Scanning module and scanning laser radar

Abstract

The utility model provides a scanning module and a scanning laser radar, and relates to the technical field of laser radars. The scanning module comprises a refracting optical element, the refracting optical element has a preset incident direction and a preset refracting direction, the refracting optical element comprises a plane mirror, the plane mirror has an emergent surface, the emergent surface is provided with a metasurface, and a refracting layer is formed on the metasurface; or, a microprism array is distributed on the emergent surface, and the microprism array is limited to form a refraction layer; wherein the refraction layer is used for refracting a light beam incident along a preset incident direction, so that the light beam is emitted along a preset refraction direction. According to the invention, by improving the scanning module of the laser radar, the stability of the scanning module can be improved, and a large pitching field angle can be scanned.

Description

Technical Field

[0001] The present application relates to the field of laser radar technology, and in particular to a scanning module and a scanning laser radar. Background Art

[0002] With the development of LiDAR technology, there are various scanning methods for LiDAR. In the field of three-dimensional mapping and vehicle-mounted radar, radar is often required to scan a large field of view. Usually, the scanning module uses a wedge mirror to refract the light beam and is used in combination with a reflector to reflect the light beam. The wedge mirror and the reflector need to rotate around the axis to form a two-dimensional point cloud. However, when it is necessary to scan a larger pitch field angle, the bevel angle of the wedge mirror needs to be large. Correspondingly, the volume of the wedge mirror is also large, which can easily lead to poor dynamic balance of the wedge mirror, that is, the stability of the scanning module is poor. Utility Model Content

[0003] In view of this, the purpose of this application is to overcome the deficiencies in the prior art and to provide a scanning module and a scanning laser radar. By improving the scanning module of the laser radar, the stability of the scanning module can be improved and a larger pitch and field angle of view can be met for scanning.

[0004] This application provides the following technical solutions:

[0005] In a first aspect, an embodiment of the present application provides a scanning module, wherein the scanning module includes a refractive optical element, wherein the refractive optical element has a preset incident direction and a preset refractive direction, and wherein the refractive optical element includes:

[0006] A plane mirror, the plane mirror having an exit surface, the exit surface being provided with a metasurface such that the metasurface forms a refractive layer;

[0007] Alternatively, the exit surface is distributed with a micro-prism array, and the micro-prism array defines a refractive layer;

[0008] The refraction layer is used to refract a light beam incident along the preset incident direction, so that the light beam emerges along the preset refraction direction.

[0009] In some embodiments of the first aspect, the scanning module includes a refractive driving element, the plane mirror has an axis, the axis of the plane mirror extends along the preset incident direction, the plane mirror is connected to the refractive driving element, and the refractive driving element is used to drive the plane mirror to rotate around the axis of the plane mirror.

[0010] In some embodiments of the first aspect, the refraction driving element includes a refraction driving motor, a main shaft of the refraction driving motor is configured as a hollow shaft, an axis of the hollow shaft coincides with an axis of the plane mirror; wherein the plane mirror is disposed in the hollow shaft.

[0011] In some embodiments of the first aspect, the scanning module further includes a reflective optical element, wherein the reflective optical element includes a reflective prism, and the reflective prism is used to receive and reflect the light beam refracted by the refractive optical element.

[0012] In some embodiments of the first aspect, the scanning module also includes a reflection driving element and a counterweight element, wherein the reflection driving element is connected to the reflection prism, the reflection prism has an axis, the reflection driving element is used to drive the reflection prism to rotate around the axis of the reflection prism, and the counterweight element is connected to the reflection prism to adjust the dynamic balance of the reflection prism.

[0013] In some embodiments of the first aspect, the counterweight element is configured as a counterweight block, and the counterweight block is connected to the reflective prism.

[0014] In some embodiments of the first aspect, the number of the reflecting prisms is a pair, the reflecting prisms are right-angle reflecting prisms, the inclined surface of the reflecting prism is a reflecting surface, the reflecting surfaces of a pair of reflecting prisms are arranged opposite to each other, the pair of reflecting prisms are connected to each other and symmetrically arranged to form a regular quadrangular prism, the pair of reflecting prisms are arranged in sequence in the preset incident direction, the reflecting prism away from the plane mirror forms the counterweight, and the center line of the regular quadrangular prism is the axis of the reflecting optical element, and the center line of the regular quadrangular prism extends along the preset incident direction.

[0015] In some embodiments of the first aspect, the refractive optical element has an axis that coincides with the axis of the reflective optical element.

[0016] In some embodiments of the first aspect, the microprism array includes a plurality of right-angled triangular prisms, a right-angled surface of the right-angled triangular prism is a refractive incident surface, the inclined surface of the right-angled triangular prism is a refractive exit surface, the refractive incident surface is arranged parallel to the exit surface, and the plurality of right-angled triangular prisms are arranged in sequence along a direction parallel to the exit surface.

[0017] In a second aspect, the present application also provides a scanning laser radar, which includes a scanning module as described in any one of the above embodiments.

[0018] The embodiments of the present application have the following advantages:

[0019] The present application provides a scanning module, which can provide more stable performance because the flat mirror cooperates with the refractive layer to replace the large wedge mirror. By optimizing the design of the metasurface or microprism array, a larger range of beam steering can be achieved to meet the needs of a wide viewing angle, and the rotational stability is stronger. Compared with traditional mechanical scanning solutions, the design and manufacture of new optical elements may be simpler and more efficient. Of course, improving the dynamic balancing ability of the refractive optical element means lower wear rate and failure rate, thereby reducing the maintenance cost for long-term use. In addition, replacing the traditional wedge mirror can help reduce the size of the radar, that is, it is conducive to miniaturization.

[0020] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A schematic diagram of the structure of a scanning laser radar according to one embodiment of the present application is shown;

[0023] Figure 2 A schematic diagram of the structure of a scanning laser radar from another perspective provided by an embodiment of the present application is shown;

[0024] Figure 3 A schematic structural diagram of a scanning laser radar according to another embodiment of the present application is shown;

[0025] Figure 4 A schematic diagram showing the principle of a scanning laser radar provided by another embodiment of the present application is shown;

[0026] Figure 5 A schematic structural diagram of a refractive optical element of a scanning laser radar provided by another embodiment of the present application is shown;

[0027] Figure 6 A schematic diagram of a scanning point cloud trajectory of 0.1s of a scanning laser radar provided in another embodiment of the present application is shown;

[0028] Figure 7 A schematic diagram of a scanning point cloud trajectory of 0.2s of a scanning laser radar provided in another embodiment of the present application is shown.

[0029] Description of main component symbols:

[0030] 100-reflective driving element; 200-weight element; 300-reflective optical element; 400-refractive optical element; 410-refractive layer; 411-metasurface; 412-microprism array; 420-plane mirror; 500-refractive driving element; X-first preset reference line; Y-second preset reference line. DETAILED DESCRIPTION

[0031] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0032] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may also be a centered element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a centered element at the same time. In contrast, when an element is referred to as being "directly on" another element, there is no intermediate element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0033] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of the template are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0036] In the related art, with the development of LiDAR technology, there are various scanning methods for LiDAR. In the field of three-dimensional mapping and vehicle-mounted radar, radar is often required to scan a large field of view. Usually, the scanning module uses a wedge mirror to refract the light beam, and is used in combination with a reflector to reflect the light beam. The wedge mirror and the reflector need to rotate around the axis to form a two-dimensional point cloud. However, when it is necessary to scan a larger pitch field angle, the bevel angle of the wedge mirror needs to be large, and accordingly, the volume of the wedge mirror is also large, which easily leads to poor dynamic balance of the wedge mirror, that is, the stability of the scanning module is poor.

[0037] As shown in Figures 1, 2 and Figure 3 As shown, in order to solve the above technical problems, an embodiment of the present application provides a scanning module, which includes a refractive optical element 400, the refractive optical element 400 has a preset incident direction and a preset refractive direction, the refractive optical element 400 includes a plane mirror 420, the plane mirror 420 has an exit surface, the exit surface is provided with a metasurface 411, so that the metasurface 411 forms a refractive layer 410; or, the exit surface is distributed with a microprism array 412, the microprism array 412 is limited to form a refractive layer 410; wherein the refractive layer 410 is used to refract a light beam incident along a preset incident direction, so that the light beam is emitted along the preset refractive direction.

[0038] In these embodiments, the scanning module design provided by the present application is to solve the dynamic balance and stability problems encountered by the wedge-shaped mirror in the traditional laser radar system when scanning at a large angle pitch field of view. The scanning module achieves this by introducing a new refractive optical element 400, which can be in two specific forms:

[0039] The first type: plane mirror 420 combined with metasurface 411 In this configuration, plane mirror 420 is used as a substrate, and its exit surface is covered with metasurface 411 material. Metasurface 411 is a two-dimensional material composed of subwavelength-scale structures that can accurately control the propagation characteristics of light, such as phase, amplitude, and polarization. By adjusting the structure on metasurface 411, the light beam incident on the plane can be refracted at a preset angle, thereby changing the direction of the light beam. This method avoids the need to use large wedge mirrors and helps to improve the stability and reliability of the entire system.

[0040] Second method: microprism array 412 Another method is to distribute microprism array 412 on the exit surface of plane mirror 420. Microprism array 412 is composed of many tiny microprism units, each of which can independently refract the incident light. When the light beam is incident on these microprisms at a specific angle, the microprism will redirect the light so that it will be emitted along the preset refraction direction. This method also avoids the need to use a large wedge mirror, which helps to improve the stability and reliability of the entire system.

[0041] Exemplarily, the micro-prism units are spread over the plane mirror 420 and are arranged in the same posture, thereby controlling the refraction angle of the light beam.

[0042] It should be noted that the end face of the refractive layer 410 close to the plane mirror 420 is the refractive incident face, and the end face of the refractive layer 410 away from the plane mirror 420 is the refractive exit face. The light beam emitted from the inside will be refracted on the outer surface, so that the laser forms an angle θ with the incident light when it is emitted. As the wedge mirror rotates, the laser will generate a solid angle of 2θ, that is, there is a field of view of 2θ in the vertical direction.

[0043] For example, the angle θ is 10°, 20°, 30°, 40°, 50°, etc.

[0044] Therefore, since the plane mirror 420 cooperates with the refractive layer 410 to replace the large wedge mirror, more stable performance can be provided. By optimizing the design of the metasurface 411 or the microprism array 412, a larger range of beam steering can be achieved to meet the needs of a wide viewing angle, and the rotational stability is stronger. Compared with the traditional mechanical scanning solution, the design and manufacture of the new optical element may be simpler and more efficient. Of course, improving the dynamic balancing ability of the refractive optical element 400 means lower wear rate and failure rate, thereby reducing the maintenance cost of long-term use. In addition, replacing the traditional wedge mirror can help reduce the size of the radar, that is, it is conducive to miniaturization.

[0045] In some embodiments, the refractive layer 410 and the plane mirror 420 are made of different transparent materials, so that the light beam can be refracted when entering the refractive layer 410 from the plane mirror 420, which is further helpful to increase the pitch field angle.

[0046] Exemplarily, the plane mirror 420 is disposed horizontally, and the refractive layer 410 is disposed horizontally.

[0047] In some embodiments, the scanning module includes a refraction driving element 500, the plane mirror 420 has an axis, the axis of the plane mirror 420 extends along a preset incident direction, the plane mirror 420 is connected to the refraction driving element 500, and the refraction driving element 500 is used to drive the plane mirror 420 to rotate around the axis of the plane mirror 420.

[0048] In these embodiments, taking the plane mirror 420 as an example, the plane mirror 420 has an axis, and the plane mirror 420 is connected to the refraction driving element 500, that is, the plane mirror 420 is arranged on the refraction driving element 500, so that the refraction driving element 500 can drive the plane mirror 420 to rotate around the axis of the plane mirror 420 to achieve scanning in the horizontal plane. Figure 1 As shown, the axis of the plane mirror 420 and the second preset reference line Y are arranged to coincide with each other.

[0049] Exemplarily, the refractive layer 410 formed by the metasurface 411:

[0050] The plane mirror 420 is used as a substrate, and its exit surface is covered with a metasurface 411 material. Metasurface 411 is a two-dimensional material composed of sub-wavelength-scale structures. These tiny structures can accurately control the phase, amplitude and polarization state of the incident light. By configuring a specific structure on the metasurface 411, a high degree of control over the propagation path of the light beam can be achieved, so that the light beam is refracted in a preset direction.

[0051] Exemplarily, the refractive layer 410 defined by the microprism array 412:

[0052] The exit surface is provided with a microprism array 412, each microprism is a small optical element that can independently change the direction of light. When a light beam is incident on the microprism array 412 at a certain angle, the light beam is redirected according to its respective geometric shape and arrangement, thereby achieving the direction adjustment of the light beam.

[0053] Preset incident direction and preset refraction direction: Whether using the metasurface 411 or the microprism array 412, both solutions are intended to ensure that the light beam enters from a clear incident direction and leaves along another preset refraction direction after passing through the refractive layer 410. This means that the steering angle of the light beam can be precisely controlled by adjusting the design parameters of the metasurface 411 or the microprism array 412 (such as structural size, spacing, etc.).

[0054] Therefore, the refractive optical element 400 provided in the present application avoids the dynamic balance problem caused by the traditional wedge mirror and its rotation mechanism. Because the volume of the refractive light source element is reduced on the basis of being able to achieve a wide range of pitch field angles, and it is convenient to control the center of gravity of the refractive light source element, the mechanical stability of the entire system is significantly improved, especially when a wide range of pitch field angle scanning is required. Secondly, by optimizing the design of the metasurface 411 or the microprism array 412, the scanning module can have a wider viewing angle capability, which is very important for application scenarios such as three-dimensional mapping and vehicle-mounted laser radar, because it allows the device to obtain data points in a wider area.

[0055] Furthermore, compared with the traditional mechanical scanning solution, the design and manufacture of the novel refractive optical element 400 is simpler and more efficient. For example, the metasurface 411 can be made by photolithography in semiconductor processes, and the microprism array 412 can also be mass-produced by mold replication.

[0056] Also, better dynamic balancing performance means lower wear and failure rates, which not only reduces the need for regular maintenance, but also extends the service life of the equipment and reduces long-term maintenance costs.

[0057] like Figure 1 , Figure 2 and Figure 3 As shown, in some embodiments, the refraction driving element 500 includes a refraction driving motor, the main shaft of the refraction driving motor is set as a hollow shaft, the axis of the hollow shaft coincides with the axis of the plane mirror 420; wherein the plane mirror 420 is set in the hollow shaft.

[0058] In these embodiments, the refraction drive element 500 specifically includes a refraction drive motor, the main shaft of which is configured as a hollow shaft, and the axis of the hollow shaft completely coincides with the axis of the plane mirror 420. In addition, the plane mirror 420 is disposed inside the hollow shaft. This not only achieves precise control of the rotational motion of the plane mirror 420, but also optimizes the structural layout and performance of the system and reduces the size of the radar.

[0059] The consistency of the incident direction of the light beam and the center of rotation is ensured by aligning the axis of the hollow shaft of the refraction drive motor with the axis of the plane mirror 420. This helps to maintain the stability and accuracy of the light beam path and maintain good optical performance even at high-speed rotation.

[0060] The plane mirror 420 is placed inside the hollow shaft: Placing the plane mirror 420 inside the hollow shaft can reduce the impact of external environmental factors (such as vibration, temperature changes, etc.) on the plane mirror 420, while providing more installation space for other components (such as light sources or receivers), which helps to compact the design and reduce the size of the radar.

[0061] The refraction drive motor can provide precise and stable rotation torque, so that the plane mirror 420 can be controlled to rotate around its axis. Combined with the refraction function of the metasurface 411 or the microprism array 412, the direction of the light beam can be adjusted in a wider range to achieve a complex and precise scanning pattern.

[0062] Because of the direct motor drive method, the system can monitor and adjust the rotation angle in real time through the feedback mechanism, thereby ensuring that each light beam is emitted in accordance with the preset requirements.

[0063] Obviously, the design of placing the plane mirror 420 inside the hollow shaft saves space, making the entire scanning module more compact, which is conducive to integration into various application scenarios, especially for devices with limited size. The plane mirror 420 is located inside the hollow shaft, which reduces the possibility of being affected by the external environment and enhances the mechanical stability of the system. At the same time, the design of coinciding axes also helps to reduce the offset or jitter generated during the rotation process.

[0064] For example, in this embodiment, the inner hole of the hollow shaft is set to a round hole, and the plane mirror 420 is set to a round shape. Of course, in other embodiments, the inner hole of the hollow shaft is set to a square hole, and the plane mirror 420 is set to a square shape. Alternatively, the inner hole of the hollow shaft is set to a triangular hole, and the plane mirror 420 is set to a triangle, and so on.

[0065] like Figure 1 , Figure 2 and Figure 3 As shown, in some embodiments, the scanning module further includes a reflective optical element 300 , and the reflective optical element 300 includes a reflective prism, and the reflective prism is used to receive and reflect the light beam refracted by the refractive optical element 400 .

[0066] In these embodiments, the scanning module further optimizes the beam path control by introducing a reflective optical element 300, specifically a reflective prism. The reflective prism is used to receive and reflect the beam that has been processed by the refractive optical element 400 (such as a plane mirror 420 with a metasurface 411 or a microprism array 412). Figure 1 As shown, the axis of the reflecting prism and the first preset reference line X are arranged to coincide with each other.

[0067] The reflecting prism receives and reflects the refracted light beam. The reflecting prism is located behind the refractive optical element 400 and is responsible for receiving the light beam whose path has been changed by the refractive optical element 400 according to a preset direction and reflecting it to a new direction. It should be noted that the reflecting prism can also perform secondary refracting on the reflected light beam to expand the light path coverage and reduce the size of the reflecting prism.

[0068] The angle and position of the reflective prism can be configured according to specific application requirements to achieve secondary adjustments to the beam path to meet more complex scanning requirements.

[0069] Obviously, the overall path of the light beam is determined by the reflective prism and the refractive optical element 400. In some application scenarios, it is necessary to first change the direction of the light beam by refraction, and then use the reflective prism to further adjust its path to ensure that the light beam can cover a specific target area or form a desired scanning pattern.

[0070] When the refractive optical element 400 (such as the plane mirror 420) is driven by the refractive drive motor to rotate around the axis, the reflective prism can remain fixed or also perform corresponding translation or rotation movements. This combination of actions can achieve a more complex and flexible beam steering mode to meet different scanning requirements.

[0071] After the introduction of the reflective prism, the pitch field of view of the scanning module can be further expanded through additional reflection operations and secondary refraction operations. This is especially important for application scenarios that need to cover a larger area (such as 3D mapping, autonomous driving vehicles, etc.). The reflective prism can help the system cover target points within a larger angle range, improving scanning efficiency and coverage area.

[0072] It should be noted that if Figure 4 As shown, since the material of the reflecting prism is different from that of the air, a second refraction will occur when the light beam reflected by the reflecting prism enters the air, which is beneficial to increase the pitch field angle.

[0073] The presence of a reflective prism allows for more freedom in planning the beam path, helping to overcome some physical space limitations, such as avoiding obstacles or optimizing component layout. In addition, it can also help reduce unnecessary optical path length and improve the compactness and efficiency of the system. Reflective prisms usually have high reflectivity and refractive index, which can ensure that the beam intensity is not lost too much.

[0074] Exemplarily, the reflective prism is a right-angle prism, a roof prism, a pentagonal prism, or the like.

[0075] like Figure 1 , Figure 2 and Figure 3 As shown, in some embodiments, the scanning module also includes a reflection driving element 100 and a counterweight element 200. The reflection driving element 100 is connected to a reflection prism. The reflection prism has an axis. The reflection driving element 100 is used to drive the reflection prism to rotate around the axis of the reflection prism. The counterweight element 200 is connected to the reflection prism to adjust the dynamic balance of the reflection prism.

[0076] In these embodiments, the scanning module not only includes a refractive optical element 400 (such as a plane mirror 420 with a metasurface 411 or a microprism array 412), a refractive driving element 500 (such as a refractive driving motor), but also introduces a reflective driving element 100 and a counterweight element 200. The reflective driving element 100 is connected to the reflective prism and is used to drive the reflective prism to rotate around its axis; and the counterweight element 200 is arranged on the reflective prism to adjust its dynamic balance.

[0077] The reflection driving element 100 is connected to the reflection prism and is responsible for driving the reflection prism to perform precise rotational motion around its axis, so that after the light beam is refracted, it can also achieve more complex direction adjustment through the rotation of the reflection prism.

[0078] The weight element 200 is mounted on the reflective prism to compensate for uneven mass distribution of the reflective prism due to manufacturing errors or other factors, ensuring that the reflective prism maintains dynamic balance when rotating at high speed. This helps to reduce vibration and jitter and improve the mechanical stability of the system.

[0079] Obviously, by reasonably designing the position and mass of the weight element 200, the rotational inertia of the reflective prism can be optimized, making it smoother during starting, stopping and accelerating, thereby improving the response speed and efficiency of the system.

[0080] When the refractive optical element 400 is driven by the refractive drive motor to rotate around the axis, the reflective prism can also rotate independently or synchronously. This combined action can achieve a more complex and flexible beam steering mode to meet different scanning requirements.

[0081] It should be emphasized that the design of the weight element 200 significantly improves the dynamic balance of the reflective prism during rotation, reduces vibration and jitter, and improves the mechanical stability of the system. This is essential to ensure long-term stable performance, especially in the case of high-speed rotation, which is conducive to improving scanning quality.

[0082] Of course, in other embodiments, the reflection adjustment of the light beam can also be achieved by cooperating with multiple reflection prisms, and the number of reflection prisms is 2, 3, 4, 5 or 6, etc. Alternatively, the reflection light beam can be achieved by cooperating with a reflection prism and a plane reflection mirror.

[0083] like Figure 1 , Figure 2 and Figure 3 As shown, in some embodiments, the weight element 200 is configured as a weight block, and the weight block and the reflective prism are connected.

[0084] In these embodiments, the weight element 200 is specifically configured as a weight block, and the weight block is directly connected to the reflective prism. The main purpose of this design is to adjust the dynamic balance of the reflective prism through the distribution of physical mass, ensure that it remains stable during rotation, reduce vibration and jitter, and thus improve the mechanical stability and scanning accuracy of the system.

[0085] The counterweight is usually made of a material with a higher density, such as metal (e.g., lead, tungsten, etc.). Of course, it can also be made of transparent glass to ensure that sufficient mass can be provided in a smaller volume for effective dynamic balance adjustment.

[0086] As for the shape and size of the counterweight, it can be customized according to the specific structure and rotation characteristics of the reflective prism. For example, the counterweight is a simple geometric shape (such as a cylinder, a cuboid) or a complex shape that is optimized to best match the mass distribution of the reflective prism.

[0087] Exemplarily, the counterweight can be fixed to the reflective prism in a variety of ways, such as screw fastening, adhesive fixing or embedded installation. No matter which method is adopted, it must be ensured that the counterweight will not loosen or shift when the reflective prism rotates.

[0088] It should be noted that due to errors in the manufacturing process or other factors, the reflective prism may have uneven mass distribution. The role of the counterweight is to compensate for these unbalanced points by adding additional mass so that the entire reflective prism can maintain dynamic balance when rotating.

[0089] like Figure 1 , Figure 2 and Figure 3 As shown, in some embodiments, the number of the reflecting prisms is a pair, the reflecting prism is a right-angle reflecting prism, the inclined surface of the reflecting prism is a reflecting surface, the reflecting surfaces of a pair of reflecting prisms are arranged opposite to each other, a pair of reflecting prisms are connected to each other and symmetrically arranged to form a regular quadrangular prism, a pair of reflecting prisms are arranged in sequence in a preset incident direction, the reflecting prism facing away from the plane mirror 420 forms the counterweight, and the center line of the regular quadrangular prism is the axis of the reflecting optical element 300, and the center line of the regular quadrangular prism is extended along the preset incident direction.

[0090] In these embodiments, the reflective optical element 300 is configured as a pair of right-angle reflective prisms, the inclined surfaces of the two reflective prisms serve as reflective surfaces, and are arranged opposite to each other. The two reflective prisms are connected to each other and arranged symmetrically to form a regular quadrangular prism structure. One side of one of the reflective prisms facing away from the plane mirror 420 is designed as a counterweight to adjust the dynamic balance of the entire structure. Obviously, not only the beam path control is optimized, but also the mechanical stability and scanning accuracy of the system are improved.

[0091] In this embodiment, the reflecting prism is a right-angle reflecting prism. That is, each reflecting prism has a right angle of 90 degrees, that is, the reflecting prism has a right-angle surface and an inclined surface, and the inclined surface serves as a reflecting surface. When the light beam enters the first reflecting prism, it undergoes a total internal reflection and finally exits through one of the right-angle surfaces.

[0092] The inclined surfaces (reflecting surfaces) of the two reflecting prisms are arranged opposite to each other, ensuring that the inclined surfaces of the two reflecting prisms are as close as possible, that is, the gap between them is reduced, in preparation for subsequent dynamic balancing. Ideally, the inclined surfaces of the two reflecting prisms are arranged to fit together and fixed by gluing.

[0093] In addition, the two reflective prisms are connected and arranged symmetrically to form a regular quadrangular prism structure. This symmetry helps simplify the manufacturing process and ensures that the system maintains good dynamic balance when rotating.

[0094] Specifically, the center line of the regular quadrangular prism is not only the axis of the reflective optical element 300, but also extends along the preset incident direction, which ensures the consistency of the incident and reflected paths of the light beam and provides a stable rotation reference.

[0095] In order to adjust the dynamic balance of the entire structure, the reflecting prism far away from the plane mirror 420 is designed as a counterweight. This can be achieved by adding additional mass or selecting a material with a higher density to ensure that the entire regular quadrangular prism remains stable during rotation.

[0096] Obviously, the light beam first propagates along a preset incident direction, and is refracted by a refractive optical element 400, such as a plane mirror 420 with a metasurface 411 or a microprism array 412, so as to be emitted in a preset refraction direction.

[0097] Next, the light beam enters the first reflecting prism, undergoes the first reflection on its inclined surface, and can also be refracted when entering and exiting the first reflecting prism.

[0098] Finally, the light beam is emitted in a preset direction, completing the entire optical path adjustment.

[0099] It should be noted that two congruent reflecting prisms are used to adjust the dynamic balance of the reflecting prism during rotation, without the need to configure and set the counterweight element 200 separately, and the dynamic balance adjustment can be quickly achieved, thereby reducing the production cost. In addition, since the two reflecting prisms are congruent, that is, they are exactly the same, if one of the reflecting prisms is damaged, the positions of the two reflecting prisms can be swapped and the prisms can continue to be used.

[0100] like Figure 1 , Figure 2 and Figure 3 As shown, in some embodiments, the refractive optical element 400 has an axis that coincides with the axis of the reflective optical element 300 .

[0101] In these embodiments, the axes of the refractive optical element 400 (such as a plane mirror 420 with a metasurface 411 or a microprism array 412) and the reflective optical element 300 (a regular quadrangular prism structure composed of a pair of right-angle reflecting prisms) are designed to coincide with each other. This design ensures the consistency and stability of the beam path and further optimizes the overall performance of the system.

[0102] The coincidence of the axis of the refractive optical element 400 and the axis of the reflective optical element 300 means that the rotation centers of the two are completely consistent, which is beneficial to miniaturization of the radar.

[0103] The coincidence of the axes reduces the mechanical errors and vibrations caused by different axes, and improves the mechanical stability of the entire system and the accuracy of the beam path. This is especially important for applications that require high precision.

[0104] The axis of the refractive optical element 400 is consistent with the axis of the plane mirror 420, and the axis is extended along the preset incident direction. The hollow shaft of the refractive drive motor also coincides with it, ensuring that the plane mirror 420 can rotate without interfering with the optical path.

[0105] The reflective optical element 300 is composed of a pair of right-angle reflective prisms to form a regular quadrangular prism structure, whose axis also extends along the preset incident direction and coincides with the axis of the refractive optical element 400. The reflective prism facing away from the plane mirror 420 is used as a counterweight to adjust the dynamic balance.

[0106] Since the axes of the refractive optical element 400 and the reflective optical element 300 coincide, the light beam can maintain a highly consistent direction during the entire scanning process, avoiding deviations caused by different axes and improving the accuracy of the light beam path.

[0107] The coincidence of the axes significantly reduces mechanical errors and vibrations, and improves the mechanical stability of the system. Especially in the case of high-speed rotation, this design helps to maintain good dynamic balance and reduce unnecessary jitter.

[0108] like Figure 3 , Figure 4 and Figure 5 As shown, in some embodiments, the microprism array 412 includes a plurality of right-angled triangular prisms, a right-angled face of the right-angled triangular prism is a refractive incident face, the inclined face of the right-angled triangular prism is a refractive exit face, the refractive incident face is arranged parallel to the exit face, and the plurality of right-angled triangular prisms are arranged in sequence along a direction parallel to the exit face.

[0109] In these embodiments, the micro-prism array 412 is composed of a plurality of right-angled triangular prisms, a right-angled face of each right-angled triangular prism is used as a refraction incident face, and the inclined face is used as a refraction exit face. The refraction incident faces of these right-angled triangular prisms are arranged parallel to the exit face, and the plurality of right-angled triangular prisms are arranged in sequence along a direction parallel to the exit face. Exemplarily, the plane mirror 420 has a first direction, and the first direction is arranged parallel to the plane mirror 420.

[0110] A right-angled surface of each right-angled triangular prism serves as a refraction incident surface of the light beam, and the light beam enters the right-angled triangular prism through this refraction incident surface.

[0111] The inclined surface of the right-angled triangular prism serves as the refraction output surface of the light beam. After refraction, the light beam leaves the right-angled triangular prism from this refraction output surface.

[0112] The refraction incident surfaces of all right-angled triangular prisms are arranged parallel to the exit surface of the plane mirror 420, ensuring that the propagation path of the light beam in the entire array is consistent, thereby reducing the light path deviation caused by angle differences.

[0113] For example, among all the right-angled triangular prisms, any two right-angled triangular prisms are arranged adjacent to each other, and the adjacent right-angled triangular prisms are arranged in parallel to form a regular array structure, which is fully covered on the plane mirror 420, thereby ensuring that the light beam can be evenly distributed on the entire array.

[0114] Obviously, the refractive properties of each right-angled triangular prism determine the steering angle of the light beam. By precisely designing the angle and position of each prism, the final exit direction of the light beam can be controlled to meet different scanning requirements.

[0115] That is to say, by using a micro-prism array 412 composed of a plurality of right-angled triangular prisms, it is possible to achieve fine control over the beam path and improve the accuracy of beam steering.

[0116] It should be emphasized that the use of microprisms in conjunction with the plane mirror 420 can replace the traditional thicker wedge mirror, which can effectively improve the stability of the refractive optical element 400 during rotation and ensure high-quality imaging and measurement results.

[0117] In addition, the following tests are provided:

[0118] like Figure 6 As shown, this embodiment is a schematic diagram of the scanning point cloud trajectory of 0.1s;

[0119] like Figure 7 As shown, this embodiment is a schematic diagram of a scanning point cloud trajectory of 0.2s.

[0120] In some embodiments, the present application also provides a scanning laser radar, which includes a scanning module as described in any of the above embodiments.

[0121] Since the above-mentioned scanning module has the above-mentioned technical effects, the scanning laser radar including the scanning module should have the same technical effects, which will not be repeated here.

[0122] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not as limiting, and thus other examples of the exemplary embodiments may have different values.

[0123] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0124] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. A scanning module, comprising a refractive optical element, characterized in that: The refractive optical element has a preset incident direction and a preset refractive direction, and the refractive optical element comprises: A plane mirror, the plane mirror having an exit surface, the exit surface being provided with a metasurface such that the metasurface forms a refractive layer; Alternatively, the exit surface is distributed with a micro-prism array, and the micro-prism array defines a refractive layer; The refraction layer is used to refract a light beam incident along the preset incident direction, so that the light beam emerges along the preset refraction direction.

2. The scanning module according to claim 1, characterized in that: The scanning module includes a refractive driving element, the plane mirror has an axis, the axis of the plane mirror is extended along the preset incident direction, the plane mirror is connected to the refractive driving element, and the refractive driving element is used to drive the plane mirror to rotate around the axis of the plane mirror.

3. The scanning module according to claim 2, characterized in that: The refraction driving element comprises a refraction driving motor, the main shaft of the refraction driving motor is arranged as a hollow shaft, the axis of the hollow shaft coincides with the axis of the plane mirror; wherein the plane mirror is arranged in the hollow shaft.

4. The scanning module according to claim 1, characterized in that: The scanning module further includes a reflective optical element, which includes a reflective prism, and the reflective prism is used to receive and reflect the light beam refracted by the refractive optical element.

5. The scanning module according to claim 4, characterized in that: The scanning module also includes a reflection driving element and a counterweight element. The reflection driving element is connected to the reflection prism. The reflection prism has an axis. The reflection driving element is used to drive the reflection prism to rotate around the axis of the reflection prism. The counterweight element is connected to the reflection prism to adjust the dynamic balance of the reflection prism.

6. The scanning module according to claim 5, characterized in that: The counterweight element is configured as a counterweight block, and the counterweight block is connected to the reflective prism.

7. The scanning module according to claim 6, characterized in that: The number of the reflecting prisms is a pair, and the reflecting prisms are right-angle reflecting prisms. The inclined surface of the reflecting prism is a reflecting surface. The reflecting surfaces of a pair of reflecting prisms are arranged opposite to each other. The pair of reflecting prisms are connected to each other and are symmetrically arranged to form a regular quadrangular prism. The pair of reflecting prisms are arranged in sequence in the preset incident direction. The reflecting prism facing away from the plane mirror forms the counterweight block, and the center line of the regular quadrangular prism is the axis of the reflecting optical element. The center line of the regular quadrangular prism is extended along the preset incident direction.

8. The scanning module according to claim 7, characterized in that: The refractive optical element has an axis which coincides with the axis of the reflective optical element.

9. The scanning module according to claim 1, characterized in that: The micro-prism array includes a plurality of right-angled triangular prisms, a right-angled surface of the right-angled triangular prism is a refraction incident surface, the inclined surface of the right-angled triangular prism is a refraction exit surface, the refraction incident surface is arranged parallel to the exit surface, and the plurality of right-angled triangular prisms are arranged in sequence along a direction parallel to the exit surface.

10. A scanning laser radar, characterized in that: The scanning laser radar comprises a scanning module as described in any one of claims 1 to 9.

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