area Z500 with the illumination device 500 that projects light only in a single direction using a light source that emits light of a radiation flux similar to the light source 15 of the illumination device 10, In the area Z500, the closer to the illumination device 500, the clearer and brighter the pattern illumination is, the visibility is good, and the projected pattern is more blurred and darker illumination as the distance from the illumination device 500 is smaller. The region illuminated with good visibility in a clear and bright pattern by the light L500 illuminating the light is a region of length L500 ranging from the point E51 to the point E52 shown in FIG.
　このように、照明装置１０は、照明装置１０の一側の地点Ｅ１２から他側の地点Ｅ２２に亘る長さＬ１０の領域を、明瞭且つ明るいパターンで視認性良く照明するのに用いることができるのに対し、照明装置５００が明瞭且つ明るいパターンで視認性良く照明可能な領域は、照明装置５００の一側の地点Ｅ５１から地点Ｅ５２に亘る長さＬ５００の領域のみである。一般に、上記長さＬ１０は、上記長さＬ５００と比較して顕著に長い。すなわち、照明装置１０は、照明装置５００と比較して、より長い領域を、明瞭且つ明るいパターンで視認性良く照明するのに用いることができる。言い換えると、上記長さＬ５００よりも長い長さＬ１０の領域を照明する場合、照明装置１０を当該領域の中間地点に配置して、当該中間地点から光を投射すれば、当該領域内において照明装置１０から最も離れた地点Ｅ１２，Ｅ２２まで、明瞭且つ明るいパターンで視認性良く照明することができる。 Thus, the lighting device 10 can be used to illuminate a region of length L10 from the point E12 on one side of the lighting device 10 to the point E22 on the other side with a clear and bright pattern with good visibility. On the other hand, the illumination device 500 can illuminate with a clear and bright pattern with high visibility only in the region of length L500 extending from the point E51 on one side of the illumination device 500 to the point E52. In general, the length L10 is significantly longer than the length L500. That is, the illumination device 10 can be used to illuminate longer regions in a clear and bright pattern with high visibility as compared to the illumination device 500. In other words, in the case of illuminating a region having a length L10 longer than the above-mentioned length L500, if the lighting device 10 is disposed at the middle point of the region and light is projected from the middle point, the lighting device within the region It is possible to illuminate in a clear and bright pattern with good visibility to the points E12 and E22 farthest from 10.
　なお、上述した変形例１の説明では、照明装置１０が一直線上に延びる第１被照明領域Ｚ１および第２被照明領域Ｚ２を照明する場合について説明したが、これに限られない。すなわち、第１被照明領域Ｚ１および第２被照明領域Ｚ２は厳密な一直線上に延びていなくてもよい。第１被照明領域Ｚ１および第２被照明領域Ｚ２は、例えば後述する図９に示す領域Ｚ１ｂおよび領域Ｚ２ａのように、互いに交差する方向に延びていてもよい。この場合であっても、第１被照明領域Ｚ１および第２被照明領域Ｚ２が全体として直線に沿って延びていれば、第１被照明領域Ｚ１および第２被照明領域Ｚ２が一直線上に延びている場合と同様の効果を得ることができる。 In the description of the first modification described above, the illumination device 10 illuminates the first illuminated area Z1 and the second illuminated area Z2 extending in a straight line. However, the present invention is not limited to this. That is, the first illuminated area Z1 and the second illuminated area Z2 may not extend in a straight line. The first illuminated area Z1 and the second illuminated area Z2 may extend in directions crossing each other, for example, an area Z1b and an area Z2a shown in FIG. 9 described later. Even in this case, if the first illuminated area Z1 and the second illuminated area Z2 extend along a straight line as a whole, the first illuminated area Z1 and the second illuminated area Z2 extend in a straight line. The same effect as in the case of
　以上のような変形例１によれば、投射光学系５０は、回折光学素子４０で回折された１次回折光の一部Ｌ１１および他の一部Ｌ１２を反射または屈折させて、それぞれ投影面Ｓの第１被照明領域Ｚ１および第２被照明領域Ｚ２に向ける。そして、第１被照明領域Ｚ１および第２被照明領域Ｚ２は、全体として直線に沿って延びている。とりわけ図示の例では、第１被照明領域Ｚ１および第２被照明領域Ｚ２は、一直線上に延びている。この場合、照明装置１０は、照明装置１０の一側の地点Ｅ１２から他側の地点Ｅ２２に亘る長さＬ１０の領域を、明瞭且つ明るいパターンで視認性良く（したがって綺麗に）照明することができるが、この長さＬ１０は、照明装置１０の光源１５と同程度の放射束の光を射出する光源を用いて単一の方向のみを照明する照明装置５００が明瞭且つ明るいパターンで視認性良く照明可能な領域の長さＬ５００と比較して、顕著に長い。 According to the first modification as described above, the projection optical system 50 reflects or refracts a part L11 and a part L12 of the first-order diffracted light diffracted by the diffractive optical element 40 to form the projection surface S respectively. The light is directed to the first illuminated area Z1 and the second illuminated area Z2. The first illuminated area Z1 and the second illuminated area Z2 extend along a straight line as a whole. Particularly in the illustrated example, the first illuminated area Z1 and the second illuminated area Z2 extend in a straight line. In this case, the lighting device 10 can illuminate a region with a length L10 ranging from the point E12 on one side of the lighting device 10 to the point E22 on the other side with a clear and bright pattern with good visibility (therefore clean) However, with this length L10, the illumination device 500 that illuminates only a single direction with a light source that emits light of a radiant flux similar to that of the light source 15 of the illumination device 10 illuminates in a clear and bright pattern with good visibility It is significantly longer than the possible region length L500.
　＜変形例２＞
　上述した第１の実施形態において、回折光学素子４０が２つの要素回折光学素子４１，４２を有し、照明装置１０が２つの被照明領域Ｚ１，Ｚ２を照明する場合について説明してきたが、これに限られない。例えば、図４に示すように、回折光学素子は、３つ以上の要素回折光学素子を有してもよい。この場合、照明装置は、３方向以上の方向に光を投射して３つ以上の被照明領域を照明し得る。 <Modification 2>
In the first embodiment described above, the case has been described in which the diffractive optical element 40 has the two element diffractive optical elements 41 and 42 and the illumination device 10 illuminates the two illumination areas Z1 and Z2. It is not limited to. For example, as shown in FIG. 4, the diffractive optical element may have three or more element diffractive optical elements. In this case, the lighting device may project light in three or more directions to illuminate three or more illuminated areas.
　図４に示す照明装置１００は、３方向に光を投射して３つの被照明領域Ｚ１，Ｚ２，Ｚ３を照明する。図４に示す照明装置１００において、回折光学素子１４０は３つの要素回折光学素子４１，４２，４３を有しており、投射光学系１５０は、３つの反射面５１，５２，５３を有している。その他の構成は、図２に示す照明装置１０と略同一である。なお、図３では、理解を容易にするため、筐体６０の図示を省略している。 The illuminating device 100 shown in FIG. 4 projects light in three directions to illuminate the three illumination regions Z1, Z2, and Z3. In the illumination device 100 shown in FIG. 4, the diffractive optical element 140 has three element diffractive optical elements 41, 42 and 43, and the projection optical system 150 has three reflective surfaces 51, 52 and 53. There is. The other configuration is substantially the same as the illumination device 10 shown in FIG. In FIG. 3, the casing 60 is omitted to facilitate understanding.
　回折光学素子１４０は、第１要素回折光学素子４１および第２要素回折光学素子４２の他に、第３要素回折光学素子４３を有している。第３要素回折光学素子４３は、他の要素回折光学素子４１，４２と同様に、例えば干渉縞パターンを記録されたホログラム記録媒体として構成される。図４に示す回折光学素子１４０において、第１要素回折光学素子４１は、コリメートレンズ３２からの光の一部を回折して投射光学系１５０に向ける。また、第２要素回折光学素子４２は、当該光の他の一部を回折して投射光学系１５０に向ける。また、第３要素回折光学素子４３は、当該光のさらに他の一部を回折して投射光学系１５０に向ける。 The diffractive optical element 140 has a third element diffractive optical element 43 in addition to the first element diffractive optical element 41 and the second element diffractive optical element 42. Similar to the other element diffractive optical elements 41 and 42, the third element diffractive optical element 43 is configured as, for example, a hologram recording medium on which an interference fringe pattern is recorded. In the diffractive optical element 140 shown in FIG. 4, the first element diffractive optical element 41 diffracts part of the light from the collimator lens 32 and directs it to the projection optical system 150. In addition, the second element diffractive optical element 42 diffracts another part of the light and directs it to the projection optical system 150. In addition, the third element diffractive optical element 43 diffracts another portion of the light and directs it to the projection optical system 150.
　投射光学系１５０は、第１反射面５１および第２反射面５２の他に、第３反射面５３を有している。図４に示す例において、投射光学系１５０は、三角錐の形状を有している。そして、その底面以外の３つの面が反射機能を有し、それぞれ反射面５１，５２，５３をなしている。第３反射面５３は、第３要素回折光学素子４３で回折された１次回折光（以下、「第３回折光」とも称する。）Ｌ１３を、第１回折光Ｌ１１および第２回折光Ｌ１２のいずれとも異なる第３の方向に向ける。第３反射面５３は、第３回折光Ｌ１３の進行方向を９０°を超える角度で変化させ、第３回折光Ｌ１３を、投影面Ｓ上の第３被照明領域Ｚ３に向けるようになっている。なお、投射光学系１５０の形状としては、角錐形状以外に、円錐形状等、様々な形状が採用可能である。 The projection optical system 150 has a third reflection surface 53 in addition to the first reflection surface 51 and the second reflection surface 52. In the example shown in FIG. 4, the projection optical system 150 has a triangular pyramid shape. And three surfaces other than the bottom have a reflective function, and have constituted the reflective surfaces 51, 52, and 53, respectively. The third reflection surface 53 is a first-order diffracted light (hereinafter also referred to as “third diffracted light”) L13 diffracted by the third element diffractive optical element 43, whichever of the first diffracted light L11 and the second diffracted light L12. Also turn in a different third direction. The third reflection surface 53 changes the traveling direction of the third diffracted light L13 at an angle exceeding 90 °, and directs the third diffracted light L13 to the third illuminated region Z3 on the projection surface S. . In addition, as a shape of the projection optical system 150, various shapes, such as conical shape, are employable besides pyramid shape.
　＜変形例３＞
　上述した第１の実施形態において、照明装置１０が投影面Ｓ上に設置される場合について説明してきた。しかしながら、例えば照明装置１０を小さく見せたい場合、図５に示すように、照明装置１０は、その一部が投影面Ｓの下方、すなわち地中または床下に配置されていてもよい。また、水面を投影面Ｓとする場合、照明装置１０は、その一部が水中に配置されていてもよい。 <Modification 3>
In the first embodiment described above, the case where the illumination device 10 is installed on the projection surface S has been described. However, for example, when it is desired to make the illumination device 10 appear smaller, a portion of the illumination device 10 may be disposed below the projection surface S, ie, in the ground or floor, as shown in FIG. Moreover, when making a water surface into the projection surface S, the one part of the illuminating device 10 may be arrange | positioned in water.
　＜変形例４＞
　上述した第１の実施形態において、照明装置１０が地面または床面に設置される場合について説明してきたが、これに限られない。照明装置１０は、種々の分野、例えば車や船等の移動体の照明装置として、使用され得る。 <Modification 4>
In the first embodiment described above, the case where the lighting device 10 is installed on the ground or floor has been described, but is not limited thereto. The lighting device 10 can be used in various fields, for example, as a lighting device for moving objects such as cars and ships.
　図６に示す例では、照明装置１０は、車両Ｃに設置され、車両Ｃの右前下方および車両Ｃの左前下方の２方向に光を投射する。そして、照明装置１０は、車両Ｃの右前方に位置する第１被照明領域Ｚ１および左前方に位置する第２被照明領域Ｚ２を照明する。 In the example illustrated in FIG. 6, the lighting device 10 is installed in the vehicle C, and projects light in two directions, the front lower right of the vehicle C and the front lower left of the vehicle C. Then, the lighting device 10 illuminates the first illuminated area Z1 located on the right front of the vehicle C and the second illuminated area Z2 located on the left front.
　また、図７に示す例では、照明装置１０は、車両Ｃに設置され、共に車両Ｃの前下方ではあるが投影面Ｓである地面または床面に対して異なる角度をなす２方向に光を投射する。そして、照明装置１０は、車両Ｃのニアフィールドの被照明領域とファーフィールドの被照明領域とを照明する。 Further, in the example shown in FIG. 7, the lighting device 10 is installed in the vehicle C, and light is provided in two directions which are both in front of and below the vehicle C but have different angles with respect to the ground or floor which is the projection surface S. Project Then, the lighting device 10 illuminates the near-field illuminated region of the vehicle C and the far-field illuminated region.
　なお、図６及び図７に示された照明装置１０は、上述してきた照明装置と同様に、光源１５と整形光学系３０と、複数の要素回折光学素子を含む回折光学素子４０と、投射光学系５０と、を有する。投射光学系５０は、プリズムによって形成されている。このプリズムは、第１回折光Ｌ１１の光路を屈折によって変化させる第１プリズム面５１ａと、第１プリズム面５１ａに対して傾斜して第２回折光Ｌ１２の光路を屈折によって第１回折光Ｌ１１の光路とは異なる方向へ向ける第２プリズム面５２ａと、を有している。 The illumination device 10 shown in FIGS. 6 and 7 has a light source 15, a shaping optical system 30, a diffractive optical element 40 including a plurality of element diffractive optical elements, and projection optics, as in the illumination device described above. And a system 50. The projection optical system 50 is formed of a prism. This prism inclines with respect to the first prism surface 51a that changes the optical path of the first diffracted light L11 by refraction, and the first prism surface 51a, and refracts the optical path of the second diffracted light L12 by refracting the optical path of the first diffracted light L11. And a second prism surface 52a directed in a direction different from the light path.
　＜変形例５＞
　上述した第１の実施形態および上記変形例において、投射光学系が反射素子またはプリズムである場合について説明してきたが、これに限られない。投射光学系は、回折光学素子４０によって回折された１次回折光に回折作用を及ぼす投射用回折光学素子であってもよい。 <Modification 5>
Although the case where the projection optical system is the reflective element or the prism has been described in the first embodiment and the modification described above, the present invention is not limited to this. The projection optical system may be a projection diffractive optical element that exerts a diffractive action on the first-order diffracted light diffracted by the diffractive optical element 40.
　以下、図８を参照して、変形例５について説明する。図８に示す照明装置２００は、図２に示す照明装置１０と比較して、投射光学系が投射用回折光学素子２５０である点で異なっている。 Hereinafter, the fifth modification will be described with reference to FIG. The illumination device 200 shown in FIG. 8 differs from the illumination device 10 shown in FIG. 2 in that the projection optical system is a projection diffractive optical element 250.
　投射用回折光学素子２５０は、一例として、干渉縞パターンを記録されたホログラム記録媒体として構成される。干渉縞パターンを種々に調整することで、投射用回折光学素子２５０で回折される光の進行方向、言い換えると、投射用回折光学素子２５０で拡散される光の進行方向を、制御することができる。投射用回折光学素子２５０は、回折光学素子４０の各要素回折光学素子４１，４２と同様に作製することができる。 As an example, the projection diffractive optical element 250 is configured as a hologram recording medium on which an interference fringe pattern is recorded. By adjusting the interference fringe pattern variously, it is possible to control the traveling direction of the light diffracted by the projection diffractive optical element 250, in other words, the traveling direction of the light diffused by the projection diffractive optical element 250. . The projection diffractive optical element 250 can be manufactured in the same manner as the element diffractive optical elements 41 and 42 of the diffractive optical element 40.
　図８に示す例では、投射用回折光学素子２５０は、第１要素回折光学素子４１で回折された１次回折光である第１回折光Ｌ１１が入射する第１投射用回折領域２５１と、第２要素回折光学素子４２で回折された１次回折光である第２回折光Ｌ１２が入射する第２投射用回折領域２５２とを有する。そして、投射用回折光学素子２５０は、第１要素回折光学素子４１からの第１回折光Ｌ１１を、その第１投射用回折領域２５１における回折特性に応じた方向に向ける。また、投射用回折光学素子２５０は、第２要素回折光学素子４２からの第２回折光Ｌ１２を、その第２投射用回折領域２５２における回折特性に応じた方向に向ける。 In the example illustrated in FIG. 8, the projection diffractive optical element 250 includes a first projection diffraction region 251 on which the first diffracted light L11 that is first-order diffracted light diffracted by the first element diffractive optical element 41 is incident; And a second projection diffraction region 252 on which the second diffracted light L12 that is the first-order diffracted light diffracted by the element diffractive optical element 42 is incident. Then, the projection diffractive optical element 250 directs the first diffracted light L11 from the first element diffractive optical element 41 in a direction according to the diffraction characteristic of the first projection diffraction region 251. Further, the projection diffractive optical element 250 directs the second diffracted light L12 from the second element diffractive optical element 42 in a direction according to the diffraction characteristic of the second projection diffraction area 252.
　図示の例では、第１投射用回折領域２５１は、第１要素回折光学素子４１からの第１回折光Ｌ１１を回折して、第１被照明領域Ｚ１に向ける。また、第２投射用回折領域２５２は、第２要素回折光学素子４２からの第２回折光Ｌ１２を回折して、第２被照明領域Ｚ２に向ける。 In the illustrated example, the first projection diffraction region 251 diffracts the first diffracted light L11 from the first element diffractive optical element 41 and directs it to the first illuminated region Z1. Further, the second projection diffraction area 252 diffracts the second diffracted light L12 from the second element diffractive optical element 42 and directs it to the second illumination area Z2.
　このような投射用回折光学素子２５０を投射光学系として用いた場合、照明装置２００によって照明される被照明領域Ｚ１，Ｚ２は、投射用回折光学素子２５０の回折特性に応じた領域となる。したがって、投射用回折光学素子２５０を、当該投射用回折光学素子２５０とは異なる回折特性を有する他の投射用回折光学素子と交換することにより、照明装置２００によって照明される被照明領域Ｚ１，Ｚ２を、例えば図９に示す被照明領域Ｚ１ａ，Ｚ２ａから被照明領域Ｚ１ｂ，Ｚ２ｂに、変更することができる。 When such a projection diffractive optical element 250 is used as a projection optical system, the illuminated areas Z1 and Z2 illuminated by the illumination device 200 become areas according to the diffraction characteristics of the projection diffractive optical element 250. Therefore, by replacing the projection diffractive optical element 250 with another projection diffractive optical element having a diffraction characteristic different from that of the projection diffractive optical element 250, the illuminated regions Z1 and Z2 are illuminated by the illumination device 200. For example, the illumination areas Z1a and Z2a shown in FIG. 9 can be changed to illumination areas Z1b and Z2b.
　以上のように変形例５によれば、投射光学系２５０は、回折光学素子４０によって回折された光Ｌ１１，Ｌ１２を回折する投射用回折光学素子である。これにより、投射用回折光学素子２５０を、当該投射用回折光学素子２５０とは異なる回折特性を有する他の投射用回折光学素子と交換することにより、照明装置２００によって照明される被照明領域Ｚ１，Ｚ２を変更することができる。 As described above, according to the fifth modification, the projection optical system 250 is a projection diffractive optical element that diffracts the lights L11 and L12 diffracted by the diffractive optical element 40. As a result, by replacing the projection diffractive optical element 250 with another projection diffractive optical element having a diffraction characteristic different from that of the projection diffractive optical element 250, the illuminated area Z1, which is illuminated by the illumination device 200. Z2 can be changed.
　＜変形例６＞
　上述した変形例５において、投射用回折光学素子２５０の第１投射用回折領域２５１の部分と第２投射用回折領域２５２の部分とが一体に形成されている場合について説明してきたが、これに限られない。 <Modification 6>
In the fifth modification described above, the case where the portion of the first projection diffraction region 251 of the projection diffractive optical element 250 and the portion of the second projection diffraction region 252 are integrally formed has been described. It is not limited.
　図１０に示す例において、投射用回折光学素子２５０の第１投射用回折領域２５１の部分と第２投射用回折領域２５２の部分とは、別体として構成されている。より具体的には、投射用回折光学素子２５０は、第１要素回折光学素子４１で回折された１次回折光が入射する第１投射用要素回折光学素子２５３と、第２要素回折光学素子４２で回折された１次回折光が入射する第２投射用要素回折光学素子２５４とを有する。第１投射用要素回折光学素子２５３は、第１要素回折光学素子４１からの１次回折光である第１回折光Ｌ１１を回折して、第１の方向に、より具体的には第１被照明領域Ｚ１に向ける。また、第２投射用要素回折光学素子２５４は、第２要素回折光学素子４２からの１次回折光である第２回折光Ｌ１２を回折して、第１の方向とは異なる第２の方向に、より具体的には第２被照明領域Ｚ２に向ける。 In the example shown in FIG. 10, the portion of the first projection diffraction region 251 of the projection diffractive optical element 250 and the portion of the second projection diffraction region 252 are configured separately. More specifically, the projection diffractive optical element 250 includes the first projection element diffractive optical element 253 on which the first-order diffracted light diffracted by the first element diffractive optical element 41 is incident, and the second element diffractive optical element 42. And a second projection element diffractive optical element 254 on which the diffracted first-order diffracted light is incident. The first projection element diffractive optical element 253 diffracts the first diffracted light L11, which is the first-order diffracted light from the first element diffractive optical element 41, and more specifically the first illuminated light in the first direction. Aim at area Z1. The second projection element diffractive optical element 254 diffracts the second diffracted light L12, which is the first-order diffracted light from the second element diffractive optical element 42, to a second direction different from the first direction. More specifically, the light is directed to the second illuminated area Z2.
　このような投射用回折光学素子２５０を投射光学系として用いた場合、第１および第２投射用要素回折光学素子２５３，２５４のいずれか一方を当該投射用要素回折光学素子２５３，２５４とは異なる回折特性を有する他の投射用要素回折光学素子と交換することにより、第１および第２被照明領域Ｚ１，Ｚ２の一方のみを、例えば図９に示す被照明領域Ｚ１ａから被照明領域Ｚ１ｂに、あるいは被照明領域Ｚ２ａから被照明領域Ｚ２ｂに、変更することができる。 When such a projection diffractive optical element 250 is used as a projection optical system, one of the first and second projection element diffractive optical elements 253 and 254 is different from the projection element diffractive optical elements 253 and 254. By replacing with another projection element diffractive optical element having diffraction characteristics, only one of the first and second illuminated areas Z1 and Z2 is switched from the illuminated area Z1a shown in FIG. 9 to the illuminated area Z1b, for example, Alternatively, the illumination area Z2a can be changed to the illumination area Z2b.
　以上のように変形例６によれば、回折光学素子４０は、光源１５から射出した光の一部を回折する第１要素回折光学素子４１と、光源１５から射出した光の他の一部を回折する第２要素回折光学素子４１と、を有している。また、投射用回折光学素子２５０は、第１要素回折光学素子４１で回折された１次回折光である第１回折光Ｌ１１を回折して第１の方向に向ける第１投射用要素回折光学素子２５３と、第２要素回折光学素子４２で回折された１次回折光である第２回折光Ｌ１２を回折して第１の方向とは異なる第２の方向に向ける第２投射用要素回折光学素子２５４と、有する。これにより、第１および第２投射用要素回折光学素子２５３，２５４のいずれか一方を当該投射用要素回折光学素子２５３，２５４とは異なる回折特性を有する他の投射用要素回折光学素子と交換することにより、第１および第２被照明領域Ｚ１，Ｚ２の一方のみを変更することができる。 As described above, according to the sixth modification, the diffractive optical element 40 includes the first element diffractive optical element 41 that diffracts a part of the light emitted from the light source 15 and the other part of the light emitted from the light source 15 And a second element diffractive optical element 41 that diffracts. In addition, the projection diffractive optical element 250 diffracts the first diffracted light L11 which is the first-order diffracted light diffracted by the first element diffractive optical element 41 and directs it in the first direction. And a second projection element diffractive optical element 254 for diffracting the second diffracted light L12 which is the first order diffracted light diffracted by the second element diffractive optical element 42 and directing it to a second direction different from the first direction; Have. Thereby, any one of the first and second projection element diffractive optical elements 253 and 254 is replaced with another projection element diffractive optical element having diffraction characteristics different from those of the projection element diffractive optical elements 253 and 254. Thus, only one of the first and second illumination areas Z1 and Z2 can be changed.
　＜変形例７＞
　上述した第１の実施形態および変形例１～６において、回折光学素子４０が複数の要素回折光学素子を有する場合について説明してきたが、これに限られない。回折光学素子４０は、単一の要素回折光学素子により構成されていてもよい。 <Modification 7>
Although the case where the diffractive optical element 40 includes a plurality of element diffractive optical elements has been described in the first embodiment and the first to sixth modifications described above, the present invention is not limited to this. The diffractive optical element 40 may be composed of a single element diffractive optical element.
　以下、図１１を参照して、変形例７について説明する。図１１に示す照明装置３００は、図２に示す照明装置と比較して、回折光学素子４０が単一の要素回折光学素子で構成されている点で異なっている。また、投射光学系３５０が、ハーフミラー３５１と反射素子３５２とを含む点で異なっている。 Hereinafter, the seventh modification will be described with reference to FIG. The illumination device 300 shown in FIG. 11 is different from the illumination device shown in FIG. 2 in that the diffractive optical element 40 is configured of a single element diffractive optical element. Further, the projection optical system 350 is different in that it includes a half mirror 351 and a reflecting element 352.
　図１１に示す例において、回折光学素子４０は、光源１５から射出した光の全てを回折する。 In the example shown in FIG. 11, the diffractive optical element 40 diffracts all of the light emitted from the light source 15.
　投射光学系３５０のハーフミラー３５１および反射素子３５２は、回折光学素子４０で回折された１次回折光Ｌ１の光路上に配置されている。ハーフミラー３５１は、回折光学素子４０から反射素子３５２までの光路に沿った回折光学素子４０と反射素子３５２との間に配置されている。 The half mirror 351 and the reflection element 352 of the projection optical system 350 are disposed on the optical path of the first-order diffracted light L1 diffracted by the diffractive optical element 40. The half mirror 351 is disposed between the diffractive optical element 40 and the reflective element 352 along the optical path from the diffractive optical element 40 to the reflective element 352.
　ハーフミラー３５１は、回折光学素子３４０で回折された１次回折光Ｌ１の一部Ｌ１１を反射させて第１方向に向け、他の一部Ｌ１２を透過させる。反射素子３５２は、ハーフミラー３５１を透過した１次回折光Ｌ１の他の一部Ｌ１２を反射させて第２方向に向ける。図示の例では、ハーフミラー３５１で反射された光Ｌ１１は第１被照明領域Ｚ１に向けられ、反射素子３５２で反射された光Ｌ１２は第２被照明領域Ｚ２に向けられる。 The half mirror 351 reflects a portion L11 of the first-order diffracted light L1 diffracted by the diffractive optical element 340, directs it in the first direction, and transmits the other portion L12. The reflective element 352 reflects the other part L12 of the first order diffracted light L1 transmitted through the half mirror 351 and directs it in the second direction. In the illustrated example, the light L11 reflected by the half mirror 351 is directed to the first illuminated area Z1, and the light L12 reflected by the reflecting element 352 is directed to the second illuminated area Z2.
　このような照明装置３００によっても、光源１５から射出された光を複数の方向に向けて、複数の被照明領域Ｚ１，Ｚ２を照明することができる。なお、図示の例では、回折光学素子４０は単一の要素回折光学素子で構成されているが、これに限られない。図２に示す例と同様に、回折光学素子４０は、複数の要素回折光学素子４１，４２を含んでいてもよい。 Also with such an illumination device 300, it is possible to direct the light emitted from the light source 15 in a plurality of directions to illuminate the plurality of illumination regions Z1 and Z2. In the illustrated example, the diffractive optical element 40 is configured of a single element diffractive optical element, but is not limited thereto. Similar to the example shown in FIG. 2, the diffractive optical element 40 may include a plurality of element diffractive optical elements 41 and 42.
　以上のように変形例７によれば、投射光学系３５０は、回折光学素子４０で回折された１次回折光Ｌ１の一部Ｌ１１を反射させ他の一部Ｌ１２を透過させるハーフミラー３５１と、ハーフミラー３５１を透過した１次回折光Ｌ１の他の一部Ｌ１２を反射する反射素子３５２と、を含む。このような照明装置３００では、投射光学系３５０によって、回折光学素子４０で回折された１次回折光Ｌ１の一部Ｌ１１と他の一部Ｌ１２とが異なる方向に向けられる。このため、照明装置３００は、複数方向に光を投射して複数の被照明領域Ｚ１，Ｚ２を照明することができる。 As described above, according to the seventh modification, the projection optical system 350 includes the half mirror 351 that reflects a part L11 of the first-order diffracted light L1 diffracted by the diffractive optical element 40 and transmits the other part L12. And a reflective element 352 for reflecting another portion L12 of the first-order diffracted light L1 transmitted through the mirror 351. In such an illumination device 300, the projection optical system 350 directs one portion L11 of the first-order diffracted light L1 diffracted by the diffractive optical element 40 and the other portion L12 in different directions. Therefore, the lighting device 300 can project light in a plurality of directions to illuminate the plurality of illumination target areas Z1 and Z2.
　＜変形例８＞
　上述した変形例５および６において、投射用回折光学素子２５０の一部または全てを交換することにより、被照明領域Ｚ１，Ｚ２を移動させる場合について説明してきたが、これに限られない。例えば、照明装置１０，１００，２００，３００を収容する筐体６０を回転可能な台座の上に載置する等して回転可能に配置して、筐体６０を照明装置１０，１００，２００，３００と共に回転させることにより、被照明領域をＺ１，Ｚ２，Ｚ３を移動させてもよい。あるいは、筐体６０内の照明装置１０，１００，２００，３００を回転可能に支持して、照明装置１０，１００，２００，３００を回転させることにより、被照明領域Ｚ１，Ｚ２，Ｚ３を移動させてもよい。あるいは、回折光学素子４０，１４０を回転可能に支持して、回折光学素子４０，１４０を回転させることにより、被照明領域Ｚ１，Ｚ２，Ｚ３を移動させてもよい。あるいは、投射光学系５０，１５０，２５０，３５０を回転可能に支持し、投射光学系５０，１５０，２５０，３５０を回転させることにより、被照明領域Ｚ１，Ｚ２，Ｚ３を移動させてもよい。あるいは、回折光学素子４０，１４０および投射光学系５０，１５０，２５０，３５０を回転可能に支持し、回折光学素子４０，１４０と共に投射光学系５０，１５０，２５０，３５０を回転させることにより、被照明領域Ｚ１，Ｚ２，Ｚ３を移動させてもよい。 <Modification 8>
In the fifth and sixth modifications described above, the case where the illuminated regions Z1 and Z2 are moved by replacing part or all of the projection diffractive optical element 250 has been described, but the present invention is not limited thereto. For example, the housing 60 containing the lighting devices 10, 100, 200, and 300 is rotatably disposed by mounting the housing 60 on a rotatable pedestal or the like, and the lighting device 10, 100, 200, The illumination area may be moved by Z1, Z2, and Z3 by rotating along with 300. Alternatively, the illumination devices 10, 100, 200, and 300 in the housing 60 are rotatably supported, and the illumination devices 10, 100, 200, and 300 are rotated to move the illumination regions Z1, Z2, and Z3. May be Alternatively, the illumination regions Z1, Z2, and Z3 may be moved by rotatably supporting the diffractive optical elements 40 and 140 and rotating the diffractive optical elements 40 and 140. Alternatively, the projection optical systems 50, 150, 250, and 350 may be rotatably supported, and the projection optical systems 50, 150, 250, and 350 may be rotated to move the illumination regions Z1, Z2, and Z3. Alternatively, the diffractive optical elements 40 and 140 and the projection optical systems 50, 150, 250, and 350 are rotatably supported, and the projection optical systems 50, 150, 250, and 350 are rotated together with the diffractive optical elements 40 and 140. The illumination areas Z1, Z2, and Z3 may be moved.
　＜第２の実施形態＞
　次に、図１２を参照して、第２の実施形態について説明する。以下の説明および以下の説明で用いる図面では、上述した第１の実施形態と同様に構成され得る部分について、上述の第１の実施形態における対応する部分に対して用いた符号と同一の符号を用いることとし、重複する説明を省略する。 Second Embodiment
Next, a second embodiment will be described with reference to FIG. In the following description and the drawings used in the following description, for the parts that can be configured in the same manner as the first embodiment described above, the same reference numerals as the reference numerals used for the corresponding parts in the first embodiment described above are used. It shall be used and the duplicate explanation is omitted.
　まず、図１および図２に示す照明装置において、光源からの光の一部は、回折光学素子で回折されることなく当該回折光学素子を透過し、いわゆる０次光となる。このような０次光が投射光学系で反射または屈折されると、観察者の目に入り込むなどの安全上の問題を引き起こすおそれがある。また、０次光が被照明領域に入射してしまうと、周囲と比較して明るさ（輝度）が急激に上昇する点状領域、線状領域、面状領域等の異常領域が被照明領域内に発生してしまう。 First, in the illumination device shown in FIGS. 1 and 2, a part of light from the light source is transmitted through the diffractive optical element without being diffracted by the diffractive optical element, and becomes so-called zero-order light. If such zero-order light is reflected or refracted by the projection optical system, it may cause safety problems such as penetration into the eyes of the observer. In addition, when zero-order light is incident on the illuminated area, abnormal areas such as a dotted area, a linear area, and a planar area where the brightness (brightness) rises sharply compared to the surroundings are the illuminated area It will occur inside.
　また、上述のように、ホログラム素子のような要素回折光学素子では、回折光として、１次回折光の他に２次以上の高次の回折光が生じる。高次回折光が投射光学系で反射または屈折されると、観察者の目に入り込むなどの安全上の問題を引き起こすおそれがある。また、高次回折光が投影面に投射されると、被照明領域以外の領域も照明されて被照明領域を認識しづらくなるなどの問題を引き起こすおそれがある。 Further, as described above, in an element diffractive optical element such as a hologram element, second-order or higher-order diffracted light is generated as the diffracted light in addition to the first-order diffracted light. When the high-order diffracted light is reflected or refracted by the projection optical system, it may cause safety problems such as penetration into the eyes of the observer. In addition, when the high-order diffracted light is projected onto the projection plane, a region other than the region to be illuminated is also illuminated, which may cause problems such as difficulty in recognizing the region to be illuminated.
　このような問題を解決するため、第２の実施形態においては、０次光および高次回折光が投射光学系に入射することを防ぐための工夫がなされている。以下、図１２を参照して、第２の実施形態の照明装置４００について、より詳細に説明する。 In order to solve such a problem, in the second embodiment, a device for preventing zero-order light and high-order diffracted light from being incident on the projection optical system is made. Hereinafter, with reference to FIG. 12, the illumination device 400 of the second embodiment will be described in more detail.
　図１２に示す照明装置４００は、図１に示す照明装置１０と比較して、回折光学素子４０と投射光学系５０との間に第１レンズ７１、第２レンズ７２、０次光マスク８１および高次回折光マスク８２が配置されている点が異なるのみであり、その他の構成は、図１および図２に示す照明装置１０と略同一である。 The illumination device 400 shown in FIG. 12 is different from the illumination device 10 shown in FIG. 1 in that the first lens 71, the second lens 72, the zeroth-order light mask 81, and the diffractive optical element 40 and the projection optical system 50. The only difference is that the high-order diffraction light mask 82 is disposed, and the other configuration is substantially the same as the illumination device 10 shown in FIGS. 1 and 2.
　第１レンズ７１および第２レンズ７２は、回折光学素子４０から投射光学系５０までの光路に沿った回折光学素子４０と投射光学系５０との間に配置されている。より具体的には、次のように、回折光学素子４０、投射光学系５０、第１レンズ７１および第２レンズ７２が配置されている。 The first lens 71 and the second lens 72 are disposed between the diffractive optical element 40 and the projection optical system 50 along the optical path from the diffractive optical element 40 to the projection optical system 50. More specifically, the diffractive optical element 40, the projection optical system 50, the first lens 71, and the second lens 72 are disposed as follows.
　第１レンズ７１は、回折光学素子４０から投射光学系５０までの光路に沿った回折光学素子４０と投射光学系５０との間に、回折光学素子４０から第１レンズ７１の焦点距離ｆ１だけ離間して配置されている。また、第２レンズ７２は、第１レンズ７１から投射光学系５０までの光路に沿った第１レンズ７１と投射光学系５０との間に配置されている。第２レンズ７２は、第１レンズ７１から第１レンズ７１の焦点距離ｆ１と第２レンズ７２の焦点距離ｆ２との和だけ離間して配置されている。なお、第２レンズ７２と投射光学系５０との距離については、特に限定されない。図１２に示す例では、第２レンズ７２は、投射光学系５０における第１回折光Ｌ１１および第２回折光Ｌ１２の入射位置から第２レンズ７２の焦点距離ｆ２だけ離間して配置されているが、第２レンズ７２と投射光学系５０との距離は、焦点距離ｆ２よりも大きくてもよいし小さくてもよい。図１２に示す例では、第１レンズ７１、第２レンズ７２、回折光学素子４０により４ｆ光学系を形成している。 The first lens 71 is separated between the diffractive optical element 40 and the projection optical system 50 along the optical path from the diffractive optical element 40 to the projection optical system 50 by the focal distance f1 of the first lens 71 from the diffractive optical element 40 It is arranged. The second lens 72 is disposed between the first lens 71 and the projection optical system 50 along the optical path from the first lens 71 to the projection optical system 50. The second lens 72 is spaced from the first lens 71 by the sum of the focal length f1 of the first lens 71 and the focal length f2 of the second lens 72. The distance between the second lens 72 and the projection optical system 50 is not particularly limited. In the example shown in FIG. 12, the second lens 72 is disposed apart from the incident position of the first diffracted light L11 and the second diffracted light L12 in the projection optical system 50 by the focal distance f2 of the second lens 72. The distance between the second lens 72 and the projection optical system 50 may be larger or smaller than the focal length f2. In the example shown in FIG. 12, the 4f optical system is formed by the first lens 71, the second lens 72, and the diffractive optical element 40.
　第１レンズ７１は、第１要素回折光学素子４１を透過した０次光Ｌ０１および第２要素回折光学素子４２を透過した０次光Ｌ０２を、第１レンズ７１の焦点面Ｐ上の点ａに向ける。また、第１レンズ７１は、第１要素回折光学素子４１での１次回折光（第１回折光）Ｌ１１および高次回折光Ｌ２１の進行方向を、第１レンズ７１を通過した０次光Ｌ０１の進行方向と平行な方向に変える。また、第１レンズ７１は、第２要素回折光学素子４２での１次回折光（第２回折光）Ｌ１２および高次回折光Ｌ２２の進行方向を、第１レンズ７１を通過した０次光Ｌ０２の進行方向と平行な方向に変える。これにより、図１２に示すように、０次光Ｌ０１，Ｌ０２、１次回折光Ｌ１１，Ｌ１２および高次回折光Ｌ２１，Ｌ２２の焦点面Ｐへの入射位置は、それぞれ、点ａ、点ａの周辺領域、当該周辺領域の外側領域に集約されることとなる。 The first lens 71 sets the zeroth-order light L01 transmitted through the first element diffractive optical element 41 and the zeroth-order light L02 transmitted through the second element diffractive optical element 42 to a point a on the focal plane P of the first lens 71. Turn. The first lens 71 also advances the 0th-order light L01 that has passed through the first lens 71 in the traveling direction of the first-order diffracted light (first diffracted light) L11 and the high-order diffracted light L21 of the first element diffractive optical element 41. Change the direction parallel to the direction. The first lens 71 also advances the 0th-order light L02 that has passed through the first lens 71 in the direction of travel of the first-order diffracted light (second diffracted light) L12 and the high-order diffracted light L22 at the second element diffractive optical element 42. Change the direction parallel to the direction. Thereby, as shown in FIG. 12, the incident positions of the zero-order light L01, L02, the first-order diffracted lights L11, L12 and the high-order diffracted lights L21, L22 on the focal plane P are the area around point a and point a, respectively. , It will be summarized in the outer region of the peripheral region.
　第２レンズ７２は、後述する０次光マスク８１および高次回折光マスク８２の間の領域を通過した光、すなわち第１回折光Ｌ１１および第２回折光Ｌ１２を、それぞれ投射光学系５０に向けて集光させる。 The second lens 72 directs, to the projection optical system 50, light which has passed through a region between a zero-order light mask 81 and a high-order diffracted light mask 82 described later, that is, first diffracted light L11 and second diffracted light L12. Focus.
　０次光マスク８１は、第１レンズ７１から第２レンズ７２までの光路に沿った第１レンズ７１と第２レンズ７２との間に配置される。０次光マスク８１は、第１レンズ７１から第１レンズ７１の焦点距離ｆ１だけ離間して、第１レンズ７１の焦点面Ｐ上に配置される。０次光マスク８１は、焦点面Ｐの０次光Ｌ０１，Ｌ０２が入射する位置ａと重なるが、１次回折光Ｌ１１，Ｌ１２および高次回折光Ｌ２１，Ｌ２２が入射する位置とは重ならない位置に配置される。この結果、０次光マスク８１は、回折光学素子４０での回折光のうち、０次光Ｌ０１，Ｌ０２のみを遮断することができるようになっている。 The zero-order light mask 81 is disposed between the first lens 71 and the second lens 72 along the optical path from the first lens 71 to the second lens 72. The zero-order light mask 81 is disposed on the focal plane P of the first lens 71 at a distance from the first lens 71 by the focal length f 1 of the first lens 71. The 0th-order light mask 81 overlaps with the position a of the focal plane P where the 0th-order light L01, L02 is incident, but is disposed at a position not overlapping with the 1st-order diffracted light L11, L12 and the high-order diffracted light L21, L22. Be done. As a result, the 0th-order light mask 81 can block only the 0th-order lights L01 and L02 among the diffracted lights in the diffractive optical element 40.
　高次回折光マスク８２も、０次光マスク８１と同一面上に配置される。すなわち、高次回折光マスク８２は、第１レンズ７１から第２レンズ７２までの光路に沿った第１レンズ７１と第２レンズ７２との間に配置される。高次回折光マスク８２は、第１レンズ７１から第１レンズ７１の焦点距離ｆ１だけ離間して、第１レンズ７１の焦点面Ｐ上に配置される。高次回折光マスク８２は、焦点面Ｐの高次回折光Ｌ２１，Ｌ２２が入射する位置と重なるが、０次回折光Ｌ０１，Ｌ０２および１次回折光Ｌ１１，Ｌ１２が入射する位置とは重ならない位置に配置される。この結果、高次回折光マスク８２は、回折光学素子４０での回折光のうち、高次回折光Ｌ２１，Ｌ２２のみを遮断することができるようになっている。 The high-order diffracted light mask 82 is also disposed on the same plane as the zero-order light mask 81. That is, the high-order diffraction light mask 82 is disposed between the first lens 71 and the second lens 72 along the optical path from the first lens 71 to the second lens 72. The high-order diffracted light mask 82 is disposed on the focal plane P of the first lens 71 at a distance from the first lens 71 by the focal length f 1 of the first lens 71. The high-order diffracted light mask 82 overlaps the position where the high-order diffracted light L21, L22 on the focal plane P is incident, but is disposed at a position not overlapping the position where the zero-order diffracted light L01, L02 and the first-order diffracted light L11, L12 are incident. Ru. As a result, the high-order diffracted light mask 82 can block only the high-order diffracted lights L21 and L22 among the diffracted lights in the diffractive optical element 40.
　図示の例では、０次光マスク８１および高次回折光マスク８２は、それぞれ、０次光Ｌ０１，Ｌ０２および高次回折光Ｌ２１，Ｌ２２を吸収する板状部材であるが、これに限られない。例えば、０次光マスク８１および高次回折光マスク８２は、それぞれ、０次光Ｌ０１，Ｌ０２および高次回折光Ｌ２１，Ｌ２２を投射光学系５０以外に向けるものであってもよい。 In the illustrated example, the zero-order light mask 81 and the high-order diffracted light mask 82 are plate-like members that absorb the zero-order lights L01 and L02 and the high-order diffracted lights L21 and L22, respectively. For example, the zero-order light mask 81 and the high-order diffracted light mask 82 may direct the zero-order lights L01 and L02 and the high-order diffracted lights L21 and L22 to other than the projection optical system 50, respectively.
　次に、以上に説明した構成からなる照明装置４００の作用について説明する。 Next, the operation of the illumination device 400 configured as described above will be described.
　光源１５から射出した光は、まず、整形光学系３０に入射する。整形光学系３０では、光源１５から射出した光を拡大する。 The light emitted from the light source 15 first enters the shaping optical system 30. The shaping optical system 30 magnifies the light emitted from the light source 15.
　整形光学系３０で整形された光は、次に、回折光学素子４０へと向かう。第１要素回折光学素子４１では、光源１５から射出した光の一部を回折する。また、第２要素回折光学素子４２は、光源１５から射出した光の他の一部を回折する。 The light shaped by the shaping optical system 30 then travels to the diffractive optical element 40. The first element diffractive optical element 41 diffracts part of the light emitted from the light source 15. Further, the second element diffractive optical element 42 diffracts another part of the light emitted from the light source 15.
　回折光学素子４０で回折された光は、次に、第１レンズ７１へと向かう。また、各要素回折光学素子４１，４２を透過した０次光Ｌ０１，Ｌ０２も、第１レンズ７１へと向かう。第１レンズ７１では、０次光Ｌ０１，Ｌ０２を、第１レンズ７１の焦点面Ｐ上の点ａに向ける。また、第１レンズ７１では、第１要素回折光学素子４１での１次回折光Ｌ１１および高次回折光Ｌ２１を、０次光Ｌ０１の進行方向と平行な方向に向ける。また、第１レンズ７１では、第２要素回折光学素子４２での１次回折光Ｌ１２および高次回折光Ｌ２２を、０次光Ｌ０２の進行方向と平行な方向に向ける。 The light diffracted by the diffractive optical element 40 then travels to the first lens 71. Further, the zeroth-order lights L 01 and L 02 transmitted through the element diffractive optical elements 41 and 42 also travel to the first lens 71. The first lens 71 directs zero-order light L01 and L02 to a point a on the focal plane P of the first lens 71. In the first lens 71, the first-order diffracted light L11 and the high-order diffracted light L21 from the first element diffractive optical element 41 are directed in a direction parallel to the traveling direction of the zero-order light L01. Further, in the first lens 71, the first-order diffracted light L12 and the high-order diffracted light L22 in the second element diffractive optical element 42 are directed in the direction parallel to the traveling direction of the zero-order light L02.
　第１レンズ７１を通過した光のうち、０次光Ｌ０１，Ｌ０２は、０次光マスク８１に入射する。また、高次回折光Ｌ２１，Ｌ２２は、高次回折光マスク８２に入射する。一方、１次回折光（第１回折光および第２回折光）Ｌ１１，Ｌ１２は、０次光マスク８１および高次回折光マスク８２の間の領域を通過して、その進行方向を維持したまま第２レンズ７２に入射する。 Of the light having passed through the first lens 71, zero-order light L 01 and L 02 are incident on the zero-order light mask 81. The high-order diffracted lights L21 and L22 enter the high-order diffracted light mask 82. On the other hand, the first-order diffracted lights (first and second diffracted lights) L11 and L12 pass through the region between the zero-order light mask 81 and the high-order diffracted light mask 82, and the second traveling direction is maintained. The light is incident on the lens 72.
　第２レンズ７２に入射した第１回折光Ｌ１１および第２回折光Ｌ１２は、それぞれ、投射光学系５０の第１反射面５１上の点および第２反射面５２上の点に向かって集光する。 The first diffracted light L11 and the second diffracted light L12 incident on the second lens 72 are condensed toward a point on the first reflection surface 51 of the projection optical system 50 and a point on the second reflection surface 52, respectively. .
　第１反射面５１に入射した第１回折光Ｌ１１は、反射して、その進行方向を９０°を超える角度で変える。そして、第１反射面５１で反射した第１回折光Ｌ１１は、筒状の筐体６０に設けられた開口６１を通過して、投影面Ｓ上の第１被照明領域Ｚ１に入射する。また、第２反射面５２に入射した第２回折光Ｌ１２は、反射して、その進行方向を９０°を超える角度で変える。このとき、第２反射面５２で反射した第２回折光Ｌ１２は、第１反射面５１で反射した第１回折光Ｌ１１とは異なる方向に向かう。そして、第２反射面５２で反射した第２回折光Ｌ１２は、筒状の筐体６０に設けられた開口６１を通過して、投影面Ｓ上の第１被照明領域Ｚ１とは異なる第２被照明領域Ｚ２に入射する。 The first diffracted light L11 incident on the first reflection surface 51 is reflected to change its traveling direction at an angle of more than 90 °. Then, the first diffracted light L11 reflected by the first reflection surface 51 passes through the opening 61 provided in the cylindrical casing 60, and is incident on the first illumination area Z1 on the projection surface S. In addition, the second diffracted light L12 incident on the second reflection surface 52 is reflected to change its traveling direction at an angle of more than 90 °. At this time, the second diffracted light L12 reflected by the second reflection surface 52 travels in a direction different from that of the first diffracted light L11 reflected by the first reflection surface 51. Then, the second diffracted light L12 reflected by the second reflection surface 52 passes through the opening 61 provided in the cylindrical casing 60, and the second diffracted light L12 is different from the first illumination area Z1 on the projection surface S. The light is incident on the illuminated area Z2.
　以上のような第２の実施形態によれば、照明装置４００は、回折光学素子４０から投射光学系５０までの光路に沿った回折光学素子４０と投射光学系５０との間に配置された第１レンズ７１であって、回折光学素子４０から第１レンズ７１の焦点距離ｆ１だけ離間して配置された第１レンズ７１と、第１レンズ７１から投射光学系５０までの光路に沿った第１レンズ７１と投射光学系５０との間に配置された第２レンズで７２あって、第１レンズ７１から第１レンズ７１の焦点距離ｆ１と第２レンズ７２の焦点距離ｆ２との和だけ離間して配置された第２レンズ７２と、第１レンズ７１から第２レンズ７２までの光路に沿った第１レンズ７１と第２レンズ７２との間に配置され、回折光学素子４０での０次光Ｌ０１，Ｌ０２を遮断する０次光マスク８１と、を更に備えている。 According to the second embodiment as described above, the illumination device 400 is disposed between the diffractive optical element 40 and the projection optical system 50 along the optical path from the diffractive optical element 40 to the projection optical system 50. The first lens 71 is a single lens 71 and is separated from the diffractive optical element 40 by the focal length f1 of the first lens 71, and the first along the optical path from the first lens 71 to the projection optical system 50 The second lens 72 is disposed between the lens 71 and the projection optical system 50, and is separated from the first lens 71 by the sum of the focal length f1 of the first lens 71 and the focal length f2 of the second lens 72. And the second lens 72 disposed between the first lens 71 and the second lens 72 along the optical path from the first lens 71 to the second lens 72, and the zeroth-order light by the diffractive optical element 40 0th order to shut off L01 and L02 Further comprising a mask 81, a.
　このような照明装置４００によれば、回折光学素子４０を透過する０次光Ｌ０１，Ｌ０２が投射光学系５０で反射または屈折されることを防止することができる。これにより、０次光Ｌ０１，Ｌ０２が観察者の目に入り込んで安全上の問題を引き起こしたり、０次光が被照明領域に入射して、周囲と比較して明るさ（輝度）が急激に上昇する異常領域が被照明領域内に発生してしまうことが防止される。また、第１レンズ７１が回折光学素子４０から上述の距離だけ離間して配置されているため、回折光学素子４０での０次光Ｌ０１，Ｌ０２、１次回折光Ｌ１１，Ｌ１２および高次回折光Ｌ２１，Ｌ２２の進路が調整され、０次光マスク８１を、０次光Ｌ０１，Ｌ０２のみを遮断するように配置することが容易である。さらに、第２レンズ７２が第１レンズ７１から上述の距離だけ離間して配置されているため、第１レンズ７１および第２レンズ７２を通過した第１回折光Ｌ１１および第２回折光Ｌ１２の特性を、回折光学素子４０での第１回折光Ｌ１１および第２回折光Ｌ１２の特性に応じたものとすることができる。この結果、被照明領域Ｚ１，Ｚ２を、回折光学素子４０の回折特性（例えば要素回折光学素子４１，４２に記録された干渉縞パターン）に応じた所望のパターンで照明することが可能である。 According to such an illumination device 400, it is possible to prevent the zeroth-order light L01 and L02 transmitted through the diffractive optical element 40 from being reflected or refracted by the projection optical system 50. As a result, the 0th-order light L01 and L02 enter the eyes of the observer and cause a safety problem, or the 0th-order light enters the area to be illuminated, and the brightness (brightness) is abrupt compared to the surroundings. The rising abnormal area is prevented from occurring in the illuminated area. In addition, since the first lens 71 is disposed apart from the diffractive optical element 40 by the above-described distance, zero-order light L01, L02, first-order diffracted light L11, L12 and high-order diffracted light L21, The path of L22 is adjusted, and it is easy to arrange the zero-order light mask 81 so as to block only the zero-order lights L01 and L02. Furthermore, since the second lens 72 is disposed apart from the first lens 71 by the above-described distance, the characteristics of the first diffracted light L11 and the second diffracted light L12 that have passed through the first lens 71 and the second lens 72 Can be determined according to the characteristics of the first diffracted light L11 and the second diffracted light L12 in the diffractive optical element 40. As a result, it is possible to illuminate the illuminated areas Z1 and Z2 with a desired pattern according to the diffraction characteristics of the diffractive optical element 40 (for example, the interference fringe pattern recorded in the element diffractive optical elements 41 and 42).
　また、以上のような第２の実施形態によれば、照明装置４００は、回折光学素子４０から投射光学系５０までの光路に沿った回折光学素子４０と投射光学系５０との間に配置された第１レンズ７１であって、回折光学素子４０から第１レンズ７１の焦点距離ｆ１だけ離間して配置された第１レンズ７１と、第１レンズ７１から投射光学系５０までの光路に沿った第１レンズ７１と投射光学系５０との間に配置された第２レンズ７２であって、第１レンズ７１から第１レンズ７１の焦点距離ｆ１と第２レンズ７２の焦点距離ｆ２との和だけ離間して配置された第２レンズ７２と、第１レンズ７１から第２レンズ７２までの光路に沿った第１レンズ７１と第２レンズ７２との間に配置され、回折光学素子４０での高次回折光Ｌ２１，Ｌ２２を遮断する高次回折光マスク８２と、を更に備えている。 Further, according to the second embodiment as described above, the illumination device 400 is disposed between the diffractive optical element 40 and the projection optical system 50 along the optical path from the diffractive optical element 40 to the projection optical system 50. The first lens 71 is a first lens 71 disposed apart from the diffractive optical element 40 by the focal distance f1 of the first lens 71, and along the optical path from the first lens 71 to the projection optical system 50. The second lens 72 is disposed between the first lens 71 and the projection optical system 50, and is the sum of the focal distance f1 of the first lens 71 to the first lens 71 and the focal distance f2 of the second lens 72. It is disposed between the second lens 72 and the first lens 71 and the second lens 72 along the optical path from the first lens 71 to the second lens 72, and the height of the diffractive optical element 40 is high. Next-order diffracted light L21 and L22 And higher-order diffracted light mask 82, further comprising a.
　このような照明装置４００によれば、回折光学素子４０での高次回折光Ｌ２１，Ｌ２２が投射光学系５０で反射または屈折されることを防止することができる。これにより、高次回折光Ｌ２１，Ｌ２２が観察者の目に入り込んで安全上の問題を引き起こしたり、高次回折光Ｌ２１，Ｌ２２が投影面Ｓに投射されて被照明領域Ｚ１，Ｚ２以外の領域も照明され、被照明領域Ｚ１，Ｚ２を認識しづらくなることが防止される。また、第１レンズ７１が回折光学素子４０から上述の距離だけ離間して配置されているため、回折光学素子４０での０次光Ｌ０１，Ｌ０２、１次回折光Ｌ１１，Ｌ１２および高次回折光Ｌ２１，Ｌ２２の進路が調整され、高次回折光マスク８２を、高次回折光Ｌ２１，Ｌ２２のみを遮断するように配置することが容易である。さらに、第２レンズ７２が第１レンズ７１から上述の距離だけ離間して配置されているため、第１レンズ７１および第２レンズ７２を通過した第１回折光Ｌ１１および第２回折光Ｌ１２の特性を、回折光学素子４０での第１回折光Ｌ１１および第２回折光Ｌ１２の特性に応じたものとすることができる。この結果、被照明領域Ｚ１，Ｚ２を、回折光学素子４０の回折特性（例えば要素回折光学素子４１，４２に記録された干渉縞パターン）に応じた所望のパターンで照明することが可能である。 According to such an illumination device 400, it is possible to prevent the high-order diffracted lights L21 and L22 in the diffractive optical element 40 from being reflected or refracted by the projection optical system 50. As a result, the high-order diffracted lights L21 and L22 enter the eyes of the observer and cause a safety problem, or the high-order diffracted lights L21 and L22 are projected on the projection surface S and the areas other than the illuminated areas Z1 and Z2 are also illuminated. As a result, it is possible to prevent the illumination regions Z1 and Z2 from being difficult to recognize. In addition, since the first lens 71 is disposed apart from the diffractive optical element 40 by the above-described distance, zero-order light L01, L02, first-order diffracted light L11, L12 and high-order diffracted light L21, The path of L22 is adjusted, and it is easy to arrange the high-order diffracted light mask 82 so as to block only the high-order diffracted lights L21 and L22. Furthermore, since the second lens 72 is disposed apart from the first lens 71 by the above-described distance, the characteristics of the first diffracted light L11 and the second diffracted light L12 that have passed through the first lens 71 and the second lens 72 Can be determined according to the characteristics of the first diffracted light L11 and the second diffracted light L12 in the diffractive optical element 40. As a result, it is possible to illuminate the illuminated areas Z1 and Z2 with a desired pattern according to the diffraction characteristics of the diffractive optical element 40 (for example, the interference fringe pattern recorded in the element diffractive optical elements 41 and 42).
　以上において、複数の実施の形態とその変形例を説明してきたが、当然に、異なる実施形態や異なる変形例として説明された複数の構成を適宜組み合わせることも可能である。 In the above, although several embodiment and its modification were demonstrated, it is also possible to combine suitably the several structure demonstrated as a different embodiment and a different modification, of course.
Ｚ１　第１被照明領域
Ｚ２　第２被照明領域
１０　照明装置
１５　光源
３２　コリメートレンズ
４０　回折光学素子
４１　第１要素回折光学素子
４２　第２要素回折光学素子
５０　投射光学系
５１　第１反射面
５２　第２反射面
７１　第１レンズ
７２　第２レンズ
８１　０次光マスク
８２　高次回折光マスク Z1 First Illuminated Region Z2 Second Illuminated Region 10 Illumination Device 15 Light Source 32 Collimator Lens 40 Diffractive Optical Element 41 First Element Diffractive Optical Element 42 Second Element Diffractive Optical Element 50 Projection Optical System 51 First Reflective Surface 52 Second Reflecting surface 71 First lens 72 Second lens 81 0th order light mask 82 High order diffracted light mask

Claims (16)

  1. 　光を射出する光源と、
    　前記光源から射出した前記光を回折する回折光学素子と、
    　前記回折光学素子によって回折された光を反射または屈折させて投影面に向ける投射光学系と、を備え、
    　前記投射光学系は、前記回折光学素子で回折された１次回折光の一部と他の一部とを異なる方向に向ける、照明装置。     A light source for emitting light,
    A diffractive optical element that diffracts the light emitted from the light source;
    And a projection optical system that reflects or refracts the light diffracted by the diffractive optical element and directs it to a projection surface.
    The projection optical system directs a part of first-order diffracted light diffracted by the diffractive optical element in a different direction from another part.
  2. 　前記回折光学素子は、前記光源から射出した前記光の一部を回折する第１要素回折光学素子と、前記光源から射出した前記光の他の一部を回折する第２要素回折光学素子と、を有し、
    　前記投射光学系は、前記第１要素回折光学素子で回折された１次回折光である第１回折光と、前記第２要素回折光学素子で回折された１次回折光である第２回折光と、を異なる方向に向ける、請求項１に記載の照明装置。     The diffractive optical element includes: a first element diffractive optical element that diffracts a part of the light emitted from the light source; and a second element diffractive optical element that diffracts another part of the light emitted from the light source. Have
    The projection optical system includes: first diffracted light which is first order diffracted light diffracted by the first element diffractive optical element; and second diffracted light which is first order diffracted light diffracted by the second element diffractive optical element; The lighting device according to claim 1, wherein the light sources are directed in different directions.
  3. 　前記投射光学系は、反射素子またはプリズムである、請求項１または２に記載の照明装置。 The illumination device according to claim 1, wherein the projection optical system is a reflective element or a prism.
  4. 　前記投射光学系は、前記回折光学素子で回折された１次回折光の一部を反射させ他の一部を透過させるハーフミラーと、前記ハーフミラーを透過した前記１次回折光の他の一部を反射する反射素子と、を含む、請求項１または２に記載の照明装置。 The projection optical system includes a half mirror that reflects a part of the first-order diffracted light diffracted by the diffractive optical element and transmits another part, and the other part of the first-order diffracted light transmitted through the half mirror. And a reflective element that reflects light.
  5. 　前記投射光学系は、前記回折光学素子によって回折された光を回折する投射用回折光学素子である、請求項１または２に記載の照明装置。 The illumination device according to claim 1, wherein the projection optical system is a projection diffractive optical element that diffracts the light diffracted by the diffractive optical element.
  6. 　前記回折光学素子は、前記光源から射出した前記光の一部を回折する第１要素回折光学素子と、前記光源から射出した前記光の他の一部を回折する第２要素回折光学素子と、を有し、
    　前記投射用回折光学素子は、前記第１要素回折光学素子で回折された１次回折光である第１回折光を回折して第１の方向に向ける第１投射用要素回折光学素子と、前記第２要素回折光学素子で回折された１次回折光である第２回折光を回折して前記第１の方向とは異なる第２の方向に向ける第２投射用要素回折光学素子と、有する、請求項５に記載の照明装置。     The diffractive optical element includes: a first element diffractive optical element that diffracts a part of the light emitted from the light source; and a second element diffractive optical element that diffracts another part of the light emitted from the light source. Have
    The projection diffractive optical element is a first projection element diffractive optical element that diffracts first diffraction light, which is first-order diffraction light that is diffracted by the first element diffractive optical element, and directs the first diffraction light in a first direction; A second projection element diffractive optical element for diffracting second diffracted light, which is first-order diffracted light diffracted by the two-element diffractive optical element, and directing it to a second direction different from the first direction; The lighting device according to 5.
  7. 　前記光源から前記回折光学素子までの光路に沿った前記光源と前記回折光学素子との間に配置されたコリメートレンズを更に備える、請求項１乃至６のいずれか一項に記載の照明装置。 The illumination device according to any one of claims 1 to 6, further comprising: a collimating lens disposed between the light source and the diffractive optical element along the optical path from the light source to the diffractive optical element.
  8. 　前記投射光学系は、前記回折光学素子で回折された１次回折光の一部の進行方向を９０°を超える角度で変化させ、且つ、前記回折光学素子で回折された１次回折光の他の一部の進行方向を９０°を超える角度で変化させる、請求項１乃至７のいずれか一項に記載の照明装置。 The projection optical system changes the traveling direction of a part of the first-order diffracted light diffracted by the diffractive optical element by an angle exceeding 90 °, and another one of the first-order diffracted light diffracted by the diffractive optical element The lighting device according to any one of claims 1 to 7, wherein the traveling direction of the part is changed at an angle of more than 90 °.
  9. 　前記照明装置は、筒状の筐体内に収容されている、請求項１乃至８のいずれか一項に記載の照明装置。 The lighting device according to any one of claims 1 to 8, wherein the lighting device is housed in a cylindrical casing.
  10. 　前記筐体は、回転可能に配置されている、請求項９に記載の照明装置。 The lighting device according to claim 9, wherein the housing is rotatably disposed.
  11. 　回転可能に支持されている、請求項１乃至１０のいずれか一項に記載の照明装置。 The lighting device according to any one of claims 1 to 10, which is rotatably supported.
  12. 　前記投射光学系は、回転可能に支持されている、請求項１乃至１１のいずれか一項に記載の照明装置。 The lighting device according to any one of claims 1 to 11, wherein the projection optical system is rotatably supported.
  13. 　前記回折光学素子は、回転可能に支持されている、請求項１乃至１２のいずれか一項に記載の照明装置。 The illumination device according to any one of claims 1 to 12, wherein the diffractive optical element is rotatably supported.
  14. 　前記回折光学素子から前記投射光学系までの光路に沿った前記回折光学素子と前記投射光学系との間に配置された第１レンズであって、前記回折光学素子から当該第１レンズの焦点距離だけ離間して配置された第１レンズと、
    　前記第１レンズから前記投射光学系までの光路に沿った前記第１レンズと前記投射光学系との間に配置された第２レンズであって、前記第１レンズから前記第１レンズの焦点距離と当該第２レンズの焦点距離との和だけ離間して配置された第２レンズと、
    　前記第１レンズから前記第２レンズまでの光路に沿った前記第１レンズと前記第２レンズとの間に配置され、前記回折光学素子での０次光を遮断する０次光マスクと、を更に備えた、請求項１乃至１３のいずれか一項に記載の照明装置。     A first lens disposed between the diffractive optical element along the optical path from the diffractive optical element to the projection optical system and the projection optical system, wherein a focal distance of the first lens from the diffractive optical element A first lens spaced apart by
    A second lens disposed between the first lens along the optical path from the first lens to the projection optical system and the projection optical system, wherein a focal distance of the first lens to the first lens And a second lens disposed spaced apart by the sum of the focal length of the second lens and the second lens,
    A zero-order light mask disposed between the first lens and the second lens along the optical path from the first lens to the second lens, for blocking zero-order light in the diffractive optical element; The lighting device according to any one of claims 1 to 13, further comprising:
  15. 　前記回折光学素子から前記投射光学系までの光路に沿った前記回折光学素子と前記投射光学系との間に配置された第１レンズであって、前記回折光学素子から当該第１レンズの焦点距離だけ離間して配置された第１レンズと、
    　前記第１レンズから前記投射光学系までの光路に沿った前記第１レンズと前記投射光学系との間に配置された第２レンズであって、前記第１レンズから前記第１レンズの焦点距離と当該第２レンズの焦点距離との和だけ離間して配置された第２レンズと、
    　前記第１レンズから前記第２レンズまでの光路に沿った前記第１レンズと前記第２レンズとの間に配置され、前記回折光学素子での高次回折光を遮断する高次回折光マスクと、を更に備えた、請求項１乃至１４のいずれか一項に記載の照明装置。     A first lens disposed between the diffractive optical element along the optical path from the diffractive optical element to the projection optical system and the projection optical system, wherein a focal distance of the first lens from the diffractive optical element A first lens spaced apart by
    A second lens disposed between the first lens along the optical path from the first lens to the projection optical system and the projection optical system, wherein a focal distance of the first lens to the first lens And a second lens disposed spaced apart by the sum of the focal length of the second lens and the second lens,
    A high-order diffracted light mask disposed between the first lens and the second lens along the optical path from the first lens to the second lens, which blocks high-order diffracted light from the diffractive optical element; The lighting device according to any one of claims 1 to 14, further comprising:
  16. 　前記投射光学系は、前記回折光学素子で回折された１次回折光の一部および他の一部を反射または屈折させて、それぞれ前記投影面の第１被照明領域および第２被照明領域に向け、
    　前記第１被照明領域および前記第２被照明領域は、全体として直線に沿って延びる、請求項１乃至１５のいずれか一項に記載の照明装置。     The projection optical system reflects or refracts a part and another part of the first-order diffracted light diffracted by the diffractive optical element, and directs them to a first illuminated area and a second illuminated area of the projection surface, respectively. ,
    The lighting device according to any one of claims 1 to 15, wherein the first illuminated area and the second illuminated area extend along a straight line as a whole.
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