High-precision target simulation lens with variable magnification
By designing a high-precision target simulation lens with variable magnification, the problem of needing to replace the target in camera module calibration was solved, achieving efficient and accurate target simulation, reducing space requirements and optical distortion, and making the lens compact.
Patent Information
- Application Number
- CN202410702945.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-03
- Publication Date
- 2026-02-03
AI Technical Summary
In existing technologies, camera module calibration requires constantly changing targets at different distances, which takes up a lot of space and is inefficient.
Design a high-precision target simulation lens with variable magnification. By combining a simulated target, entrance pupil, convex and concave lenses, a first biconvex lens, a first biconcave lens, a second biconvex lens, and a cemented doublet lens, target simulation from 150mm to infinity can be achieved, reducing space requirements.
It achieves high-precision calibration at different distances, reduces space requirements, improves calibration efficiency, and controls optical distortion to within 0.19%, while keeping the overall lens size compact.
Smart Images
Figure CN121454733A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of camera module calibration, and more specifically to a high-precision target simulation lens with variable magnification. Background Technology
[0002] Target simulation lens: This is a method of projecting light to project a pre-set image from a near distance to a desired distance, thereby simulating targets at various distances up to infinity within a small space. This provides the same calibration effect for camera modules as a large actual target surface. With the continuous development of mobile phone lenses, automotive lenses, security lenses, and other fields, the production volume of camera modules is increasing daily, and the imaging requirements and calibration requirements for camera modules are also becoming more stringent. Currently, different targets are generally used for calibration of different camera imaging distances. Constantly changing the calibration target surface during the actual calibration process not only occupies testing space but also has very low calibration efficiency. Therefore, whether a high-precision target simulator capable of simulating targets from near distances to infinity is a technical problem that this invention urgently needs to solve. Summary of the Invention
[0003] In view of the shortcomings of the prior art, the present invention provides a high-precision target simulation lens with variable magnification. The technical problem to be solved is that, for different camera imaging distances, the calibration target surface needs to be changed continuously during the actual calibration process, which not only occupies the space of the test site, but also has very low calibration efficiency.
[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a high-precision target simulation lens with variable magnification, the lens comprising a simulated target, an entrance pupil, a convex and concave lens, a first biconvex lens, a first biconcave lens, a second biconvex lens, a cemented doublet lens, and a preset pattern arranged sequentially from the simulated target to the preset pattern.
[0005] The concave-convex lens includes a first convex surface and a first concave surface. The first convex surface is disposed adjacent to the entrance pupil, and the first concave surface is disposed adjacent to the convex surface of the first biconvex lens.
[0006] Specifically, the cemented doublet lens includes a concave-convex lens and a second biconcave lens, wherein the second convex surface of the concave-convex lens is cemented together with the concave surface of the second biconcave lens; and the second concave surface of the concave-convex lens is disposed adjacent to the second biconcave lens.
[0007] More specifically, the focal length fG of the target simulation lens is fG = 80.18mm;
[0008] The convex and concave lenses are of positive optical power, and the focal length is fL1, satisfying 1 < |fL1 / fG| < 1.5;
[0009] The first biconvex lens has positive optical power and a focal length of fL2, satisfying 2 < |fL2 / fG| < 3;
[0010] The first biconcave lens has negative optical power and a focal length of fL3 satisfying 0 < |fL3 / fG| < 0.5;
[0011] The second biconvex lens has positive optical power and a focal length of fL4, satisfying 0 < |fL4 / fG| < 0.5;
[0012] The doublet lens has negative optical power and a focal length of fL5, satisfying 0 < |fL5 / fG| < 1.
[0013] More specifically, the entrance pupil diameter of the target simulation lens is 6mm, and the distance between the entrance pupil and the front surface of the convex and concave lens is 80mm.
[0014] Specifically, the distance between the preset graphic position and the rear surface of the doublet lens is not less than 5.56 mm and not more than 46.79 mm.
[0015] More specifically, when the position of the preset graphic is set at a distance of 5.56 mm from the rear surface of the doublet lens, the distance between the target simulation lens and the entrance pupil is 150 mm.
[0016] More specifically, when the position of the preset graphic is set at a distance of 44.64 mm from the rear surface of the doublet lens, the distance between the target simulation lens and the entrance pupil is 3000 mm.
[0017] More specifically, when the position of the preset pattern is set at a distance of 46.79 mm from the rear surface of the doublet lens, the distance between the target simulation lens and the entrance pupil is infinite.
[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0019] This invention utilizes a combination of a simulated target, entrance pupil, convex and concave lenses, a first biconvex lens, a first biconcave lens, a second biconvex lens, a cemented doublet lens, and a preset pattern to create a high-precision target simulation lens capable of simulating distances from 150mm to infinity, offering the following advantages:
[0020] First, the magnification is variable, which can simulate the calibration of camera modules from 150mm to infinity according to different application scenarios. This can reduce the requirement for a large field for real targets. When calibrating camera modules, if targets at different distances are needed, the targets do not need to be changed.
[0021] Second, optical distortion is well controlled, with distortion controlled within 0.58% at 150mm, within 0.2% at 3000mm, and within 0.19% at infinity.
[0022] Third, the target simulation of the lens is highly accurate, with an MTF of 75 lp / mm at 150mm, 71 lp / mm at 3000mm, and 71 lp / mm at infinity.
[0023] Fourth, the target simulation lens is small in size, with a lens length of 41.31mm. Attached Figure Description
[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0025] Figure 1 This is a schematic diagram of the target simulation optical path structure of the present invention.
[0026] Figure 2 This is a schematic diagram of the MTF curve at a simulated distance of 150mm according to the present invention.
[0027] Figure 3 This is a schematic diagram of the MTF curve for a simulated distance of 3000mm according to the present invention.
[0028] Figure 4 This is a schematic diagram of the MTF curve simulating an infinite distance according to the present invention.
[0029] Figure 5 This is a schematic diagram of the distortion curve at a simulated distance of 150mm according to the present invention.
[0030] Figure 6 This is a schematic diagram of the distortion curve at a simulated distance of 3000mm according to the present invention.
[0031] Figure 7 This is a schematic diagram of the distortion curve simulating an infinitely far distance, as presented in this invention.
[0032] Figure 8 This is a reference table of optical path structure parameters described in this invention.
[0033] Figure 9 This is a reference table for the aspherical coefficients in the optical path structure formed by the present invention.
[0034] The attached diagram is labeled as follows: 1: Simulated target, 2: Entrance pupil, 3: Convex and concave lens, 4: First biconvex lens, 5: First biconcave lens, 6: Second biconvex lens, 7: Cemented doublet lens, 71: Concave and convex lens, 72: Second biconcave lens, 8: Preset pattern. Detailed Implementation
[0035] To better understand the present invention, the following embodiments further illustrate the content of the invention, but the scope of protection of the present invention is not limited to the following embodiments. Numerous specific details are set forth in the following description to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details.
[0036] In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.
[0037] Example: Figure 1 As shown, a high-precision target simulation lens with variable magnification is provided. The lens is set sequentially from the simulated target to the preset pattern as follows: simulated target 1, entrance pupil 2, convex and concave lens 3, first biconvex lens 4, first biconcave lens 5, second biconvex lens 6, cemented doublet lens 7, and preset pattern 8.
[0038] The concave-convex lens includes a first convex surface and a first concave surface. The first convex surface is disposed adjacent to the entrance pupil 2, and the first concave surface is disposed adjacent to the convex surface of the first biconvex lens.
[0039] Specifically, the doublet lens 7 is composed of a concave-convex lens 71 and a second double concave lens 72, wherein the second convex surface of the concave-convex lens 71 is bonded together with the concave surface of the second double concave lens 72.
[0040] The second concave surface of the concave-convex lens 71 is disposed adjacent to the second biconvex lens 6.
[0041] In this embodiment, the relevant optical power and focal length parameters of the lens of the present invention are as follows:
[0042] The focal length fG of the target simulation lens is fG = 80.18mm;
[0043] The convex-concave lens 3 has positive optical power and a focal length of fL1, satisfying 1 < |fL1 / fG| < 1.5;
[0044] The first biconvex lens 4 has positive optical power and a focal length of fL2, satisfying 2 < |fL2 / fG| < 3;
[0045] The first biconcave lens 5 has a negative optical power and a focal length of fL3, satisfying 0 < |fL3 / fG| < 0.5;
[0046] The second biconvex lens 6 has a positive optical power and a focal length of fL4, satisfying 0 < |fL4 / fG| < 0.5;
[0047] The cemented doublet lens 7 has negative optical power and a focal length of fL5, satisfying 0 < |fL5 / fG| < 1.
[0048] In practical use, the focal lengths fL1 of the concave-convex lens, fL2 of the first biconvex lens 4, fL3 of the first biconcave lens 5, fL4 of the second biconvex lens 6, and fL5 of the cemented doublet lens 7 can be set within the above range according to actual needs.
[0049] For example, the focal length of the concave-convex lens can be 90mm, the focal length of the first biconvex lens 4 can be 170mm, the focal length of the first biconcave lens 5 can be 30mm, the focal length of the second biconvex lens 6 can be 20mm, and the focal length of the cemented doublet lens 7 can be 75mm.
[0050] Alternatively, the focal length of the concave-convex lens can be 100mm, the focal length of the first biconvex lens 4 can be 185mm, the focal length of the first biconcave lens 5 can be 25mm, the focal length of the second biconvex lens 6 can be 23mm, and the focal length of the cemented doublet lens 7 can be 70mm.
[0051] like Figure 8 The table shown is a reference table of mirror information parameters for all lenses in the imaging optical path structure described in this embodiment:
[0052] The first convex surface of the concave-convex lens is aspherical, with a radius of curvature of 32.136 mm, a center thickness of 6.75 mm, a refractive index of 1.59, and an Abbe number of 68.34.
[0053] The first concave surface of the concave-convex lens is spherical with a radius of curvature of 80.003 mm and a center thickness of 2.97 mm.
[0054] The left convex surface of the first biconvex lens 4 is aspherical, with a radius of curvature of 40.273 mm, a center thickness of 6.04 mm, a refractive index of 1.59, and an Abbe number of 68.34.
[0055] The right convex surface of the first biconvex lens 4 is spherical with a radius of curvature of -435.498 mm and a center thickness of 1.42 mm.
[0056] The left concave surface of the first biconcave lens 5 is spherical, with a radius of curvature of -332.890 mm, a center thickness of 2.98 mm, a refractive index of 1.63, and an Abbe number of 35.71.
[0057] The right concave surface of the first biconcave lens 5 is spherical with a radius of curvature of 26.393 mm and a center thickness of 2.99 mm.
[0058] The left convex surface of the second biconvex lens 6 is aspherical, with a radius of curvature of 27.133 mm, a center thickness of 7.23 mm, a refractive index of 1.59, and an Abbe number of 68.34.
[0059] The right convex surface of the second biconvex lens 6 is spherical with a radius of curvature of -106.355 mm and a center thickness of 3.70 mm.
[0060] The second concave surface of the concave-convex lens 71 is spherical with a radius of curvature of -4.64E+01, a center thickness of 4.26mm, a refractive index of 1.92, and an Abbe number of 18.90.
[0061] The second convex surface of the concave-convex lens 71 is spherical with a radius of curvature of -4.12E+01, a center thickness of 2.97mm, a refractive index of 1.47, and an Abbe number of 66.89. Since the second convex surface of the concave-convex lens 71 is cemented with the left concave surface of the second biconcave lens 72, the parameters of the two mirror surfaces are the same.
[0062] The right concave surface of the second biconcave lens 72 is aspherical with a radius of curvature of 219.713.
[0063] Furthermore, for the aspherical surfaces in the aforementioned mirror surface, the following aspherical surface formula must be satisfied:
[0064]
[0065] In this formula, r represents curvature, k represents conic coefficient, and k2, k4, k6, and k8 are aspherical coefficients.
[0066] like Figure 9 As shown, specifically in this embodiment, the k value of the first convex surface of the concave-convex lens is -0.949, k2 is 2.77E-04, k4 is -2.02E-06, k6 is -3.43E-08, and k8 is 5.46E-12;
[0067] The k-values of the left convex surface of the first biconvex lens 4 are 3.497, k2 is -8.85E-03, k4 is 1.12E-05, k6 is 5.38E-08, and k8 is -1.12E-10.
[0068] The k-values of the left convex surface of the second biconvex lens 6 are -1.994, k2 is 2.74E-03, k4 is -3.57E-06, k6 is -3.49E-08, and k8 is -171E-10.
[0069] The k-values of the right concave surface of the second biconcave lens 72 are 276.456, k2 is 1.85E-03, k4 is 2.91E-06, k6 is -5.64E-08, and k8 is -1.80E-10.
[0070] More specifically, the entrance pupil 2 of the target simulation lens has a diameter of 6mm, and the distance between the entrance pupil 2 and the front surface of the convex and concave lens 3 is 80mm.
[0071] The distance between the preset pattern 8 and the rear surface of the doublet lens 7 is not less than 5.56 mm and not more than 46.79 mm. More specifically:
[0072] When the position of the preset pattern 8 is set at a distance of 5.56 mm from the rear surface of the doublet lens 7, the distance between the target simulation lens simulated target 1 and the entrance pupil 2 is 150 mm.
[0073] When the position of the preset pattern 8 is set at a distance of 44.64 mm from the rear surface of the doublet lens 7, the distance between the target simulation lens simulated target 1 and the entrance pupil 2 is 3000 mm;
[0074] When the position of the preset pattern 8 is set at a distance of 46.79 mm from the rear surface of the doublet lens 7, the distance between the target simulation lens simulated target 1 and the entrance pupil 2 is infinite.
[0075] MTF simulation of the present invention was performed. During the MTF simulation, the distance between the simulated target 1 and the entrance pupil 2 was preset to 150mm. The simulation diagram of the present invention at this time is as follows. Figure 2 As shown, the MTF reaches 75 lp / mm at the 150 mm position. Simultaneously, combined with... Figure 5 It can be seen that the distortion at the 150mm position is controlled within 0.58%.
[0076] When performing MTF simulation, if the distance between the simulated target 1 and the entrance pupil 2 is preset to 3000mm, the simulation diagram of the present invention is as follows. Figure 3 As shown, the MTF reaches 71 lp / mm at the 3000mm position. Simultaneously, combined with... Figure 6 It can be seen that the distortion at the 3000mm position is controlled within 0.2%.
[0077] When performing MTF simulation, if the distance between the simulated target 1 and the entrance pupil 2 is set to infinite, the simulation diagram of this invention is as follows. Figure 4 As shown, the MTF reaches 71 lp / mm at infinity. Simultaneously, combined with... Figure 5 It can be seen that the distortion at infinity is controlled within 0.19%, indicating good optical distortion control.
[0078] In combination with the above, in practical use, the target simulation lens of the present invention can simulate camera module calibration targets from 150mm to infinity according to different application scenarios, which can reduce the requirement of a large site for real targets. When calibrating camera modules, if targets at different distances are needed, the target does not need to be changed.
[0079] Optical distortion is well controlled, with distortion at infinity controlled to within 0.19%.
[0080] The target simulation lens is small in size, with a lens length of 41.31mm.
[0081] Furthermore, those skilled in the art should understand that although many problems exist in the prior art, each embodiment or technical solution of the present invention can be improved in only one or a few aspects, without necessarily solving all the technical problems listed in the prior art or the background art simultaneously. Those skilled in the art should understand that any content not mentioned in a claim should not be construed as a limitation on that claim.
[0082] Finally, it should be noted that the above embodiments are only used to illustrate preferred embodiments of the present invention and are not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention, as long as they do not depart from the spirit and scope of the technical solutions of the present invention, should be covered within the scope of the claims of the present invention.
Claims
1. A high-precision target simulation lens with variable magnification, characterized in that, The lens includes a simulated target, an entrance pupil, a convex and concave lens, a first biconvex lens, a first biconcave lens, a second biconvex lens, a cemented doublet lens, and a preset pattern arranged sequentially from the simulated target to the preset pattern. The concave-convex lens includes a first convex surface and a first concave surface. The first convex surface is disposed adjacent to the entrance pupil, and the first concave surface is disposed adjacent to the convex surface of the first biconvex lens.
2. A high-precision target simulation lens with variable magnification according to claim 1, characterized in that, The doublet lens includes a concave-convex lens and a second biconcave lens, wherein the second convex surface of the concave-convex lens is bonded together with the concave surface of the second biconcave lens; the second concave surface of the concave-convex lens is disposed adjacent to the second biconcave lens.
3. A high-precision target simulation lens with variable magnification according to claim 2, characterized in that, The focal length fG of the target simulation lens is fG = 80.18mm; The convex and concave lenses are of positive optical power, and the focal length is fL1, satisfying 1 < |fL1 / fG| < 1.5; The first biconvex lens has positive optical power and a focal length of fL2, satisfying 2 < |fL2 / fG| < 3; The first biconcave lens has negative optical power and a focal length of fL3 satisfying 0 < |fL3 / fG| < 0.5; The second biconvex lens has positive optical power and a focal length of fL4, satisfying 0 < |fL4 / fG| < 0.5; The doublet lens has negative optical power and a focal length of fL5, satisfying 0 < |fL5 / fG| < 1.
4. A high-precision target simulation lens with variable magnification according to claim 3, characterized in that, The entrance pupil diameter of the target simulation lens is 6mm, and the distance between the entrance pupil and the front surface of the convex and concave lens is 80mm.
5. A high-precision target simulation lens with variable magnification according to claim 4, characterized in that, The preset graphic position is set at a distance of not less than 5.56 mm and not more than 46.79 mm from the rear surface of the doublet lens.
6. A high-precision target simulation lens with variable magnification according to claim 5, characterized in that, When the position of the preset graphic is set to be 5.56 mm away from the rear surface of the doublet lens, the distance between the target simulation lens and the entrance pupil is 150 mm.
7. A high-precision target simulation lens with variable magnification according to claim 5, characterized in that, When the position of the preset graphic is set at a distance of 44.64 mm from the rear surface of the doublet lens, the distance between the target simulation lens and the entrance pupil is 3000 mm.
8. A high-precision target simulation lens with variable magnification according to claim 5, characterized in that, When the position of the preset graphic is set at a distance of 46.79 mm from the rear surface of the doublet lens, the distance between the target simulation lens and the entrance pupil is infinite.