Optical lenses and lidar

Abstract

This application provides an optical lens and a lidar, relating to the field of radar technology. The optical lens provided in this application comprises, along the optical axis from the object side to the image side, a first lens with positive optical power, a second lens with negative optical power, a third lens with positive optical power, a fourth lens with positive optical power, and a fifth lens with negative optical power. The total optical length (TTL) of the optical lens and the overall focal length (f) satisfy: 1.3 < TTL / f < 1.8. By optimizing the shape of each lens and rationally allocating the optical power of each lens and the ratio of the total optical length to the overall focal length, this application enables the optical lens to have a smaller FNO and a smaller CRA, achieving a higher incident light quantity in a smaller volume, thereby increasing the lidar's range, improving its resistance to ambient light, and also improving angular resolution consistency and reducing distortion. The lidar including the above-described optical lens possesses superior performance and is easily implemented in a small volume with a long range.

Description

Technical Field

[0001] This application relates to the field of radar technology, and more specifically, to an optical lens and a lidar. Background Technology

[0002] LiDAR receiver modules typically use receiving lenses to capture reflected laser light. For a LiDAR receiving lens to acquire weak light signals, it needs to have the smallest possible relative aperture (FNO) to increase its light transmission capacity. To better suppress ambient light, the receiving lens needs a smaller chief ray angle (CRA). However, achieving a small FNO and CRA with existing lens structures results in a large size, making it difficult to integrate into a LiDAR system. Summary of the Invention

[0003] The purpose of this application includes providing an optical lens that has a small size, low FNO and CRA, and ensures good reception performance. Another purpose of this application includes providing a lidar.

[0004] The embodiments of this application can be implemented as follows:

[0005] In a first aspect, this application provides an optical lens, comprising, along the optical axis from the object side to the image side, the following components in sequence:

[0006] A first lens with positive optical power, wherein the object side of the first lens is convex and the image side is concave;

[0007] A second lens with negative optical power, wherein both the object-side and image-side surfaces of the second lens are concave.

[0008] A third lens with positive optical power, wherein both the object-side and image-side surfaces of the third lens are convex.

[0009] A fourth lens with positive optical power, the object side of the fourth lens is convex and the image side is concave;

[0010] A fifth lens with negative optical power, wherein both the object-side and image-side surfaces of the fifth lens are concave.

[0011] Among them, the total optical length TTL of the optical lens and the overall focal length f satisfy: 1.3 < TTL / f < 1.8.

[0012] In an optional implementation, the focal length f1 of the first lens satisfies the following condition with respect to the overall focal length f: f1 / f ≤ 1.4.

[0013] In an optional implementation, the focal length f2 of the second lens satisfies the following condition: |f2 / f|≥0.9.

[0014] In an optional implementation, the focal length f3 of the third lens satisfies the following condition: f3 / f ≤ 1.1.

[0015] In an optional implementation, the focal length f4 of the fourth lens satisfies the following condition: f4 / f≤1.2.

[0016] In an optional implementation, the focal length f5 of the fifth lens satisfies the following condition: |f5 / f|≥0.6.

[0017] In an optional implementation, the maximum field of view (FOV) of the optical lens satisfies: 25°≤FOV≤30°.

[0018] In an optional implementation, the aperture value FNO of the optical lens satisfies: FNO≤1.33.

[0019] In an optional implementation, the focal length f4 of the fourth lens, the focal length f5 of the fifth lens, and the center distance d between the fourth and fifth lenses satisfy: f4*f5 / (f4+f5-d)≥100mm.

[0020] In an optional implementation, the relative illumination RI corresponding to the maximum field of view of the optical lens satisfies: RI > 75%.

[0021] In an optional implementation, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens are all spherical lenses.

[0022] In an optional embodiment, the object-side radius of curvature of the first lens is 16–21 mm, the image-side radius of curvature is 220–250 mm, and the thickness is 3–5 mm; and / or,

[0023] The second lens has an object-side radius of curvature of -12 to -16 mm, an image-side radius of curvature of 40 to 50 mm, and a thickness of 1 to 2 mm; and / or,

[0024] The object-side radius of curvature of the third lens is 60–70 mm, the image-side radius of curvature is -18–-25 mm, and the thickness is 4–5 mm; and / or,

[0025] The fourth lens has an object-side radius of curvature of 15–20 mm, an image-side radius of curvature of 50–60 mm, and a thickness of 4–5 mm; and / or,

[0026] The fifth lens has an object-side radius of curvature of -20 to -25 mm, an image-side radius of curvature of 40 to 45 mm, and a thickness of 1 to 2 mm.

[0027] In an optional implementation, the refractive index of the first lens is not less than 1.7.

[0028] In an optional embodiment, the optical lens further includes a filter disposed on the side of the fifth lens opposite to the fourth lens.

[0029] In an optional embodiment, the optical lens further includes an aperture stop disposed on the object side of the first lens.

[0030] Secondly, this application provides a lidar, including the optical lens of any of the foregoing embodiments.

[0031] The beneficial effects of the embodiments of this application include, for example:

[0032] The optical lens provided in this application comprises, along the optical axis from the object side to the image side, a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. The first lens has positive optical power, with a convex object side and a concave image side; the second lens has negative optical power, with both its object side and image side being concave; the third lens has positive optical power, with both its object side and image side being convex; the fourth lens has positive optical power, with a convex object side and a concave image side; and the fifth lens has negative optical power, with both its object side and image side being concave. The total optical length (TTL) and overall focal length (f) of the optical lens satisfy the condition: 1.3 < TTL / f < 1.8. This application optimizes the shape of each lens and rationally allocates the optical power of each lens and the ratio of the total optical length to the overall focal length, enabling the optical lens to have a smaller FNO and a smaller CRA, achieving a higher incident light quantity within a small volume, thereby improving the range of the lidar and enhancing its resistance to ambient light. Furthermore, the optical lens provided in this application improves angular resolution consistency and reduces distortion through structural and parameter optimization.

[0033] The lidar provided in this application includes the optical lens described above, which has better performance and is easy to achieve in terms of small size and long range. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of an optical lens in one embodiment of this application;

[0036] Figure 2 Table 1 shows the F-Theta distortion curves of the optical lenses in the embodiments.

[0037] Figure 3The table shows the relative illumination curves of the optical lenses in the embodiments.

[0038] Icons: 010 - Optical lens; 100 - First lens; 110 - Aperture stop; 200 - Second lens; 300 - Third lens; 400 - Fourth lens; 500 - Fifth lens; 600 - Filter. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0041] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0042] In the description of this application, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed during use, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0043] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0044] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0045] In the rapidly developing field of autonomous driving, LiDAR has become a crucial 3D perception sensor. In practical applications, automobiles are demanding increasingly higher performance from LiDAR while simultaneously requiring smaller sizes. LiDAR operates on an active detection basis, thus requiring the receiving lens to collect as much signal reflected from the target as possible. Unlike ordinary optical lenses, collecting as much reflected laser light as possible is more important than image quality, enabling LiDAR to detect weak signals at greater distances. This necessitates a lens with a large light transmittance, i.e., a large aperture. Simultaneously, due to LiDAR's high angular resolution, the lens demands minimal distortion to ensure consistent angular resolution. Furthermore, since LiDAR is an active detection system, its receiving lens only needs to receive the emitted laser wavelength; ambient light is considered interference and requires filtering. Therefore, narrowband filters are needed for ambient light suppression. The transmission center wavelength of the filter is related to the angle of incidence; therefore, to reduce the filter bandwidth, the angle of incidence through the filter needs to be reduced. To further enhance ambient light suppression, the lens needs a smaller CRA (chief ray angle). Therefore, for lidar receiving lenses, it is necessary to achieve a smaller FNO (relative aperture or f-number, the smaller the value, the greater the light transmission), a smaller size, less distortion, and a smaller CRA.

[0046] Traditional lenses, in order to achieve smaller FNO and CRA, result in a large size, making them difficult to fit inside a lidar system. Forcing their inclusion results in a large lidar system itself, which fails to meet usage requirements. To overcome at least one of the shortcomings of the prior art, this application provides an optical lens that can serve as a receiving lens for a lidar system. Through optimization of its shape and parameters, it achieves both a smaller FNO and CRA within a smaller size, better meeting the requirements for use as a lidar receiving lens.

[0047] Figure 1 This is a schematic diagram of an optical lens 010 in one embodiment of this application. Please refer to... Figure 1The optical lens 010 provided in this embodiment includes, along the optical axis from the object side to the image side, a first lens 100, a second lens 200, a third lens 300, a fourth lens 400, and a fifth lens 500. The first lens 100 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens 200 has negative optical power, with both its object-side surface S3 and image-side surface S4 being concave. The third lens 300 has positive optical power, with both its object-side surface S5 and image-side surface S6 being convex. The fourth lens 400 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. The fifth lens 500 has negative optical power, with both its object-side surface S9 and image-side surface S10 being concave. Furthermore, the total optical length TTL of the optical lens 010 and the overall focal length f satisfy the condition: 1.3 < TTL / f < 1.8. The optical lens 010 uses five lenses. Through optimization of its shape and parameters, it can reduce the FNO while maintaining miniaturization, thereby increasing the range of the lidar. It also reduces the image plane CRA and the maximum incident angle to accommodate the narrower narrowband filter 600, thus improving the ambient light suppression effect of the optical lens 010.

[0048] Optionally, the optical lens 010 of this embodiment further includes a filter 600, which is disposed on the side of the fifth lens 500 away from the fourth lens 400, with its object-side surface S11 facing the fifth lens 500 and its image-side surface S12 away from the fifth lens 500. After passing through the first lens 100, the second lens 200, the third lens 300, the fourth lens 400, the fifth lens 500, and the filter 600 in sequence, light is projected onto the image plane S13.

[0049] Furthermore, in this embodiment, the focal length f1 of the first lens 100 and the overall focal length f satisfy: f1 / f ≤ 1.4; the focal length f2 of the second lens 200 and the overall focal length f satisfy: |f2 / f| ≥ 0.9; the focal length f3 of the third lens 300 and the overall focal length f satisfy: f3 / f ≤ 1.1; the focal length f4 of the fourth lens 400 and the overall focal length f satisfy: f4 / f ≤ 1.2; and the focal length f5 of the fifth lens 500 and the overall focal length f satisfy: |f5 / f| ≥ 0.6. It should be noted that when the optical power of the lens is positive, the corresponding focal length is positive; when the optical power of the lens is negative, the corresponding focal length is negative; the overall focal length f (i.e., the effective focal length of the five lenses) and the total optical length TTL of the optical lens 010 are positive values.

[0050] By setting the relationship between the focal length of each lens and the overall focal length f in the manner described above, the focal lengths of the first lens 100 to the fifth lens 500 are not set too small. This allows for gentler light deflection, improving edge imaging quality, and simultaneously increasing the energy entering the lens, thus achieving a high light intake. Therefore, the optical lens 010 provided in this embodiment can effectively shorten its overall optical length while ensuring good imaging quality, which is beneficial for the miniaturization of the optical lens 010.

[0051] In this embodiment, the first lens 100 is a positive optical power, which is a meniscus lens with its convex surface facing the object side. The first lens 100 can be made of a high refractive index material, such as a material with a refractive index Nd≥1.7, which is beneficial for collecting more light and increasing the incident light transmission, thereby improving the ranging range of the lidar used by the optical lens 010.

[0052] In this embodiment, the optical lens 010 also includes an aperture stop 110, which is disposed on the object side surface S1 of the first lens 100. The aperture stop 110 can effectively reduce the enlargement of the diameter of the first lens 100 caused by the large field of view, which is beneficial to the miniaturization of the optical lens 010.

[0053] The second lens 200 has negative optical power, and both its object-side surface S3 and image-side surface S4 are concave. The second lens 200 can diverge light rays from different fields of view, causing light rays from different fields of view to fall at different pupil positions of the third lens 300, corresponding to different image heights for each field of view, which helps to reduce the image plane CRA.

[0054] The third lens 300 has positive optical power, and both its object side S5 and image side S6 are convex surfaces, which redirect the direction of light rays from the large field of view, causing them to converge towards the center of the image plane S13. By setting the first lens to positive optical power, the second lens to negative optical power, and the third lens to positive optical power, the CRA of the image plane can be reduced.

[0055] The fourth lens 400 has positive optical power, with its object side S7 being convex and its image side S8 being concave, and is used to correct spherical aberration and reduce focal length.

[0056] The fifth lens 500 has negative optical power, and both its object-side surface S9 and image-side surface S10 are concave. The combination of the fourth lens 400 and the fifth lens 500 can optimize the imaging quality of peripheral rays.

[0057] Furthermore, the focal length f4 of the fourth lens 400, the focal length f5 of the fifth lens 500, and the center distance d between the fourth lens 400 and the fifth lens 500 satisfy: f4*f5 / (f4+f5-d)≥100mm. It should be understood that the expression on the left side of the above inequality represents the combined focal length of the fourth lens 400 and the fifth lens 500 at a distance of d. In other words, in this embodiment, the combined focal length of the fourth lens 400 and the fifth lens 500 is not less than 100mm. By setting the combined focal length of the fourth lens 400 and the fifth lens 500 to a relatively large value (not less than 100mm), light rays from different fields of view enter different pupil positions, optimizing the incident angle of edge rays and resulting in a smaller image plane CRA.

[0058] Furthermore, in this embodiment, the maximum field of view (FOV) of the optical lens 010 satisfies: 25° ≤ FOV ≤ 30°. When the maximum field of view (FOV) meets the above range, it can be guaranteed that the optical lens 010, when applied as a receiving lens for a lidar system, meets the required field of view characteristics.

[0059] Furthermore, in this embodiment, the aperture value FNO of the optical lens 010 satisfies: FNO≤1.33. This enables the optical lens 010 to have a large aperture characteristic, increasing the amount of incident light.

[0060] Optionally, the relative illumination RI corresponding to the maximum field of view of the optical lens 010 satisfies: RI > 75%. Meeting the above condition is beneficial for improving the edge field of view illumination, thereby improving the energy collection consistency on the lidar array detector and thus improving the range consistency.

[0061] Optionally, the first lens 100, the second lens 200, the third lens 300, the fourth lens 400, and the fifth lens 500 are all spherical lenses, specifically glass spherical lenses. Using spherical lenses for each lens reduces manufacturing costs. Even with lower-cost spherical lenses, it is possible to achieve smaller size, lower FNO and CRA, lower distortion, and higher angular resolution consistency while meeting the aforementioned shape and parameter requirements. In other optional embodiments, aspherical lenses may also be used for each lens.

[0062] Optionally, the object side surface S1 of the first lens 100 has a radius of curvature of 16-21 mm, the image side surface S2 has a radius of curvature of 220-250 mm, and a thickness of 3-5 mm.

[0063] The object side surface S3 of the second lens 200 has a radius of curvature of -12 to -16 mm, the image side surface S4 has a radius of curvature of 40 to 50 mm, and a thickness of 1 to 2 mm.

[0064] The object side surface S5 of the third lens 300 has a radius of curvature of 60-70 mm, the image side surface S6 has a radius of curvature of -18 to -25 mm, and a thickness of 4-5 mm.

[0065] The object side surface S7 of the fourth lens 400 has a radius of curvature of 15-20 mm, the image side surface S8 has a radius of curvature of 50-60 mm, and a thickness of 4-5 mm.

[0066] The object side surface S9 of the fifth lens 500 has a radius of curvature of -20 to -25 mm, the image side surface S10 has a radius of curvature of 40 to 45 mm, and a thickness of 1 to 2 mm.

[0067] A positive radius of curvature indicates that the surface arches towards the object side, while a negative radius of curvature indicates that the surface arches towards the image side. In other words, when the radius of curvature of the object side is positive, it is a convex surface, and when it is negative, it is a concave surface; similarly, when the radius of curvature of the image side is positive, it is a concave surface, and when it is negative, it is a convex surface.

[0068] Optionally, the thickness of filter 600 is 0.3 to 1 mm.

[0069] Table 1 shows the parameters of each lens in the optical lens 010 of a specific embodiment of this application, where Nd is the refractive index and Vd is the Abbe number.

[0070] Table 1:

[0071]

[0072]

[0073] In the two thickness parameters corresponding to each lens, the upper column corresponds to the thickness of the lens, and the lower column corresponds to the distance between the lens and the next lens. Calculations from the table above show that the distance from the object-side surface S1 of the first lens 100 to the image-side surface S13 of the optical lens 010 in this embodiment is 35.21 mm, which is relatively small.

[0074] Figure 2 Table 1 shows the F-Theta distortion curve of the optical lens 010 in the embodiment. The horizontal axis represents the distortion percentage, and the vertical axis represents the half-field angle. From... Figure 2 It can be seen that when the maximum half field of view is 12.5°, the distortion of the optical lens is less than 3%, which corresponds to a 3% deviation in the angular resolution of the lidar and a 0.375° deviation in the field of view. The deviation in the field of view is small and has virtually no impact on the application of lidar.

[0075] Figure 3 Table 1 shows the relative illumination curves of the optical lens 010 in the embodiment. The horizontal axis represents the half-field angle, and the vertical axis represents the relative illumination of the image plane. Figure 3 It can be seen that at the maximum half-field-of-view angle of 12.5°, the ratio of the lens image plane illuminance to the central field of view is 79%. This means that the signal strength of the receiver detector channel at the maximum half-field-of-view angle is attenuated to 79% of that at the central field of view due to the receiving lens. According to the lidar equation, the range is proportional to the square root of the signal strength. Therefore, the range of the receiver detector channel at the maximum field of view is approximately 89% of that at the central field of view. The difference in range between receiver detector channels at different field of view angles is relatively small.

[0076] This application also provides a lidar (not shown in the figure), which includes the optical lens 010 provided in the above embodiments. Furthermore, the lidar also includes modules or components for realizing basic lidar functions, such as a laser emitting module, a galvanometer, a rotating mirror, etc.; the specific structure and principles of other lidar components can be found in the prior art and will not be elaborated here.

[0077] The optical lens 010 provided in this embodiment has the following advantages:

[0078] 1. By optimizing the shape and material of each lens and rationally allocating the optical power of each lens, the FNO can be reduced, thus achieving a higher incident light quantity in a small volume and improving the range of lidar.

[0079] 2. Reduce the image plane CRA and maximum incident angle to accommodate narrower narrowband filters and improve ambient light suppression (i.e., improve resistance to ambient light).

[0080] 3. This optical lens 010 can reduce distortion and improve the angular resolution consistency between LiDAR array detectors;

[0081] 4. Balance the relationship between lens distortion, aperture and relative illumination of the image plane, improve the consistency of energy collected on the lidar array detector, and thus improve the consistency of the measurement range;

[0082] 5. Reduce astigmatism, simplify the assembly and adjustment of the optical lens 010 and the receiving chip, and improve the consistency of the assembly and adjustment effects between array detectors;

[0083] 6. Setting the object-side and image-side surfaces of all lenses to be spherical can effectively reduce the cost of optical lens 010 and increase production capacity;

[0084] 7. By reasonably setting the refractive index and Abbe number of each lens, it is helpful to achieve a smooth transition of light in the optical lens 010, without producing excessive angle of deflection, thereby obtaining high incident light quantity and low tolerance sensitivity.

[0085] In summary, the optical lens provided in this application comprises, sequentially from the object side to the image side along the optical axis, a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. The first lens has positive optical power, with a convex object side and a concave image side; the second lens has negative optical power, with both its object side and image side being concave; the third lens has positive optical power, with both its object side and image side being convex; the fourth lens has positive optical power, with a convex object side and a concave image side; and the fifth lens has negative optical power, with both its object side and image side being concave. The total optical length (TTL) and overall focal length (f) of the optical lens satisfy the condition: 1.3 < TTL / f < 1.8. This application optimizes the shape of each lens and rationally allocates the optical power of each lens and the ratio of the total optical length to the overall focal length, enabling the optical lens to have a smaller FNO and a smaller CRA, achieving a higher incident light quantity within a small volume, thereby improving the range of the lidar and enhancing its resistance to ambient light. In addition, the optical lens provided in this application improves angular resolution consistency and reduces distortion through optimization of structure and parameters.

[0086] The lidar provided in this application includes the optical lens described above, which has better performance and is easy to achieve in terms of small size and long range.

[0087] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An optical lens, characterized in that, The optical lens has five lenses, which are arranged sequentially along the optical axis from the object side to the image side: A first lens with positive optical power, wherein the object side of the first lens is convex and the image side is concave; A second lens with negative optical power, wherein both the object-side and image-side surfaces of the second lens are concave. A third lens with positive optical power, wherein both the object-side surface and the image-side surface of the third lens are convex. A fourth lens with positive optical power, wherein the object side of the fourth lens is convex and the image side is concave; A fifth lens with negative optical power, wherein both the object-side and image-side surfaces of the fifth lens are concave. The total optical length TTL of the optical lens and the overall focal length f satisfy: 1.3 < TTL / f < 1.

8.

2. The optical lens according to claim 1, characterized in that, The focal length f1 of the first lens and the overall focal length f satisfy: f1 / f≤1.

4.

3. The optical lens according to claim 1, characterized in that, The focal length f2 of the second lens satisfies the following condition with respect to the overall focal length f: |f2 / f|≥0.

9.

4. The optical lens according to claim 1, characterized in that, The focal length f3 of the third lens satisfies the following condition as the overall focal length f: f3 / f≤1.

1.

5. The optical lens according to claim 1, characterized in that, The focal length f4 of the fourth lens satisfies the following condition as the overall focal length f: f4 / f≤1.

2.

6. The optical lens according to claim 1, characterized in that, The focal length f5 of the fifth lens satisfies the following condition as the overall focal length f: |f5 / f|≥0.

6.

7. The optical lens according to any one of claims 1-6, characterized in that, The maximum field of view (FOV) of the optical lens satisfies: 25°≤FOV≤30°.

8. The optical lens according to any one of claims 1-6, characterized in that, The aperture value FNO of the optical lens satisfies: FNO≤1.

33.

9. The optical lens according to any one of claims 1-6, characterized in that, The focal length f4 of the fourth lens, the focal length f5 of the fifth lens, and the center distance d between the fourth lens and the fifth lens satisfy: f4*f5 / (f4+f5-d)≥100mm.

10. The optical lens according to any one of claims 1-6, characterized in that, The relative illumination RI corresponding to the maximum field of view of the optical lens satisfies: RI > 75%.

11. The optical lens according to any one of claims 1-6, characterized in that, The first lens, the second lens, the third lens, the fourth lens, and the fifth lens are all spherical lenses.

12. The optical lens according to claim 11, characterized in that, The object-side radius of curvature of the first lens is 16~21mm, the image-side radius of curvature is 220~250mm, and the thickness is 3~5mm; and / or, The object-side surface of the second lens has a radius of curvature of -12 to -16 mm, the image-side surface has a radius of curvature of 40 to 50 mm, and a thickness of 1 to 2 mm; and / or, The third lens has an object-side radius of curvature of 60-70 mm, an image-side radius of curvature of -18--25 mm, and a thickness of 4-5 mm; and / or, The fourth lens has an object-side radius of curvature of 15-20 mm, an image-side radius of curvature of 50-60 mm, and a thickness of 4-5 mm; and / or, The fifth lens has an object-side radius of curvature of -20 to -25 mm, an image-side radius of curvature of 40 to 45 mm, and a thickness of 1 to 2 mm.

13. The optical lens according to any one of claims 1-6, characterized in that, The refractive index of the first lens is not less than 1.

7.

14. The optical lens according to any one of claims 1-6, characterized in that, The optical lens also includes a filter, which is disposed on the side of the fifth lens opposite to the fourth lens.

15. The optical lens according to any one of claims 1-6, characterized in that, The optical lens also includes an aperture stop, which is disposed on the object side of the first lens.

16. A lidar, characterized in that, The optical lens included in any one of claims 1-15.

Images