Large-angle small-distortion optical system and relay lens applied by same

Abstract

The utility model provides a large-angle small-distortion optical system and a relay lens using the same, mainly comprising six lenses, the first lens has positive focal power, the object side surface is a convex surface, the image side surface is a concave surface, the second lens has negative focal power, the object side surface is a convex surface, and the image side surface is a concave surface. The third lens has negative focal power, the image side surface is a concave surface, the fourth lens has positive focal power, the object side surface is a convex surface, the image side surface is a convex surface, the fifth lens has negative focal power, the object side surface is a plane, the image side surface is a concave surface, the sixth lens has positive focal power, the object side surface is a convex surface, and the image side surface is a concave surface. Through reasonable matching of the lens shape and the focal power, the purposes of large field angle and distortion correction are achieved, the measurement length error caused by large distortion of a large-angle relay lens to a large-angle measured lens module is solved, the exit pupil diameter of the relay lens carrying the optical system is increased, and the measurement precision is improved. And the accuracy of the centering requirement of the test equipment on the tested lens module and the relay lens is greatly reduced.

Description

Technical Field

[0001] This application relates to the field of optical imaging, and more particularly to a relay mirror for a large-angle, small-distortion optical system and its applications. Background Technology

[0002] Currently, testing of wide-angle camera modules typically uses wide-angle repeater lenses to simulate near and far views. According to optical principles, lens distortion is related to the field of view; the larger the field of view, the greater the distortion. Therefore, conventional wide-angle repeater lenses generally exhibit significant distortion. When customers use conventional wide-angle repeater lenses to test the lens module under test, the distortion introduced by the repeater lens adds superimposed distortion to the original lens on the camera module, causing a change in the calibrated test length on the original camera lens. Therefore, it is necessary to develop a wide-angle, low-distortion repeater lens to solve this problem. Utility Model Content

[0003] This application aims to solve the measurement length error caused by the large distortion of the large-angle repeater lens to the lens module under test at a large angle. It provides a large-angle small-distortion optical system and a repeater lens for its application, which has a long working distance, large space, and is convenient for product testing and handling.

[0004] A large-angle, small-distortion optical system comprises, along the optical axis from the object plane to the image plane, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens.

[0005] The first lens has positive optical power, its object side is convex, and its image side is concave.

[0006] The second lens has negative optical power, its object side is convex, and its image side is concave.

[0007] The third lens has negative optical power, and its object side is concave, as is its image side.

[0008] The fourth lens has positive optical power, and its object side is convex, and its image side is convex.

[0009] The fifth lens has negative optical power, its object side is concave or flat, and its image side is concave.

[0010] The sixth lens has positive optical power, its object side is convex, and its image side is concave.

[0011] As described above, in a large-angle, small-distortion optical system, each lens of the optical system satisfies the following condition:

[0012] 752mm <f1<898mm;

[0013] -221mm <f2<-147mm;

[0014] -173mm <f3<-151mm;

[0015] 148mm <f4<183mm;

[0016] -481mm <f5<-298mm;

[0017] 109mm <f6<131mm;

[0018] Where f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, f4 is the effective focal length of the fourth lens, f5 is the effective focal length of the fifth lens, and f6 is the effective focal length of the sixth lens.

[0019] As described above, in a large-angle, small-distortion optical system, each lens of the optical system satisfies the following condition:

[0020] 2.13 <f1 / f<3.27;

[0021] -0.82 <f2 / f<-0.38;

[0022] -0.77 <f3 / f<-0.31;

[0023] 0.37 <f4 / f<0.79;

[0024] -2.1 <f5 / f<-0.73;

[0025] 0.21 <f6 / f<0.73;

[0026] Where f is the focal length of the entire optical system, f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, f4 is the effective focal length of the fourth lens, f5 is the effective focal length of the fifth lens, and f6 is the effective focal length of the sixth lens.

[0027] In the large-angle, small-distortion optical system described above, the refractive index Nd1 and Abbe number constant Vd1 of the first lens satisfy: 1.7 < Nd1 < 1.9, 25.0 < Vd1 < 45.0.

[0028] In the large-angle, small-distortion optical system described above, the refractive index Nd2 and Abbe number constant Vd2 of the second lens material satisfy: 1.7 < Nd2 < 1.88, 40 < Vd2 < 55.

[0029] In the large-angle, small-distortion optical system described above, the refractive index Nd3 and Abbe number constant Vd3 of the third lens satisfy the following conditions: 1.65 < Nd3 < 1.85, 40 < Vd3 < 56.

[0030] In the large-angle, small-distortion optical system described above, the refractive index Nd4 and Abbe number constant Vd4 of the fourth lens satisfy the following conditions: 1.65 < Nd4 < 1.8, 45 < Vd4 < 65.

[0031] In the large-angle, small-distortion optical system described above, the refractive index Nd5 and Abbe number constant Vd5 of the fifth lens satisfy the following conditions: 1.71 < Nd5 < 1.85, 20 < Vd5 < 40.

[0032] In the large-angle, small-distortion optical system described above, the refractive index Nd6 and Abbe number constant Vd6 of the sixth lens satisfy the following conditions: 1.65 < Nd6 < 1.75, 45 < Vd6 < 55.

[0033] In the large-angle, small-distortion optical system described above, the radius of curvature R1 on the object plane side and the radius of curvature R2 on the image plane side of the first lens satisfy: -228 < R1 < -136; -268 < R2 < -178.

[0034] In the large-angle, small-distortion optical system described above, the radius of curvature R3 on the object plane side and the radius of curvature R4 on the image plane side of the second lens satisfy: -255 < R3 < -165; -120 < R4 < -65.

[0035] In the large-angle, small-distortion optical system described above, the radius of curvature R5 on the object plane side and the radius of curvature R6 on the image plane side of the third lens satisfy: 395 < R5 < 550; -200 < R6 < -100.

[0036] In the large-angle, small-distortion optical system described above, the radius of curvature R7 on the object plane side and the radius of curvature R8 on the image plane side of the fourth lens satisfy: -252 < R7 < -145; 275 < R8 < 388.

[0037] In the large-angle, small-distortion optical system described above, the radius of curvature R9 on the object plane side and the radius of curvature R10 on the image plane side of the fifth lens satisfy: 630 < R9; -500 < R10 < -325.

[0038] In the large-angle, small-distortion optical system described above, the radius of curvature R11 on the object plane side and the radius of curvature R12 on the image plane side of the sixth lens satisfy: -80 < R11 < -45; -225 < R2 < -118.

[0039] As described above, in a large-angle, small-distortion optical system, the effective focal length f of the optical system satisfies: 280mm < f < 330mm.

[0040] As described above, a large-angle, small-distortion optical system has a full field of view (FOV) of [120°, 180°].

[0041] In the large-angle, small-distortion optical system described above, the first lens, second lens, third lens, fourth lens, fifth lens, and sixth lens are all glass spherical lenses.

[0042] On the other hand, embodiments of this application also provide a relay lens, which includes at least an optical lens, and the optical lens is equipped with the above-mentioned large-angle small-distortion optical system.

[0043] Compared with the prior art, the beneficial effects of this application are as follows:

[0044] This invention provides a large-angle, low-distortion optical system and its application relay lens, which mainly consists of 6 lenses. Through the reasonable combination of lens shape and optical power, it achieves a large field of view and the purpose of distortion correction, solving the measurement length error caused by the large distortion of the large-angle relay lens to the lens module under test. The exit pupil diameter of the relay lens equipped with this optical system is increased, which will greatly reduce the accuracy required for the alignment of the lens module under test and the relay lens by the testing equipment. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0046] Figure 1 This is a schematic diagram of the optical system or relay mirror in Embodiment 1 of this application;

[0047] Figure 2 This is the MTF curve of the optical system or relay mirror in Embodiment 1 of this application;

[0048] Figure 3 These are the field curvature curves and distortion curves of the optical system or relay mirror in Embodiment 1 of this application;

[0049] Figure 4 This is a schematic diagram illustrating the application of the optical system or relay mirror in the embodiments of this application. Detailed Implementation

[0050] like Figures 1-4 As shown, this application provides a large-angle, small-distortion optical system, which includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens in sequence along the optical axis from the object plane to the image plane;

[0051] The first lens has positive optical power, its object side is convex, and its image side is concave.

[0052] The second lens has negative optical power, its object side is convex, and its image side is concave.

[0053] The third lens has a negative optical power, its object side is concave, and its image side is concave;

[0054] The fourth lens has a positive optical power, its object side is convex, and its image side is convex;

[0055] The fifth lens has a negative optical power, its object side is concave or flat, and its image side is concave;

[0056] The sixth lens has a positive optical power, its object side is convex, and its image side is concave.

[0057] The optical system of the embodiment of the present invention is mainly composed of six lenses. Through the reasonable combination of the lens shapes and optical powers, the purpose of achieving a large field angle and correcting distortion is achieved, and the measurement length error caused by the large distortion of the large-angle relay lens to the large-angle measured lens module is solved. The exit pupil diameter of the relay lens equipped with this optical system is increased, which will greatly reduce the accuracy requirements for the centering of the measured lens module and the relay lens by the test equipment.

[0058] Furthermore, as a preferred implementation manner rather than a limitation of the present invention, the lenses of this optical system satisfy the following conditions: 752mm < f1 < 898mm; -221mm < f2 < -147mm; -173mm < f3 < -151mm; 148mm < f4 < 183mm; -481mm < f5 < -298mm; 109mm < f6 < 131mm; where f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, f4 is the effective focal length of the fourth lens, f5 is the effective focal length of the fifth lens, and f6 is the effective focal length of the sixth lens. Through the reasonable control of the effective focal lengths of each lens of the optical system in this application, while the optical system meets the large field angle, the effective diameter of the component can be controlled, the distortion can be corrected, which is beneficial to correcting the system aberration. The distortion correction amount of this application can reach ≤0.1%. Generally, the distortion amount of such a field angle is about 30%, and this relay lens reduces the distortion by about 99%.

[0059] Further, as a preferred embodiment of the present invention rather than a limitation, each lens of the optical system satisfies the following conditions: 2.13 < f1 / f < 3.27; -0.82 < f2 / f < -0.38; -0.77 < f3 / f < -0.31; 0.37 < f4 / f < 0.79; -2.1 < f5 / f < -0.73; 0.21 < f6 / f < 0.73; where f is the focal length of the entire optical system, where f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, f4 is the effective focal length of the fourth lens, f5 is the effective focal length of the fifth lens, and f6 is the effective focal length of the sixth lens. By limiting the ratio of the effective focal length of each lens to the effective focal length of the optical system, the exit pupil diameter can be large, up to ∮5mm, which can increase the exit pupil diameter of the relay lens equipped with this optical system, and will greatly reduce the accuracy requirements for the alignment of the test equipment to the measured lens module and the relay lens.

[0060] Furthermore, as a preferred embodiment of this utility model and not a limitation thereof, the first lens of this application uses a glass material with a high refractive index and a low dispersion coefficient. The refractive index Nd1 and Abbe number constant Vd1 of the first lens material satisfy: 1.7 < Nd1 < 1.9, 25.0 < Vd1 < 45.0; the radius of curvature R1 on the object plane side and the radius of curvature R2 on the image plane side of the first lens satisfy: -228 < R1 < -136; -268 < R2 < -178; the second lens of this application uses a glass material with a high refractive index and a high dispersion coefficient. The refractive index Nd2 and Abbe number constant Vd2 of the second lens material satisfy: 1.7 < Nd2 < 1.88, 40 < Vd2 < 55; the radius of curvature R3 on the object plane side and the radius of curvature R4 on the image plane side of the second lens satisfy: -255 < R3 < -165; -120 < R4 < -65; The third lens of this application uses a glass material with a high refractive index and a high dispersion coefficient. The refractive index Nd3 and Abbe number constant Vd3 of the third lens satisfy: 1.65 < Nd3 < 1.85, 40 < Vd3 < 56; The radius of curvature R5 on the object plane side and the radius of curvature R6 on the image plane side of the third lens satisfy: 395 < R5 < 550; -200 < R6 < -100; The fourth lens of this application uses a glass material with a high refractive index and a high dispersion coefficient. The refractive index Nd4 and Abbe number constant Vd4 of the fourth lens satisfy: 1.65 < Nd4 < 1.8, 45 < Vd4 < 65; The radius of curvature R7 on the object plane side and the radius of curvature R8 on the image plane side of the fourth lens satisfy: -252 < R7 < -145; 275 < R8 < 388; The fifth lens of this application uses a glass material with a high refractive index and a low dispersion coefficient. The refractive index Nd5 and Abbe number constant Vd5 of the fifth lens satisfy: 1.71 < Nd5 < 1.85, 20 < Vd5 < 40; The radius of curvature R9 on the object plane side and the radius of curvature R10 on the image plane side of the fifth lens satisfy: 630 < R9; -500 < R10 < -325; The sixth lens of this application uses a glass material with a low refractive index and a low dispersion coefficient. The refractive index Nd6 and Abbe number constant Vd6 of the sixth lens satisfy: 1.65 < Nd6 < 1.75, 45 < Vd6 < 55; The radius of curvature R11 on the object plane side and the radius of curvature R12 on the image plane side of the sixth lens satisfy: -80 < R11 < -45; -225 < R2 < -118. This application achieves the purpose of correcting distortion in a large field-of-view optical system by selecting and combining materials with different refractive indices and Abbe numbers.

[0061] Furthermore, as a preferred embodiment of this utility model and not a limitation, the full field of view (FOV) of this optical system is [120°, 180°]. This application's large-angle relay lens can achieve a full field of view of 126° and a long working distance, which is beneficial for adding some process steps or tooling fixtures between the lens module under test and the relay lens. Specific implementation examples:

[0063] Example 1

[0064] An optical imaging lens according to an exemplary embodiment of this application comprises, in sequence along the optical axis from the object side to the image side: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, and an aperture stop. The field of view (FOV) is 126°, and the focal length is 316mm.

[0065] The first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has negative optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has negative optical power, with its object-side surface S5 being concave and its image-side surface S6 being concave. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being convex. The fifth lens E5 has negative optical power, with its object-side surface S9 being concave and its image-side surface S10 being concave. The sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being concave.

[0066] Table 1 shows the radius of curvature, thickness, material, and focal length of each lens in the optical imaging lens of Example 1, wherein the units of radius of curvature, focal length, and thickness are all millimeters (mm).

[0067] Table 1

[0068]

[0069] Example 2

[0070] An optical imaging lens according to an exemplary embodiment of this application comprises, in sequence along the optical axis from the object side to the image side: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, and an aperture stop. The field of view (FOV) is 126°, and the focal length is 325mm.

[0071] The first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has negative optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has negative optical power, with its object-side surface S5 being concave and its image-side surface S6 being concave. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being convex. The fifth lens E5 has negative optical power, with its object-side surface S9 being concave and its image-side surface S10 being concave. The sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being concave.

[0072] Table 2 shows the radius of curvature, thickness, material, and focal length of each lens in the optical imaging lens of Example 2, wherein the units of radius of curvature, focal length, and thickness are all millimeters (mm).

[0073] Table 2

[0074]

[0075] Example 3

[0076] An optical imaging lens according to an exemplary embodiment of this application comprises, in sequence along the optical axis from the object side to the image side: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, and an aperture stop. The field of view (FOV) is 126°, and the focal length is 285mm.

[0077] The first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has negative optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has negative optical power, with its object-side surface S5 being concave and its image-side surface S6 being concave. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being convex. The fifth lens E5 has negative optical power, with its object-side surface S9 being flat and its image-side surface S10 being concave. The sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being concave.

[0078] Table 3 shows the radius of curvature, thickness, material, and focal length of each lens in the optical imaging lens of Example 3, wherein the units for radius of curvature, focal length, and thickness are millimeters (mm).

[0079]

[0080] A repeater lens includes at least an optical lens, within which the aforementioned vehicle-mounted optical system is installed. It employs six spherical optical glass lenses and achieves distortion correction for a large field-of-view optical system by selecting and combining materials with different refractive indices and Abbe numbers. This large-angle repeater lens can correct distortion across the entire 126° field of view, achieving a distortion correction of ≤0.1%. Conventionally, the distortion for this type of field of view is around 30%, while this repeater lens significantly reduces distortion by approximately 99%. Furthermore, the increased exit pupil diameter of the repeater lens greatly reduces the accuracy required for alignment between the tested lens module and the repeater lens in the testing equipment. The longer working distance also facilitates the addition of additional process steps or tooling fixtures between the tested lens module and the repeater lens.

[0081] The above description provides one or more embodiments in conjunction with specific content, and does not imply that the specific implementation of this utility model is limited to these descriptions. Any methods or structures that are similar to or identical to those of this utility model, or any technical deductions or substitutions made based on the concept of this utility model, should be considered within the protection scope of this utility model.

Claims

1. A large-angle, low-distortion optical system, comprising, sequentially from the object plane to the image plane along the optical axis, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens, characterized in that: The first lens has positive optical power, its object side is convex, and its image side is concave. The second lens has negative optical power, its object side is convex, and its image side is concave. The third lens has negative optical power, and its object side is concave, as is its image side. The fourth lens has positive optical power, and its object side is convex, and its image side is convex. The fifth lens has negative optical power, its object side is concave or flat, and its image side is concave. The sixth lens has positive optical power, its object side is convex, and its image side is concave.

2. The large-angle, small-distortion optical system according to claim 1, characterized in that: Each lens in this optical system satisfies the following condition: 752mm < f1 < 898mm; or -221mm < f2 < -147mm; or -173mm < f3 < -151mm; or 148mm < f4 < 183mm; or -481mm < f5 < -298mm; or 109mm < f6 < 131mm; Where f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, f4 is the effective focal length of the fourth lens, f5 is the effective focal length of the fifth lens, and f6 is the effective focal length of the sixth lens.

3. The large-angle, small-distortion optical system according to claim 1, characterized in that: Each lens in this optical system satisfies the following condition: 2.13 < f1 / f < 3.27; or -0.82 < f2 / f < -0.38; or -0.77 < f3 / f < -0.31; or 0.37 < f4 / f < 0.79; or -2.1 < f5 / f < -0.73; or 0.21 < f6 / f < 0.73; Where f is the focal length of the entire optical system, f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, f4 is the effective focal length of the fourth lens, f5 is the effective focal length of the fifth lens, and f6 is the effective focal length of the sixth lens.

4. The large-angle, small-distortion optical system according to any one of claims 1-3, characterized in that: The refractive index Nd1 and Abbe number Vd1 of the first lens satisfy: 1.7 < Nd1 < 1.9, 25.0 < Vd1 < 45.0; or The refractive index Nd2 and Abbe number Vd2 of the material of the second lens satisfy: 1.7 < Nd2 < 1.88, 40 < Vd2 < 55; or The refractive index Nd3 and Abbe number Vd3 of the material of the third lens satisfy: 1.65 < Nd3 < 1.85, 40 < Vd3 < 56; or The refractive index Nd4 and Abbe number Vd4 of the fourth lens satisfy: 1.65 < Nd4 < 1.8, 45 < Vd4 < 65; or The refractive index Nd5 and Abbe number Vd5 of the fifth lens material satisfy: 1.71 < Nd5 < 1.85, 20 < Vd5 < 40; or The refractive index Nd6 and Abbe number Vd6 of the material of the sixth lens satisfy the following conditions: 1.65 < Nd6 < 1.75, 45 < Vd6 < 55.

5. The large-angle, small-distortion optical system according to any one of claims 1-3, characterized in that: The radius of curvature R1 on the object plane side and the radius of curvature R2 on the image plane side of the first lens satisfy: -228 < R1 < -136; -268 < R2 < -178; or The radius of curvature R3 on the object plane side and the radius of curvature R4 on the image plane side of the second lens satisfy: -255 < R3 < -165; -120 < R4 < -65; or The radius of curvature R5 on the object plane side and the radius of curvature R6 on the image plane side of the third lens satisfy: 395 < R5 < 550; -200 < R6 < -100; or The radius of curvature R7 on the object plane side and the radius of curvature R8 on the image plane side of the fourth lens satisfy: -252 < R7 < -145; 275 < R8 < 388; or The radius of curvature R9 on the object plane side and the radius of curvature R10 on the image plane side of the fifth lens satisfy: 630 < R9; -500 < R10 < -325; or The radius of curvature R11 on the object plane side and the radius of curvature R12 on the image plane side of the sixth lens satisfy: -80 < R11 < -45; -225 < R2 < -118.

6. The large-angle, small-distortion optical system according to any one of claims 1-3, characterized in that: The effective focal length f of the optical system satisfies: 280mm < f < 330mm.

7. The large-angle, small-distortion optical system according to any one of claims 1-3, characterized in that: The full field of view (FOV) of the optical system is [120°, 180°].

8. The large-angle, small-distortion optical system according to any one of claims 1-3, characterized in that: The first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are all glass spherical lenses.

9. A relay lens, comprising at least an optical lens, characterized in that: The optical lens is equipped with a large-angle, low-distortion optical system as described in any one of claims 1-8.

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