Optical system and lidar

Abstract

This application provides an optical system and a lidar. The optical system includes a light source, a microlens assembly, and a microprism assembly. The microlens assembly is used to collimate the light emitted by the light source. The microprism assembly includes a light-transmitting substrate, a first microprism array, a second microprism array, and a third microprism array. The first microprism array is formed on a first surface of the light-transmitting substrate, the second microprism array is formed on a second surface of the light-transmitting substrate, and the third microprism array is formed on the first and / or second surfaces of the light-transmitting substrate. The microprisms in the first, second, and third microprism arrays correspond to the microlenses in the microlens array. The optical system is mounted horizontally on the lidar, and the elevation field of view of the lidar is increased by the external reflection of the first microprism array, the internal reflection of the second microprism array, and the refraction of the third microprism array.

Description

Technical Field

[0001] This application relates to the field of lidar technology, and more particularly to an optical system and lidar. Background Technology

[0002] With the development and application of LiDAR technology, the market demand for LiDAR with a large pitch field of view is increasing. Currently, in order to improve the pitch field of view, LiDARs on the market have the entire optomechanical module tilted on the LiDAR. Although this tilting can improve the pitch field of view to a certain extent, it also causes the size of the optomechanical module to increase rapidly, making the entire LiDAR larger and failing to meet the requirements of machine miniaturization.

[0003] Therefore, how to make lidar both have a large pitch field of view and be miniaturized has become an urgent technical problem to be solved. Summary of the Invention

[0004] The main objective of this application is to provide an optical system and a lidar that enables lidar using the optical system to have both a large pitch field of view and a miniaturized size.

[0005] In a first aspect, one embodiment of this application provides an optical system applied to lidar, the optical system comprising:

[0006] A light source, comprising multiple light-emitting units;

[0007] A microlens assembly, comprising at least one microlens array, wherein the microlenses in the microlens array correspond to the light-emitting unit, the light-emitting unit is located at the focal point of the microlens, and the microlens array is used to collimate the light emitted by the light-emitting unit;

[0008] A microprism assembly includes a light-transmitting substrate, a first microprism array, a second microprism array, and a third microprism array. The first microprism array is formed on a first surface of the light-transmitting substrate, the second microprism array is formed on a second surface of the light-transmitting substrate, and the third microprism array is formed on the first and / or second surfaces of the light-transmitting substrate. The first surface is the surface of the light-transmitting substrate facing the microlens array, and the second surface is the surface of the light-transmitting substrate facing away from the microlens array. The microprisms in the first, second, and third microprism arrays correspond to the microlenses in the microlens array.

[0009] The optical system is mounted horizontally on the lidar. It increases the pitch field of view of the lidar by reflecting and collimating light externally through the first microprism array, reflecting and collimating light internally through the second microprism array, and refracting and collimating light through the third microprism array.

[0010] In one embodiment, the inclined surfaces of the microprisms in the first microprism array are coated with an external reflective film, or the inclined surfaces of the microprisms in the second microprism array are coated with an internal reflective film, or the inclined surfaces of the microprisms in the third microprism array are coated with an antireflective film.

[0011] In one embodiment, the microprisms in the first microprism array include at least two first microprisms, and in the direction from the edge of the light-transmitting substrate to the center of the light-transmitting substrate, the first tilt angle of the inclined surface of the at least two first microprisms decreases sequentially, wherein the first tilt angle is the angle between the inclined surface of the first microprism and the first surface of the light-transmitting substrate.

[0012] In one embodiment, the first microprism in the first microprism array near the edge of the light-transmitting substrate is a triangular microprism, and the other first microprisms are trapezoidal microprisms.

[0013] In one embodiment, the microprisms in the first microprism array include at least one first microprism, the first microprism including at least two inclined surfaces, the first tilt angles of the at least two inclined surfaces being different, and the first tilt angles of the at least two inclined surfaces decreasing sequentially in the direction from the edge of the light-transmitting substrate to the center of the light-transmitting substrate, wherein the first tilt angle is the angle between the inclined surface of the first microprism and the first surface of the light-transmitting substrate.

[0014] In one embodiment, the microprisms in the second microprism array include at least one second microprism, wherein the second tilt angle of the inclined surface of the second microprism is greater than or equal to the refraction critical angle of the second microprism, wherein the second tilt angle is the angle between the inclined surface of the second microprism and the second surface of the light-transmitting substrate.

[0015] In one embodiment, when the number of the second microprisms is at least two, the second tilt angle of the at least two second microprisms increases sequentially in the direction from the edge of the light-transmitting substrate to the center of the light-transmitting substrate.

[0016] In one embodiment, in the microlens assembly, at least one microlens corresponds to the light-transmitting substrate instead of the microprism, so that light collimated by the microlens can directly pass through the light-transmitting substrate and be emitted directly.

[0017] In one embodiment, the optical system satisfies the following relationship:

[0018]

[0019] Wherein, d1 is the diameter of the microlens, d2 is the width of the microprism corresponding to the microlens, the width being the width of the surface of the microprism in contact with the light-transmitting substrate, f is the focal length of the microlens, and β is the divergence angle of the light-emitting unit.

[0020] Secondly, one embodiment of this application also provides a lidar, which includes an optical system provided in any embodiment of this application.

[0021] This application provides an optical system that can be horizontally mounted on a lidar. By reflecting collimated light through a first microprism array, reflecting collimated light through a second microprism array, and refracting collimated light through a third microprism array, the system increases the lidar's elevation field of view. This optical system achieves a large elevation field of view without requiring tilting on the lidar. Furthermore, because the microlens and microprism components in the optical system can be made very thin, the system's size can be minimized, meeting the miniaturization requirements of lidar. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A schematic diagram of an optical system provided in an embodiment of this application;

[0024] Figure 2 for Figure 1 A schematic diagram of the micro prism assembly in the optical system shown.

[0025] Figure 3 A schematic diagram of an optical system provided in an embodiment of this application;

[0026] Figure 4 A schematic diagram of an optical system provided in an embodiment of this application;

[0027] Figure 5 A schematic diagram of an optical system provided in an embodiment of this application;

[0028] Figure 6 A schematic diagram of an optical system provided in an embodiment of this application;

[0029] Figure 7 A schematic diagram of an optical system provided in an embodiment of this application;

[0030] Figure 8 for Figure 1 A schematic diagram of a partial structure of an optical system is shown.

[0031] Figure 9 for Figure 1 A schematic diagram of the field of view range of the optical system shown.

[0032] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0033] 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, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0035] Please refer to Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the structure of an optical system provided in one embodiment of this application. Figure 2 for Figure 1 The diagram shows a schematic of the microprism assembly in the optical system. This optical system 100 can be applied to devices such as lidar, 3D SLAM scanners, and 3D spatial scanners. The optical system 100 includes a light source 10, a microlens assembly 20, and a microprism assembly 30.

[0036] The light source 10 can be a laser light source, which includes multiple light-emitting units 11. Figure 1 The structural diagram shown only illustrates ten light-emitting units 11. It can be understood that the number and arrangement of these light-emitting units 11 can be set according to actual needs, and no specific restrictions are imposed here.

[0037] In one embodiment, the light-emitting unit 11 can be a vertical-cavity surface-emitting laser (VCSEL), or other lasers, such as an edge-emitting laser (EEL). The specific type of the light-emitting unit 11 can be set according to actual needs, and no specific limitation is made here.

[0038] The microlens assembly 20 includes a first light-transmitting substrate 21 and at least one microlens array 22. Figure 1 In the schematic diagram shown, there is one microlens array 22, which is formed on a surface of the first light-transmitting substrate 21 away from the light-emitting unit 11, and is used to collimate the laser emitted by the light-emitting unit 11.

[0039] The microlenses in the microlens array 22 correspond to the light-emitting unit 11, which is located at the focal point of the microlens, thereby enabling the microlens to collimate the laser emitted by the corresponding light-emitting unit 11.

[0040] In one embodiment, when the light-emitting unit 11 is a vertical-cavity surface-emitting laser, the microlens array 22 can be a microspherical lens array or a microaspherical lens array. The microlenses in the microlens array 22 can correspond one-to-one with the light-emitting units 11, and the number of microlenses is the same as the number of light-emitting units 11. It is understood that the correspondence between the microlenses and the light-emitting units 11 is not limited to a one-to-one correspondence; other correspondences are also possible, and no specific limitations are imposed here.

[0041] In one embodiment, when the light-emitting unit 11 is a side-emitting laser, at least one of the microlens arrays 22 can be a combination of a fast-axis collimating microcylindrical lens array and a slow-axis collimating microcylindrical lens array. That is, the microlens assembly 20 includes two first transparent substrates 21, with the fast-axis collimating microcylindrical lens array and the slow-axis collimating microcylindrical lens array respectively formed on the surfaces of the two first transparent substrates 21 away from the light-emitting unit 11. Thus, after the laser is emitted from the light-emitting unit 11, it passes sequentially through the first transparent substrate 21, the fast-axis collimating microcylindrical lens array, the other first transparent substrate 21, and the slow-axis collimating microcylindrical lens array. At this time, one microlens in the microlens array 22 can correspond to multiple light-emitting units 11.

[0042] like Figure 1 and Figure 2 As shown, the microprism assembly 30 includes a light-transmitting substrate 31 and a first microprism array 32, a second microprism array 33, and a third microprism array 34 formed on the light-transmitting substrate 31. The light-transmitting substrate 31 can also be referred to as the second light-transmitting substrate.

[0043] like Figure 1 As shown, the first microprism array 32 is formed on the first surface of the light-transmitting substrate 31, wherein the first surface is the surface of the light-transmitting substrate 31 facing the microlens array 22, that is, the surface facing the light source 10. The inclined surfaces of the microprisms in the first microprism array 32 are coated with an external reflection film, which is used to externally reflect the light after it has been collimated by the microlens assembly 20, thereby forming a beam with a negative field of view.

[0044] It should be noted that the negative field of view refers to the angle between the reflected light and the horizontal plane, with the plane containing the light-transmitting substrate 31 as the horizontal plane and moving clockwise. In other words, when the optical system 100 is mounted on the lidar in a horizontal direction, it can have scanning laser light below the horizontal plane, thus increasing the pitch field of view.

[0045] In one embodiment, the microprisms in the first microprism array 32 include at least two first microprisms 321. In the direction from the edge of the light-transmitting substrate 31 to its center, the first tilt angle θ1 of the inclined surfaces of the at least two first microprisms 321 decreases sequentially, wherein the first tilt angle θ1 is the angle between the inclined surface of the first microprism 321 and the first surface of the light-transmitting substrate 31. For example, in... Figure 1 In the two first microprisms 321 shown, the first tilt angle θ1 of the inclined planes of the two first microprisms 321 decreases sequentially from right to left. In this way, beams with different negative field angles can be obtained through different first microprisms 321.

[0046] In one embodiment, the first microprism 321 near the edge of the light-transmitting substrate 31 in the first microprism array 32 is a triangular microprism, while the other first microprisms 321 are trapezoidal microprisms. For example, in Figure 1 In the two first microprisms 321 shown, the heights of the two adjacent sides of the trapezoidal microprism and the triangular microprism are set to the same value. This can avoid problems such as the light reflected by the trapezoidal microprism 321 being blocked by the triangular microprism.

[0047] In one embodiment, the microprisms in the first microprism array 32 include at least one first microprism 321, the first microprism 321 including at least two inclined surfaces, wherein the first tilt angles θ1 of the at least two inclined surfaces are different, and in the direction from the edge of the light-transmitting substrate 31 to the center of the light-transmitting substrate 31, the first tilt angles θ1 of the at least two inclined surfaces decrease sequentially.

[0048] For example, such as Figure 3 As shown, Figure 3 This is a schematic diagram of the structure of an optical system provided in an embodiment of this application. Figure 3In the optical system 100 shown, the first microprism array 32 includes a first microprism 321, which has two inclined surfaces with different first tilt angles θ1. Clearly, the first tilt angle θ1 corresponding to the inclined surface closer to the edge of the light-transmitting substrate 31 is greater than the first tilt angle θ1 of the other inclined surface. The different inclined surfaces externally reflect the collimated light to form beams with different negative field angles.

[0049] Understandable Figure 3 The number, shape, and number of inclined surfaces of the first microprism 321 shown are only one of many embodiments. The number, shape, and number of inclined surfaces of the first microprism 321 can be designed according to actual needs, and no specific restrictions are imposed here.

[0050] like Figure 1 As shown, the second microprism array 33 is formed on the second surface of the light-transmitting substrate 31, wherein the second surface is the surface of the light-transmitting substrate 31 facing away from the microlens array 22, that is, the surface facing away from the light source 10. The inclined surfaces of the microprisms in the second microprism array 33 are coated with an internal reflection film, which is used to perform internal reflection on the light collimated by the microlens assembly 20, thereby increasing the positive field of view above the horizontal plane.

[0051] In one embodiment, the microprisms in the second microprism array 33 include at least one second microprism 331, the second tilt angle θ2 of the inclined surface of the second microprism 331 is greater than or equal to the critical angle of refraction of the second microprism 331, wherein the second tilt angle θ2 is the angle between the inclined surface of the second microprism 331 and the second surface of the light-transmitting substrate 31.

[0052] Furthermore, when the number of the second microprisms 331 is at least two, the second tilt angle θ2 of the at least two second microprisms 331 increases sequentially in the direction from the edge of the light-transmitting substrate 31 to the center of the light-transmitting substrate 31. For example, as... Figure 1 As shown, Figure 1 Three second microprisms 331 are shown, with their second tilt angles θ2 increasing sequentially from right to left. This increases the beam size of the optical system 100 at a positive, small field of view through internal reflection.

[0053] It should be noted that the inclined surfaces of the microprisms in the second microprism array 33 may not be coated with an internal reflection film, or may be partially coated with an internal reflection film; no specific restrictions are imposed here.

[0054] like Figure 1As shown, the third microprism array 34 is formed on the first and second surfaces of the light-transmitting substrate 31. The beveled surfaces of the microprisms in the third microprism array 34 are coated with an antireflective film, and the microprisms in the third microprism array 34 can be referred to as third microprisms 341. The third microprism array 34 is used to refract aligned light rays, thereby forming refracted light rays in different directions.

[0055] It is understood that in other embodiments, the inclined surface of the third microprism 341 may not be coated with an anti-reflection film, as long as its refractive function can be achieved and refracted light at the corresponding angle can be obtained.

[0056] Furthermore, the third microprism array 34 is not limited to being formed on the first and second surfaces of the light-transmitting substrate 31; it can also be formed on either the first or second surface of the light-transmitting substrate 31. For example, as Figure 4 As shown, Figure 4 This is a schematic diagram of the optical system provided in an embodiment of this application. The third microprism array 34 is formed on the second surface of the light-transmitting substrate 31. For example, as... Figure 5 As shown, Figure 5 This is a schematic diagram of an optical system provided in an embodiment of this application. The third microprism array 34 is formed on the first surface of the light-transmitting substrate 31.

[0057] exist Figure 1 In the optical system shown, the microprisms in the first microprism array 32, the second microprism array 33, and the third microprism array 34 correspond to the microlenses in the microlens array 22. The correspondence between the microprisms and microlenses can be varied; for example, it can be a one-to-one correspondence. Figure 1 As shown, each microprism corresponds to a microlens. For example, the correspondence between the microprism and the microlens can be one-to-many, such as... Figure 3 As shown, Figure 3 A first microprism 321 is shown, which corresponds to two microlenses. The correspondence between the microprism and the microlenses can be designed according to actual needs, and no specific restrictions are imposed here.

[0058] In one embodiment, in the microlens assembly 20, at least one microlens does not correspond to a microprism but corresponds to the light-transmitting substrate 31, so that light collimated by the microlens can directly pass through the light-transmitting substrate 31 and be emitted directly. For example, in Figure 1In the middle, counting from left to right, the third microlens does not correspond to the microprism, but corresponds to the area marked A in the light-transmitting substrate 31. In this way, the light collimated by the third microlens can be directly transmitted out of the light-transmitting substrate 31, forming a light ray with a 90° field of view angle to the horizontal plane, so that the pitch field of view of the optical system 100 has a 90° field of view angle.

[0059] exist Figures 1 to 5 In the optical system 100 shown, two third microprisms 341 are disposed on the left side of region A, which directly corresponds to the microlens, in the light-transmitting substrate 31. These two third microprisms 341 are used to obtain a field of view greater than 90°. When the optical system 100 is mounted on the lidar in a horizontal direction, a large pitch field of view from less than 0° to greater than 90° can be obtained through the external reflection of the first microprism array 32, the internal reflection of the second microprism array 33, and the refraction of the third microprism array 34.

[0060] Of course, in other embodiments, the optical system 100 may not include a microprism for obtaining a field of view greater than 90°. For example, as Figure 6 As shown, Figure 6 This is a schematic diagram of the structure of an optical system provided in an embodiment of this application. Figure 6 The optical system 100 shown can achieve a large elevation field of view of less than 0° to 90°. When the optical system 100 is mounted on the rotary motor of the lidar, the rotary motor can drive the optical system 100 to rotate 360° in all directions, forming a 360° azimuth angle and a large elevation field of view of less than 0° to 90°. However, in practical applications, due to factors such as the rotation speed and movement speed of the lidar, Figure 6 The optical system 100 shown may not be able to scan in time, and Figures 1 to 5 The optical system 100 shown, by adding a microprism for obtaining a field of view greater than 90°, can cover a wider area, avoid the aforementioned situation of not being able to scan in time, and improve the scanning quality and scanning accuracy of the lidar.

[0061] It should be noted that the region A in the light-transmitting substrate 31 that directly corresponds to the microlens is not limited to... Figures 1 to 5 The position shown can also be other positions, for example, [the position shown can be] Figure 1 Region A in the diagram is placed to the left of the microprism used to obtain a field of view greater than 90°, etc.

[0062] Furthermore, the microprisms used to obtain a field of view greater than 90° are not limited to those employing... Figures 1 to 5 The method of the third microprism 341 shown can also be achieved using the internal reflection effect of the second microprism array 33. For example, as Figure 7 As shown, Figure 7 This is a schematic diagram of the structure of an optical system provided in an embodiment of this application. Figure 7 In the optical system 100 shown, the microprism used to obtain a field of view angle greater than 90° is the second microprism 331.

[0063] In one embodiment, in order to improve the quality of the field of view of the optical system 100, the diameter d1 of the microlens in the microlens assembly 20 and the width d2 of the microprism corresponding to the microlens satisfy the following relationship:

[0064]

[0065] Wherein, the width of the microprism is the width of the surface of the microprism in contact with the light-transmitting substrate 31, f is the focal length of the microlens, and β is the divergence angle of the light-emitting unit 11.

[0066] In one embodiment, such as Figure 1 As shown, in the first microprism array 32, the second microprism array 33, and the third microprism array 34, multiple microprisms have the same width, that is, the first microprism 321, the second microprism 331, and the third microprism 341 have the same width.

[0067] In one embodiment, the microprism assembly 30 can be made of a high refractive index material, for example, the material of the microprism assembly 30 can be flint glass, specifically, such as H-ZLAF92.

[0068] To verify that the optical system 100 in this embodiment can obtain a large pitch field of view when it is mounted on the lidar in a horizontal direction, a specific experiment is given below.

[0069] In this experiment, the following methods were used: Figure 1 The optical system 100 shown, while referencing Figure 8 , Figure 8 for Figure 1 The diagram shows a partial structural schematic of the optical system. The light-emitting unit 11 is a VCSEL with a wavelength of 905 nm. The distance between two adjacent light-emitting units 11 is 2 mm. The light-emitting size of each unit 11 is 20 μm, and the full width at half maximum (FWHM) divergence angle is 16°. After collimation by the microlens assembly 20, the divergence angle is required to be reduced to 0.2°. The focal length f of the microlens is 5.7 mm, the diameter d1 is 1.8 mm, the distance between two adjacent microlenses is 2 mm, and the thickness of the first transparent substrate 21 is 1.5 mm. The microprisms in the microprism assembly 30 are made of H-ZLAF92, and the width d2 of all microprisms is 1.8 mm. Figure 1The microlens assembly 30 shown contains nine microprisms. Counting from right to left, the second microprism is a trapezoidal microprism. Apart from that, all other microprisms are triangular microprisms. The heights h of the triangular microprisms from right to left are 1.31 mm, 1.8 mm, 2.38 mm, 3.53 mm, 1.2 mm, 0.584 mm, 0.584 mm, and 0.989 mm, respectively. The heights h1 and h2 of the trapezoidal microprisms are 1.4 mm and 2.31 mm, respectively.

[0070] The laser emitted by the light-emitting unit 11, after being collimated by the lens assembly 20, enters the microprism assembly 30. After internal reflection, external reflection, and refraction, it forms beams with different field of view angles. From right to left, the angles of the emitted beams corresponding to the triangular microprisms are -18°, 0°, 18°, 36°, 54°, 72°, 108°, and 120°, respectively, while the angle of the emitted beam corresponding to the trapezoidal microprism is -36°. Furthermore, in... Figure 1 In the microlens assembly 20 shown, the third microlens from left to right does not correspond to a microprism, but rather to region A of the light-transmitting substrate 31. The angle of the emitted beam corresponding to the third microlens is 90°. Therefore, Figure 1 The optical system 100 shown can form a large pitch field of view from -36° to 120°; when the optical system 100 is mounted horizontally on the rotary motor of the lidar and rotates 360°, it will form a field of view as shown in the figure. Figure 9 The field of view range is shown.

[0071] from Figure 9 As can be seen, the optical system 100 in this embodiment can achieve a large pitch field of view of more than 150° without tilting, which meets the large pitch field of view requirement of lidar. At the same time, since the microlens assembly 20 and the microprism assembly 30 can be made very thin, the size of the optical system 100 can be made very small, which is conducive to the miniaturization of lidar. In addition, the manufacturing cost of the optical system 100 is also low, reducing the manufacturing cost of lidar.

[0072] One embodiment of this application also provides a lidar that utilizes the optical system described in any of the above embodiments. For the sake of brevity, the structure and working principle of the optical system used in this lidar can be referred to the foregoing embodiments, and will not be repeated here.

[0073] Because this lidar uses the optical system provided in this application, it can meet the requirements of a large pitch field of view, as well as the requirements of miniaturization, while also having low manufacturing costs, which is conducive to commercialization.

[0074] The foregoing disclosure provides many different implementations or examples for carrying out different structures of this application. To simplify the disclosure, the components and arrangements of specific examples are described above. Of course, these are merely examples and are not intended to limit the scope of this application. Any non-substantial changes and substitutions made by those skilled in the art based on this application are within the scope of protection claimed by this application.

[0075] Furthermore, reference numerals and / or reference letters may be repeated in different examples in this application. Such repetition is for simplification and clarity purposes and does not in itself indicate a relationship between the various embodiments and / or settings discussed. In addition, this application provides examples of various specific processes and materials; however, those skilled in the art will recognize the application of other processes and / or the use of other materials.

Claims

1. An optical system, characterized in that, The optical system, used in lidar, includes: A light source, comprising multiple light-emitting units; A microlens assembly, comprising at least one microlens array, wherein the microlenses in the microlens array correspond to the light-emitting unit, the light-emitting unit is located at the focal point of the microlens, and the microlens array is used to collimate the light emitted by the light-emitting unit; A microprism assembly includes a light-transmitting substrate, a first microprism array, a second microprism array, and a third microprism array. The first microprism array is formed on a first surface of the light-transmitting substrate, the second microprism array is formed on a second surface of the light-transmitting substrate, and the third microprism array is formed on the first and / or second surfaces of the light-transmitting substrate. The first surface is the surface of the light-transmitting substrate facing the microlens array, and the second surface is the surface of the light-transmitting substrate facing away from the microlens array. The microprisms in the first, second, and third microprism arrays correspond to the microlenses in the microlens array. The optical system is mounted horizontally on the lidar, and increases the pitch field of view of the lidar by reflecting and collimating light externally through the first microprism array, reflecting and collimating light internally through the second microprism array, and refracting and collimating light through the third microprism array. Wherein, the inclined surfaces of the microprisms in the first microprism array are coated with an external reflective film, or the inclined surfaces of the microprisms in the second microprism array are coated with an internal reflective film, or the inclined surfaces of the microprisms in the third microprism array are coated with an antireflective film.

2. The optical system according to claim 1, characterized in that, The microprisms in the first microprism array include at least two first microprisms. In the direction from the edge of the light-transmitting substrate to the center of the light-transmitting substrate, the first tilt angle of the inclined surface of the at least two first microprisms decreases sequentially. The first tilt angle is the angle between the inclined surface of the first microprism and the first surface of the light-transmitting substrate.

3. The optical system according to claim 2, characterized in that, In the first microprism array, the first microprism closest to the edge of the light-transmitting substrate is a triangular microprism, and the other first microprisms are trapezoidal microprisms.

4. The optical system according to claim 1, characterized in that, The microprisms in the first microprism array include at least one first microprism, the first microprism includes at least two inclined surfaces, the first inclination angles of the at least two inclined surfaces are different, and in the direction from the edge of the light-transmitting substrate to the center of the light-transmitting substrate, the first inclination angles of the at least two inclined surfaces decrease sequentially, wherein the first inclination angle is the angle between the inclined surface of the first microprism and the first surface of the light-transmitting substrate.

5. The optical system according to claim 1, characterized in that, The microprisms in the second microprism array include at least one second microprism, wherein the second tilt angle of the inclined surface of the second microprism is greater than or equal to the refraction critical angle of the second microprism, wherein the second tilt angle is the angle between the inclined surface of the second microprism and the second surface of the light-transmitting substrate.

6. The optical system according to claim 5, characterized in that, When there are at least two second microprisms, the second tilt angle of the at least two second microprisms increases sequentially in the direction from the edge of the light-transmitting substrate to the center of the light-transmitting substrate.

7. The optical system according to claim 1, characterized in that, In the microlens assembly, at least one microlens does not correspond to the microprism but corresponds to the light-transmitting substrate, so that light collimated by the microlens can directly pass through the light-transmitting substrate and be emitted.

8. The optical system according to any one of claims 1-7, characterized in that, The optical system satisfies the following relationship: in, The diameter of the microlens is [missing information]. The width of the microprism corresponding to the microlens, wherein the width is the width of the surface of the microprism in contact with the light-transmitting substrate. The focal length of the microlens is... The divergence angle of the light-emitting unit is given.

9. A lidar, characterized in that, The lidar includes the optical system described in any one of claims 1 to 8.

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