Small-F-number athermalization double telecentric lens
By designing a small F-number thermally-free dual telecentric lens containing ten spherical lenses, the problem of large F-number and lack of thermally-free design in the prior art is solved, and higher image resolution and imaging quality stability when temperature changes are achieved.
Patent Information
- Application Number
- CN202510394241.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-31
- Publication Date
- 2025-05-30
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The existing dual telecentric lenses have the problem of large F-number and lack of thermal-free design, which limits the lens resolution and measurement accuracy, and leads to unstable imaging quality when temperature changes.
A small F-number heat-free dual telecentric lens is designed, including ten spherical lenses, arranged in a lens barrel made of aluminum alloy material, with F-number = 6, and can maintain high-resolution imaging within a temperature range of -10 to 50°C, with both telecentricity and distortion less than 0.05%.
It realizes higher image resolution and thermal-free function than traditional dual telecentric lenses, maintaining high-resolution imaging at different temperatures without refocusing, with telecentricity and distortion less than 0.05%.
Smart Images
Figure CN120065483A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of optical systems, and particularly to a small F - number athermalized double telecentric lens. Background Art
[0002] In modern manufacturing, online inspection systems play a crucial role. They can monitor in real - time whether the dimensions of the machined workpieces meet the preset standards, thereby ensuring product quality and production efficiency. In this field, telecentric optical lenses, due to their unique optical characteristics such as high telecentricity and low distortion, have significant advantages compared to ordinary lenses and are thus widely used in the field of precision measurement.
[0003] However, with the progress of technology and the development of manufacturing, certain specific application scenarios have put forward higher requirements for the performance of lenses, especially the requirements for small F - number and athermalization. A small F - number means that the lens has higher resolution and can capture more detailed information, which is crucial for high - precision measurement and inspection. However, the F - number range of traditional double telecentric lenses is usually limited between 8 - 13, which cannot meet the requirements of some high - resolution application scenarios.
[0004] On the other hand, athermalization technology is also an important challenge in modern optical lens design. Athermalization means that the lens can maintain stable imaging quality in high - and low - temperature environments and can form clear images without refocusing. This is particularly important for application scenarios with large temperature differences. However, traditional lens designs often only consider the imaging quality at a single temperature. When the external environmental temperature changes, the actual effect of the lens often fails to reach the imaging quality of the expected design.
[0005] Specifically, when the temperature changes, the refractive index of the optical material will change accordingly, resulting in a change in the focal length of the optical system. In addition, the parameters of each lens (such as the radius of curvature, thickness, etc.) and the spacing between adjacent lenses will also be affected by temperature and change, and these changes will all cause a decline in imaging quality.
[0006] In summary, the existing double telecentric lenses have problems of large F - number and lack of athermalization design, which limits the resolution and measurement accuracy of the lenses and causes unstable imaging quality when the temperature changes. Summary of the Invention
[0007] The purpose of the present invention is to provide a small F - number athermalized double telecentric lens, aiming to solve the technical problems that the existing double telecentric lenses have large F - number and lack of athermalization design, which limits the resolution and measurement accuracy of the lenses and causes unstable imaging quality when the temperature changes.
[0008] To achieve the above object, a small F-number athermalized double telecentric lens adopted by the present invention includes a first spherical lens, a second spherical lens, a third spherical lens, a fourth spherical lens, a fifth spherical lens, a sixth spherical lens, a seventh spherical lens, an eighth spherical lens, a ninth spherical lens, and a tenth spherical lens;
[0009] The first spherical lens, the second spherical lens, the third spherical lens, the fourth spherical lens, the fifth spherical lens, the sixth spherical lens, the seventh spherical lens, the eighth spherical lens, the ninth spherical lens, and the tenth spherical lens are all arranged in a lens barrel made of aluminum alloy material;
[0010] The second spherical lens is located between the first spherical lens and the third spherical lens, the fourth spherical lens is located between the third spherical lens and the fifth spherical lens, the sixth spherical lens is located between the fifth spherical lens and the seventh spherical lens, the eighth spherical lens is located between the seventh spherical lens and the ninth spherical lens, and the tenth spherical lens is located on the side of the ninth spherical lens away from the eighth spherical lens.
[0011] Among them, the front and rear surface curvature radii of the first spherical lens are both greater than 0 and are curved towards the imaging plane;
[0012] The front surface curvature radius of the second spherical lens is greater than 0 and is curved towards the imaging plane, and the rear surface curvature radius is less than 0 and is curved towards the object plane.
[0013] Among them, the front and rear surface curvature radii of the third spherical lens are both greater than 0 and are curved towards the imaging plane;
[0014] The front surface curvature radius of the fourth spherical lens is less than 0 and is curved towards the object plane, and the rear surface curvature radius is greater than 0 and is curved towards the image plane.
[0015] Among them, the rear surface curvature radius of the fifth spherical lens is less than 0 and is curved towards the object plane;
[0016] The front surface curvature radius of the sixth spherical lens is greater than 0 and is curved towards the imaging plane, and the rear surface curvature radius is less than 0 and is curved towards the object plane.
[0017] Among them, the front surface curvature radius of the seventh spherical lens is less than 0 and is curved towards the object plane;
[0018] The front and rear surface curvature radii of the eighth spherical lens are both greater than 0 and are curved towards the imaging plane.
[0019] Among them, the front and rear surface curvature radii of the ninth spherical lens are both less than 0 and are curved towards the object plane;
[0020] The front surface curvature radius of the tenth spherical lens is greater than 0 and it is curved towards the imaging plane.
[0021] Among them, the small F-number athermalized double telecentric lens is designed with F / # = 6, the camera target surface is 1 inch, the magnification is 0.168X, and it is a double telecentric lens operating at a working temperature of -10 to 50°C. The telecentricity of the lens is <0.05 degrees, and the lens distortion is less than 0.05%.
[0022] Among them, the small F-number athermalized double telecentric lens is designed with F / # = 6, the camera target surface is 1 inch, the magnification is 0.1X, and it is a double telecentric lens operating at a working temperature of -10 to 50°C. The telecentricity of the lens is <0.05 degrees, and the lens distortion is less than 0.05%.
[0023] Among them, the small F-number athermalized double telecentric lens is designed with F / # = 6, the camera target surface is 1 inch, the magnification is 0.075X, and it is a double telecentric lens operating at a working temperature of -10 to 50°C. The telecentricity of the lens is <0.05 degrees, and the lens distortion is less than 0.05%.
[0024] A small F-number athermalized double telecentric lens of the present invention. The small F-number athermalized double telecentric lens has an F-number = 6, that is, it can obtain the advantage of higher image resolution compared with traditional double telecentric lenses. At the same time, it has the advantage of athermalization and can achieve high-resolution imaging at -10 to 50°C without refocusing. The telecentricity of the lens is <0.05 degrees, and the lens distortion is less than 0.05%.
[0025] In this way, the problem that the double telecentric lens in the prior art has a large F-number and lacks athermalization design is solved. This limits the resolution and measurement accuracy of the lens and causes the technical problem of unstable imaging quality when the temperature changes. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.
[0027] Figure 1 It is a schematic structural diagram of the small F-number athermalized double telecentric lens of the present invention.
[0028] Figure 2 It is a schematic structural diagram of Embodiment 1.
[0029] Figure 3 It is a schematic diagram of the MTF curves of Embodiment 1 of the present invention at -10°C, 22°C, and 50°C.
[0030] Figure 4It is a schematic structural diagram of Embodiment 2.
[0031] Figure 5 It is a schematic diagram of the MTF curves of Embodiment 2 of the present invention at -10°C, 22°C, and 50°C.
[0032] Figure 6 It is a schematic structural diagram of Embodiment 3.
[0033] Figure 7 It is a schematic diagram of the MTF curves of Embodiment 3 of the present invention at -10°C, 22°C, and 50°C.
[0034] 1 - First spherical lens, 2 - Second spherical lens, 3 - Third spherical lens, 4 - Fourth spherical lens, 5 - Fifth spherical lens, 6 - Sixth spherical lens, 7 - Seventh spherical lens, 8 - Eighth spherical lens, 9 - Ninth spherical lens, 10 - Tenth spherical lens, 11 - Camera window plate, 12 - Diaphragm, 13 - Object plane, 14 - Imaging plane. Detailed implementation manners
[0035] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation of the present invention.
[0036] Please refer to Figure 1 , Figure 1 It is a schematic structural diagram of a small F - number athermalized double - telecentric lens of the present invention.
[0037] The present invention provides a small F - number athermalized double - telecentric lens, including a first spherical lens 1, a second spherical lens 2, a third spherical lens 3, a fourth spherical lens 4, a fifth spherical lens 5, a sixth spherical lens 6, a seventh spherical lens 7, an eighth spherical lens 8, a ninth spherical lens 9, and a tenth spherical lens 10;
[0038] The first spherical lens 1, the second spherical lens 2, the third spherical lens 3, the fourth spherical lens 4, the fifth spherical lens 5, the sixth spherical lens 6, the seventh spherical lens 7, the eighth spherical lens 8, the ninth spherical lens 9, and the tenth spherical lens 10 are all arranged in a lens barrel made of aluminum alloy material;
[0039] The second spherical lens 2 is located between the first spherical lens 1 and the third spherical lens 3, the fourth spherical lens 4 is located between the third spherical lens 3 and the fifth spherical lens 5, the sixth spherical lens 6 is located between the fifth spherical lens 5 and the seventh spherical lens 7, the eighth spherical lens 8 is located between the seventh spherical lens 7 and the ninth spherical lens 9, and the tenth spherical lens 10 is located on the side of the ninth spherical lens 9 away from the eighth spherical lens 8.
[0040] Further, the front and rear surface curvature radii of the first spherical lens 1 are both greater than 0, and it is curved towards the imaging plane 14;
[0041] The front surface curvature radius of the second spherical lens 2 is greater than 0 and it is curved towards the imaging plane 14, and the rear surface curvature radius is less than 0 and it is curved towards the object plane 13.
[0042] Among them, the front and rear surface curvature radii of the third spherical lens 3 are both greater than 0, and it is curved towards the imaging plane 14;
[0043] The front surface curvature radius of the fourth spherical lens 4 is less than 0 and it is curved towards the object plane 13, and the rear surface curvature radius is greater than 0 and it is curved towards the image plane.
[0044] Moreover, the rear surface curvature radius of the fifth spherical lens 5 is less than 0 and it is curved towards the object plane 13;
[0045] The front surface curvature radius of the sixth spherical lens 6 is greater than 0 and it is curved towards the imaging plane 14, and the rear surface curvature radius is less than 0 and it is curved towards the object plane 13. The front surface curvature radius of the seventh spherical lens 7 is less than 0 and it is curved towards the object plane 13; the front and rear surface curvature radii of the eighth spherical lens 8 are both greater than 0 and it is curved towards the imaging plane 14.
[0046] Meanwhile, the front and rear surface curvature radii of the ninth spherical lens 9 are both less than 0 and it is curved towards the object plane 13;
[0047] The front surface curvature radius of the tenth spherical lens 10 is greater than 0 and it is curved towards the imaging plane 14.
[0048] For this specific embodiment, the small F-number athermalized double telecentric lens has an F-number = 6, that is, it can obtain the advantage of higher image resolution compared with the traditional double telecentric lens, and at the same time has the advantage of athermalization, and can achieve high-resolution imaging at -10 to 50 °C without re-focusing. The telecentricity of the lens is <0.05 degrees, and the lens distortion is less than 0.05%.
[0049] In this way, the problems existing in the double telecentric lens in the prior art, such as a relatively large F-number and the lack of an athermalization design, are solved. These problems limit the resolution and measurement accuracy of the lens and cause unstable imaging quality when the temperature changes.
[0050] Example 1:
[0051] Please refer to Figure 2 and Figure 3 , Figure 2 which is the structural schematic diagram of Example 1, Figure 3 and
[0052] is the schematic diagram of the MTF curve of Example 1 of the present invention at -10°C, 22°C, and 50°C.
[0053] Table 1 Detailed lens parameters of Example 1
[0054]
[0055]
[0056] It can be seen from Figure 3 that the MTF of Example 1 at 100 lp / mm is greater than 0.2, achieving the athermalization function.
[0057] Example 2:
[0058] Please refer to Figure 4 and Figure 5 , Figure 4 which is the structural schematic diagram of Example 2, Figure 5 and
[0059] is the schematic diagram of the MTF curve of Example 2 of the present invention at -10°C, 22°C, and 50°C.
[0060] Table 2 Detailed lens parameters of Example 2
[0061]
[0062]
[0063] It can be seen from Figure 5 that the MTF of Example 2 at 100 lp / mm is greater than 0.2, achieving the athermalization function.
[0064] Example 3:
[0065] Please refer to Figure 6 and Figure 7 , Figure 6 which is a schematic structural diagram of Example 3, Figure 7 and
[0066] is a schematic diagram of the MTF curve of Example 3 of the present invention at -10°C, 22°C, and 50°C.
[0067] Table 3 Detailed lens parameters of Example 3
[0068]
[0069]
[0070] It can be seen from Figure 7 that the MTF of Example 3 at 100 lp / mm is greater than 0.2, achieving the athermalization function.
[0071] When using a small F-number athermalized double telecentric lens of the present invention, specifically during use, the small F-number athermalized double telecentric lens has an F-number = 6, that is, it can obtain the advantage of higher image resolution compared with traditional double telecentric lenses. At the same time, it has the advantage of athermalization and can achieve high-resolution imaging at -10°C to 50°C without readjusting the focus. The telecentricity of the lens is <0.05 degrees, and the lens distortion is less than 0.05%.
[0072] In this way, the problem in the prior art that the double telecentric lens has a large F-number and lacks athermalization design is solved. This limits the resolution and measurement accuracy of the lens and causes the technical problem of unstable imaging quality when the temperature changes.
[0073] The above-disclosed is only a preferred embodiment of the present invention. Of course, it cannot be used to limit the scope of the rights of the present invention. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present invention still fall within the scope covered by the invention.
Claims
1. A small F-number athermal bi-telecentric lens, characterized in that: including a first spherical lens, a second spherical lens, a third spherical lens, a fourth spherical lens, a fifth spherical lens, a sixth spherical lens, a seventh spherical lens, an eighth spherical lens, a ninth spherical lens and a tenth spherical lens; The first spherical lens, the second spherical lens, the third spherical lens, the fourth spherical lens, the fifth spherical lens, the sixth spherical lens, the seventh spherical lens, the eighth spherical lens, the ninth spherical lens and the tenth spherical lens are all disposed in a lens barrel made of an aluminum alloy material; The second spherical lens is located between the first spherical lens and the third spherical lens, the fourth spherical lens is located between the third spherical lens and the fifth spherical lens, the sixth spherical lens is located between the fifth spherical lens and the seventh spherical lens, the eighth spherical lens is located between the seventh spherical lens and the ninth spherical lens, and the tenth spherical lens is located on a side of the ninth spherical lens away from the eighth spherical lens.
2. The small F-number athermal bi-telecentric lens according to claim 1, wherein: The curvature radii of the front and rear surfaces of the first spherical lens are both greater than 0 and are curved toward the imaging plane; The front surface curvature radius of the second spherical lens is greater than 0 and is curved toward the imaging plane, and the rear surface curvature radius is less than 0 and is curved toward the object plane.
3. The small F-number athermal bi-telecentric lens according to claim 2, wherein: The front and rear surfaces of the third spherical lens have a curvature radius greater than 0 and are curved toward the imaging plane; The front surface curvature radius of the fourth spherical lens is less than 0 and is curved toward the object plane, and the rear surface curvature radius is greater than 0 and is curved toward the image plane.
4. The small F-number athermal bi-telecentric lens according to claim 3, wherein: The radius of curvature of the rear surface of the fifth spherical lens is less than 0 and is curved toward the object plane; The front surface curvature radius of the sixth spherical lens is greater than 0 and is curved toward the imaging plane, and the rear surface curvature radius is less than 0 and is curved toward the object plane.
5. The small F-number athermal bi-telecentric lens according to claim 4, characterized in that: The radius of curvature of the front surface of the seventh spherical lens is less than 0 and is curved toward the object plane; The curvature radii of the front and rear surfaces of the eighth spherical lens are both greater than 0 and are curved toward the imaging plane.
6. The small F-number athermal bi-telecentric lens according to claim 5, characterized in that: The front and rear surfaces of the ninth spherical lens have a curvature radius less than 0 and are curved toward the object plane; The front surface curvature radius of the tenth spherical lens is greater than 0 and is curved toward the imaging plane.
7. The small F-number athermal bi-telecentric lens according to claim 6, wherein: The small F number athermal double telecentric lens is designed with F / #=6, a camera target surface of 1 inch, a magnification of 0.168X, an operating temperature of -10 to 50° C., a lens telecentricity of <0.05 degrees, and a lens distortion of less than 0.05%.
8. The small F-number athermal bi-telecentric lens according to claim 6, wherein: The small F number athermal double telecentric lens is designed with F / #=6, a camera target surface of 1 inch, a magnification of 0.1X, an operating temperature of -10 to 50° C., a lens telecentricity of <0.05 degrees, and a lens distortion of less than 0.05%.
9. The small F-number athermal bi-telecentric lens according to claim 6, wherein: The small F number athermal double telecentric lens is designed with F / #=6, a camera target surface of 1 inch, a magnification of 0.075X, an operating temperature of -10 to 50° C., a lens telecentricity of <0.05 degrees, and a lens distortion of less than 0.05%.