Laser emission module and laser radar
By using a combination of microcylindrical lens arrays and cylindrical lenses in the lidar transmitting module, the problem of uneven light spot in the slow axis direction of the lidar lens is solved, achieving more efficient field of view and reflectivity consistency, while reducing the number of lenses and assembly complexity.
Patent Information
- Application Number
- CN202423240894.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-26
- Publication Date
- 2026-01-20
- Estimated Expiration
- 2034-12-26
AI Technical Summary
Existing multi-channel edge-emitting laser lidar lenses struggle to achieve uniformly distributed linear light spots along the slow axis, affecting the consistency of the field of view and reflectivity. Furthermore, they require a large number of lenses, are complex to assemble and adjust, and are costly.
A combination of microcylindrical lens arrays and cylindrical lenses is used. The curvature direction of the microcylindrical lens array is the same as the slow axis direction of the laser beam, and the curvature direction of the first cylindrical lens is also the same as the slow axis direction, so as to achieve uniform distribution and collimation in the slow axis direction and reduce the number of lenses.
This achieves a uniform linear spot distribution of the lidar in the slow axis direction, improves the field of view range and reflectivity consistency, and reduces the difficulty and cost of lens assembly and adjustment.
Smart Images
Figure CN223815435U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to laser ranging technical field, specifically, relate to a laser emission module and laser radar. BACKGROUND
[0002] The principle of laser radar is that a radar emits one or more laser beams to the outside world, and realizes the detection function by receiving the laser signal reflected from the outside world. The laser radar mainly consists of a transmitting module, a receiving module, a scanning module and a signal processing module. Among them, the transmitting module is used to emit detection laser, the receiving module is used to receive echo signal, the scanning module is used to expand the angle of radar detection, and the signal processing module is used to convert the signal received by the receiving module into environmental information.
[0003] The transmitting module of the laser radar includes a transmitting lens and a laser. In order to improve the ranging capability of the laser radar, the energy of the single-tube semiconductor laser is far from enough, and generally requires an array laser, and a multi-channel edge-emitting laser is commonly used. The transmitting lens is composed of one or more optical lenses, which is used to form the light beam emitted by the laser into a required linear light spot.
[0004] The existing laser radar transmitting lens using multi-channel edge-emitting laser is difficult to realize the uniform distribution of linear light spot in the slow axis direction, which affects the range and reflectivity consistency of different fields of view. At the same time, the number of transmitting lens lenses is large, the assembly and adjustment are complex, and the cost is high. UTILITY MODEL CONTENT
[0005] The purpose of the utility model includes providing a laser emission module and laser radar, which can realize the uniform distribution of linear light spot in a certain angle range in the slow axis direction, improve the range and reflectivity consistency of different fields of view of the laser radar, reduce the number of optical lenses, and reduce the difficulty and cost of transmitting lens assembly and adjustment.
[0006] The embodiment of the utility model can be realized as follows:
[0007] In a first aspect, the utility model provides a laser emission module, which comprises a laser and a micro-cylindrical lens array and a first cylindrical lens arranged in sequence along the laser beam emission direction of the laser;
[0008] The laser is a multi-channel laser;
[0009] The curvature direction of the micro-cylindrical lens array is the same as the slow axis direction of the laser beam, and the plane direction is the same as the fast axis direction of the laser beam. Each micro-cylindrical lens is a convex cylindrical surface, and corresponds to one channel in the laser;
[0010] The first cylindrical lens is a convex cylindrical lens, and its curvature direction is the same as the slow axis direction of the laser beam, and the plane direction is the same as the fast axis direction of the laser beam.
[0011] In an optional embodiment, the distance between the laser and the micro-cylindrical lens array is less than the focal length of the micro-cylindrical lens array.
[0012] The distance between the micro-cylindrical lens array and the first cylindrical lens is greater than the focal length of the first cylindrical lens.
[0013] In an optional embodiment, the magnification of each micro-cylindrical lens to one channel of the laser is 1.35.
[0014] In an optional embodiment, after passing through the micro-cylindrical lens array and the first cylindrical lens, the slow-axis flat-top angle of the laser beam is greater than or equal to a preset angle, and the slow-axis flat-top uniformity is less than or equal to a preset uniformity.
[0015] In an optional embodiment, the preset angle is 1.7°.
[0016] The preset uniformity is 7%.
[0017] After passing through the micro-cylindrical lens array and the first cylindrical lens, the slow-axis divergence angle of the laser beam is less than or equal to 2°.
[0018] In an optional embodiment, the slow-axis flat-top uniformity X is calculated according to the following formula:
[0019] X = {X n -X * | / X *} max ;
[0020] Wherein, X n- is the power average value within the range of 0.1°, and X * is the average value of n segments, and n is the slow-axis flat-top angle divided by 0.1.
[0021] In an optional embodiment, the micro-cylindrical lens array has a radius of curvature of 1.363 mm and a thickness of 0.5 mm.
[0022] The first cylindrical lens has a radius of curvature of 19.307 mm and a thickness of 2 mm.
[0023] In an optional embodiment, one side of the first cylindrical lens close to the micro-cylindrical lens array is a flat surface.
[0024] In an optional embodiment, the laser emission module further comprises a second cylindrical lens between the first cylindrical lens and the micro cylindrical lens array, the second cylindrical lens is a convex cylindrical lens, the curvature direction of the second cylindrical lens is the same as the fast axis direction of the laser beam, and the plane direction of the second cylindrical lens is the same as the slow axis direction of the laser beam.
[0025] In an optional embodiment, the distance between the laser and the second cylindrical lens is greater than the focal length of the second cylindrical lens, and the distance between the first cylindrical lens and the second cylindrical lens is 20.589 mm.
[0026] In an optional embodiment, one plane of the micro cylindrical lens array and the second cylindrical lens close to each other is a plane.
[0027] In an optional embodiment, the micro cylindrical lens array and the second cylindrical lens are an integrated structure, a glued structure or a separate structure.
[0028] In an optional embodiment, the curvature radius of the second cylindrical lens is 3.743 mm, and the thickness of the second cylindrical lens is 10.141 mm.
[0029] After passing through the second cylindrical lens, the fast axis divergence angle of the laser beam is less than or equal to 0.1°.
[0030] In a second aspect, the utility model provides a kind of laser radar, comprising the laser emission module of any one of the foregoing embodiments.
[0031] The laser emission module and the laser radar provided in the embodiments of the utility model have the following beneficial effects.
[0032] By arranging the micro cylindrical lens array on the laser beam path of the laser, since each micro cylindrical lens in the micro cylindrical lens array corresponds to one emission channel in the laser, the micro cylindrical lens is convex, and the curvature direction of the micro cylindrical lens array is the same as the slow axis direction of the laser beam, so the micro cylindrical lens has positive focal power in the slow axis direction, and can homogenize and collimate in the slow axis direction, and then pass through the first cylindrical lens with the same curvature direction as the slow axis direction, the first cylindrical lens has positive focal power in the slow axis direction to collimate in the slow axis direction, and has no effect in the fast axis direction, so that a linear light spot uniformly distributed within a certain angle range in the slow axis direction is realized, the range, reflectivity consistency of different fields of view of the laser radar are improved, the number of optical lenses is reduced, and the difficulty and cost of emission lens assembly are reduced. BRIEF DESCRIPTION OF DRAWINGS
[0033] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the premise of the drawings.
[0034] Figure 1 A schematic diagram of each channel of the laser emitting;
[0035] Figure 2 A Figure 1 A schematic diagram of the angular space slow axis energy distribution;
[0036] Figure 3 A schematic diagram of the structure of the emission module in the slow axis direction;
[0037] Figure 4 A schematic diagram of the structure of the emission module in the fast axis direction;
[0038] Figure 5 A Figure 4 An enlarged schematic diagram of the micro-cylindrical lens array structure;
[0039] Figure 6 An enlarged schematic diagram of the micro-cylindrical lens array single-channel into a virtual image;
[0040] Figure 7 A schematic diagram of the angular space slow axis energy distribution of the output linear spot of the emission module.
[0041] Figure legend: S0-laser; S1-micro convex cylindrical surface; S2-flattened surface; S3-second plane; S4-second curved surface; S5-first plane; S6-first curved surface; L1-micro cylindrical lens array; L2-second cylindrical lens; L3-first cylindrical lens. DETAILED DESCRIPTION
[0042] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.
[0043] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.
[0044] It should be noted that similar reference numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in one drawing, it need not be further defined and explained in subsequent drawings.
[0045] In the description of the present application, it should be noted that if the terms "upper", "lower", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly placed when the product of the present application is used, and are merely for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.
[0046] In addition, if the terms "first", "second" and the like appear, they are only used to distinguish the description and cannot be understood as indicating or implying relative importance.
[0047] It should be noted that the features in the embodiments of the present application can be combined with each other without conflict.
[0048] The embodiments of the present application disclose a laser emission module, which is mainly applied to a laser radar, and of course can also be applied to other devices that need to emit laser.
[0049] The laser emission module comprises a laser S0 and a micro-cylindrical lens array L1 and a first cylindrical lens L3 arranged in sequence along the laser beam emission direction of the laser S0.
[0050] The laser S0 is a multi-channel laser S0, for example, is a four-channel edge-emitting laser S0 as shown in Figure 1 The angular spatial slow-axis energy distribution is as shown in Figure 2 The energy of each channel is separated from each other.
[0051] In combination with Figure 3 and Figure 5 The curvature direction of the micro-cylindrical lens array L1 is the same as the slow-axis direction of the laser beam, and the plane direction is the same as the fast-axis direction of the laser beam, each micro-cylindrical lens is a convex cylindrical surface, and corresponds to one channel in the laser S0; the array direction of each corresponding micro-cylindrical lens is the same as the slow-axis direction of the laser beam.
[0052] The first cylindrical lens L3 is a convex cylindrical lens, the curvature direction of which is the same as the slow axis direction of the laser beam, and the plane direction is the same as the fast axis direction of the laser beam.
[0053] In this way, by arranging the micro-cylindrical lens array L1 on the laser beam path of the laser S0, since each micro-cylindrical lens in the micro-cylindrical lens array L1 corresponds to one emission channel in the laser S0, the micro-cylindrical lens is convex, and the curvature direction of the micro-cylindrical lens array L1 is the same as the slow axis direction of the laser beam, so it has positive focal power in the slow axis direction, and can homogenize and collimate in the slow axis direction, and then pass through the first cylindrical lens L3 with the same curvature direction as the slow axis direction, which has positive focal power in the slow axis direction to collimate in the slow axis direction, and has no effect in the fast axis direction, thereby realizing a linear light spot uniformly distributed within a certain angle range in the slow axis direction, improving the range and reflectivity consistency of different fields of view of the laser radar, reducing the number of optical lenses, and reducing the difficulty and cost of emission lens assembly.
[0054] The distance between the laser S0 and the micro-cylindrical lens array L1 is less than the focal length of the micro-cylindrical lens array L1, so that the laser beam passing through the micro-cylindrical lens array L1 can be diverged into a virtual image, as shown in Figure 6 The distance between the laser S0 and the micro-cylindrical lens array L1 is less than the focal length of the micro-cylindrical lens array L1, so that the laser beam passing through the micro-cylindrical lens array L1 can be diverged into a virtual image, as shown in
[0055] The first cylindrical lens L3 is a convex cylindrical lens, the curvature direction of which is the same as the slow axis direction of the laser beam, and the plane direction is the same as the fast axis direction of the laser beam.
[0056] In combination with Figure 3 and Figure 4In the embodiment, the laser emission module further comprises a second cylindrical lens L2 between the first cylindrical lens L3 and the micro cylindrical lens array L1. The second cylindrical lens L2 is a convex cylindrical lens, the curvature direction of which is the same as the fast axis direction of the laser beam, and the plane direction is the same as the slow axis direction of the laser beam. Therefore, the second cylindrical lens L2 has positive focal power in the fast axis direction, and can collimate the laser beam in the fast axis direction, and has no effect in the slow axis direction.
[0057] In detail, the distance between the laser S0 and the second cylindrical lens L2 is greater than the focal length of the second cylindrical lens L2, so as to focus and converge the collimation of the divergence angle of the laser beam in the fast axis direction, and improve the brightness of the line light spot.
[0058] The one face of the micro cylindrical lens array L1 and the second cylindrical lens L2 close to each other is a plane. The one face of the micro cylindrical lens array L1 close to the laser S0 has a plurality of micro convex cylindrical lenses S1, the micro convex cylindrical lenses S1 have an arc in the slow axis direction and no arc in the fast axis direction. The one face of the micro cylindrical lens array L1 away from the laser S0 is a flat plane S2. The one face of the second cylindrical lens L2 close to the laser S0 is a second plane S3. The one face of the second cylindrical lens L2 away from the laser S0 is a second curved surface S4, which has an arc segment in the fast axis direction and no arc in the slow axis direction. In this way, the light emitted by each channel of the laser S0 first passes through the corresponding micro convex cylindrical lens S1 to perform virtual image magnification and shaping, so as to ensure the uniformity of the line light spot in the slow axis direction, and then passes through the flat plane S2 and the second plane S3. The plane will not change the direction of the light, so the light incident to the second cylindrical lens L2 almost maintains the original direction in the fast axis direction before meeting the second curved surface S4, so that the light converges later, so that the line light spot has a certain size in the width direction.
[0059] The micro cylindrical lens array L1 and the second cylindrical lens L2 are an integral structure, a cemented structure or a separate structure, and the specific structure is not limited. For example, in the embodiment, the micro cylindrical lens array L1 and the second cylindrical lens L2 are an integral structure or a cemented structure, so as to further reduce the number of lenses and achieve the purpose of reducing the difficulty and cost of assembly and adjustment. The separate structure means that there is a gap between the micro cylindrical lens array L1 and the second cylindrical lens L2.
[0060] The micro cylindrical lens array L1, the first cylindrical lens L3 and the second cylindrical lens L2 can be made of the same material or different materials. When the micro cylindrical lens array L1 and the second cylindrical lens L2 are an integral structure, they are made of the same material.
[0061] For example, in the embodiment, the micro cylindrical lens array L1, the first cylindrical lens L3 and the second cylindrical lens L2 are made of the same material, and the refractive index of the material is 1.5168 and the Abbe number is 64.199.
[0062] It should be noted that the curvature direction, i.e. the focusing axis of the cylindrical lens, is the side of the cylindrical lens with curvature, which determines the behavior of light in this direction. When light passes through the cylindrical lens, it is refracted, focused or collimated in the curvature direction. The flat direction, i.e. the non-focusing axis, is the flat side of the cylindrical lens, i.e. the direction without curvature. In this direction, the cylindrical lens does not change the propagation path of the light.
[0063] The slow-axis flat-top region of the laser beam is a region where the intensity of the laser beam is uniformly distributed in the slow-axis direction. The non-uniformity of the slow-axis flat-top region is the non-uniformity of the intensity distribution of the laser beam in the slow-axis direction. After passing through the micro-cylindrical lens array L1 and the first cylindrical lens L3, the angle of the slow-axis flat-top region of the laser beam is greater than or equal to the preset angle, i.e. the angle of the slow-axis flat-top region of the linear light spot formed after passing through the first cylindrical lens L3 is greater than or equal to the preset angle, and the non-uniformity of the slow-axis flat-top region is less than or equal to the preset non-uniformity, so that the linear light spot has a uniform energy distribution, as shown in FIG. 2, ensuring the range and reflectivity consistency of different fields of view of the laser radar. Figure 7
[0064] The non-uniformity X of the slow-axis flat-top region is calculated according to the following formula (1):
[0065] X = {X n -X *| / X *} max ; (1)
[0066] wherein X n- is the power average value within the range of 0.1°, and X * is the average value of n segments, and n is the angle of the slow-axis flat-top region divided by 0.1.
[0067] In this embodiment, the micro-cylindrical lens array L1 has a curvature radius of 1.363 mm and a thickness of 0.5 mm. The first cylindrical lens L3 has a curvature radius of 19.307 mm and a thickness of 2 mm. The second cylindrical lens L2 has a curvature radius of 3.743 mm and a thickness of 10.141 mm. The distance between the first cylindrical lens L3 and the second cylindrical lens L2 is 20.589 mm. The magnification of each micro-cylindrical lens to one channel of the laser S0 is 1.35.
[0068] The preset angle is 1.7°, and the preset non-uniformity is 7%. That is, the angle of the slow-axis flat-top region of the laser beam (linear light spot) after passing through the micro-cylindrical lens array L1 and the first cylindrical lens L3 is greater than or equal to 1.7°, and the non-uniformity X of the flat-top region is less than or equal to 7%.
[0069] After passing through the micro-cylindrical lens array L1 and the first cylindrical lens L3, the slow-axis divergence angle of the laser beam (line spot) is less than or equal to 2°. The difference between the slow-axis flat-top angle and the slow-axis divergence angle is less than or equal to 0.3°, and the slow-axis divergence angle is close to the flat-top angle, so that the edge of the uniformly distributed line spot is sharp. After passing through the second cylindrical lens L2, the fast-axis divergence angle of the laser beam (line spot) is less than or equal to 0.1°. The smaller fast-axis divergence angle can improve the energy density of the beam.
[0070] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.
Claims
1. A laser emission module, characterized by, The laser (S0) and a micro cylindrical lens array (L1) and a first cylindrical lens (L3) arranged in sequence along the laser beam emission direction of the laser (S0); The laser (S0) is a multi-channel laser (S0); The curvature direction of the micro cylindrical lens array (L1) is the same as the slow axis direction of the laser beam, and the plane direction is the same as the fast axis direction of the laser beam, each micro cylindrical lens is a convex cylindrical lens, and corresponds to one channel in the laser (S0); The first cylindrical lens (L3) is a convex cylindrical lens, and the curvature direction is the same as the slow axis direction of the laser beam, and the plane direction is the same as the fast axis direction of the laser beam.
2. The laser launch module of claim 1, wherein, The distance between the laser (S0) and the micro cylindrical lens array (L1) is less than the focal length of the micro cylindrical lens array (L1); The distance between the micro cylindrical lens array (L1) and the first cylindrical lens (L3) is greater than the focal length of the first cylindrical lens (L3).
3. The laser launch module of claim 2, wherein, The magnification of each micro cylindrical lens to one channel of the laser (S0) is 1.
35.
4. The laser launch module of claim 1, wherein, After passing through the micro cylindrical lens array (L1) and the first cylindrical lens (L3), the slow axis flat top area angle of the laser beam is greater than or equal to a preset angle, and the slow axis flat top area non-uniformity is less than or equal to a preset non-uniformity.
5. The laser launch module of claim 4, wherein, The preset angle is 1.7°; The preset non-uniformity is 7%; After passing through the micro cylindrical lens array (L1) and the first cylindrical lens (L3), the slow axis divergence angle of the laser beam is less than or equal to 2°.
6. The laser launch module of claim 5, wherein, The slow axis flat top area non-uniformity X is calculated according to the following formula: X = { X n - X *| / X *} max ; where X n- is the power average in the range of 0.1°, X * is the average of n segments, n is the slow axis flat-top region angle divided by 0.
1.
7. The laser emission module according to any one of claims 1 to 6, characterized in that, The curvature radius of the micro cylindrical lens array (L1) is 1.363mm, and the thickness is 0.5mm; the curvature radius of the first cylindrical lens (L3) is 19.307mm, and the thickness is 2mm; And / or, One side of the first cylindrical lens (L3) close to the micro cylindrical lens array (L1) is a plane.
8. The laser launch module of claim 1, wherein, The laser emission module further comprises a second cylindrical lens (L2) between the first cylindrical lens (L3) and the micro cylindrical lens array (L1), the second cylindrical lens (L2) is a convex cylindrical lens, and the curvature direction is the same as the fast axis direction of the laser beam, and the plane direction is the same as the slow axis direction of the laser beam.
9. The laser launch module of claim 8, wherein, The distance between the laser (S0) and the second cylindrical lens (L2) is greater than the focal length of the second cylindrical lens (L2), and the distance between the first cylindrical lens (L3) and the second cylindrical lens (L2) is 20.589mm; And / or, One side of the micro cylindrical lens array (L1) and the second cylindrical lens (L2) close to each other is a plane; And / or, The micro cylindrical lens array (L1) and the second cylindrical lens (L2) are an integral structure, a glued structure or a separate structure; And / or, The curvature radius of the second cylindrical lens (L2) is 3.743mm, and the thickness is 10.141mm; after passing through the second cylindrical lens (L2), the fast axis divergence angle of the laser beam is less than or equal to 0.1°.
10. A lidar, comprising: The laser emission module according to any one of claims 1 to 9. The laser emission module according to any one of claims 1 to 9.