Light beam emitting device, laser radar and light beam emitting method
Through the combination of light source, the first lens and the second lens, the free curved surface design of the lens is used to solve the problem of insufficient energy uniformity and angle control accuracy in beam shaping technology, and the efficient beam emission of lidar is achieved, and the measurement accuracy is improved. and performance.
Patent Information
- Application Number
- CN202310781274.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-28
- Publication Date
- 2024-12-31
AI Technical Summary
The existing beam shaping technology has problems of insufficient energy uniformity and insufficient angle control accuracy, which affects the measurement accuracy and distance measurement performance of lidar.
Using a beam emitting device including a light source, a first lens and a second lens, the light intensity of the light beam is homogenized through the first lens, and the second lens divides the light beam to accurately control the exit angle of each beam of light, using the free curved surface. Lens are designed to enable flexible beam control.
It realizes uniform distribution of beam energy and precise control of exit angle, improves the measurement accuracy and performance of lidar, and is suitable for automotive lidar and other fields.
Smart Images
Figure CN119224736A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of optical transmission, and in particular to a light beam emitting device, a laser radar and a light beam emitting method. Background Art
[0002] As an active emission measurement technology, the divergence angle of the optical beam emitted by LiDAR has a great influence on the measurement accuracy and measurement distance. The successful application of beam shaping technology can effectively improve the performance of LiDAR. The general components of LiDAR include optical modules, scanning modules, circuit modules and algorithm software. Among them, the optical module is divided into a transmitting optical module and a receiving optical module. The main optical function of the transmitting optical module is the beam shaping function. The transmitting optical module emits a shaped pulse beam, and the pulse beam reflected by the detected object is received by the receiving optical module. The information between the transmitting beam and the receiving beam is calculated to obtain information such as the distance of the object.
[0003] Beam shaping can be achieved by using geometric optical devices and diffractive optical devices. Diffractive optical devices mainly use grating elements, holographic elements or binary optical elements for optical shaping. Geometric optical devices mainly use lenses and prisms for beam shaping. The current beam shaping technology has the problems of insufficient energy uniformity and insufficient angle control accuracy. Summary of the invention
[0004] The embodiment of the present application provides a light beam emitting device, a laser radar and a light beam emitting method. The light beam emitting device provided by the present application can be applied to fields such as vehicle-mounted laser radar, and can ensure that the energy of each light beam output is uniform, and can accurately control the emission angle of each light beam.
[0005] In a first aspect, an embodiment of the present application provides a light beam emitting device. The light beam emitting device includes a light source, a first lens, and a second lens. The light source is used to emit a first light beam. The first lens is used to perform beam shaping on the first light beam to obtain a second light beam. The second light beam forms a light spot on the second lens, and the maximum difference in light intensity of the light spot in the first direction is less than a preset value. In other words, the first lens achieves light intensity homogenization by beam shaping the first light beam, that is, the light intensity distribution of the second light beam in at least one dimension is uniform. The second lens is used to split the second light beam to obtain multiple third light beams, wherein some or all of the third light beams are distributed along the first direction. In other words, the second lens splits the second light beam in at least one dimension.
[0006] In this embodiment, the first lens homogenizes the light intensity of the light beam emitted by the light source, thereby overcoming the unevenness of the light emission of the light source. Furthermore, the second lens splits the light beam, and can accurately control the exit angle of each light beam. In addition, since the light intensity distribution of the light beam input to the second lens is uniform, it is ensured that the light intensity of each light beam output from the second lens is the same or close.
[0007] In some possible implementations, the light incident surface and / or the light exit surface of the first lens adopts a free-form surface, and the light incident surface and / or the light exit surface of the second lens adopts a free-form surface. By designing the surface shape of the free-form surface of the first lens, the light intensity of the light beam can be homogenized, and by designing the surface shape of the free-form surface of the first lens, the light beam can be split. The use of a lens with a free-form surface can achieve more flexible light beam control.
[0008] In some possible implementations, the maximum difference in light intensity of the light spot in the second direction is less than a preset value, and the first direction and the second direction are perpendicular to each other. In other words, the first lens can also achieve two-dimensional light intensity homogenization of the incident light beam, thereby facilitating application in more different application scenarios.
[0009] In some possible implementations, a first portion of the third light beams in the plurality of third light beams is distributed along a first direction, a second portion of the third light beams in the plurality of third light beams is distributed along a second direction, and the first direction and the second direction are perpendicular to each other. In other words, the second lens can also perform two-dimensional beam splitting on the incident light beam, thereby facilitating application in more different application scenarios.
[0010] In some possible implementations, the maximum difference in light intensity between the multiple third light beams is less than a preset value. It should be understood that since the light intensity distribution of the light beam input to the second lens is uniform, the second lens can achieve the same or similar light intensity of each light beam after splitting by controlling the exit angle of the light beam emitted at each position. For example, the second light beam is split into 8 third light beams, and the 8 third light beams have 8 different transmission directions respectively. The 8 third light beams can be regarded as being emitted from 8 different positions on the second lens respectively, and the sizes of these 8 different positions are the same or close, which is equivalent to dividing the light intensity of the second light beam into 8 parts, so that the light intensities of the 8 third light beams are the same or close.
[0011] In some possible implementations, the emission angle of the third light beam depends on the surface shape of the third light beam at the emission position on the second lens, so that the surface shape of the second lens can be flexibly designed according to actual needs.
[0012] In some possible implementations, the light source includes a laser and a collimation module, and the collimation module is used to collimate the light beam emitted by the laser to obtain the first light beam. This implementation provides a specific implementation of a light source with better practical effect.
[0013] In a second aspect, an embodiment of the present application provides a laser radar. The laser radar includes a beam receiving device and a beam emitting device as described in any embodiment of the first aspect. Specifically, the beam emitting device is used to emit a beam to a target object, and the beam receiving device is used to receive a beam reflected by the target object. Among them, the beam receiving device can process the received beam to calculate the flight time of the beam, thereby realizing the radar ranging function.
[0014] In a third aspect, an embodiment of the present application provides a light beam emitting method. The light beam emitting method is applied to a light beam emitting device, and the light beam emitting device includes a light source, a first lens, and a second lens. The light beam emitting method includes the following steps. First, a first light beam is emitted by a light source. Thereafter, the first light beam is beam shaped by the first lens to obtain a second light beam. The second light beam forms a light spot on the second lens, and the maximum difference in light intensity of the light spot in the first direction is less than a preset value. Furthermore, the second light beam is split by the second lens to obtain multiple third light beams. Part or all of the third light beams are distributed along the first direction.
[0015] In this embodiment, the first lens homogenizes the light intensity of the light beam emitted by the light source, thereby overcoming the unevenness of the light emission of the light source. Furthermore, the second lens splits the light beam, and can accurately control the exit angle of each light beam. In addition, since the light intensity distribution of the light beam input to the second lens is uniform, it is ensured that the light intensity of each light beam output from the second lens is the same or close.
[0016] In some possible implementations, the light incident surface and / or the light exit surface of the first lens adopts a free-form surface, and the light incident surface and / or the light exit surface of the second lens adopts a free-form surface. By designing the surface shape of the free-form surface of the first lens, the light intensity of the light beam can be homogenized, and by designing the surface shape of the free-form surface of the first lens, the light beam can be split. The use of a lens with a free-form surface can achieve more flexible light beam control.
[0017] In some possible implementations, the maximum difference in light intensity of the light spot in the second direction is less than a preset value, and the first direction and the second direction are perpendicular to each other. In other words, the first lens can also achieve two-dimensional light intensity homogenization of the incident light beam, thereby facilitating application in more different application scenarios.
[0018] In some possible implementations, a first portion of the third light beams in the plurality of third light beams is distributed along a first direction, a second portion of the third light beams in the plurality of third light beams is distributed along a second direction, and the first direction and the second direction are perpendicular to each other. In other words, the second lens can also perform two-dimensional beam splitting on the incident light beam, thereby facilitating application in more different application scenarios.
[0019] In some possible implementations, the maximum difference in light intensity between the multiple third light beams is less than a preset value. It should be understood that since the light intensity distribution of the light beam input to the second lens is uniform, the second lens can achieve the same or similar light intensity of each light beam after splitting by controlling the exit angle of the light beam emitted at each position. For example, the second light beam is split into 8 third light beams, and the 8 third light beams have 8 different transmission directions respectively. The 8 third light beams can be regarded as being emitted from 8 different positions on the second lens respectively, and the sizes of these 8 different positions are the same or close, which is equivalent to dividing the light intensity of the second light beam into 8 parts, so that the light intensities of the 8 third light beams are the same or close.
[0020] In some possible implementations, the emission angle of the third light beam depends on the surface shape of the third light beam at the emission position on the second lens, so that the surface shape of the second lens can be flexibly designed according to actual needs.
[0021] In some possible implementations, the light source includes a laser and a collimation module. The emitting the first light beam through the light source includes: collimating the light beam emitted by the laser through the collimation module to obtain the first light beam.
[0022] From the above introduction, it can be seen that the light beam emitting device includes a light source, a first lens and a second lens. The first lens is used to perform beam shaping on the first light beam emitted by the light source to obtain a second light beam. Among them, the light intensity of the second light beam in at least one dimension is uniformly distributed. The second lens splits the second light beam to obtain multiple third light beams, and the multiple third light beams are distributed in at least one dimension. Therefore, the first lens homogenizes the light intensity of the light beam emitted by the light source, thereby overcoming the unevenness of the light emission of the light source. Furthermore, the second lens splits the light beam and can accurately control the exit angle of each light beam. In addition, since the light intensity distribution of the light beam input to the second lens is uniform, it is ensured that the light intensity of each light beam output from the second lens is the same or close. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 This is a schematic diagram of the structure of a light beam emitting device in an embodiment of the present application;
[0024] Figure 2 This is a schematic diagram of the light intensity distribution of the first light beam after collimation in an embodiment of the present application;
[0025] Figure 3 A schematic diagram of a light spot formed by the second light beam in an embodiment of the present application;
[0026] Figure 4 Schematic diagram of light intensity distribution of a light spot formed by the second light beam in the Y direction in an embodiment of the present application;
[0027] Figure 5Schematic diagram of the light intensity distribution of the light spot formed by the second light beam in the X direction in the embodiment of the present application;
[0028] Figure 6 A schematic diagram of a light spot formed by multiple third light beams in an embodiment of the present application;
[0029] Figure 7 Schematic diagram of light intensity distribution in the Y direction of a light spot formed by multiple third light beams in an embodiment of the present application;
[0030] Figure 8 A schematic diagram of the structure of the first lens in the embodiment of the present application;
[0031] Fig. 9 A schematic diagram of the structure of the second lens in the embodiment of the present application;
[0032] Fig.10 This is a schematic diagram of an application scenario of the laser radar in the embodiment of the present application;
[0033] Fig.11 This is a schematic diagram of an embodiment of the light beam emission method in the embodiment of the present application. DETAILED DESCRIPTION
[0034] The embodiment of the present application provides a light beam emitting device, a laser radar and a light beam emitting method. The light beam emitting device provided by the present application can be applied to fields such as vehicle-mounted laser radar, and can ensure that the energy of each light beam output is uniform, and can accurately control the emission angle of each light beam.
[0035] It should be noted that the terms "first", "second", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the term "comprising" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.
[0036] Figure 1 Schematic diagram of the structure of a light beam emitting device in an embodiment of the present application. Figure 1As shown, the light beam emitting device includes: a laser 1, a collimation module 2, a first lens 3 and a second lens 4. As an example, the collimation module 2 is specifically a fiber collimation lens. The laser 1 and the collimation module 2 can also be integrated together, collectively referred to as a light source. Specifically, the collimation module 2 is used to collimate the light beam emitted by the laser to obtain a first light beam. Figure 2 Schematic diagram of the light intensity distribution of the first light beam after collimation in the embodiment of the present application. For example, the collimation module 2 uses a plano-convex aspheric lens to collimate the light beam, and the light intensity distribution of the first light beam after collimation is as follows: Figure 2 As shown, it can be seen that it is an obvious Gaussian distribution.
[0037] The first lens 3 is used to perform beam shaping on the first light beam to obtain a second light beam, wherein beam shaping can be understood as adjusting the light intensity distribution of the light beam. The purpose of beam shaping is to make the light intensity distribution of the second light beam uniform in at least one dimension, so the operation of beam shaping can also be referred to as homogenizing the light intensity of the light beam. A specific method for measuring the uniform distribution of the light intensity of the second light beam is provided below.
[0038] Figure 3 FIG. 1 is a schematic diagram of a light spot formed by the second light beam in an embodiment of the present application. Figure 3 As shown, the second light beam forms a light spot on the second lens 4, the horizontal axis represents the position coordinate in the X direction (in mm), and the vertical axis represents the position coordinate in the Y direction (in mm). It can be seen that the light spot is a rectangular light spot in the Y direction, and the maximum difference of the light intensity distribution of the light spot in the Y direction is less than the preset value. In other words, the light intensity distribution of the light spot in the Y direction is uniform.
[0039] Figure 4 FIG. 1 is a schematic diagram of the light intensity distribution of the light spot formed by the second light beam in the Y direction in the embodiment of the present application. Figure 4 As shown, the horizontal axis represents the position coordinate in the Y direction (in mm), and the vertical axis represents the lumen (in cd). It can be seen that the light intensity distribution of the light spot in the Y direction is uniform. Figure 5 FIG. 1 is a schematic diagram of the light intensity distribution of the light spot formed by the second light beam in the X direction in the embodiment of the present application. Figure 5 As shown, the horizontal axis represents the position coordinate in the X direction (in mm), and the vertical axis represents the lumen (in cd). It can be seen that the light intensity distribution of the light spot in the X direction is a Gaussian distribution.
[0040] It should be understood that the above Figure 3-Figure 5The first lens 3 is used to homogenize the light intensity of the first light beam in the Y direction. As another example, the first lens 3 can also homogenize the light intensity of the first light beam in the X direction. As another example, the first lens 3 can also homogenize the light intensity of the first light beam in the X direction and the Y direction at the same time. In other words, the first lens 3 can homogenize the light intensity of the first light beam in one dimension or in two dimensions. The schematic diagram of the light spot after the light intensity of the first light beam is homogenized in two dimensions can refer to the above Figure 3-Figure 5 The deformation is carried out and no drawings are provided here for display.
[0041] The second lens 4 is used to split the second light beam to obtain multiple third light beams. The present application does not limit the number of third light beams. For example, four third light beams can be split; for another example, eight third light beams can be split. It should be understood that the emission angle of each third light beam depends on the surface shape of each third light beam at the emission position on the second lens 4. In other words, the emission angle of the light beams emitted at each position on the second lens 4 can be controlled by designing the surface shape of the second lens 4, so that the light beams emitted from the second lens 4 are dispersed according to different emission angles to form multiple third light beams. This is equivalent to designing the surface shape of the second lens 4 according to the emission angles of each third light beam actually required.
[0042] In one possible implementation, the second lens 4 performs one-dimensional beam splitting on the second light beam, and all the third light beams after the beam splitting are distributed along a certain direction (such as the X direction or the Y direction). In another possible implementation, the second lens 4 performs two-dimensional beam splitting on the second light beam, and a portion of the third light beams after the beam splitting are distributed along the X direction, and another portion of the third light beams after the beam splitting are distributed along the Y direction.
[0043] Figure 6 Schematic diagram of the light spot formed by multiple third light beams in the embodiment of the present application. Figure 6 As shown, the horizontal axis represents the position coordinate in the X direction (in mm), and the vertical axis represents the position coordinate in the Y direction (in mm). It can be seen that the third light beam forms 8 obvious light spots in the Y direction, that is, 8 third light beams are obtained after beam splitting.
[0044] Figure 7 Schematic diagram of the light intensity distribution of the light spot formed by the multiple third light beams in the Y direction in the embodiment of the present application. Figure 7 As shown, the horizontal axis represents the position coordinate in the Y direction (in mm), and the vertical axis represents the lumen (in cd). Figure 7It can be clearly seen that there are 8 positions with greater light intensity distributed along the Y direction, and each position with greater light intensity corresponds to a third light beam. Since the light intensity distribution of the second light beam input to the second lens 4 in the Y direction is uniform, the light intensity distribution of each third light beam in the Y direction is also uniform, that is, the maximum difference in light intensity between multiple third light beams is less than the preset value. For example, the second light beam is split into 8 third light beams, and the 8 third light beams have 8 different transmission directions respectively. The 8 third light beams can be regarded as being emitted from 8 different positions on the second lens respectively, and the sizes of these 8 different positions are the same or close, which is equivalent to dividing the light intensity of the second light beam into 8 equal parts, so that the light intensities of the 8 third light beams are the same or close. It should be understood that the schematic diagram of the light spot after two-dimensional beam splitting can refer to the above Figure 6-Figure 7 The deformation is carried out and no drawings are provided here for display.
[0045] In a possible implementation, the light incident surface and / or the light emitting surface of the first lens 3 is a free-form surface, and the light incident surface and / or the light emitting surface of the second lens 4 is a free-form surface. It should be understood that the free-form surface can be processed by mechanical grinding, computer numerical control (CNC), injection molding, molding, etc. The material of the free-form surface can be optical glass, optical plastic, infrared material or optical crystal, etc. The free-form surface design adopted by the first lens 3 and the second lens 4 is introduced below.
[0046] It should be noted that, for the first lens 3, it is necessary to first determine the relationship between the input beam and the output beam associated with the first lens 3, and then determine the relationship between the output beam associated with the first lens 3 and the free-form surface of the first lens 3. Among them, the input beam associated with the first lens 3 refers to the first beam output by the collimation module 2, and the output beam associated with the first lens 3 refers to the second beam output from the first lens 3. Similarly, for the second lens 4, it is necessary to first determine the relationship between the input beam and the output beam associated with the second lens 4, and then determine the relationship between the output beam associated with the second lens 4 and the free-form surface of the second lens 4. Among them, the input beam associated with the second lens 4 refers to the second beam output by the first lens 3, and the output beam associated with the second lens 4 refers to the third beam output from the second lens 4.
[0047] The first light beam emitted by the laser 1 is a Gaussian light beam, and the intensity distribution of the first light beam satisfies the following conditions:
[0048]
[0049] Among them, R represents the coordinate along the outward direction of the beam waist, which can also be understood as the direction of beam transmission. w represents the Gaussian beam waist, x represents the coordinate along the beam waist to reach x, and A(x) represents the energy integral of the Gaussian beam within the circle with a radius of x.
[0050] The intensity distribution of the second light beam output by the first lens 3 is defined as:
[0051] B(t)=EtK
[0052] Wherein, t represents the position coordinate of a certain point on the second light beam.
[0053] It should be understood that P represents the intensity of the first beam, which is a constant. E represents the illumination distribution of the second beam, and for a uniform distribution, E is a constant. K is the width of the second beam, which is also a constant. Therefore, the relationship between the first beam and the second beam can be established:
[0054] A(x)=B(t)
[0055] In addition, the boundary conditions are defined as follows: when x approaches infinity, t approaches the length H of the second beam. It can be obtained:
[0056]
[0057] It should be understood that the function of t with respect to x is obtained above, and the relationship between the first light beam and the second light beam is determined.
[0058] Next, the relationship between the free-form surface of the first lens 3 and the first light beam and the second light beam is determined.
[0059] The vector representation of the first beam is:
[0060] The vector representation of the second beam is:
[0061] in,
[0062]
[0063] The normal vector of the free-form surface of the first lens 3 is expressed as:
[0064]
[0065] Wherein, f is the free surface equation f(x, y, z) of the first lens 3, and according to the law of refraction, it can be obtained:
[0066]
[0067] It should be understood that the relationship between the free-form surface of the first lens 3 and the first light beam and the second light beam is determined, and its essence is a partial differential equation. By numerical solution, f(x, y, z) can be obtained, and the free-form surface of the first lens 3 is designed. Figure 8 Schematic diagram of the structure of the first lens in the embodiment of the present application. Figure 8 As shown, a first lens having a free-form surface is used to perform beam shaping on an input first light beam to obtain a second light beam with uniform light intensity distribution.
[0068] Similarly, the free-form surface of the second lens 4 can also be designed in a similar manner as described above. Specifically, the intensity distribution of the second light beam input to the second lens 4 is first determined, and then the intensity distribution of the third light beam output from the second lens 4 is defined, thereby determining the relationship between the second light beam and the third light beam. Next, the vector of the second light beam, the vector of the third light beam, and the normal vector of the free-form surface of the second lens 4 are defined, thereby obtaining the free-form surface equation of the second lens 4, so as to complete the design of the free-form surface of the second lens 4.
[0069] Furthermore, since the emission angle of each third light beam depends on the surface shape of each third light beam at the emission position on the second lens 4, it is necessary to design the surface shape of the second lens 4 according to the emission angle of the third light beam. The design method of the surface shape of the second lens 4 is introduced below.
[0070] Taking one of the third light beams output from the second lens 4 as an example, the vector of the third light beam is expressed as:
[0071]
[0072] Here, θ represents the angle at which the third light beam emerges from the second lens 4 .
[0073] The vector of the second light beam input to the second lens 4 is expressed as:
[0074]
[0075] Here, α is the angle at which the second light beam emerges from the first lens 3 .
[0076] According to Snell's law in vector form, we can get:
[0077]
[0078] Therefore, the normal vector at each position on the free-form surface of the second lens 4 can be obtained: Then, the coordinates of each point on the free-form surface of the second lens 4 are obtained to complete the surface shape design of the second lens 4. It should be understood that the free-form surface of the second lens 4 can be divided into regions according to the number of beam splittings of the second lens 4 to determine the light beam emission angle θ corresponding to each region, that is, the emission angle of each third light beam. The surface shape of each region on the free-form surface of the second lens 4 is obtained in the above manner, and the surface shapes of these regions are connected as a whole to obtain the free-form surface of the second lens 4. Fig. 9 Schematic diagram of the structure of the second lens in the embodiment of the present application. Fig. 9 As shown, the input second light beam is split by a second lens with a free-form surface to obtain a plurality of third light beams, and the emission angle of each third light beam can be precisely controlled.
[0079] It can be seen from the above introduction that the light beam emitting device includes a light source, a first lens and a second lens. The first lens is used to perform beam shaping on the first light beam emitted by the light source to obtain a second light beam. Among them, the light intensity of the second light beam in at least one dimension is uniformly distributed. The second lens splits the second light beam to obtain multiple third light beams, and the multiple third light beams are distributed in at least one dimension. Therefore, the first lens homogenizes the light intensity of the light beam emitted by the light source, thereby overcoming the unevenness of the light emission of the light source. Furthermore, the second lens splits the light beam and can accurately control the exit angle of each beam of light. In addition, since the light intensity distribution of the light beam input to the second lens is uniform, the light intensity of each beam of light output from the second lens is guaranteed to be the same or close.
[0080] Fig.10 Schematic diagram of an application scenario of the laser radar in the embodiment of the present application. Fig.10 As shown in FIG. 1 , the laser radar includes a beam emitting device and a beam receiving device. The beam emitting device emits a beam to a target object, and the beam receiving device receives the beam reflected by the target object. The beam receiving device can process the received beam to calculate the flight time of the beam, thereby realizing the radar ranging function. It should be understood that the beam emitting device can be specifically referred to in the above Figure 1 The relevant introduction of the illustrated embodiment will not be repeated here.
[0081] The light beam emitting method provided in the embodiment of the present application is introduced below.
[0082] Fig.11 Schematic diagram of an embodiment of the light beam emission method in the embodiment of the present application. It should be noted that the light beam emission method is implemented based on the light beam emission device introduced above. For the introduction of the light beam emission device, please refer to the relevant description of the above embodiments, which will not be repeated here. In this example, the light beam emission method includes the following steps.
[0083] 101. A first light beam is emitted through a light source.
[0084] In a possible implementation, the light source includes a laser and a collimation module. Specifically, the laser first emits a light beam, and then the collimation module collimates the light beam emitted by the laser to obtain the first light beam.
[0085] 102. Perform beam shaping on the first light beam through a first lens to obtain a second light beam.
[0086] It should be understood that the first light beam is a Gaussian light beam, and the light intensity distribution of the first light beam is non-uniform. The light intensity is homogenized by beam shaping the first light beam through the first lens, that is, by observing the light spot formed by the second light beam, it can be seen that the light intensity distribution of the second light beam in at least one dimension is uniform. In other words, the first lens can achieve both one-dimensional light intensity homogenization and two-dimensional light intensity homogenization.
[0087] 103. Split the second light beam through a second lens to obtain multiple third light beams.
[0088] It should be understood that by designing the surface shape of the second lens, the emission angle of the light beam emitted from each position on the second lens can be controlled, so that the light beam emitted from the second lens is dispersed according to different emission angles to form multiple third light beams. Since the light intensity distribution of the second light beam incident on the second lens is uniform, the light intensity distribution of each third light beam among the multiple third light beams is also uniform. In different scenarios, both one-dimensional beam splitting and two-dimensional beam splitting can be achieved through the second lens.
[0089] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application is described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims
1. A light beam emitting device, characterized in that: include: A light source, a first lens and a second lens; The light source is used to emit a first light beam; The first lens is used to perform beam shaping on the first light beam to obtain a second light beam, wherein the second light beam forms a light spot on the second lens, and the maximum difference of the light intensity of the light spot in the first direction is less than a preset value; The second lens is used to split the second light beam to obtain multiple third light beams, wherein part or all of the third light beams are distributed along the first direction.
2. The light beam emitting device according to claim 1, characterized in that: The light incident surface and / or the light exiting surface of the first lens adopts a free-form surface, and the light incident surface and / or the light exiting surface of the second lens adopts a free-form surface.
3. The light beam emitting device according to claim 1 or 2, characterized in that: The maximum difference of the light intensity of the light spot in the second direction is smaller than the preset value, and the first direction is perpendicular to the second direction.
4. The light beam emitting device according to any one of claims 1 to 3, characterized in that: A first portion of the third light beams in the plurality of third light beams is distributed along the first direction, and a second portion of the third light beams in the plurality of third light beams is distributed along a second direction. The first direction and the second direction are perpendicular to each other.
5. The light beam emitting device according to any one of claims 1 to 4, characterized in that: The maximum difference in light intensity among the plurality of third light beams is smaller than the preset value.
6. The light beam emitting device according to any one of claims 1 to 5, characterized in that: The emission angle of the third light beam depends on the surface shape of the third light beam at the emission position on the second lens.
7. The light beam emitting device according to any one of claims 1 to 6, characterized in that: The light source includes a laser and a collimation module; The collimation module is used to collimate the light beam emitted by the laser to obtain the first light beam.
8. A laser radar, characterized in that: comprising a light beam emitting device and a light beam receiving device as claimed in any one of claims 1 to 7; The light beam emitting device is used to emit a light beam toward a target object; The light beam receiving device is used to receive the light beam reflected by the target object.
9. A light beam emitting method, characterized in that: The light beam emitting method is applied to a light beam emitting device, the light beam emitting device comprises a light source, a first lens and a second lens, and the method comprises: emitting a first light beam through the light source; Performing beam shaping on the first light beam through the first lens to obtain a second light beam, wherein the second light beam forms a light spot on the second lens, and a maximum difference in light intensity of the light spot in a light intensity distribution in a first direction is less than a preset value; The second light beam is split by the second lens to obtain a plurality of third light beams, wherein part or all of the third light beams are distributed along the first direction.
10. The light beam emitting method according to claim 9, characterized in that: The light incident surface and / or the light exiting surface of the first lens adopts a free-form surface, and the light incident surface and / or the light exiting surface of the second lens adopts a free-form surface.
11. The light beam emitting method according to claim 9 or 10, characterized in that: The maximum difference of the light intensity of the light spot in the second direction is smaller than the preset value, and the first direction is perpendicular to the second direction.
12. The light beam emitting method according to any one of claims 9 to 11, characterized in that: A first portion of the third light beams in the plurality of third light beams is distributed along the first direction, and a second portion of the third light beams in the plurality of third light beams is distributed along a second direction. The first direction and the second direction are perpendicular to each other.
13. The light beam emitting method according to any one of claims 9 to 12, characterized in that: The maximum difference in light intensity among the plurality of third light beams is smaller than the preset value.
14. The light beam emitting method according to any one of claims 9 to 13, characterized in that: The emission angle of the third light beam depends on the surface shape of the third light beam at the emission position on the second lens.
15. The light beam emitting method according to any one of claims 9 to 14, characterized in that: The light source includes a laser and a collimation module, and emitting a first light beam through the light source includes: The first light beam is obtained by collimating the light beam emitted by the laser through the collimation module.