CN112269254A - Imaging lens - Google Patents
Imaging lens Download PDFInfo
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- CN112269254A CN112269254A CN202011037629.5A CN202011037629A CN112269254A CN 112269254 A CN112269254 A CN 112269254A CN 202011037629 A CN202011037629 A CN 202011037629A CN 112269254 A CN112269254 A CN 112269254A
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- 238000003384 imaging method Methods 0.000 title claims abstract description 113
- 230000003287 optical effect Effects 0.000 claims abstract description 36
- 230000005499 meniscus Effects 0.000 claims description 3
- 230000004075 alteration Effects 0.000 description 13
- 238000010586 diagram Methods 0.000 description 10
- 201000009310 astigmatism Diseases 0.000 description 6
- 101100402341 Caenorhabditis elegans mpk-1 gene Proteins 0.000 description 5
- 101100422780 Caenorhabditis elegans sur-5 gene Proteins 0.000 description 5
- 101100378809 Schizosaccharomyces pombe (strain 972 / ATCC 24843) alf1 gene Proteins 0.000 description 5
- 101150080038 Sur-8 gene Proteins 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 235000012149 noodles Nutrition 0.000 description 5
- 101150114085 soc-2 gene Proteins 0.000 description 5
- 206010010071 Coma Diseases 0.000 description 4
- 230000035945 sensitivity Effects 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B15/00—Optical objectives with means for varying the magnification
- G02B15/14—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective
- G02B15/143—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having three groups only
- G02B15/1431—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having three groups only the first group being positive
- G02B15/143103—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having three groups only the first group being positive arranged ++-
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Abstract
The invention relates to an imaging lens, which comprises a first lens group (G1) with positive focal power, a diaphragm, a second lens group (G2) with positive focal power and a third lens group (G3) with positive focal power or negative focal power, which are arranged in sequence from an object side to an image side, wherein the third lens group (G3) is a fixed group, and the first lens group (G1) and the second lens group (G2) form a focusing group capable of moving along an optical axis. The imaging lens is arranged according to the limitation, and can realize the characteristics of large aperture, high resolution, low distortion, uniform image quality, large depth of field, good color reproduction and high contrast.
Description
Technical Field
The invention relates to the field of optical devices, in particular to an imaging lens.
Background
Machine vision means that a robot replaces human eyes to measure and judge, a shot target is converted into an image signal and transmitted to a special image processing system to obtain form information of the shot target, and the form information is converted into a digital signal according to information such as pixel distribution, brightness, color and the like; the image system performs various operations on the signals to extract the characteristics of the target, such as position, size, appearance and the like, and then outputs the result according to preset conditions to realize the functions of automatic identification, judgment, measurement and the like.
Therefore, imaging systems for machine vision have very high requirements on pixels, picture uniformity, distortion, brightness, color rendition, etc. However, the machine vision lens on the market at present has small optical magnification, small imaging frame, large distortion, uneven picture definition, small range of working object distance and the like, and although the machine vision lens has wide shooting range, the machine vision lens has the defects of insufficient imaging fineness, low dynamic range during imaging and insufficient color and contrast.
Along with the wider and wider application range of machine vision, the requirements on a machine vision imaging system are higher and higher, machine vision lenses on the market at present cannot meet the market demands more and more, and are particularly severely limited in some high-precision high-tech fields with higher imaging quality requirements.
Disclosure of Invention
The present invention is directed to solving the above-mentioned problems and providing an imaging lens having a large aperture, a high resolution, a low distortion, a uniform image quality, a large depth of field, a good color reproduction, and a high contrast.
In order to achieve the object of the present invention, the present invention provides an imaging lens, including a first lens group having positive power, a diaphragm, a second lens group having positive power, and a third lens group having positive power or negative power, which are sequentially disposed from an object side to an image side, wherein the third lens group is a fixed group, and the first lens group and the second lens group constitute a focusing group capable of moving along an optical axis.
According to an aspect of the present invention, the first lens group includes at least two positive power lenses and one negative power lens, and a lens closest to the object side in the first lens group is a positive power lens, and a lens closest to the image side is a negative power lens.
According to an aspect of the present invention, a lens closest to the object side in the first lens group is one of a biconvex lens, a convex-concave lens, or a convex-flat lens in a direction from the object side to the image side.
According to an aspect of the present invention, the first lens group includes a double cemented lens, and the double cemented lens is formed by combining a positive power lens and a negative power lens along an object-side to image-side direction.
According to an aspect of the present invention, the positive power lens of the cemented double lens in the first lens group has a refractive index ND and an abbe number VD, and satisfies: VD is more than or equal to 60 and less than or equal to 96, ND is more than or equal to 1.43 and less than or equal to 1.65.
According to an aspect of the present invention, the second lens group includes at least two positive power lenses and one negative power lens, and a lens closest to the object side in the second lens group is a negative power lens, and a lens closest to the image side in the second lens group is a positive power lens.
According to an aspect of the invention, a lens closest to the image side in the second lens group in a direction from the object side to the image side is one of a biconvex lens, a meniscus lens, or a plano-convex lens.
According to an aspect of the invention, the second lens group includes a double cemented lens, and the double cemented lens is formed by combining a negative power lens and a positive power lens along the direction from the object side to the image side.
According to an aspect of the present invention, the third lens group includes at least one positive power lens and one negative power lens, and two lenses close to the object side in the third lens group are arranged in the order of the positive power lens, the negative power lens, or the order of the negative power lens and the positive power lens in a direction from the object side to the image side.
According to an aspect of the present invention, the positive power lens in the third lens group is one of a biconvex lens, a convex-concave lens, or a convex-flat lens, and the negative power lens is one of a biconcave lens, a concave-convex lens, or a convex-concave lens.
According to an aspect of the present invention, a focal length of a focusing group composed of the first lens group, the stop, and the second lens group is fm, a focal length of the imaging lens is f, and the following relation is satisfied: fm/f is more than or equal to 1.0 and less than or equal to 1.5.
According to an aspect of the present invention, a focal length of the third lens group is fg3, and a focal length of the imaging lens is f, satisfying: the | fg3/f | is more than or equal to 3.5 and less than or equal to 8.5.
According to one aspect of the invention, the total optical length of the imaging lens is TTL, the focal length of the imaging lens is f, and the condition that TTL/f is more than or equal to 1.35 and less than or equal to 1.75 is met.
The imaging lens adopts the first lens group with positive focal power, the second lens group with positive focal power and the third lens group with positive or negative focal power, so that the imaging system has smaller distortion and smaller dispersion.
In the imaging lens, the first lens group comprises at least two positive focal power lenses and one negative focal power lens, and the lens closest to the object side in the first lens group is the positive focal power lens, and the lens closest to the image side is the negative focal power lens. By the arrangement, the matched use of the positive and negative focal powers is beneficial to correcting spherical aberration, astigmatism and distortion in the first lens group, and is beneficial to realizing large aperture and reducing tolerance sensitivity in the group.
In the imaging lens, the first lens group comprises a double-cemented lens which is formed by combining a positive focal power lens and a negative focal power lens along the direction from the object side to the image side. So set up for two cemented lens match suitable focal power, have the correction effect to correcting optical system's distortion, coma and lateral chromatic aberration, thereby can guarantee that optical system has the image quality and the image plane uniformity that are close to diffraction limit.
According to the imaging lens, the refractive index of a positive focal power lens in a double-cemented lens in a first lens group is ND, the Abbe number is VD, and the following requirements are met: VD is more than or equal to 60 and less than or equal to 96, ND is more than or equal to 1.43 and less than or equal to 1.65. The condition is met, the focal power and the Abbe number are reasonably matched, the chromatic aberration of the imaging system can be effectively corrected, and the imaging quality of the imaging system is improved. Meanwhile, the lens greatly contributes to maintaining the stability of the image plane of the imaging system in an extremely warm state.
In the imaging lens of the invention, the second lens group comprises a double-cemented lens which is formed by combining a negative focal power lens and a positive focal power lens along the direction from the object side to the image side. The use of the double-cemented lens is matched with proper focal power and matched with the first lens group, so that the spherical aberration, astigmatism, coma and distortion in the focusing lens group can be corrected. Meanwhile, the burden proportion of the first lens group to aberration correction is reduced, and the tolerance sensitivity of the movable group can be better reduced, so that the optical system is greatly ensured to have good image plane consistency. The imaging quality of the optical system is comprehensively improved.
The imaging lens meets the following relation: 1.0-fm/f-1.5, so that the optical system can realize and maintain smaller distortion while rapidly collecting incident light and reducing field curvature and astigmatism.
The imaging lens of the invention satisfies the following conditions: the absolute value of fg3/f is more than or equal to 3.5 and less than or equal to 8.5, the burden proportion of the first lens group and the second lens group of the optical system on aberration correction can be balanced by reasonably matching the positive and negative focal powers and the focal powers of the first lens group and the second lens group, the focusing performance can be favorably ensured, and the imaging system can be better ensured to meet the high image quality requirement close to the diffraction limit.
The imaging lens is arranged according to the limitation, and can realize the characteristics of large aperture, high resolution, low distortion, uniform image quality, large depth of field, good color reproduction and high contrast.
Drawings
Fig. 1 schematically shows a configuration diagram of an imaging lens according to embodiment 1 of the present invention;
fig. 2 schematically shows an MTF chart when an imaging lens according to embodiment 1 of the present invention is in an optimal working object distance focusing;
fig. 3 schematically shows MTF defocus diagrams of an imaging lens according to embodiment 1 of the present invention in a low temperature state of an optimal working object distance;
fig. 4 schematically shows an MTF defocus diagram of an imaging lens in an optimal working object distance high temperature state according to embodiment 1 of the present invention;
fig. 5 schematically shows an optical distortion diagram of an imaging lens according to embodiment 1 of the present invention;
fig. 6 is a schematic structural view showing an imaging lens according to embodiment 2 of the present invention;
fig. 7 is a schematic MTF chart of an imaging lens according to embodiment 2 of the present invention when the best working object distance is in focus;
fig. 8 is a schematic view showing an MTF defocus map of an imaging lens in an optimal operating object distance low temperature state according to embodiment 2 of the present invention;
fig. 9 is a schematic view showing an MTF defocus map of an imaging lens in an optimal operating object distance high temperature state according to embodiment 2 of the present invention;
fig. 10 schematically shows an optical distortion diagram of an imaging lens according to embodiment 2 of the present invention;
fig. 11 is a schematic structural view showing an imaging lens according to embodiment 3 of the present invention;
fig. 12 is a schematic MTF chart showing an imaging lens according to embodiment 3 of the present invention when the optimal working object distance is in focus;
fig. 13 is a schematic view showing an MTF defocus map in an optimal operating object distance low temperature state of an imaging lens according to embodiment 3 of the present invention;
fig. 14 is a schematic view showing an MTF defocus map of an imaging lens in an optimal operating object distance high temperature state according to embodiment 3 of the present invention;
fig. 15 schematically shows an optical distortion diagram of an imaging lens according to embodiment 3 of the present invention;
fig. 16 is a schematic structural view showing an imaging lens according to embodiment 4 of the present invention;
fig. 17 is a schematic MTF chart showing an imaging lens according to embodiment 4 of the present invention when an optimal working object distance is in focus;
fig. 18 is a schematic view showing an MTF defocus map in an optimal operating object distance low temperature state of an imaging lens according to embodiment 4 of the present invention;
fig. 19 schematically shows MTF defocus diagrams in the high temperature state of the optimal working object distance of the imaging lens according to embodiment 4 of the present invention;
fig. 20 schematically shows an optical distortion diagram of an imaging lens according to embodiment 4 of the present invention;
fig. 21 is a schematic view showing the configuration of an imaging lens according to embodiment 5 of the present invention;
fig. 22 is a schematic MTF chart showing the best-working object-distance focusing of the imaging lens according to embodiment 5 of the present invention;
fig. 23 is a schematic view showing an MTF defocus map in an optimal operating object distance low temperature state of an imaging lens according to embodiment 5 of the present invention;
fig. 24 is a schematic view showing an MTF defocus map of an imaging lens in an optimal operating object distance high temperature state according to embodiment 5 of the present invention;
fig. 25 schematically shows an optical distortion diagram of an imaging lens according to embodiment 5 of the present invention.
Detailed Description
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.
The present invention is described in detail below with reference to the drawings and the specific embodiments, which are not repeated herein, but the embodiments of the present invention are not limited to the following embodiments.
Referring to fig. 1, the present invention provides an imaging lens including a first lens group G1 having positive power, a stop, and a second lens group G2 having positive power and a third lens group G3 having positive power or negative power, which are disposed in order from an object side to an image side. The third lens group G3 is a fixed group, and the first lens group G1, the stop and the second lens group G2 form a focusing group, which can move along the optical axis when imaging from an infinite object to a close object. The imaging lens adopts the first lens group G1 with positive focal power, the second lens group G2 with positive focal power and the third lens group G3 with positive or negative focal power, so that the imaging system has smaller distortion and smaller dispersion.
In the present invention, the first lens group G1 includes at least two positive power lenses and one negative power lens, and the lens closest to the object side in the first lens group G1 is a positive power lens, and the lens closest to the image side is a negative power lens.
By the arrangement, the spherical aberration, astigmatism and distortion in the first lens group G1 can be corrected by matching the positive and negative focal powers, the large aperture can be realized, and meanwhile, the tolerance sensitivity in the group can be reduced.
According to an embodiment of the present invention, a lens closest to the object side in the first lens group G1 is one of a biconvex lens, a convex-concave lens, or a convex-flat lens in a direction from the object side to the image side.
In the present invention, the first lens group G1 includes a double cemented lens formed by a combination of positive and negative power lenses along the object-to-image direction. So set up for two cemented lens match suitable focal power, have the correction effect to correcting optical system's distortion, coma and lateral chromatic aberration, thereby can guarantee that optical system has the image quality and the image plane uniformity that are close to diffraction limit.
In the present invention, the refractive index of the positive power lens in the double cemented lens in the first lens group G1 is ND, and the abbe number is VD, satisfying: VD is more than or equal to 60 and less than or equal to 96, ND is more than or equal to 1.43 and less than or equal to 1.65. The condition is met, the focal power and the Abbe number are reasonably matched, the chromatic aberration of the imaging system can be effectively corrected, and the imaging quality of the imaging system is improved. Meanwhile, the lens greatly contributes to maintaining the stability of the image plane of the imaging system in an extremely warm state.
In the present invention, the second lens group G2 includes at least two positive power lenses and one negative power lens, and the lens closest to the object side in the second lens group G2 is a negative power lens, and the lens closest to the image side is a positive power lens. In the object-to-image direction, the lens closest to the image side in the second lens group G2 is one of a biconvex lens, a meniscus lens, or a plano-convex lens. The second lens group G2 includes a double cemented lens formed by a combination of a negative power lens and a positive power lens along the object-to-image direction. The use of the double-cemented lens is matched with proper focal power and matched with the first lens group, so that the spherical aberration, astigmatism, coma and distortion in the focusing lens group can be corrected. Meanwhile, the burden proportion of the first lens group G1 on aberration correction is reduced, the tolerance sensitivity of the movable group can be better reduced, and the optical system is greatly ensured to have good image plane consistency. The imaging quality of the optical system is comprehensively improved.
In the present invention, the third lens group G3 includes at least one positive power lens and one negative power lens, and two lenses close to the object side in the third lens group G3 are arranged in the order of the positive power lens, the negative power lens, or the order of the negative power lens and the positive power lens along the object-to-image direction. The positive power lens in the third lens group G3 is one of a biconvex lens, a convex-concave lens, or a convex-flat lens, and the negative power lens is one of a biconcave lens, a convex-concave lens, or a convex-concave lens.
The imaging lens of the invention is provided with the first lens group G1, the second lens group G2 and the third lens group G3 according to the definition, so that an imaging system of the imaging lens of the invention forms a Gaussian structure, and can well correct distortion and beam convergence light, eliminate dark angles and reduce spherical aberration.
In the invention, the focal length of a focusing group consisting of the first lens group G1, the diaphragm and the second lens group G2 is fm, the focal length of the imaging lens is f, and the relation is satisfied: fm/f is more than or equal to 1.0 and less than or equal to 1.5. Within the above relationship, the optical system is able to achieve and maintain less distortion while collecting incident light rays quickly, reducing curvature of field and astigmatism.
In the present invention, the focal length of the third lens group G3 is fg3, and the focal length of the imaging lens is f, satisfying: the | fg3/f | is more than or equal to 3.5 and less than or equal to 8.5. The limitation of the relational expression is met, the burden proportion of the first lens group G1 and the second lens group G2 of the optical system on aberration correction can be balanced by reasonably matching the positive and negative focal powers and the focal powers of the first lens group G1 and the second lens group G2, the focusing performance can be favorably ensured, and the imaging system can be better ensured to meet the high image quality requirement close to the diffraction limit.
In addition, in the invention, the optical total length of the imaging lens is TTL, the focal length of the imaging lens is f, and the condition that TTL/f is more than or equal to 1.35 and less than or equal to 1.75 is met.
In summary, the imaging lens of the present invention is configured according to the above limitations, and can realize the characteristics of large aperture, high resolution, low distortion, uniform image quality, large depth of field, good color rendition and high contrast.
The imaging lens according to the present invention is specifically explained below by giving five sets of specific embodiments according to the above-described arrangement of the present invention.
Five sets of embodiment data are as in table 1 below:
TABLE 1
The first implementation mode comprises the following steps:
fig. 1 is a diagram schematically showing the configuration of an imaging lens according to a first embodiment of the present invention.
In the first embodiment, the total optical system length TTL is 42.9mm, the system focal length F is 25.1mm, the system imaging object distance range is 0.15m to inf, the system frame Y is 12mm, and the F number FNO is 3.1.
Table 2 below lists relevant parameters of each lens of the present embodiment, including surface type, radius of curvature, thickness, refractive index of material, abbe number:
| number of noodles | Surface type | R value | Thickness of | Refractive index | Abbe of AbbeNumber of |
| sur1 | standard | 20.54 | 2.35 | 1.85 | 52.35 |
| sur2 | standard | 52.41 | 0.5 | ||
| sur3 | standard | 8.45 | 2.95 | 1.6 | 68.0 |
| sur4 | standard | 25.71 | 1.2 | 1.58 | 46.17 |
| sur5 | standard | 6.88 | 5.57 | ||
| Stop | standard | infinity | 3.15 | ||
| Sur7 | standard | -8.84 | 0.8 | 1.68 | 33.85 |
| Sur8 | standard | -45.37 | 2.5 | 1.76 | 50.35 |
| Sur9 | standard | -8.34 | 0.3 | ||
| Sur10 | standard | 75.35 | 1.7 | 1.76 | 50.35 |
| sur11 | standard | -45.65 | 3.13 | ||
| sur12 | standard | 30.22 | 1.6 | 1.68 | 35.85 |
| sur13 | standard | 18.34 | 0.5 | ||
| sur14 | standard | 25.73 | 3.5 | 1.64 | 60.4 |
| sur15 | standard | 95.37 | 13.1 | ||
| Image plane phi I | standard | infinity | - |
TABLE 2
In the present embodiment, as shown in fig. 1, the first lens group G1 includes 3 lenses (L1-L3), wherein the lens L2 and the lens L3 form a double cemented lens. The second lens group G2 comprises 3 lenses (L4-L6), wherein the lens L4 and the lens L5 are double cemented lenses. The third lens group G3 includes 2 lenses (L7 and L8).
Fig. 2 to 5 schematically show an MTF chart in focusing, an MTF defocus chart in a low temperature state, an MTF defocus chart in a high temperature state, and an optical distortion chart in an optimal working object distance of the imaging lens according to embodiment 1 of the present invention. As can be seen from the accompanying drawings, the imaging lens obtained in embodiment 1 of the present invention achieves the characteristics of a large aperture, high resolution, low distortion, uniform image quality, large depth of field, good color reproduction, and high contrast.
The second embodiment:
fig. 6 is a view schematically showing the configuration of an imaging lens according to a second embodiment of the present invention.
In the second embodiment, the total optical system length TTL is 43.5mm, the system focal length F is 26.4mm, the system imaging object distance range is 0.15m to inf, the system frame Y is 12.5mm, and the F number FNO is 2.5.
Table 3 below lists relevant parameters of each lens of the present embodiment, including surface type, radius of curvature, thickness, refractive index of material, abbe number:
| number of noodles | Surface type | R value | Thickness of | Refractive index | Abbe number |
| sur1 | standard | 22.5 | 2.45 | 1.78 | 60.23 |
| sur2 | standard | 64.2 | 0.15 | ||
| sur3 | standard | 10.73 | 3.56 | 1.55 | 75.0 |
| sur4 | standard | -54.07 | 2.0 | 1.58 | 49.2 |
| sur5 | standard | 8.83 | 2.38 | ||
| Stop | standard | infinity | 4.80 | ||
| Sur7 | standard | -10.24 | 1.2 | 1.65 | 33.84 |
| Sur8 | standard | 43.81 | 3.88 | 1.79 | 47.52 |
| Sur9 | standard | -12.91 | 0.15 | ||
| Sur10 | standard | infinity | 2.2 | 1.65 | 50.12 |
| sur11 | standard | -26.12 | 2.61 | ||
| sur12 | standard | 108.75 | 2.0 | 1.72 | 49.61 |
| sur13 | standard | 15.68 | 1.13 | ||
| sur14 | standard | 20.51 | 4.9 | 1.80 | 46.57 |
| sur15 | standard | infinity | 9.6 | ||
| Image plane phi I | standard | infinity | - |
TABLE 3
Referring to fig. 6, in the present embodiment, the first lens group G1 includes 3 lenses (L1-L3), wherein the lens L2 and the lens L3 form a double cemented lens. The second lens group G2 comprises 3 lenses (L4-L6), wherein the lens L4 and the lens L5 are double cemented lenses. The third lens group G3 includes 2 lenses (L7 and L8).
Fig. 7 to 10 schematically show an MTF chart in focus, an MTF defocus chart in a low temperature state, an MTF defocus chart in a high temperature state, and an optical distortion chart in an optimal working object distance of the imaging lens according to embodiment 2 of the present invention. As can be seen from the attached drawings, the imaging lens obtained in embodiment 2 of the present invention has the characteristics of large aperture, high resolution, low distortion, uniform image quality, large depth of field, good color rendition, and high contrast.
The third embodiment is as follows:
fig. 11 is a view schematically showing the configuration of an imaging lens according to a third embodiment of the present invention.
In the third embodiment, the total optical system length TTL is 53.00mm, the system focal length F is 33.5mm, the system imaging object distance range is 0.15m to inf, the system frame Y is 11.5mm, and the F number FNO is 2.6.
Table 4 below lists relevant parameters of each lens of the present embodiment, including surface type, radius of curvature, thickness, refractive index of material, abbe number:
| number of noodles | Surface type | R value | Thickness of | Refractive index | Abbe number |
| sur1 | standard | 35.02 | 4.2 | 1.85 | 37.5 |
| sur2 | standard | 165.14 | 0.2 | ||
| sur3 | standard | 18.2 | 4.1 | 1.50 | 80.2 |
| sur4 | standard | infinity | 3.85 | 1.70 | 35.15 |
| sur5 | standard | 13.5 | 4.89 | ||
| Stop | standard | infinity | 4.5 | ||
| Sur7 | standard | -15.75 | 2.54 | 1.62 | 36.35 |
| Sur8 | standard | 96.57 | 2.35 | 1.76 | 53.34 |
| Sur9 | standard | -25.26 | 0.2 | ||
| Sur10 | standard | 79.25 | 3.82 | 1.90 | 40.2 |
| Sur11 | standard | -82.35 | 5.45 | ||
| Sur12 | standard | 45.47 | 3.62 | 1.78 | 50.61 |
| sur13 | standard | -45.28 | 2.08 | ||
| sur14 | standard | -35.03 | 1.1 | 1.62 | 45.35 |
| sur15 | standard | 38.13 | 10.3 | ||
| Image plane phi I | standard | infinity | - |
TABLE 4
As shown in fig. 11, in the present embodiment, the first lens group G1 includes 3 lenses (L1-L3), wherein the lens L2 and the lens L3 form a double cemented lens. The second lens group G2 comprises 3 lenses (L4-L6), wherein the lens L4 and the lens L5 are double cemented lenses. The third lens group G3 includes 2 lenses (L7 and L8).
Fig. 12 to 15 schematically show an MTF chart in focusing, an MTF defocus chart in a low temperature state, an MTF defocus chart in a high temperature state, and an optical distortion chart in an optimal working object distance of the imaging lens according to embodiment 3 of the present invention. As can be seen from the attached drawings, the imaging lens obtained in embodiment 3 of the present invention achieves the characteristics of a large aperture, high resolution, low distortion, uniform image quality, large depth of field, good color reproduction, and high contrast.
The fourth embodiment:
fig. 16 is a view schematically showing the configuration of an imaging lens according to the fourth embodiment of the present invention.
In the fourth embodiment, the total optical system length TTL is 49.1mm, the system focal length F is 35.1mm, the system imaging object distance range is 0.15m to inf, the system frame Y is 12mm, and the F number FNO is 2.8.
Table 5 below lists relevant parameters of each lens of the present embodiment, including surface type, radius of curvature, thickness, refractive index of material, abbe number:
| number of noodles | Surface type | R value | Thickness of | Refractive index | Abbe number |
| sur1 | standard | 27.5 | 2.12 | 1.85 | 43.5 |
| sur2 | standard | -80.2 | 0.2 | ||
| sur3 | standard | 14.035 | 3.7 | 1.43 | 96.0 |
| sur4 | standard | infinity | 3.0 | 1.85 | 35.4 |
| sur5 | standard | 10.08 | 3.5 | ||
| Stop | standard | infinity | 3.6 | ||
| Sur7 | standard | -15.2 | 1.45 | 1.70 | 31.25 |
| Sur8 | standard | -30.1 | 1.90 | 1.78 | 45.21 |
| Sur9 | standard | -14.2 | 0.21 | ||
| Sur10 | standard | 35.7 | 1.78 | 1.75 | 50.34 |
| Sur11 | standard | -402.2 | 6.85 | ||
| sur12 | standard | -153.06 | 1.5 | 1.82 | 30.1 |
| sur13 | standard | -21.1 | 3.78 | ||
| sur14 | standard | -25.8 | 1.2 | 1.78 | 23.5 |
| sur15 | standard | -300.5 | 13.4 | ||
| Image plane phi I | standard | infinity | - |
TABLE 5
Referring to fig. 16, in the present embodiment, the first lens group G1 includes 3 lenses (L1-L3), wherein the lens L2 and the lens L3 form a double cemented lens. The second lens group G2 comprises 3 lenses (L4-L6), wherein the lens L4 and the lens L5 are double cemented lenses. The third lens group G3 includes 2 lenses (L7 and L8).
Fig. 17 to 20 schematically show an MTF graph in focus of an optimal working object distance of an imaging lens, an MTF defocus graph in a low temperature state, an MTF defocus graph in a high temperature state, and an optical distortion graph, respectively, according to embodiment 4 of the present invention. As can be seen from the attached drawings, the imaging lens obtained in embodiment 4 of the present invention achieves the characteristics of a large aperture, high resolution, low distortion, uniform image quality, large depth of field, good color reproduction, and high contrast.
The fifth embodiment:
fig. 21 is a view schematically showing the configuration of an imaging lens according to the fifth embodiment of the present invention.
In the fifth embodiment, the total optical system length TTL is 47.83mm, the system focal length F is 30.6mm, the system imaging object distance range is 0.15m to inf, the system frame Y is 11.6mm, and the F number FNO is 2.5.
Table 6 below lists relevant parameters of each lens of the present embodiment, including surface type, radius of curvature, thickness, refractive index of material, abbe number:
| number of noodles | Surface type | R value | Thickness of | Refractive index | Abbe number |
| sur1 | standard | 25.6 | 2.14 | 1.75 | 42.5 |
| sur2 | standard | 75.33 | 0.18 | ||
| sur3 | standard | 12.03 | 3.5 | 1.55 | 68.0 |
| sur4 | standard | 20.12 | 2.0 | 1.67 | 40.2 |
| sur5 | standard | 11.0 | 3.1 | ||
| Stop | standard | infinity | 3.25 | ||
| Sur7 | standard | -13.97 | 1.32 | 1.69 | 37.5 |
| Sur8 | standard | -32.61 | 1.85 | 1.75 | 42.5 |
| Sur9 | standard | -14.47 | 1.1 | ||
| Sur10 | standard | 436.1 | 1.5 | 1.78 | 42.5 |
| sur11 | standard | -34.5 | 7.5 | ||
| sur12 | standard | -195.06 | 2.2 | 1.85 | 25.1 |
| sur13 | standard | -35.78 | 4.0 | ||
| sur14 | standard | -24.65 | 1.2 | 1.81 | 23.7 |
| sur15 | standard | infinity | 13 | ||
| Image plane phi I | standard | infinity | - |
TABLE 6
Referring to fig. 21, in the present embodiment, the first lens group G1 includes 3 lenses (L1-L3), wherein the lens L2 and the lens L3 form a double cemented lens. The second lens group G2 comprises 3 lenses (L4-L6), wherein the lens L4 and the lens L5 are double cemented lenses. The third lens group G3 includes 2 lenses (L7 and L8).
Fig. 22 to 25 schematically show an MTF graph in focus of an optimal working object distance of an imaging lens, an MTF defocus graph in a low temperature state, an MTF defocus graph in a high temperature state, and an optical distortion graph, respectively, according to embodiment 5 of the present invention. As can be seen from the attached drawings, the imaging lens obtained in embodiment 5 of the present invention achieves the characteristics of a large aperture, high resolution, low distortion, uniform image quality, large depth of field, good color reproduction, and high contrast.
The above description is only one embodiment of the present invention, and is not intended to limit the present invention, and it is apparent to those skilled in the art that various modifications and variations can be made in the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (13)
1. An imaging lens includes, in order from an object side to an image side, a first lens group (G1) having positive power, a stop, a second lens group (G2) having positive power, and a third lens group (G3) having positive power or negative power, the third lens group (G3) being a fixed group, and the first lens group (G1) and the second lens group (G2) constituting a focusing group movable along an optical axis.
2. The imaging lens according to claim 1, wherein the first lens group (G1) includes at least two positive power lenses and one negative power lens, and a lens closest to the object side in the first lens group (G1) is a positive power lens, and a lens closest to the image side is a negative power lens.
3. The imaging lens according to claim 2, wherein a lens closest to the object side in the first lens group (G1) is one of a biconvex lens, a convex-concave lens, or a convex-flat lens in an object-to-image direction.
4. The imaging lens according to claim 3, wherein the first lens group (G1) comprises a double cemented lens formed by a combination of positive power lens and negative power lens along the object-to-image direction.
5. An imaging lens according to claim 4, characterized in that the positive power lens of the cemented doublet in the first lens group (G1) has a refractive index ND and an Abbe number VD, satisfying: VD is more than or equal to 60 and less than or equal to 96, ND is more than or equal to 1.43 and less than or equal to 1.65.
6. The imaging lens according to claim 1 or 5, wherein the second lens group (G2) includes at least two positive power lenses and one negative power lens, and a lens closest to the object side in the second lens group (G2) is a negative power lens, and a lens closest to the image side is a positive power lens.
7. The imaging lens according to claim 6, wherein a lens closest to an image side in the second lens group (G2) is one of a biconvex lens, a meniscus lens, or a plano-convex lens in an object-to-image direction.
8. The imaging lens according to claim 7, wherein the second lens group (G2) comprises a double cemented lens formed by a combination of negative power lens and positive power lens along the object-to-image direction.
9. The imaging lens according to claim 1 or 8, wherein the third lens group (G3) includes at least one positive power lens and one negative power lens, and two lenses close to the object side in the third lens group (G3) are arranged in the order of the positive power lens, the negative power lens, or the order of the negative power lens and the positive power lens in the object-to-image direction.
10. The imaging lens according to claim 9, characterized in that the positive power lens in the third lens group (G3) is one of a biconvex lens, a convex-concave lens, or a convex-flat lens, and the negative power lens is one of a biconcave lens, a convex-concave lens, or a convex-concave lens.
11. An imaging lens according to claim 1, wherein a focal length of a focusing group consisting of the first lens group (G1), the stop, and the second lens group (G2) is fm, and a focal length of the imaging lens is f, satisfying the relation: fm/f is more than or equal to 1.0 and less than or equal to 1.5.
12. An imaging lens according to claim 1, characterized in that the focal length of the third lens group (G3) is fg3 and the focal length of the imaging lens is f, satisfying: the | fg3/f | is more than or equal to 3.5 and less than or equal to 8.5.
13. The imaging lens of claim 1, wherein the total optical length of the imaging lens is TTL, and the focal length of the imaging lens is f, which satisfies TTL/f 1.35 ≤ 1.75.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114690388A (en) * | 2022-06-01 | 2022-07-01 | 江西联益光学有限公司 | Zoom lens |
| CN116009220A (en) * | 2023-03-24 | 2023-04-25 | 联创电子科技股份有限公司 | Optical lens and camera module |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016061919A (en) * | 2014-09-17 | 2016-04-25 | 株式会社リコー | Imaging lens and imaging apparatus |
| CN107894648A (en) * | 2016-10-04 | 2018-04-10 | 富士胶片株式会社 | Imaging len and camera device |
| CN108919466A (en) * | 2018-08-20 | 2018-11-30 | 广东奥普特科技股份有限公司 | A kind of wide operating distance focusing machine visual lens of high-resolution |
| CN210572978U (en) * | 2019-09-19 | 2020-05-19 | 凤凰光学股份有限公司 | Low-distortion high-pixel large-target-surface machine vision lens |
| CN111474685A (en) * | 2020-06-01 | 2020-07-31 | 中国科学院长春光学精密机械与物理研究所 | Long-focus wide-spectrum achromatic optical lens |
| CN212302051U (en) * | 2020-09-28 | 2021-01-05 | 舜宇光学(中山)有限公司 | Imaging lens |
-
2020
- 2020-09-28 CN CN202011037629.5A patent/CN112269254A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016061919A (en) * | 2014-09-17 | 2016-04-25 | 株式会社リコー | Imaging lens and imaging apparatus |
| CN107894648A (en) * | 2016-10-04 | 2018-04-10 | 富士胶片株式会社 | Imaging len and camera device |
| CN108919466A (en) * | 2018-08-20 | 2018-11-30 | 广东奥普特科技股份有限公司 | A kind of wide operating distance focusing machine visual lens of high-resolution |
| CN210572978U (en) * | 2019-09-19 | 2020-05-19 | 凤凰光学股份有限公司 | Low-distortion high-pixel large-target-surface machine vision lens |
| CN111474685A (en) * | 2020-06-01 | 2020-07-31 | 中国科学院长春光学精密机械与物理研究所 | Long-focus wide-spectrum achromatic optical lens |
| CN212302051U (en) * | 2020-09-28 | 2021-01-05 | 舜宇光学(中山)有限公司 | Imaging lens |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114690388A (en) * | 2022-06-01 | 2022-07-01 | 江西联益光学有限公司 | Zoom lens |
| CN116009220A (en) * | 2023-03-24 | 2023-04-25 | 联创电子科技股份有限公司 | Optical lens and camera module |
| CN116009220B (en) * | 2023-03-24 | 2023-07-25 | 联创电子科技股份有限公司 | Optical lens and camera module |
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