Multi-face rotating mirror, manufacturing method thereof, rotating mirror module and laser radar

Abstract

The embodiment of the invention discloses a multi-surface rotating mirror, a manufacturing method thereof, a rotating mirror module and a laser radar. The multi-surface rotating mirror comprises a rotating mirror main body and an extinction piece. The rotating mirror body is provided with at least three reflecting surfaces, and every two adjacent reflecting surfaces are connected with each other. Each reflecting surface comprises a first area and a second area, the first area is provided with a reflecting film, in the two mutually connected reflecting surfaces, the two second areas are mutually connected and are positioned between the two first areas, and one end, deviating from the connected first area, of each second area is not provided with a reflecting film. The second area is provided with a light extinction piece, and the light extinction piece is used for carrying out light extinction on light beams entering the second area. The first area is an exposed area in the reflecting surface, and the second area is a non-exposed area in the reflecting surface. According to the embodiment of the invention, the extinction piece is arranged in the second area of the reflecting surface, so that the light can be prevented from directly entering one end, which is not provided with the reflecting film, of the second area to generate a transversely-expanded accompanying light spot, and the point cloud quality of the laser radar is improved.

Description

Technical Field

[0001] This application relates to the technical field of lidar detection devices, and particularly to a multi-faceted rotating mirror, a manufacturing method thereof, a rotating mirror module, and a lidar. Background Art

[0002] In an optical system, stray light is caused by phenomena such as reflection, refraction, diffraction, and scattering of light during propagation, resulting in the light deviating from the expected optical path. The main sources of stray light are as follows: reflection on the surface of optical elements, scattering of light on structural components, and diffraction phenomena that may occur when light passes through an aperture or other structures, generating stray light.

[0003] For the lidar optical system, in order to ensure good ranging performance, since the echo energy returned by a distant target object is weak, the lidar uses a detector with high sensitivity to line light to capture these weak signals. Correspondingly, the lidar optical system is sensitive to internal stray light. Severe stray light will cause the lidar point cloud signal to form an expanded area around the edge of an object with a high reflectivity. This phenomenon can be called high-reflectivity expansion, which will affect the detection performance of the lidar. Using a rotating mirror for scanning is a common one-dimensional or two-dimensional scanning scheme in the current lidar field. Therefore, eliminating the stray light brought by the rotating mirror is extremely important in the design of such lidar optical systems. Summary of the Invention

[0004] In a lidar using a multi-faceted rotating mirror, when the light spot of the beam emitted by the laser falls on the edge of the rotating mirror, a relatively serious laterally expanded accompanying light spot will be generated, which affects the lidar point cloud. In related technologies, there is a solution to increase the size of the rotating mirror to prevent light from entering the edge of the rotating mirror, but this will cause an increase in the volume of the rotating mirror, and then lead to an increase in the volume of the lidar.

[0005] Embodiments of this application provide a multi-faceted rotating mirror, a manufacturing method thereof, a rotating mirror module, and a lidar, which are used to improve the deficiency that when the rotating mirror rotates to a large angle, that is, when the light spot of the beam emitted by the laser is incident on the edge of the multi-faceted rotating mirror, a relatively serious laterally expanded accompanying light spot will be generated, affecting the lidar point cloud quality.

[0006] In a first aspect, an embodiment of the present application provides a multi-faceted rotating mirror, which includes a rotating mirror body and an extinction member. The rotating mirror body has at least three reflecting surfaces, and the reflecting surfaces are arranged in an array around a first axis, and two adjacent reflecting surfaces are connected to each other. The reflecting surface includes a first region and a second region. A reflecting film is provided in the first region. Among the two reflecting surfaces that are connected to each other, the two second regions are connected to each other and are located between the two first regions. The second region is not provided with a reflecting film at one end facing away from the connected first region. An extinction member is provided in the second region, and the extinction member is used to extinguish the light beam incident on the second region. Wherein, the first region is the exposed region of the reflecting surface, and the second region is the non-exposed region of the reflecting surface.

[0007] In the multi-faceted rotating mirror according to the embodiment of the present application, an extinction member is provided in the second region of the reflecting surface, so that the extinction member can extinguish the light beam incident on the second region, and it can avoid the accompanying light spot with lateral expansion caused by the light beam directly incident on the end of the second region where there is no reflecting film, thereby improving the point cloud quality of the lidar. And the setting of the extinction member hardly affects the size of the multi-faceted rotating mirror and does not cause an increase in the volume of the lidar.

[0008] In a second aspect, an embodiment of the present application provides a multi-faceted rotating mirror, which includes a rotating mirror body. The rotating mirror body has at least three reflecting surfaces, and the reflecting surfaces are arranged in an array around a first axis. A transition surface connecting the two reflecting surfaces is provided between two adjacent reflecting surfaces of the rotating mirror body. A reflecting film is provided on the reflecting surface, and the reflecting film extends from one end of the reflecting surface close to the connected transition surface to the end of the reflecting surface away from the same transition surface. The transition surface is not provided with a reflecting film.

[0009] In the multi-faceted rotating mirror according to the embodiment of the present application, the transition surface is connected between the two reflecting surfaces, eliminating the sharp angle between the two reflecting surfaces. During the rotation of the multi-faceted rotating mirror, when the laser beam is incident on the edge region of the reflecting surface at a large incident angle, due to the elimination of the above-mentioned sharp angle, the laser beam will not be incident on the transition surface, so that the accompanying light spot with lateral expansion caused by the light beam incident on the end where there is no reflecting film can be improved, and the point cloud quality of the lidar can be improved. Among them, the transition surface can be formed by chamfering the multi-faceted rotating mirror, which can reduce the size of the multi-faceted rotating mirror.

[0010] In a third aspect, an embodiment of the present application provides a rotating mirror module, which includes the above-mentioned multi-faceted rotating mirror and a driving module. The driving module is connected to the multi-faceted rotating mirror, and the driving module is used to drive the multi-faceted rotating mirror to rotate around the first axis.

[0011] Fourth aspect, an embodiment of the present application provides a lidar, which includes a transceiver module and the above-mentioned polygon mirror module. The transceiver module includes a transmitter and a receiver. The transmitter is used to emit transmitted optical signals, and the receiver is used to receive reflected optical signals. The polygon mirror module is used to receive the transmitted optical signals and transmit the transmitted optical signals to the target object, and the polygon mirror module is also used to receive the reflected optical signals reflected from the target object and transmit the reflected optical signals to the receiver.

[0012] Fifth aspect, an embodiment of the present application provides a manufacturing method of a multi-faceted mirror, including:

[0013] Coating a reflective film on each first surface of the multi-faceted prism. Wherein, the multi-faceted prism has at least three first surfaces, and the first surfaces are arranged in an array around a first axis, and two adjacent first surfaces are connected to each other.

[0014] Cutting off the corners formed by connecting two adjacent first surfaces, so that the first surfaces provided with the reflective film form reflective surfaces, and a transition surface is formed between two adjacent reflective surfaces, and the reflective film is provided on the connecting edge of the reflective surface and the transition surface.

[0015] In the manufacturing method of the multi-faceted mirror according to the embodiment of the present application, the film is coated first and then the corners are cut, so that the reflective film is provided on the connecting edge of the reflective surface and the transition surface, which can avoid the accompanying light spots with lateral expansion caused by direct incidence of light on the edge, and improve the point cloud quality of the lidar. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to these drawings.

[0017] Figure 1 is a schematic structural diagram of a multi-faceted mirror provided by the first embodiment of the present application;

[0018] Figure 2 is Figure 1 an exploded structural diagram of the multi-faceted mirror shown;

[0019] Figure 3 is Figure 1 a top view structural diagram of the multi-faceted mirror shown;

[0020] Figure 4 is a top view structural diagram of a multi-faceted mirror provided by the second embodiment of the present application;

[0021] Figure 5It is a top - view structural schematic diagram of a multi - faceted rotating mirror provided by the third embodiment of the present application;

[0022] Figure 6 It is a top - view structural schematic diagram of a multi - faceted rotating mirror provided by the fourth embodiment of the present application;

[0023] Figure 7 It is a structural schematic diagram of a rotating mirror module provided by an embodiment of the present application;

[0024] Figure 8 It is a structural schematic diagram of a lidar provided by an embodiment of the present application;

[0025] Figure 9 It is another structural schematic diagram of a lidar provided by an embodiment of the present application;

[0026] Figure 10 It is a structural schematic diagram of a multi - faceted rotating mirror provided by the fifth embodiment of the present application;

[0027] Figure 11 It is Figure 10 An exploded structural schematic diagram of the multi - faceted rotating mirror shown;

[0028] Figure 12 It is Figure 10 A top - view structural schematic diagram of the multi - faceted rotating mirror shown;

[0029] Figure 13 It is a structural schematic diagram of a multi - faceted rotating mirror provided by the sixth embodiment of the present application;

[0030] Figure 14 It is Figure 13 An exploded structural schematic diagram of the multi - faceted rotating mirror shown;

[0031] Figure 15 It is a flowchart of the manufacturing method of the multi - faceted rotating mirror provided by an embodiment of the present application.

[0032] Description of reference numerals:

[0033] 1. Rotating mirror module;

[0034] 10. Multi - faceted rotating mirror;

[0035] 11. Rotating mirror body; 111. Reflective surface; 1111. First region; 1112. Second region; 1113. First sub - region; 1114. Second sub - region; 112. Transition surface; 113. Non - reflective surface;

[0036] 12. Extinction member;

[0037] 20. Driving module;

[0038] 2. Transceiving module; 21. Transmitter; 22. Receiver;

[0039] 3. Lidar

[0040] 4. Galvanometer

[0041] x. First axis; y. Second axis Detailed implementation manners

[0042] To make the objectives, technical solutions and advantages of this application clearer, the following will further describe in detail the embodiments of this application in conjunction with the accompanying drawings.

[0043] When the following description involves the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with this application. On the contrary, they are only examples of devices and methods consistent with some aspects of this application as detailed in the appended claims.

[0044] Embodiment 1

[0045] The embodiment of this application provides a multi-faceted rotating mirror, which includes a rotating mirror body and an extinction member. The rotating mirror body has at least three reflecting surfaces, and the reflecting surfaces are arranged in an array around the first axis, and two adjacent reflecting surfaces are connected to each other. The reflecting surface includes a first region and a second region. A reflecting film is provided in the first region. Among the two connected reflecting surfaces, the two second regions are connected to each other and are located between the two first regions. The second region is not provided with a reflecting film at one end facing away from the connected first region. An extinction member is provided in the second region, and the extinction member is used to extinguish the light beam incident on the second region. In this way, it is possible to avoid the accompanying light spot with lateral expansion caused by the direct incidence of light on the end of the second region without the reflecting film, and improve the point cloud quality of the lidar. And the setting of the extinction member hardly affects the size of the multi-faceted rotating mirror and does not cause an increase in the volume of the lidar.

[0046] In the first aspect, please refer to Figure 1 , the embodiment of this application provides a multi-faceted rotating mirror 10, where "multi-" is mostly used to modify a noun in terms of quantity, meaning more than two.

[0047] Refer to Figures 1 to 3, the multi-faceted rotating mirror 10 includes a rotating mirror body 11 and an extinction member 12. The rotating mirror body 11 has at least three reflecting surfaces 111, and the reflecting surfaces 111 are arranged in an array around a first axis x, and two adjacent reflecting surfaces 111 are connected to each other. The reflecting surface 111 includes a first region 1111 and a second region 1112. A reflecting film is provided in the first region 1111. Among the two reflecting surfaces 111 connected to each other, the two second regions 1112 are connected to each other and are located between the two first regions 1111. The second region 1112 is not provided with a reflecting film at one end facing away from the connected first region 1111. Among them, the above-mentioned first region 1111 is the exposed region of the reflecting surface 111, and the second region 1112 is the unexposed region of the reflecting surface 111. An extinction member 12 is provided in the second region 1112, and the extinction member 12 is used to extinguish the light beam incident on the second region 1112.

[0048] Here, taking the multi-faceted rotating mirror 10 made by plating a reflecting film on the side of a multi-faceted prism as an example, the specific structure of the multi-faceted rotating mirror 10 will be described in detail. During the process of plating a reflecting film on the multi-faceted prism to form a reflecting surface, since the edge of the multi-faceted prism is a sharp mutation part, it is difficult to completely coat the reflecting film, but there will be a non-coated region with a certain width; the existence of this non-coated region makes it that when a laser beam falls on it, complex optical phenomena such as scattering of the laser beam will occur, thus forming stray light. The second region of the above-mentioned reflecting surface 111 is a region including this non-coated region.

[0049] Setting the extinction member 12 in the second region 1112 of the reflecting surface 111 enables the extinction member 12 to extinguish the light beam incident on the second region 1112, avoiding the generation of laterally expanding accompanying light spots and stray light when light directly enters the end (the above-mentioned edge) of the second region 1112 where no reflecting film is provided, so as to improve the point cloud quality of the lidar 3. And the setting of the extinction member 12 hardly affects the size of the multi-faceted rotating mirror 10 and does not cause an increase in the volume of the lidar 3. Optionally, the extinction member 12 includes at least one of extinction flannel, extinction glue, and extinction coating; among them, the extinction flannel can be connected to the rotating mirror body 11 by bonding or other means; the extinction glue has adhesiveness and can be directly bonded to the rotating mirror body 11; the extinction coating can be attached to the rotating mirror body 11 through processes such as coating. Of course, the extinction member 12 can also be any other component with an extinction function, and the present application does not limit this.

[0050] In some embodiments, the fact that the second region 1112 is not provided with a reflecting film at one end facing away from the connected first region 1111 can be: Refer to Figures 1 to 3, the second region 1112 is not provided with a reflective film as a whole. At this time, the light extinction member 12 just covers the region without the reflective film, which can save the amount of the light extinction member 12 and reduce the material cost. In some other embodiments, the situation that the second region 1112 is not provided with a reflective film at one end facing away from the connected first region 1111 can be: Refer to Figure 4 , the first sub-region 1113 of the second region 1112 close to the connected first region 1111 is provided with a reflective film, while the second sub-region 1114 of the second region 1112 facing away from the connected first region 1111 is not provided with a reflective film. At this time, the light extinction member 12 covers both the second sub-region 1114 without the reflective film and the first sub-region 1113 with the reflective film; compared with the situation that the light extinction member 12 just covers the region without the reflective film, this solution can reduce the setting difficulty of the light extinction member 12 and improve the production efficiency of the multi-faceted rotating mirror 10.

[0051] In summary, when setting the light extinction member 12, the light extinction member 12 may just cover the region of the reflecting surface 111 without the reflective film. When setting the light extinction member 12, the light extinction member 12 may also invade the region of the reflecting surface 111 with the reflective film in addition to covering the region of the reflecting surface 111 without the reflective film. In the embodiments of the present application, the region where the light extinction member 12 is set on the reflecting surface 111 corresponds to the second region 1112 of the reflecting surface 111, and the region where the light extinction member 12 is not set on the reflecting surface 111 corresponds to the first region 1111 of the reflecting surface 111.

[0052] The above-mentioned rotating mirror body 11 includes at least three reflecting surfaces 111, and each reflecting surface 111 includes a second region 1112. Thus, the rotating mirror body 11 includes a plurality of second regions 1112.

[0053] In some embodiments, among the plurality of second regions 1112 of the rotating mirror body 11, all the second regions 1112 are not provided with a reflective film as a whole. In some other embodiments, among the plurality of second regions 1112 of the rotating mirror body 11, some of the second regions 1112 are not provided with a reflective film as a whole, while the remaining second regions 1112 are provided with a reflective film in the first sub-region 1113 and not provided with a reflective film in the second sub-region 1114. In still some other embodiments, among the plurality of second regions 1112 of the rotating mirror body 11, all the second regions 1112 are provided with a reflective film in the first sub-region 1113 and not provided with a reflective film in the second sub-region 1114.

[0054] In some embodiments, when setting the light extinction member 12 on the rotating mirror body 11, it is necessary to first determine the boundary line between the region with the reflective film and the region without the reflective film on the same reflecting surface 111. The light extinction member 12 is set based on the boundary line between the region with the reflective film and the region without the reflective film on the same reflecting surface 111, so that the light extinction member 12 can at least cover the region without the reflective film, so as to extinguish the light beam incident on the region without the reflective film through the light extinction member 12.

[0055] Among them, the operation of setting the light extinction member 12 on the rotating mirror body 11 can be carried out manually or by an automated device, and this is not limited. For example, in some embodiments, a microscope with visible light supplementary lighting is used to observe the boundary line between the region with the reflective film and the region without the reflective film on the same reflecting surface 111. Specifically, under the irradiation of visible light, the region without the reflective film is similar to frosted glass, which will diverge the visible light so that it can be observed in the microscope; while the region with the reflective film will specularly reflect the visible light to other positions and is not easy to observe the high-brightness effect in the microscope. In this way, the boundary line between the region with the reflective film and the region without the reflective film on the same reflecting surface 111 can be determined. Another example is that in some other embodiments, the boundary line between the region with the reflective film and the region without the reflective film on the same reflecting surface 111 is roughly determined by the production process of the rotating mirror body 11. In the same production process, the boundary line between the region with the reflective film and the region without the reflective film on the same reflecting surface 111 of the rotating mirror body 11 is usually stable, and the boundary line between the region with the reflective film and the region without the reflective film on the same reflecting surface 111 can be directly determined. At this time, an automated device can be used to set the light extinction member 12 so that the light extinction member 12 can at least cover the region without the reflective film.

[0056] Regarding the width of the second region 1112, please refer to Figure 3 and Figure 4, in the same reflecting surface 111, along the width direction of the reflecting surface 111, the ratio of the width W1 of the first region 1111 to the width W2 of the second region 1112 is greater than 20. Wherein, the width direction of the reflecting surface 111 is the direction from one of the first region 1111 and the second region 1112 to the other in the same reflecting surface 111. In the above design, the ratio of the width W1 of the first region 1111 to the width W2 of the second region 1112 being greater than 20 can ensure that in the same reflecting surface 111, the proportion of the width of the first region 1111 is sufficient, so that the first region 1111 in the reflecting surface 111 can provide a larger scanning range and ensure the ranging performance of the lidar 3. For example, in some embodiments, in the same reflecting surface 111, along the width direction of the reflecting surface 111, the ratio of the width W1 of the first region 1111 to the width W2 of the second region 1112 can be 20, 25, 30, 35, 40, 45, etc., and no limitation is made thereto. By reasonably designing the ratio of the width W1 of the first region 1111 to the width W2 of the second region 1112, it is possible to ensure that the width of the second region 1112 is not too small on the basis of ensuring that the proportion of the width of the first region 1111 is sufficient, so as to set the extinction member 12.

[0057] In addition, please refer to Figure 4 , along the width direction of the reflecting surface 111, the ratio of the width W2 of the second region 1112 to the width W 21 of the region (second sub-region 1114) in the second region 1112 where no reflective film is provided is between 1.1 and 1.3. In this way, in the second region 1112, the width of the second sub-region 1114 where no reflective film is provided is relatively large compared to the width of the first sub-region 1113 where a reflective film is provided, reducing the intrusion of the extinction member 12 provided in the second region 1112 into the region of the reflecting surface 111 where a reflective film is provided, ensuring that the first region 1111 in the reflecting surface 111 can provide a larger scanning range and ensuring the ranging performance of the lidar 3. For example, in some embodiments, along the width direction of the reflecting surface 111, the ratio of the width W2 of the second region 1112 to the width W 21 of the region (second sub-region 1114) in the second region 1112 where no reflective film is provided can be 1.1, 1.15, 1.2, 1.25, 1.3, etc., and no limitation is made thereto.

[0058] In some embodiments, refer to Figures 1 to 4, along the direction of surrounding the first axis x, the reflecting surfaces 111 of the rotating mirror body 11 are sequentially connected in a closed shape. In this way, when the polygonal rotating mirror 10 is applied to the lidar 3, the polygonal rotating mirror 10 can rotate 360° around the first axis x, and during the process of the polygonal rotating mirror 10 rotating 360° around the first axis x, there will always be a reflecting surface 111 for beam scanning, which can simplify the control process of the polygonal rotating mirror 10. It can be understood that if the reflecting surfaces 111 of the rotating mirror body 11 are sequentially connected in a closed shape, then along the direction of surrounding the first axis x, both sides of each reflecting surface 111 are connected to the reflecting surfaces 111. In this way, each reflecting surface 111 includes two second regions 1112. Along the direction of surrounding the first axis x, in the same reflecting surface 111, the two second regions 1112 are located on the opposite sides of the first region 1111; among two adjacent reflecting surfaces 111, the two second regions 1112 are located between the two first regions 1111. Correspondingly, the polygonal rotating mirror 10 includes a plurality of extinction members 12, and each extinction member 12 covers two adjacent second regions 1112; wherein, the specific number of the extinction members 12 can be adaptively changed according to the number of the reflecting surfaces 111; of course, in other embodiments, each extinction member 12 can also cover only one second region 1112.

[0059] For example, in some embodiments, referring to Figures 1 to 4 , the rotating mirror body 11 may include three reflecting surfaces 111 sequentially connected in a closed shape, and the included angle between two adjacent reflecting surfaces 111 is 60 degrees; correspondingly, the polygonal rotating mirror 10 includes three extinction members 12. At this time, the sizes of the reflecting surfaces 111 of the rotating mirror body 11 are substantially similar, and the scanning ranges corresponding to the reflecting surfaces 111 are substantially similar, which can reduce the data processing difficulty of the lidar 3.

[0060] It should be noted that the rotating mirror body 11 may also include four, five, six, seven reflecting surfaces 111, etc. The number of reflecting surfaces 111 included in the rotating mirror body 11 can be flexibly designed according to actual needs, and no limitation is made thereto.

[0061] In other embodiments, referring to Figure 5 and Figure 6 , along the direction of surrounding the first axis x, a plurality of reflecting surfaces 113 of the rotating mirror body 11 are connected, and the rotating mirror body 11 may also have a non-reflecting surface 113; along the direction of surrounding the first axis x, the non-reflecting surface 113 is connected between the two reflecting surfaces 111 located on the side among the plurality of reflecting surfaces 111, and the non-reflecting surface 113 is not provided with a reflective film and is not used for reflecting laser beams. For example, in some embodiments, referring to Figure 5 , the non-reflecting surface 113 may include one or more planes. Among them, if the non-reflecting surface 113 includes a plurality of planes, each adjacent two planes among the plurality of planes are arranged at an included angle. Also for example, in other embodiments, referring toFigure 6 , the non-reflective surface 113 may include an arc surface. In some other embodiments, the non-reflective surface 113 includes both a flat surface and an arc surface, and this is not limited.

[0062] If the rotating mirror body 11 includes a non-reflective surface 113, when the multi-faceted rotating mirror 10 is used in the lidar 3, the multi-faceted rotating mirror 10 can be controlled to reciprocally rotate within a preset angular range around the first axis x, where the preset angular range can be equal to the sum of the central angles corresponding to all the reflective surfaces 111 on the multi-faceted rotating mirror 10. When the multi-faceted rotating mirror 10 rotates within the preset angular range around the first axis x, all the reflective surfaces 111 can receive and scan the light beam, and the non-reflective surface 113 will not rotate to the area where the light beam arrives and will not process the light beam. Of course, the multi-faceted rotating mirror 10 can also be controlled to perform a 360° cyclic rotation around the first axis x, and by controlling the light emission timing of the emitter, the emitter emits light when the reflective surface 111 is on the light emission path, and the emitter does not emit light when the non-reflective surface 113 is on the light emission path.

[0063] It can be understood that along the direction of surrounding the first axis x, if both sides of a reflective surface 111 are connected to the reflective surface 111, then this reflective surface 111 has two second regions 1112, and along the direction of surrounding the first axis x, in the same reflective surface 111, the two second regions 1112 are located on opposite sides of the first region 1111. And along the direction of surrounding the first axis x, if a reflective surface 111 is only connected to the reflective surface 111 on one side and is connected to the non-reflective surface 113 on the other side, then this reflective surface 111 has one second region 1112.

[0064] In some embodiments, if the same reflective surface 111 has two second regions 1112, in the same reflective surface 111, along the width direction of the reflective surface 111, the widths W2 of the two second regions 1112 can be approximately equal, and reference can be made to Figure 3 and Figure 4 . In some other embodiments, if the same reflective surface 111 has two second regions 1112, in the same reflective surface 111, along the width direction of the reflective surface 111, the widths W2 of the two second regions 1112 can be unequal, and this is not limited.

[0065] In some embodiments, referring to Figure 1 and Figure 2 , all the reflective surfaces 111 of the multi-faceted rotating mirror 10 extend along the first axis x direction. At this time, the rotating mirror body 11 can be formed by coating a reflective film on a multi-faceted prism. In some other embodiments, the extending directions of all the reflective surfaces 111 of the multi-faceted rotating mirror 10 are arranged at an angle with the first axis x. Further, the angles between the extending directions of all the reflective surfaces 111 of the multi-faceted rotating mirror 10 and the first axis x can be approximately equal. At this time, the rotating mirror body 11 can be formed by coating a reflective film on a multi-faceted frustum.

[0066] It should be noted that even though this embodiment is described by taking the multi-faceted rotating mirror 10 made by plating a reflective film on a multi-faceted prism as an example, the present application is not limited thereto. In other embodiments of the present application, the multi-faceted rotating mirror may also include a rotating mirror base body and be mounted on the rotating mirror base body by means of patching. Among them, the reflective surface of each lens is equivalent to the reflective surface in the above embodiment.

[0067] In a second aspect, referring to Figure 7 , an embodiment of the present application provides a rotating mirror module 1. The rotating mirror module 1 includes the above-mentioned multi-faceted rotating mirror 10 and a driving module 20. The driving module 20 is connected to the multi-faceted rotating mirror 10, and the driving module 20 is used to drive the multi-faceted rotating mirror 10 to rotate around the first axis x.

[0068] In some embodiments, the driving module 20 may include a stator and a rotor. The rotor is connected to the multi-faceted rotating mirror 10, and the rotor can rotate relative to the stator around the first axis x, thereby driving the multi-faceted rotating mirror 10 to rotate around the first axis x. Among them, one of the stator and the rotor may include a coil, and the other may include a magnet, etc., which is not limited thereto.

[0069] In some embodiments, at least a part of the driving module 20 may extend into the multi-faceted rotating mirror 10 to reduce the size of the rotating mirror module 1.

[0070] In a third aspect, referring to Figure 8 , an embodiment of the present application provides a lidar 3. The lidar 3 includes a transceiver module 2 and the above-mentioned rotating mirror module 1. The transceiver module 2 includes a transmitter 21 and a receiver 22. The transmitter 21 is used to emit a transmitted optical signal, and the receiver 22 is used to receive a reflected optical signal. The rotating mirror module 1 is used to receive the transmitted optical signal and transmit the transmitted optical signal to the target object. The rotating mirror module 1 is also used to receive the reflected optical signal reflected by the target object and transmit the reflected optical signal to the receiver 22.

[0071] The present application provides an extinction member 12 in the second region 1112 of the reflective surface 111 of the rotating mirror module 1, so that the extinction member 12 can extinguish the light beam incident on the second region 1112, avoiding the generation of a laterally expanding accompanying light spot when the light directly enters one end of the second region 1112 where no reflective film is provided, and improving the point cloud quality of the lidar 3.

[0072] In some embodiments, referring to Figure 9, the lidar 3 further includes a galvanometer 4. Along the transmission path of the emitted optical signal, the galvanometer 4 is located downstream of the emitter 21 and upstream of the rotating mirror module 1. Along the transmission path of the reflected optical signal, the galvanometer 4 is located downstream of the rotating mirror module 1 and upstream of the receiver 22. Wherein, the galvanometer 4 has a second reflecting surface, and the galvanometer 4 can rotate around a second axis y, and the second axis y is perpendicular to the first axis x. The combination of the galvanometer 4 and the rotating mirror module 1 can realize the scanning of two mutually perpendicular field of view ranges, improving the scanning range of the lidar 3.

[0073] Embodiment 2

[0074] Refer to Figures 10 to 12 , the difference between the multi-faceted rotating mirror 10 in this embodiment and the multi-faceted rotating mirror 10 in Embodiment 1 is that: in this embodiment, a transition surface 112 connecting the two reflecting surfaces 111 is provided between two adjacent reflecting surfaces 111 of the rotating mirror body 11. A reflecting film is provided on the reflecting surface 111, and no reflecting film is provided on the transition surface 112. The reflecting film extends from one end of the reflecting surface 111 close to the connected transition surface 112 to the other end of the reflecting surface 111 facing away from the same transition surface 112.

[0075] It should be noted that, compared with the previous embodiment in which an extinction member is provided to cover the second region of the multi-faceted rotating mirror, the transition surface 112 in the embodiment of the present application is connected between the two reflecting surfaces 111, eliminating the sharp corner between the two reflecting surfaces. During the rotation of the multi-faceted rotating mirror 10, when the laser beam is incident on the edge region of the reflecting surface 111 at a large incident angle, due to the elimination of the above-mentioned sharp corner, the laser beam will not be incident on the transition surface 112, thereby improving the lateral expansion of the accompanying light spot generated when the light is incident on the end without the reflecting film, and improving the point cloud quality of the lidar 3.

[0076] Wherein, the reflecting film extends from one end of the reflecting surface 111 close to the connected transition surface 112 to the other end of the reflecting surface 111 facing away from the same transition surface 112, so that the reflecting surface 111 has a reflecting film on the side line connected to the transition surface 112, avoiding the lateral expansion of the accompanying light spot generated by the direct incidence of light on the side line.

[0077] In some embodiments, the transition surface 112 can be formed by chamfering the multi-faceted rotating mirror 10. Specifically, the transition surface 112 can be formed by chamfering the portion without a reflective film after a reflective film is provided on the reflective surface 111, so that the reflective surface 111 has a reflective film on the side line connected to the transition surface 112, avoiding direct incidence of light onto the side line and generating accompanying light spots with lateral expansion. For example, when forming the transition surface 112 by chamfering, the boundary line between the area with a reflective film and the area without a reflective film in the same reflective surface 111 can be first determined, and then chamfering can be performed based on the boundary line between the area with a reflective film and the area without a reflective film in the same reflective surface 111. Among them, the determination of the boundary line between the area with a reflective film and the area without a reflective film in the same reflective surface 111 can be determined by microscopic observation with visible light supplementary lighting as described in Embodiment 1, determined by the production process of the rotating mirror body 11, etc., which will not be elaborated here.

[0078] In some embodiments, the ratio of the width W4 of the transition surface 112 to the width W3 of the reflective surface 111 is less than 1 / 10. In this way, it can ensure that the width ratio of the reflective surface 111 is sufficient, providing a larger scanning range and ensuring the ranging performance of the lidar 3. For example, the ratio of the width W4 of the transition surface 112 to the width W3 of the reflective surface 111 can be 1 / 20, 1 / 17, 1 / 15, 1 / 12, 1 / 10, etc., which is not limited herein. By reasonably designing the ratio of the width W4 of the transition surface 112 to the width W3 of the reflective surface 111, it can ensure that the width ratio of the reflective surface 111 is sufficient and at the same time make the width of the transition surface 112 not too small, facilitating the formation of the transition surface 112.

[0079] In some embodiments, the angles between the transition surface 112 and the two adjacent reflective surfaces 111 are approximately equal. In other embodiments, the angles between the transition surface 112 and the two adjacent reflective surfaces 111 are not equal, which is not limited herein.

[0080] Since the same transition surface 112 may cross the direction of the laser beam propagation twice. Among them, when the laser beam is incident on the area where the transition surface 112 is located at a large angle, it will not fall on the transition surface 112, thus achieving the above effect of reducing the risk of generating stray light; but when the laser beam is incident on the area where the transition surface 112 is located at a small angle, it may cause the laser beam to be reflected in the approximate original incident optical path, affecting the operation of the transceiver module of the lidar. Based on this, please refer to Figure 13 and Figure 14, in some embodiments, the multi-faceted rotating mirror 10 further includes an extinction member 12 disposed on the transition surface 112. The extinction member 12 is configured to extinguish the light beam incident on the transition surface 112. The setting of the extinction member 12 performs an extinction process on the laser beam when the laser beam is incident on the area where the transition surface 112 is located at a small angle, so as to reduce the risk that the above-mentioned laser beam is reflected along the approximate original incident optical path and affects the operation of the transceiver module 2 of the lidar 3.

[0081] In summary, the multi-faceted rotating mirror 10 provided by the embodiments of the present application can also improve the problem that when the multi-faceted rotating mirror 10 rotates to a large angle, that is, the angle at which the laser spot can be incident on the edge of the prism, a relatively serious laterally extended accompanying spot will be generated, which affects the point cloud of the lidar.

[0082] Refer to Figure 15 , the embodiments of the present application also provide a manufacturing method of a multi-faceted rotating mirror 10, including:

[0083] Step S02, coating a reflective film on each first surface of the multi-faceted prism. First, provide a multi-faceted prism having a plurality of side surfaces. Specifically, the multi-faceted prism has at least three first surfaces, and the first surfaces are arranged in an array around the first axis x, and two adjacent first surfaces are connected to each other. Then, using the coating process in related technologies, coat a reflective film on each of the above first surfaces so that the multi-faceted prism has the function of reflecting laser beams. It should be noted that since a sharp corner is formed between two adjacent first surfaces, this sharp corner is not conducive to the attachment of the coating material during the coating process. Therefore, an uncoated area will be formed in the adjacent area between the two first surfaces.

[0084] Step S04, cut off the corners formed by connecting two adjacent first surfaces so that the first surfaces provided with the reflective film form reflective surfaces 111, and a transition surface 112 is formed between two adjacent reflective surfaces 111. The reflective surface 111 has a reflective film on the connecting line with the transition surface 112. After the coating of the multi-faceted prism is completed, use a material removal process to cut off the corners formed by two adjacent first surfaces to eliminate the above uncoated area, so that the reflective surface has a reflective film on the connecting line with the transition surface 112; wherein, the reflective surface is the surface of the first surface after removing the above corners. In this way, specular reflection can occur when the laser beam is reflected on the entire reflective surface, and when the laser beam is incident on the original corners at a large angle, it may not fall on the multi-faceted rotating mirror due to the elimination of the corners, so no stray light will be formed.

[0085] The manufacturing method of the multi-faceted rotating mirror 10 in the embodiments of the present application first coats the film and then cuts the corners, so that the reflective surface 111 has a reflective film on the connecting line with the transition surface 112, which can avoid the generation of laterally extended accompanying spots when the light is directly incident on the connecting line, and improve the point cloud quality of the lidar 3.

[0086] In the description of the present application, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances. In addition, in the description of the present application, unless otherwise specified, "a plurality of" means at least two, for example, two, three, four, etc. "And / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0087] The above-disclosed are only the preferred embodiments of the present application, and of course, the scope of rights of the present application cannot be limited thereby. Therefore, equivalent changes made according to the claims of the present application still fall within the scope covered by the present application.

Claims

1. A multi-faceted rotating mirror, characterized in that, The multi-faceted rotating mirror includes: A rotating mirror body having at least three reflecting surfaces. The reflecting surfaces are arranged in an array around a first axis, and adjacent reflecting surfaces are connected to each other. The reflecting surface includes a first region and a second region. A reflecting film is provided in the first region. Among two adjacent reflecting surfaces that are connected to each other, the two second regions are connected to each other and are located between the two first regions. The second region is not provided with a reflecting film at one end facing away from the connected first region; and An extinction member. The extinction member is provided in the second region, and the extinction member is used to extinguish the light beam incident on the second region; The first region is the exposed region of the reflecting surface, and the second region is the non-exposed region of the reflecting surface.

2. The multi-faceted rotating mirror according to claim 1, characterized in that, The multi-faceted rotating mirror includes a plurality of extinction members, and each extinction member covers two adjacent second regions.

3. The multi-faceted rotating mirror according to claim 1, characterized in that, The extinction member includes at least one of extinction velvet, extinction glue, and an extinction coating.

4. The multi-faceted rotating mirror according to claim 1, characterized in that, In the same reflecting surface, along the width direction of the reflecting surface, the ratio of the width of the first region to the width of the second region is greater than 20; Wherein, the width direction of the reflecting surface is the direction from one of the first region and the second region of the same reflecting surface to the other.

5. The multi-faceted rotating mirror according to claim 1, characterized in that, Along the width direction of the reflecting surface, the ratio of the width of the second region to the width of the region in the second region where no reflecting film is provided is between 1.1 and 1.3; Wherein, the width direction of the reflecting surface is the direction from one of the first region and the second region of the same reflecting surface to the other.

6. The multi-faceted rotating mirror according to claim 1, characterized in that, Along the direction around the first axis, the reflecting surfaces are sequentially connected in a closed shape; The rotating mirror body includes three reflecting surfaces, and the angle between two adjacent reflecting surfaces is 60 degrees; The rotating mirror body is made by providing a reflecting film on a multi-faceted prism.

7. A multi-faceted rotating mirror, characterized in that, The multi-faceted rotating mirror includes a rotating mirror body; The rotating mirror body has at least three reflecting surfaces. The reflecting surfaces are arranged in an array around a first axis. The rotating mirror body is provided with a transition surface connecting the two reflecting surfaces between two adjacent reflecting surfaces. The reflecting surface is provided with a reflecting film, and the transition surface is not provided with a reflecting film. The reflecting film extends from one end of the reflecting surface close to the connected transition surface to the other end of the reflecting surface facing away from the same transition surface.

8. The multi-faceted rotating mirror according to claim 7, characterized in that, The ratio of the width of the transition surface to the width of the reflecting surface is less than 1 / 10.

9. The multi-faceted rotating mirror according to claim 7, characterized in that, It further includes an extinction member; The extinction member is provided on the transition surface, and the extinction member is used to extinguish the light beam incident on the transition surface.

10. A rotating mirror module, characterized in that, It includes: The multi-faceted rotating mirror according to any one of claims 1 to 9; And A driving module connected to the multi-faceted rotating mirror, and the driving module is used to drive the multi-faceted rotating mirror to rotate around the first axis.

11. A lidar, characterized in that, It includes: A transceiver module. The transceiver module includes a transmitter and a receiver. The transmitter is used to emit an optical signal, and the receiver is used to receive an echo optical signal; And The rotating mirror module according to claim 10. The rotating mirror module is used to receive the emitted optical signal and transmit the emitted optical signal to a target object. The rotating mirror module is further used to receive the echo optical signal reflected by the target object and transmit the echo optical signal to the receiver.

12. A manufacturing method of a multi-faceted rotating mirror, characterized in that, Including: Coating a reflective film on each first surface of a multi-faceted prism, wherein the multi-faceted prism has at least three of the first surfaces, and the first surfaces are arranged in an array around a first axis, and adjacent first surfaces are connected to each other; Cutting off the corners formed by connecting two adjacent first surfaces so that the first surface provided with the reflective film forms a reflective surface, and a transition surface is formed between two adjacent reflective surfaces, and the reflective film is provided on the connecting edge of the reflective surface and the transition surface.

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