CN107526155B - Glass-plastic mixed prime lens - Google Patents
Glass-plastic mixed prime lens Download PDFInfo
- Publication number
- CN107526155B CN107526155B CN201710768385.XA CN201710768385A CN107526155B CN 107526155 B CN107526155 B CN 107526155B CN 201710768385 A CN201710768385 A CN 201710768385A CN 107526155 B CN107526155 B CN 107526155B
- Authority
- CN
- China
- Prior art keywords
- lens
- glass
- plastic
- focal length
- fixed focus
- Prior art date
- Legal status (The legal status 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 status listed.)
- Active
Links
- 230000003287 optical effect Effects 0.000 claims abstract description 22
- 239000011521 glass Substances 0.000 claims abstract description 18
- 239000006185 dispersion Substances 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 22
- 238000003384 imaging method Methods 0.000 description 7
- 239000000463 material Substances 0.000 description 6
- 230000007547 defect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004304 visual acuity Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B13/00—Optical objectives specially designed for the purposes specified below
- G02B13/001—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras
- G02B13/0015—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design
- G02B13/002—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design having at least one aspherical surface
- G02B13/0045—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design having at least one aspherical surface having five or more lenses
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
- G02B1/04—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of organic materials, e.g. plastics
- G02B1/041—Lenses
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Lenses (AREA)
Abstract
The invention relates to a glass-plastic mixed fixed focus lens, which comprises: a front lens group, a diaphragm, and a rear lens group arranged in order from an object side to an image side along an optical axis; the front lens group consists of a first lens, a second lens and a third lens which are sequentially arranged from an object side to an image side along an optical axis; the rear lens group consists of a fourth lens, a fifth lens, a sixth lens and a seventh lens which are sequentially arranged from the object side to the image side along the optical axis; the lens comprises a glass lens and a plastic aspherical lens; the first lens, the second lens, the fifth lens and the seventh lens are negative power lenses; the third lens, the fourth lens and the sixth lens are positive focal power lenses; the fourth lens and the fifth lens constitute a cemented lens group having positive optical power. According to the glass-plastic mixed fixed focus lens, under the condition that the FNO is more than or equal to 1.4, the 4K resolution is realized, the use performances of day-night confocal, no virtual focus at-40 ℃ to 80 ℃ and the like of the lens are taken into consideration, and the application range of the lens is enlarged.
Description
Technical Field
The invention relates to a lens, in particular to a glass-plastic mixed fixed-focus lens.
Background
The lens is used as a main component of the security system, and the imaging performance of the security system is determined by the performance of the lens. With the development of the security field, the application range of the video camera is wider and wider, and higher requirements are put forward on the aspects of resolution, aperture, high-low temperature performance, day-night confocal and the like of the lens. In the market at present, high-definition lenses become standard, and the pixels of the high-definition lenses are generally below 600 ten thousand pixels and above FNO 1.8. The FNO of the lens barrel disclosed in CN106772946A was 2.0. As another example, the resolution of the lens disclosed in CN106772939a is 500 ten thousand pixels. The resolution requirements of less than FNO1.8, 4K, namely 800 ten thousand pixels can not be met. And the common glass-plastic mixed fixed focus lens can not meet the requirements of day-night confocal and no virtual focus in the temperature range of-40 ℃ to 80 ℃.
Disclosure of Invention
The invention aims to provide a glass-plastic mixed fixed-focus lens capable of realizing 4K resolution.
The invention further aims to provide a glass-plastic mixed fixed focus lens which can realize day-night confocal and does not have virtual focus in the temperature range of-40 ℃ to 80 ℃.
The third purpose of the invention is to provide a glass-plastic mixed fixed-focus lens with a relative aperture which can meet the condition that FNO is more than or equal to 1.4.
In order to achieve the above object, the present invention provides a glass-plastic mixed fixed focus lens, comprising: a front lens group, a diaphragm, and a rear lens group arranged in order from an object side to an image side along an optical axis;
the front lens group consists of a first lens, a second lens and a third lens which are sequentially arranged from an object side to an image side along an optical axis;
the rear lens group consists of a fourth lens, a fifth lens, a sixth lens and a seventh lens which are sequentially arranged from the object side to the image side along the optical axis;
the lens comprises a glass lens and a plastic aspherical lens;
the first lens, the second lens, the fifth lens and the seventh lens are negative power lenses;
the third lens, the fourth lens and the sixth lens are positive focal power lenses;
the fourth lens and the fifth lens constitute a cemented lens group having positive optical power.
According to one aspect of the present invention, the first lens, the fourth lens, the fifth lens, and the sixth lens are glass lenses;
the second lens, the third lens and the seventh lens are plastic aspheric lenses with aspheric object side surfaces and aspheric image side surfaces.
According to one aspect of the present invention, the fourth lens, the fifth lens, and the sixth lens are glass lenses;
the first lens, the second lens, the third lens and the seventh lens are plastic aspheric lenses with aspheric object side surfaces and aspheric image side surfaces.
According to one aspect of the invention, the front lens group has a combined focal length f A The combined focal length of the rear lens group is f B The combined focal length f A And the combined focal length f B The relation is satisfied: 0. not less than f B /f A ≥-1。
According to one aspect of the invention, the effective focal length of the lens is f, which satisfies: f is more than or equal to 6mm and more than or equal to 4mm.
According to one aspect of the invention, the combined focal length f of the rear lens group B And the effective focal length f satisfies the relation: 2. not less than f B /f≥1。
According to one aspect of the present invention, the distance d from the center of the image side surface of the seventh lens to the image plane is d, and the effective focal length f of the seventh lens and the lens satisfy the relation: 1.5 More than or equal to d/f more than or equal to 1.2.
According to one aspect of the invention, the refractive index Nd of the fourth lens and the sixth lens is less than 1.5, and the dispersion coefficient Vd is more than 80.
According to one aspect of the invention, the relative aperture of the lens satisfies FNO not less than 1.4, wherein FNO is the F number of the optical system.
The glass-plastic mixed fixed-focus lens has the following beneficial technical effects:
the glass-plastic mixed fixed focus lens can realize day-night confocal, and meanwhile, the glass-plastic mixed fixed focus lens can realize the usability of no virtual focus and the like in the temperature range of-40 ℃ to 80 ℃ so that the lens has excellent imaging quality in the condition of no focusing in the temperature range of-40 ℃ to 80 ℃ at daytime and night. In addition, the glass-plastic mixed fixed-focus lens also solves the defect of insufficient lens resolution (the capability of distinguishing details of a shot object) in the prior art.
The glass-plastic mixed fixed focus lens overcomes the contradiction between large relative aperture (FNO 1.4), day-night confocal, high-low temperature virtual focus and resolving power, and gives consideration to the use performances of day-night confocal, -40 ℃ to 80 ℃ non-virtual focus and the like of the lens under the condition of ensuring the realization of 4K resolution, so that the lens has excellent imaging quality under the condition of non-focusing in the temperature range of-40 ℃ to 80 ℃ at daytime and night, and the application range of the camera lens is enlarged; meanwhile, by using the plastic aspherical lens, the cost of the lens is reduced, and the market competitiveness of the lens is improved.
Drawings
FIG. 1 schematically illustrates a block diagram of a glass-plastic hybrid fixed focus lens in accordance with one embodiment of the present invention;
FIG. 2 is an MTF diagram of the glass-plastic mixed fixed focus lens in the embodiment at normal temperature of 20 ℃ and visible light;
FIG. 3 is a view of a Through-Focus-MTF of the glass-plastic mixed fixed Focus lens of 160lp/mm under visible light at a normal temperature of 20 degrees;
FIG. 4 is a view of a Through-Focus-MTF of the glass-plastic mixed fixed Focus lens of the embodiment at room temperature of 20 ℃ and night infrared of 160 lp/mm;
FIG. 5 is a view of a Through-Focus-MTF of the glass-plastic mixed fixed Focus lens of the embodiment at a low temperature of-40 ℃ and 160lp/mm under visible light;
FIG. 6 is a view of a Through-Focus-MTF of the glass-plastic mixed fixed Focus lens of the embodiment at a high temperature of 80 ℃ and a visible light of 160 lp/mm;
fig. 7 schematically shows a block diagram of a glass-plastic hybrid fixed focus lens according to a second embodiment of the present invention;
fig. 8 is an MTF diagram of the glass-plastic mixed fixed focus lens in the second embodiment at a normal temperature of 20 ℃ and under visible light;
FIG. 9 is a view of a Through-Focus-MTF of a glass-plastic mixed fixed Focus lens of 160lp/mm under visible light at a normal temperature of 20 degrees in a specific embodiment II;
FIG. 10 is a view of a Through-Focus-MTF of a glass-plastic mixed fixed Focus lens of a second embodiment at room temperature of 20 ℃ and at night infrared of 160 lp/mm;
FIG. 11 is a view of a Through-Focus-MTF of a glass-plastic mixed fixed Focus lens of 160lp/mm under visible light at a low temperature of-40 degrees;
FIG. 12 is a view of a Through-Focus-MTF of a glass-plastic mixed fixed Focus lens of 160lp/mm under visible light at a high temperature of 80 degrees;
fig. 13 schematically shows a block diagram of a glass-plastic hybrid fixed focus lens according to a third embodiment of the present invention;
fig. 14 is an MTF diagram of the glass-plastic mixed fixed focus lens of the third embodiment at a normal temperature of 20 ℃ and under visible light;
FIG. 15 is a view of a Through-Focus-MTF of a glass-plastic hybrid fixed Focus lens according to a third embodiment at a temperature of 20 ℃ and a visible light of 160 lp/mm;
FIG. 16 is a view of a Through-Focus-MTF of a glass-plastic hybrid fixed Focus lens according to a third embodiment at room temperature of 20 degrees and at night with infrared light of 160 lp/mm;
FIG. 17 is a view of a Through-Focus-MTF of a glass-plastic hybrid fixed Focus lens according to a third embodiment at 160lp/mm under visible light at a low temperature of-40 ℃;
FIG. 18 is a view of a Through-Focus-MTF of a glass-plastic hybrid fixed Focus lens according to a third embodiment at a high temperature of 80℃and a visible light of 160 lp/mm.
Detailed Description
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments will be briefly described below. It is apparent that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained from these drawings without inventive effort for a person of ordinary skill in the art.
In describing embodiments of the present invention, the terms "longitudinal," "transverse," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in terms of orientation or positional relationship shown in the drawings for convenience of description and simplicity of description only, and do not denote or imply that the devices or elements in question must have a particular orientation, be constructed and operated in a particular orientation, so that the above terms are not to be construed as limiting the invention.
The present invention will be described in detail below with reference to the drawings and the specific embodiments, which are not described in detail herein, but the embodiments of the present invention are not limited to the following embodiments.
Fig. 1 schematically shows a block diagram of a glass-plastic hybrid fixed focus lens according to an embodiment of the present invention. As shown in fig. 1, the glass-plastic hybrid fixed-focus lens according to the present invention includes a front lens group a, a stop S, and a rear lens group B arranged in order from an object side to an image side along an optical axis. In the present embodiment, as shown in fig. 1, the front lens group a is composed of a first lens 1, a second lens 2, and a third lens 3 arranged in order from the object side to the image side along the optical axis. The rear lens group B is composed of a fourth lens 4, a fifth lens 5, a sixth lens 6, and a seventh lens 7, which are arranged in order from the object side to the image side along the optical axis. A stop S is arranged between the front lens group a and the rear lens group B, i.e. the stop S is arranged between the third lens 3 and the fourth lens 4. According to the glass-plastic mixed fixed focus lens, at least three of seven lenses are glass lenses, and the rest are plastic aspheric lenses.
In the present embodiment, the first lens 1, the second lens 2, the fifth lens 5, and the seventh lens 7 are negative power lenses; the third lens 3, the fourth lens 4, and the sixth lens 6 are positive power lenses. Wherein the fourth lens 4 and the fifth lens 5 constitute a cemented lens group having positive optical power.
Through the structural arrangement of the glass-plastic mixed fixed-focus lens, the glass-plastic mixed fixed-focus lens can achieve 4K resolution, namely resolution requirement of 800 ten thousand pixels under the condition that FNO is more than or equal to 1.4. In the present invention, FNO of 1.4 or more means each value when FNO is kept at 1.8 or less.
The seven lenses of the glass-plastic mixed fixed-focus lens can consist of glass lenses and plastic aspherical lenses, wherein the seven lenses comprise at least three glass lenses, and the rest are plastic aspherical lenses. According to one embodiment of the present invention, wherein the first lens 1, the fourth lens 4, the fifth lens 5 and the sixth lens 6 are glass lenses; the second lens 2, the third lens 3 and the seventh lens 7 are plastic aspherical lenses. According to another embodiment of the present invention, wherein the fourth lens 4, the fifth lens 5 and the sixth lens 6 are glass lenses; the first lens 1, the second lens 2, the third lens 3 and the seventh lens 7 are plastic aspherical lenses. The glass-plastic hybrid fixed focus lens according to the present invention may have other arrangements of glass lenses and plastic aspherical lenses, and is not limited to the above two embodiments, but in the present invention, the above two embodiments are only described because the obtained technical effects are good. In both of the above modes, only the material of the first lens 1 is variable, and the materials of the remaining lenses are fixed. It should be noted that in the present invention, the plastic aspherical lens is an aspherical plastic lens on both the object side and the image side, and is not an aspherical plastic lens on one side.
In addition, the front lens group A of the glass-plastic mixed fixed-focus lens according to one embodiment of the invention has a combined focal length f A The combined focal length of the rear lens group B is f B Combined focal length f A And the combined focal length f B The relation is satisfied: 0. not less than f B /f A ≥-1。
In this embodiment, the effective focal length of the glass-plastic mixed fixed-focus lens is f, and the effective focal length is the lens focal length, which satisfies the following conditions: f is more than or equal to 6mm and more than or equal to 4mm.
In the present embodiment, the combined focal length f of the rear lens group B B The effective focal length f satisfies the relation: 2. not less than f B /f≥1。
In the present embodiment, the distance from the center of the image side surface of the seventh lens 7 to the image plane 9 imaged by the lens system is d, and the distance d satisfies the relation with the effective focal length f of the lens: 1.5 More than or equal to d/f more than or equal to 1.2.
In the present embodiment, the refractive index Nd of the fourth lens 4 and the sixth lens 6 is < 1.5, and the dispersion coefficient Vd > 80.
In the present embodiment, the aspherical surface satisfies:
where r is the distance from a point on the optical surface to the optical axis, z is the sagittal height of the point along the optical axis, c is the curvature of the surface, k is the conic constant of the surface, and A, B, C, D, E, F, G are the aspheric coefficients of the fourth, sixth, eighth, tenth, fourteen and sixteen orders, respectively.
In the embodiment, the relative aperture FNO of the glass-plastic mixed fixed focus lens is more than or equal to 1.4, wherein FNO is the F number of the optical system.
According to the arrangement, the glass-plastic mixed fixed focus lens can realize day-night confocal, and meanwhile, the glass-plastic mixed fixed focus lens can realize the service performance of no virtual focus and the like in the temperature range of-40 ℃ to 80 ℃, so that the lens has excellent imaging quality under the condition of no focusing in the temperature range of-40 ℃ to 80 ℃ in daytime and at night. In addition, the glass-plastic mixed fixed-focus lens also solves the defect of insufficient lens resolution (the capability of distinguishing details of a shot object) in the prior art.
By combining the above settings, the glass-plastic mixed fixed focus lens overcomes the contradiction between large relative aperture, day-night confocal, high-low temperature virtual focus and resolving power, and gives consideration to the use performances of day-night confocal, -40 ℃ to 80 ℃ without virtual focus and the like under the condition of ensuring the realization of 4K resolution, so that the lens has excellent imaging quality under the condition of focusing without focusing in the temperature ranges of day, night and-40 ℃ to 80 ℃, and the application range of the camera lens is enlarged; meanwhile, by using the plastic aspherical lens, the cost of the lens is reduced, and the market competitiveness of the lens is improved.
The glass-plastic hybrid fixed-focus lens according to the present invention will be specifically described below by giving three embodiments according to the material variation of the first lens 1 and the differences of the respective related parameters. Because the glass-plastic mixed fixed focus lens according to the present invention has seven lenses in total, wherein the fourth lens 4 and the fifth lens 5 are a cemented lens group, the seven lenses have 13 surfaces in total, and the aperture S, the imaging surface of the lens, and four surfaces of a flat filter (IR CUT) between the imaging surface and the lens have 17 surfaces in total. The 17 faces are arranged in order according to the structural order of the present invention, and for convenience of description, the 17 faces are numbered S1 to S17.
Three sets of embodiment data are shown in table 1 below:
| conditional expression | Embodiment 1 | Embodiment 2 | Embodiment 3 |
| 0≥f B /f A ≥-1 | -0.83 | -0.58 | -0.16 |
| 2≥f B /f≥1 | 1.52 | 1.38 | 1.65 |
| FNO≥1.4 | 1.4 | 1.4 | 1.4 |
| 6mm≥f≥4mm | 4.55 | 5.77 | 4.6 |
| 1.5≥d/f≥1.2 | 1.41 | 1.37 | 1.38 |
TABLE 1
Embodiment one:
the present embodiment will be described based on the lens configuration shown in fig. 1.
As the data given in embodiment 1 in table 1, the combined focal length f of the front group lens a A Combined focal length f with rear group lens B B Satisfy f between B /f A ＝-0.83；
Combined focal length f of rear group lens B B And the effective focal length f of the lens is as follows B /f＝1.52；
The distance d from the center of the image side surface of the seventh lens 7 to the image plane and the effective focal length f of the lens satisfy d/f=1.41;
the effective focal length f=4.55, and FNO=1.4 of the glass-plastic mixed fixed focus lens.
Table 2 below lists focal lengths of the respective lenses in the present embodiment:
| f1 | f2 | f3 | f4 | f5 | f6 | f7 |
| -7.95 | -21.48 | 20.69 | 7.06 | -14.58 | 12.81 | -118.04 |
TABLE 2
Table 3 below lists relevant parameters of each lens of the present embodiment, including surface type, radius of curvature, thickness, refractive index of material, and abbe number:
TABLE 3 Table 3
As shown in table 3, when the first lens 1 is a glass lens, i.e., the glass-plastic hybrid fixed focus lens according to the present invention has four glass lenses, three plastic aspherical lenses, i.e., 6 aspherical surfaces are corresponding, and the rest are spherical surfaces. Wherein S15 and S16 are two surfaces of the filter 8, and S17 is an image surface.
In the present embodiment, the aspherical data is shown in table 4 below:
TABLE 4 Table 4
As shown in table 4, wherein the first column is aspherical on the second lens 2, the third lens 3, and the seventh lens 7; the second column represents the quadric constant K for each aspheric surface, and the remaining columns represent the aspheric coefficients a-G for fourth, sixth, eighth, tenth, fourteen and sixteen orders, respectively.
Fig. 2 to 6 schematically show MTF diagrams of the glass-plastic hybrid fixed focus lens in the present embodiment at normal temperature of 20 degrees and under visible light, respectively; a Through-Focus-MTF diagram of 160lp/mm under the condition of normal temperature of 20 ℃ and visible light; a Through-Focus-MTF diagram of 160lp/mm infrared at normal temperature of 20 ℃; a Through-Focus-MTF diagram of 160lp/mm under visible light at a low temperature of-40 ℃; a Through-Focus-MTF plot of 160lp/mm at 80℃under visible light.
As shown in fig. 2 to 6, the glass-plastic mixed fixed focus lens according to the first embodiment of the present invention realizes 4K resolution under the condition of fno=1.4, and also has the characteristics of day-night confocal and no virtual focus in the temperature range of-40 ℃ to 80 ℃, and simultaneously improves the image capturing power and expands the application range of products.
Specifically, as can be seen from fig. 2, the glass-plastic mixed fixed focus lens according to the first embodiment of the present invention has an OTF coefficient corresponding to a spatial frequency of 250LP/mm in its central field of view of over 0.3 under visible light, so that the lens of the present embodiment achieves the 4K high resolution characteristic.
As can be seen from fig. 3 and 4, the glass-plastic mixed fixed focus lens according to the first embodiment of the present invention has a central field of view defocus of no more than 0.01mm, and a corresponding OTF coefficient of 0.3 or more, so that the lens according to the present embodiment achieves characteristics of confocal day and night and no virtual focus at normal temperature.
As can be seen from fig. 5 and 6, the glass-plastic mixed fixed focus lens according to the first embodiment of the present invention has a central field of view defocus amount of not more than 0.006mm within a temperature range of-40 ℃ to 80 ℃ and a corresponding OTF coefficient of 0.3 or more, and thus the lens of the present embodiment achieves a characteristic of no virtual focus within a temperature range of-40 ℃ to 80 ℃.
Embodiment two:
fig. 7 schematically shows a block diagram of a glass-plastic hybrid fixed focus lens according to a second embodiment of the present invention. The explanation according to this embodiment is as follows:
as the data given in embodiment 1 in table 1, the combined focal length f of the front group lens a A Combined focal length f with rear group lens B B Satisfy f between B /f A ＝-0.58；
Combined focal length f of rear group lens B B And the effective focal length f of the lens is as follows B /f＝1.38；
The distance d from the center of the image side surface of the seventh lens 7 to the image plane and the effective focal length f of the lens satisfy d/f=1.37;
the effective focal length f=5.77, and FNO=1.4 of the glass-plastic mixed fixed focus lens.
Table 5 below lists focal lengths of the respective lenses in the present embodiment:
| f1 | f2 | f3 | f4 | f5 | f6 | f7 |
| -9.72 | -127.47 | 40.17 | 9.71 | -20.268 | 12.839 | -61.495 |
TABLE 5
Table 6 below lists relevant parameters of each lens of the present embodiment, including surface type, radius of curvature, thickness, refractive index of material, and abbe number:
| face number | Surface type | R value | Thickness of (L) | Refractive index | Abbe number |
| S1 | Spherical surface | 200 | 0.5 | 1.49 | 70.4 |
| S2 | Spherical surface | 4.64 | 3.03 | ||
| S3 | Aspherical surface | -8.737 | 3.53 | 1.54 | 55.8 |
| S4 | Aspherical surface | -11.429 | 0.05 | ||
| S5 | Aspherical surface | 7.893 | 3.32 | 1.64 | 24.0 |
| S6 | Aspherical surface | 9.5 | 1.89 | ||
| S7 | Spherical surface | Infinity | 0.05 | ||
| S8 | Spherical surface | 70.04 | 2.8 | 1.46 | 90.2 |
| S9 | Spherical surface | -4.71 | 0.75 | 1.81 | 25.5 |
| S10 | Spherical surface | -7.07 | 0.18 | ||
| S11 | Spherical surface | 11.96 | 3.31 | 1.46 | 90.2 |
| S12 | Spherical surface | -10.64 | 0.05 | ||
| S13 | Aspherical surface | 11.51 | 2.58 | 1.64 | 24.0 |
| S14 | Aspherical surface | 8.12 | 2 | ||
| S15 | Spherical surface | Infinity | 0.8 | 1.52 | 64.2 |
| S16 | Spherical surface | Infinity | 5.16 | ||
| S17 | Spherical surface | Infinity |
TABLE 6
As shown in table 6, when the first lens 1 is a glass lens, i.e., the glass-plastic hybrid fixed focus lens according to the present invention has four glass lenses, three plastic aspherical lenses, i.e., 6 aspherical surfaces are corresponding, and the rest are spherical surfaces. Wherein S15 and S16 are two surfaces of the filter 8, and S17 is an image surface.
In this embodiment, aspherical data is shown in table 7 below:
TABLE 7
As shown in table 7, wherein the first column is aspherical on the second lens 2, the third lens 3, and the seventh lens 7; the second column represents the quadric constant K for each aspheric surface, and the remaining columns represent the aspheric coefficients a-G for fourth, sixth, eighth, tenth, fourteen and sixteen orders, respectively.
Fig. 8 to 12 schematically show MTF diagrams of the glass-plastic hybrid fixed focus lens in the present embodiment at room temperature of 20 degrees and under visible light, respectively; an MTF diagram of infrared at normal temperature of 20 ℃ at night; a Through-Focus-MTF diagram of 160lp/mm under the condition of normal temperature of 20 ℃ and visible light; a Through-Focus-MTF diagram of 160lp/mm infrared at normal temperature of 20 ℃; a Through-Focus-MTF diagram of 160lp/mm under visible light at a low temperature of-40 ℃; a Through-Focus-MTF plot of 160lp/mm at 80℃under visible light.
As shown in fig. 8 to 12, the glass-plastic mixed fixed focus lens according to the second embodiment of the present invention realizes 4K resolution under the condition of fno=1.4, and also has the characteristics of day-night confocal and no virtual focus in the temperature range of-40 ℃ to 80 ℃, and simultaneously improves the image capturing power and expands the application range of products.
Specifically, as can be seen from fig. 8, the glass-plastic mixed fixed focus lens according to the second embodiment of the present invention has an OTF coefficient corresponding to a spatial frequency of 250LP/mm in its central field of view of over 0.3 under visible light, and thus it can be seen that the lens of the present embodiment achieves the characteristic of 4K high resolution.
As can be seen from fig. 9 and 10, the glass-plastic mixed fixed focus lens according to the second embodiment of the present invention has a central field of view defocus of no more than 0.006mm in daytime or at night, and a corresponding OTF coefficient of 0.3 or more, so that the lens according to the present embodiment achieves characteristics of confocal day and night and no virtual focus at normal temperature.
As can be seen from fig. 11 and 12, the glass-plastic mixed fixed focus lens according to the second embodiment of the present invention has a central field of view defocus amount of not more than 0.012mm in a temperature range from-40 ℃ to 80 ℃ and a corresponding OTF coefficient of not less than 0.3, and thus the lens of the present embodiment achieves a characteristic of no virtual focus in a temperature range from-40 ℃ to 80 ℃.
Embodiment III:
fig. 13 schematically shows a block diagram of a glass-plastic hybrid fixed focus lens according to a third embodiment of the present invention. The explanation according to this embodiment is as follows:
such as a watch1, the combined focal length f of the front group lens a A Combined focal length f with rear group lens B B Satisfy f between B /f A ＝-0.16；
Combined focal length f of rear group lens B B And the effective focal length f of the lens is as follows B /f＝1.65；
The distance d from the center of the image side surface of the seventh lens 7 to the image plane and the effective focal length f of the lens satisfy d/f=1.38;
the effective focal length f=4.6 and FNO=1.4 of the glass-plastic mixed fixed focus lens.
Table 8 below lists focal lengths of the respective lenses in the present embodiment:
| f1 | f2 | f3 | f4 | f5 | f6 | f7 |
| -6.77 | 22.68 | 39.5 | 6.48 | -11.79 | 11.95 | -32.91 |
TABLE 8
Table 9 below lists relevant parameters of each lens of the present embodiment, including surface type, radius of curvature, thickness, refractive index of material, and abbe number:
TABLE 9
As shown in table 9, when the first lens 1 is a plastic aspherical surface, i.e., the glass-plastic hybrid fixed focus lens according to the present invention has three glass lenses, four plastic aspherical lenses, i.e., 8 aspherical surfaces are corresponding, and the rest are spherical surfaces. Wherein S15 and S16 are two surfaces of the filter 8, and S17 is an image surface.
In the present embodiment, the aspherical data is shown in table 10 below:
table 10
As shown in table 10, wherein the first column is aspherical on the first lens 1, the second lens 2, the third lens 3, and the seventh lens 7; the second column represents the quadric constant K for each aspheric surface, and the remaining columns represent the aspheric coefficients a-G for fourth, sixth, eighth, tenth, fourteen and sixteen orders, respectively.
Fig. 14 to 18 schematically show MTF diagrams of the glass-plastic hybrid fixed focus lens in the present embodiment at room temperature of 20 degrees and under visible light, respectively; a Through-Focus-MTF diagram of 160lp/mm under the condition of normal temperature of 20 ℃ and visible light; a Through-Focus-MTF diagram of 160lp/mm infrared at normal temperature of 20 ℃; a Through-Focus-MTF diagram of 160lp/mm under visible light at a low temperature of-40 ℃; a Through-Focus-MTF plot of 160lp/mm at 80℃under visible light.
As shown in fig. 14 to 18, the glass-plastic mixed fixed focus lens according to the third embodiment of the present invention realizes 4K resolution under the condition of fno=1.4, and also has the characteristics of day-night confocal and no virtual focus in the temperature range of-40 ℃ to 80 ℃, and simultaneously improves the image capturing power and expands the application range of products.
Specifically, as can be seen from fig. 14, the glass-plastic mixed fixed focus lens according to the third embodiment of the present invention has an OTF coefficient corresponding to a spatial frequency of 250LP/mm in its central field of view of 0.3 or more under visible light, and thus it can be seen that the lens of the present embodiment achieves the characteristic of 4K high resolution.
As can be seen from fig. 15 and 16, the glass-plastic mixed fixed focus lens according to the third embodiment of the present invention has a central field of view defocus amount of not more than 0.006mm in daytime or at night, and a corresponding OTF coefficient of not less than 0.3, so that the lens according to the present embodiment achieves characteristics of confocal day and night and no virtual focus at normal temperature.
As can be seen from fig. 17 and 18, the glass-plastic mixed fixed focus lens according to the third embodiment of the present invention has a central field-of-view defocus amount of not more than 0.012mm in a temperature range of-40 ℃ to 80 ℃ and a corresponding OTF coefficient of not less than 0.3, and thus it can be seen that the lens of the present embodiment achieves a characteristic of no virtual focus in a temperature range of-40 ℃ to 80 ℃.
The above description is only one embodiment of the present invention, and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (7)
1. A glass-plastic mixed fixed focus lens, comprising: a front lens group (A), a diaphragm (S) and a rear lens group (B) which are arranged in order from an object side to an image side along an optical axis;
the front lens group (A) is composed of a first lens (1), a second lens (2) and a third lens (3) which are sequentially arranged from an object side to an image side along an optical axis;
the rear lens group (B) is composed of a fourth lens (4), a fifth lens (5), a sixth lens (6) and a seventh lens (7) which are arranged in order from the object side to the image side along the optical axis; it is characterized in that the method comprises the steps of,
the lens comprises a glass lens and a plastic aspherical lens;
the first lens (1), the second lens (2), the fifth lens (5) and the seventh lens (7) are negative power lenses;
the third lens (3), the fourth lens (4) and the sixth lens (6) are positive power lenses;
the fourth lens (4) and the fifth lens (5) form a cemented lens group having positive optical power;
the front lens group (A) has a combined focal length f A The combined focal length of the rear lens group (B) is f B The combined focal length f A And the combined focal length f B The relation is satisfied: -0.58 is greater than or equal to f B /f A ≥-1；
The relative aperture of the lens meets the condition that FNO is not less than 1.4 and not more than 1.8, wherein FNO is the F number of the optical system;
the fourth lens (4), the fifth lens (5) and the sixth lens (6) are glass lenses;
the second lens (2), the third lens (3) and the seventh lens (7) are plastic aspheric lenses with aspheric object side surfaces and aspheric image side surfaces;
the lens is free from virtual focus in a temperature range of-40 ℃ to 80 ℃.
2. The glass-plastic hybrid fixed focus lens according to claim 1, characterized in that the first lens (1) is a glass lens.
3. The glass-plastic hybrid fixed focus lens according to claim 1, wherein the first lens (1) is a plastic aspherical lens having both an object side surface and an image side surface being aspherical.
4. A glass-plastic hybrid fixed focus lens according to any one of claims 1 to 3, wherein the effective focal length of the lens is f, which satisfies: f is more than or equal to 6mm and more than or equal to 4mm.
5. A glass-plastic hybrid fixed focus lens according to one of claims 1 to 3, characterized in that the combined focal length f of the rear lens group (B) B And the effective focal length f satisfies the relation: 2. not less than f B /f≥1。
6. A glass-plastic hybrid fixed focus lens according to one of claims 1 to 3, characterized in that the center of the image side of the seventh lens (7) is at a distance d from the image plane, which satisfies the relation with the effective focal length f of the lens: 1.5 More than or equal to d/f more than or equal to 1.2.
7. A glass-plastic hybrid fixed focus lens according to one of claims 1 to 3, characterized in that the refractive index Nd of the fourth lens (4) and the sixth lens (6) is < 1.5 and the dispersion coefficient Vd > 80.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710768385.XA CN107526155B (en) | 2017-08-31 | 2017-08-31 | Glass-plastic mixed prime lens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710768385.XA CN107526155B (en) | 2017-08-31 | 2017-08-31 | Glass-plastic mixed prime lens |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107526155A CN107526155A (en) | 2017-12-29 |
| CN107526155B true CN107526155B (en) | 2023-11-07 |
Family
ID=60682978
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710768385.XA Active CN107526155B (en) | 2017-08-31 | 2017-08-31 | Glass-plastic mixed prime lens |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107526155B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110412720B (en) * | 2018-04-28 | 2021-12-17 | 宁波舜宇车载光学技术有限公司 | Optical lens |
| CN110542978B (en) * | 2018-05-28 | 2021-12-17 | 宁波舜宇车载光学技术有限公司 | Optical lens |
| CN108873270B (en) * | 2018-07-13 | 2024-04-12 | 舜宇光学(中山)有限公司 | Glass-plastic mixed prime lens |
| TWI664469B (en) * | 2018-07-25 | 2019-07-01 | 揚明光學股份有限公司 | Fixed-focus lens |
| CN108983402B (en) * | 2018-08-08 | 2024-03-19 | 舜宇光学(中山)有限公司 | Large aperture lens |
| JP7141018B2 (en) * | 2018-10-12 | 2022-09-22 | コニカミノルタ株式会社 | Optical system, lens unit, and imaging device |
| CN110275277B (en) * | 2019-06-28 | 2024-06-18 | 舜宇光学(中山)有限公司 | Glass-plastic mixed lens |
| CN113655595A (en) * | 2021-09-10 | 2021-11-16 | 舜宇光学(中山)有限公司 | Fixed focus lens |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101373262A (en) * | 2007-08-21 | 2009-02-25 | 株式会社尼康 | Optical system, imaging apparatus, and method for forming image by the optical system |
| CN105242378A (en) * | 2015-11-05 | 2016-01-13 | 福建福光股份有限公司 | High-transmittance and low-distortion aspheric zoom lens |
| CN106772941A (en) * | 2016-12-27 | 2017-05-31 | 东莞市宇瞳光学科技股份有限公司 | The big thang-kng small-sized wide-angle lens of 2.8mm |
| CN106772946A (en) * | 2017-01-22 | 2017-05-31 | 东莞市宇瞳光学科技股份有限公司 | Small-sized glass modeling mixing is without thermalization tight shot |
| CN106772939A (en) * | 2016-12-27 | 2017-05-31 | 东莞市宇瞳光学科技股份有限公司 | Small-sized super large aperture tight shot |
| CN206369893U (en) * | 2016-12-01 | 2017-08-01 | 广西师范大学 | A kind of fringe projection camera lens for three-dimensional measurement |
-
2017
- 2017-08-31 CN CN201710768385.XA patent/CN107526155B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101373262A (en) * | 2007-08-21 | 2009-02-25 | 株式会社尼康 | Optical system, imaging apparatus, and method for forming image by the optical system |
| CN105242378A (en) * | 2015-11-05 | 2016-01-13 | 福建福光股份有限公司 | High-transmittance and low-distortion aspheric zoom lens |
| CN206369893U (en) * | 2016-12-01 | 2017-08-01 | 广西师范大学 | A kind of fringe projection camera lens for three-dimensional measurement |
| CN106772941A (en) * | 2016-12-27 | 2017-05-31 | 东莞市宇瞳光学科技股份有限公司 | The big thang-kng small-sized wide-angle lens of 2.8mm |
| CN106772939A (en) * | 2016-12-27 | 2017-05-31 | 东莞市宇瞳光学科技股份有限公司 | Small-sized super large aperture tight shot |
| CN106772946A (en) * | 2017-01-22 | 2017-05-31 | 东莞市宇瞳光学科技股份有限公司 | Small-sized glass modeling mixing is without thermalization tight shot |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107526155A (en) | 2017-12-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107526155B (en) | Glass-plastic mixed prime lens | |
| KR102380229B1 (en) | Photographing lens system and photographing apparatus having the same | |
| KR101547460B1 (en) | Optical lens system | |
| CN106772935B (en) | Lens system and fixed-focus lens | |
| KR101547461B1 (en) | Optical lens system | |
| CN108318995B (en) | Lens system and lens | |
| CN105334598B (en) | A kind of optical lens | |
| KR102449626B1 (en) | Imaging Lens System | |
| CN108535834A (en) | optical lens and imaging device | |
| CN109085694B (en) | Five-piece type wide-angle lens group | |
| CN112526728A (en) | Fixed focus lens | |
| CN205067847U (en) | Optical lens | |
| KR20230016696A (en) | Optical Imaging System | |
| CN108983402B (en) | Large aperture lens | |
| CN110346920B (en) | Fish-eye lens | |
| CN110275277B (en) | Glass-plastic mixed lens | |
| CN112433346A (en) | Large-aperture optical system | |
| KR102642916B1 (en) | Optical Imaging System | |
| CN110441890B (en) | Glass-plastic mixed wide-angle lens | |
| CN204807794U (en) | Zoom lens system and camera lens | |
| KR102296115B1 (en) | Optical Imaging System | |
| CN213482549U (en) | Large-aperture optical system | |
| CN111221103B (en) | Lens | |
| CN210142228U (en) | Glass-plastic mixed fixed-focus lens | |
| CN113917668A (en) | Fixed focus lens |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |