A laser scanning system

Abstract

A laser scanning system includes an emitting device, a transmitting device, a first rotating mirror device, an optical path shaping device, a second rotating mirror device, and a receiving device. The optical path shaping device can directly reflect a first beam propagating on the same horizontal plane into multiple third beam surfaces propagating in different horizontal planes. The key to this application is that, through the combined action of the first rotating mirror device and the optical path shaping device, the single probe beam emitted by the emitting device is converted into multiple third scanning beams propagating in different horizontal planes, completely replacing the function of the galvanometer device in the prior art. Therefore, the laser scanning system can achieve surface scanning without a galvanometer motor, eliminating the limitations imposed by the galvanometer motor on the stability and lifespan of the entire laser scanning system. This significantly improves the stability and lifespan of the laser scanning system of this invention. It also reduces the regularity of the galvanometer's accelerated oscillation damage, resulting in a more uniform point cloud map.

Description

Technical Field

[0001] This invention relates to the field of optical scanning technology, and more specifically to a laser scanning system. Background Technology

[0002] LiDAR is a system that uses laser light to detect the distance, position, and / or velocity of a target object. Its working principle involves emitting a detection beam towards the target, then comparing the received echo light reflected from the target with the detection beam through photoelectric conversion to obtain information about the target, such as one or more parameters including distance, azimuth, altitude, velocity, attitude, and even shape. This allows for the detection, tracking, and / or identification of the target.

[0003] As is well known, most commonly used lidar systems rely on a galvanometer device. For example, the lidar disclosed in Chinese invention patent CN115657051A includes a transmitting device, a galvanometer device, and a rotating mirror device. The transmitting device emits a detection beam and retrieves and detects the echo beam. The galvanometer device includes a galvanometer motor and a reflector connected to the galvanometer motor. The reflector is positioned facing the transmitting device and the rotating mirror device to redirect the light beam propagation between them. Horizontally, the transmitting device is located between the galvanometer motor and the rotating mirror device. It should be understood that in the lidar field, the galvanometer device and the rotating mirror device together constitute the lidar's scanning module. The laser beam emitted by the transmitting device first reaches the galvanometer device, is reflected within the galvanometer device, and then reaches the rotating mirror device. Within the galvanometer device, the laser beam performs a reciprocating scan (line scan) within a certain angle range in the vertical direction, while within the rotating mirror device, it performs a reciprocating scan (area scan) within a certain angle range in the horizontal direction. After passing through the rotating mirror device, the laser beam is emitted to the target object and then diffusely reflected back to the transmitting device. The transmitting device receives the laser echo, and the control center calculates the distance to the target point through ranging. When the emission point is sufficient to cover the main features of the target object, the control center can identify the target shape and target distance.

[0004] Therefore, the function of the galvanometer device is to convert the point light source emitted by the transmitting device into a line light source parallel to the vertical plane, and the line light source is converted into a surface light source parallel to the vertical plane under the action of the rotating mirror device, thus realizing surface scanning.

[0005] The current problem is that existing lidar technologies suffer from high failure rates and short lifespans. The applicant's research has revealed that the root cause of these problems lies in the fact that during operation, the galvanometer motor in the galvanometer device needs to maintain high-speed operation for extended periods. This makes the galvanometer motor highly susceptible to damage and malfunction, ultimately leading to lidar failure and disposal. Furthermore, the galvanometer's method of accelerating and decelerating during scanning results in poor uniformity and irregularity in the final scanned point cloud.

[0006] Therefore, it is necessary to design a new laser scanning system to overcome the above problems. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a laser scanning system that can achieve surface scanning without the need for a galvanometer motor, thereby eliminating the limitation of the galvanometer motor on the stability and service life of the entire laser scanning system. It has the advantages of simple and stable structure and long service life.

[0008] To address the aforementioned technical problems, this invention provides a laser scanning system, comprising an emitting device, a transmitting device, a first rotating mirror device, an optical path shaping device, a second rotating mirror device, and a receiving device. The emitting device emits a probe beam. The transmitting device is positioned along the propagation path of the probe beam, allowing it to penetrate and reach the first rotating mirror device. The first rotating mirror device receives and converts the single probe beam emitted by the emitting device into multiple first scanning beams propagating in the same horizontal plane, the multiple first scanning beams forming a first beam surface. The optical path shaping device receives and converts the multiple first scanning beams propagating in the same horizontal plane into multiple third scanning beams propagating in different horizontal planes, the multiple third scanning beams forming a third beam. The surface is curved, and any two of the third scanning rays have a second included angle between their orthographic projections on the same horizontal plane; the second rotating mirror device is used to receive and convert the third beam surface into multiple fourth beam surfaces, and the multiple fourth beam surfaces are projected onto the same vertical plane that intersects with the multiple fourth beam surfaces to form a planar illumination area; the light reflected by the object in the illumination area after being illuminated by the fourth beam surfaces includes a first echo ray directed towards the second rotating mirror device; the first echo ray is processed sequentially by the second rotating mirror device, the optical path shaping device, and the first rotating mirror device before propagating towards the light-transmitting device; the first echo ray is refracted by the light-transmitting device to form a second echo ray; the receiving device is used to receive multiple second echo rays.

[0009] This invention provides another laser scanning system, comprising an emitting device, a transmitting device, a first rotating mirror device, an optical path shaping device, a second rotating mirror device, a receiving device, and a beam expander. The emitting device emits a probe beam. The transmitting device is positioned along the propagation path of the probe beam, allowing it to pass through the transmitting device and reach the first rotating mirror device. The first rotating mirror device receives and converts the single probe beam emitted by the emitting device into multiple first scanning beams propagating in the same horizontal plane, the multiple first scanning beams forming a first beam surface. The optical path shaping device receives and converts the multiple first scanning beams propagating in the same horizontal plane into multiple third scanning beams propagating in different horizontal planes, the multiple third scanning beams forming a third beam surface, and the orthographic projections of any two of the multiple third scanning beams onto the same horizontal plane are... The beams are angled together; the second rotating mirror device is used to receive and convert the third beam surface into multiple fourth beam surfaces; the beam expander is arranged on the propagation path of the multiple fourth beam surfaces, and is used to receive and expand the fourth beam surfaces to form a fifth beam surface composed of multiple non-parallel fifth scanning rays; the illumination area formed by the multiple fifth beam surfaces projected onto the same vertical plane that intersects with the multiple fifth beam surfaces is planar; the light reflected by the object in the illumination area after being illuminated by the fifth beam surface includes a first echo ray directed towards the second rotating mirror device; the first echo ray is processed sequentially by the beam expander, the second rotating mirror device, the optical path shaping device and the first rotating mirror device and then propagates towards the light transmission device; the first echo ray is refracted by the light transmission device to form a second echo ray; the receiving device is used to receive multiple second echo rays.

[0010] In a laser scanning system provided by the present invention, the first rotating mirror device includes a first motor and a first multifaceted reflector connected to the first motor. The first multifaceted reflector is in the form of a prism or a pyramid, and the first light-reflecting surface of the first multifaceted reflector is disposed on the side. The first motor is used to drive the first multifaceted reflector to rotate around its own central axis.

[0011] In a laser scanning system provided by the present invention, the second rotating mirror device includes a second multifaceted mirror in the form of a prism or pyramid. The second multifaceted mirror is arranged above or below the first multifaceted mirror and connected to the first motor. The first motor is also used to drive the second multifaceted mirror to rotate around its own central axis.

[0012] In a laser scanning system provided by the present invention, the diffusion angle of the corresponding fourth beam surface formed by the third beam surface after passing through the beam expander is between 15° and 90°.

[0013] In a laser scanning system provided by the present invention, the angle range of the second included angle formed between the orthographic projections of any two of the plurality of third scanning rays on the same horizontal plane is 0°-30°.

[0014] The present invention provides a laser scanning system in which the optical path shaping device includes a light reflecting surface and a beam adjustment unit. The light reflecting surface is used to receive and convert multiple first scanning rays propagating in the same horizontal plane into multiple second scanning rays propagating in different horizontal planes. Any two of the multiple second scanning rays have a first angle between their orthogonal projections on the same horizontal plane. The beam adjustment unit is used to receive and convert the multiple second scanning rays into multiple third scanning rays propagating in different horizontal planes. Any two of the multiple third scanning rays have a second angle between their orthogonal projections on the same horizontal plane. The angle value of the second angle is smaller than the angle value of the first angle.

[0015] The present invention provides a laser scanning system in which the optical path shaping device includes a refractive surface, a light-reflecting surface, and a beam adjustment section. The refractive surface is used to receive and refract multiple first scanning beams propagating in the same horizontal plane into multiple intermediate scanning beams propagating in the same inclined plane. The light-reflecting surface is used to receive and convert the multiple intermediate scanning beams propagating in the same inclined plane into multiple second scanning beams that do not propagate in the same horizontal plane. Any two of the multiple second scanning beams have a first angle between their orthogonal projections in the same horizontal plane. The beam adjustment section is used to receive and convert the multiple second scanning beams into multiple third scanning beams that do not propagate in the same horizontal plane. Any two of the multiple third scanning beams have a second angle between their orthogonal projections in the same horizontal plane. The angle value of the second angle is smaller than the angle value of the first angle.

[0016] In a laser scanning system provided by the present invention, the light reflecting surface and the beam adjustment part are an integral structure or a separate structure, and the beam adjustment part is not on the propagation path of the first scanning light.

[0017] In a laser scanning system provided by the present invention, the first multifaceted mirror has a first top surface and a first bottom surface opposite to each other, and a first peripheral side surface connected between the first top surface and the first bottom surface. The first peripheral side surface includes a plurality of first light reflecting surfaces connected in sequence. Each of the first light reflecting surfaces is not perpendicular to the first top surface or the second bottom surface, and the angle between each of the first light reflecting surfaces and the first top surface is different. The second multifaceted mirror has a second top surface and a second bottom surface opposite to each other, and a second peripheral side surface connected between the second top surface and the second bottom surface. The second peripheral side surface includes a plurality of second light reflecting surfaces connected in sequence. Each of the second light reflecting surfaces is not perpendicular to the second top surface or the second bottom surface, and the angle between each of the second light reflecting surfaces and the second top surface is different.

[0018] In a laser scanning system provided by the present invention, the first multifaceted mirror has a first top surface and a first bottom surface opposite to each other, and a first peripheral side surface connected between the first top surface and the first bottom surface. The first peripheral side surface includes a plurality of first light reflecting surfaces connected in sequence. Each of the first light reflecting surfaces is not perpendicular to the first top surface or the second bottom surface, and the angle between each of the first light reflecting surfaces and the first top surface is consistent. The second multifaceted mirror has a second top surface and a second bottom surface opposite to each other, and a second peripheral side surface connected between the second top surface and the second bottom surface. The second peripheral side surface includes a plurality of second light reflecting surfaces connected in sequence. Each of the second light reflecting surfaces is not perpendicular to the second top surface or the second bottom surface, and the angle between each of the second light reflecting surfaces and the second top surface is consistent.

[0019] In a laser scanning system provided by the present invention, the first light reflecting surface and the second light reflecting surface are curved surfaces.

[0020] The laser scanning system of the present invention can achieve at least the following beneficial effects: The laser scanning system provided by the present invention includes an optical path shaping device; the optical path shaping device can receive and convert multiple first scanning beams propagating in the same horizontal plane into multiple third scanning beams propagating in different horizontal planes, the multiple third scanning beams forming a third beam surface, and any two of the multiple third scanning beams have a second included angle between their orthographic projections on the same horizontal plane. It is understood that by converting the single probe beam emitted by the transmitting device into multiple third scanning beams propagating in different horizontal planes through the optical path shaping device, we completely replace the role of the galvanometer device in the prior art. Therefore, the laser scanning system can achieve surface scanning without a galvanometer motor, thereby eliminating the limitations of the galvanometer motor on the stability and lifespan of the entire laser scanning system. This significantly improves the stability and lifespan of the laser scanning system of the present invention and enables the acquisition of more regular point cloud maps. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments or prior art, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are merely embodiments of the invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the laser scanning system in Example 1;

[0023] Figure 2 This is a schematic diagram of the optical path of the laser scanning system in Example 1;

[0024] Figure 3 This is a schematic diagram of the structure and optical path of the optical path shaping device in Embodiment 1;

[0025] Figure 4 This is a schematic diagram of the laser scanning system in Example 3;

[0026] Figure 5 This is a schematic diagram of the optical path of the laser scanning system in Example 4;

[0027] Figure 6 This is a schematic diagram of the optical path of the laser scanning system in Example 5;

[0028] Figure 7 This is a schematic diagram of the structure of the first multifaceted reflector in Embodiment Six;

[0029] Figure 8 This is a schematic diagram of the structure of the second multifaceted mirror in Embodiment Six;

[0030] Figure 9 This is a schematic diagram of the structure of the first multifaceted reflector in Embodiment 7;

[0031] Figure 10 This is a schematic diagram of the structure of the second multifaceted mirror in Embodiment 7;

[0032] Figure 11 This is a schematic diagram of the structure and optical path of the optical path shaping device in Example 10;

[0033] Figure 12 This is a top view schematic diagram of the optical path shaping device in Example 10;

[0034] Figure 13 This is a schematic diagram of the structure and optical path of the optical path shaping device in Example 11.

[0035] Explanation of reference numerals in the detailed embodiments:

[0036] Launching device 401 First rotating mirror device 402 Light transmission device 403 Illuminated area IA Optical path shaping device 404 Second rotating mirror device 405 First multi-faceted mirror 421 Second multi-faceted mirror 451 First light reflecting surface 4211 Second light reflecting surface 4511 Detecting light L0 First scanning light L1 First beam surface S1 Second scanning light L2 Third scanning light L3 Third beam surface S3 Fourth beam surface S4 Fourth scanning light L4 Receiving device 406 First echo ray L8 Second echo light L9 Beam expander 407 Detailed Implementation

[0037] To facilitate understanding of the invention, a more complete description will be given below with reference to the accompanying drawings. Typical embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of the invention more thorough and complete.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0039] Example 1

[0040] See Figure 1 This is a schematic diagram of the laser scanning system provided in this embodiment. Figure 1As shown, the laser scanning system includes an emitting device 401, a light-transmitting device 403, a first rotating mirror device 402, an optical path shaping device 404, a second rotating mirror device 405, and a receiving device 406. The emitting device 401 emits a probe beam L0; the light-transmitting device 403 is positioned along the propagation path of the probe beam L0 so that the probe beam L0 penetrates the light-transmitting device 403 and reaches the first rotating mirror device 402; the first rotating mirror device 402 receives and converts the single probe beam L0 emitted by the emitting device 401 into multiple first scanning beams L1 propagating in the same horizontal plane, the multiple first scanning beams L1 forming a first beam surface S1; the optical path shaping device 404 receives and converts the multiple first scanning beams L1 propagating in the same horizontal plane into multiple third scanning beams L3 propagating in different horizontal planes, the multiple third scanning beams L3 forming a third beam surface S3, and any two of the multiple third scanning beams L3 are on the same horizontal plane. The orthographic projections have a second included angle; the second rotating mirror device 405 is used to receive and transform the third beam surface S3 into multiple fourth beam surfaces S4, and the multiple fourth beam surfaces S4 are projected onto the same vertical plane that intersects with the multiple fourth beam surfaces S4 to form an illumination area IA in the form of a plane; the light reflected by the object in the illumination area IA after being illuminated by the fourth beam surface S4 includes a first echo light L8 directed towards the second rotating mirror device 405; the first echo light L8 is processed sequentially by the second rotating mirror device 405, the optical path shaping device 404 and the first rotating mirror device 402 and then propagates toward the light transmission device 403; the first echo light L8 is refracted by the light transmission device 403 to form a second echo light L9; the receiving device 406 is used to receive multiple second echo light L9.

[0041] The working principle of the laser scanning system is described below. (Continue reading...) Figure 2The detection ray L0 (e.g., a laser beam) emitted by the transmitting device 401 first reaches the light transmission device 403. The light transmission device 403 does not affect the direction of the detection ray L0. That is, after passing through the light transmission device 403, the detection ray L0 still propagates along the initial direction to the first rotating mirror device 402. Then, it is reflected by the first rotating mirror device 402 to form multiple first scanning rays L1 that propagate in the same horizontal plane. The multiple first scanning rays L1 reach the optical path shaping device 404. After being reflected and refracted by the optical path shaping device 404, the multiple first scanning rays L1 form multiple third scanning rays L3 that do not propagate in the same horizontal plane. The multiple third scanning rays L3 constitute a third beam surface S3, and any two of the multiple third scanning rays L3 have a second included angle between their orthogonal projections in the same horizontal plane. The third beam surface S3 reaches the second rotating mirror device 405, and is then reflected by the second rotating mirror device 405 to form multiple fourth beam surfaces S4. As shown in the figure, the illumination area IA formed by multiple fourth beam surfaces S4 projected onto the same vertical plane that intersects with multiple fourth beam surfaces S4 is planar (e.g., a polygon with curved edges as shown in the figure; of course, in some other embodiments, the illumination area IA can also be other shapes). It should be understood that the coverage area of ​​the illumination area IA is the effective scanning range of the laser scanning system in the corresponding vertical plane. Furthermore, each fourth beam surface S4 contains multiple fourth scanning rays L4 that do not propagate in the same horizontal plane. The fourth scanning ray L4 of the fourth beam surface S4 illuminates the target object, and the diffuse reflection formed includes a first echo ray L8 directed towards the second rotating mirror device 405. The second rotating mirror device 405 receives and reflects the first echo ray L8 to the optical path shaping device 404. After refraction and reflection by the optical path shaping device 404, the first echo ray L8 is directed towards the first rotating mirror device 402. The first rotating mirror device 402 reflects the first echo ray L8 to the light transmission device 403. The light transmission device 403 refracts the first echo ray L8 to form a second echo ray L9 directed towards the receiving device 406. The receiving device 406 receives the second echo ray L9, and the control center calculates the target location distance through ranging. In this way, when the effective scanning range is sufficient to cover the main features of the target object, the control center can identify the target shape and target distance.

[0042] As described above, the laser scanning system of this embodiment converts the single probe light L0 emitted by the transmitting device 401 into multiple third scanning light beams L3 that do not propagate on the same horizontal plane through the combined action of the first rotating mirror device 402 and the optical path shaping device 404. This completely replaces the role of the galvanometer device in the prior art. Thus, the laser scanning system can achieve surface scanning without the need for a galvanometer motor, thereby eliminating the limitation of the galvanometer motor on the stability and service life of the entire laser scanning system. This significantly improves the stability and service life of the laser scanning system of the present invention.

[0043] In this embodiment, the first beam surface S1 is parallel to the horizontal plane. The third beam surface S3 is composed of multiple third scan lines L3 that do not propagate on the same horizontal plane. Here, the angle range of the second included angle formed between the orthographic projections of any two of the multiple third scan lines L3 on the same horizontal plane is 0°-30°, preferably between 5°-10°. Each of the fourth beam surfaces S4 intersects the third beam surface S3 at the second light reflecting surface 4511 of the second multifaceted reflector 451.

[0044] In this embodiment, the optical path shaping device includes a light-reflecting curved surface 4041 and a beam adjustment section 4042. See also Figure 3 The light-reflecting surface is used to receive and convert multiple first scanning light beams L1 propagating in the same horizontal plane into multiple second scanning light beams L2 propagating in different horizontal planes. Any two of the second scanning light beams L2 have a first angle between their orthographic projections on the same horizontal plane. Specifically, the shape of the light-reflecting surface is similar to the surface of a fan blade or other types of freeform surfaces. It should be understood that by designing the curvature at different positions of the light-reflecting surface, the multiple first scanning light beams L1 originally propagating in the horizontal plane can be directly reflected into multiple third scanning light beams L3 propagating in different horizontal planes. The beam adjustment unit is used to receive and convert the multiple second scanning light beams into multiple third scanning light beams L3 propagating in different horizontal planes. Any two of the third scanning light beams L3 have a second angle between their orthographic projections on the same horizontal plane. Most importantly, the angle value of the second angle is smaller than the angle value of the first angle. It is understood that the purpose of designing the beam adjustment section is to converge multiple second scanning beams L2 to a certain extent, so that the multiple third scanning beams L3 emitted from the optical path shaping device ultimately propagate as close as possible to the same vertical plane. To achieve this purpose, those skilled in the art will know that the beam adjustment section can be designed as a semi-cylindrical lens.

[0045] Of course, in some other embodiments, the beam adjustment part can also be a lens of other shapes, as long as it can achieve the purpose of focusing the light in the vertical direction as described above.

[0046] In this embodiment, the light-reflecting surface and the beam adjustment part are an integral structure. The beam adjustment part is closer to the first rotating mirror device 402 relative to the light-reflecting surface, and the light-reflecting surface is higher than the beam adjustment part. This is to ensure that the beam adjustment part is not in the propagation path of the first scanning light. Thus, the first scanning light reaches the light-reflecting surface directly without passing through the beam adjustment part, and the second scanning light formed by reflection from the light-reflecting surface can enter the beam adjustment part. Those skilled in the art should know that, in order to achieve the integration of the light-reflecting surface and the beam adjustment part, the optical path shaping device 404 can be made of glass. The optical path shaping device 404 is roughly boot-shaped. The light-reflecting surface is formed by surface treatment (e.g., etching, coating) on ​​the surface of the optical path shaping device 404 facing away from the first rotating mirror device 402. Then, the part of the optical path shaping device 404 near the first rotating mirror device 402 is designed as a semi-cylindrical shape, thus obtaining an integral structure optical path shaping device 404.

[0047] Of course, in some other embodiments, the light-reflecting surface and the beam adjustment section can be separate structures. The light-reflecting surface is designed on a reflector, which can be made of plastic (coated with a reflective film), glass (coated with a reflective film), or metal. The beam adjustment section is a separate semi-cylindrical lens made of plastic or glass, and the reflector and beam adjustment section are separated. Specifically, the reflector is positioned further away from the first rotating mirror device 402 than the beam adjustment section, and the height of the reflector is higher than the height of the beam adjustment section. Thus, the first scanning light reaches the light-reflecting surface directly without passing through the beam adjustment section, and the second scanning light formed by reflection from the light-reflecting surface can enter the beam adjustment section.

[0048] In this embodiment, the first rotating mirror device 402 includes a first motor and a first multifaceted reflector 421 connected to the first motor. The first multifaceted reflector 421 is prism-shaped (e.g., Figure 1 The first multifaceted mirror 421 (shown as a right hexagonal prism) has a first light-reflecting surface 4211 on its side, and the first motor drives the first multifaceted mirror 421 to rotate around its central axis. Meanwhile, the second rotating mirror device 405 includes a second multifaceted mirror 451 in the form of a prism (e.g., a right hexagonal prism). Figure 1As shown in the diagram (a right quadrangular prism), the second multifaceted mirror 451 is connected to the first motor, which also drives the second multifaceted mirror 451 to rotate around its central axis. The second multifaceted mirror 451 is arranged below the first multifaceted mirror 421, and the central axis of the first multifaceted mirror 421 is collinear with the central axis of the second multifaceted mirror 451. In this way, by using the first motor to simultaneously drive both the first multifaceted mirror 421 and the second multifaceted mirror 451, a high degree of integration between the first rotating mirror device 402 and the second rotating mirror device 405 is achieved, which is beneficial for the miniaturization of the laser scanning system. Furthermore, it minimizes the use of motors, reducing potential sources of failure and significantly lowering the failure rate of the entire laser scanning system, thus further improving the stability of the entire laser scanning system.

[0049] It should be noted that, driven by the first motor, the first multifaceted reflector 421 and the second multifaceted reflector 451 can rotate synchronously or differentially.

[0050] Of course, in some other embodiments, the second faceted mirror 451 may also be arranged above the first faceted mirror 421.

[0051] In this embodiment, the number of first light-reflecting surfaces 4211 of the first multifaceted reflector 421 is greater than the number of second light-reflecting surfaces 4511 of the second multifaceted reflector 451.

[0052] In this embodiment, the transmitting device, the receiving device, and the light-transmitting device are devices well known to those skilled in the art, and their specific structures will not be described in detail here. However, it should be noted that the transmitting device 401 can be a single light source or multiple light sources arranged in an array, and the light emitted can be one beam or multiple beams of probe light. The receiving device can be a detector array or multiple detector arrays. The light-transmitting device can be a beam splitter or an integrated device of a beam splitter and an optical isolator.

[0053] In summary, the laser scanning system provided in this embodiment can achieve the following beneficial effects:

[0054] 1. By using only the first rotating mirror device and the optical path shaping device to convert the single beam of detection light emitted by the transmitting device into multiple beams of third scanning light that do not propagate in the same horizontal plane, the function of the galvanometer device in the prior art is completely replaced. Thus, the laser scanning system can achieve surface scanning function without the need for a galvanometer motor, thereby eliminating the limitation of the galvanometer motor on the stability and service life of the entire laser scanning system. This results in a significant improvement in the stability and service life of the laser scanning system of the present invention.

[0055] 2. By using the first motor to simultaneously drive both the first and second multi-faceted reflectors, a high degree of integration between the first and second rotating mirror devices is achieved, which is beneficial for the miniaturization of the laser scanning system. Furthermore, it minimizes the use of motors, reducing potential sources of failure and significantly lowering the overall failure rate of the laser scanning system, thus further improving its stability.

[0056] 3. The light reflection surface and beam adjustment unit are integrated into one structure, which further reduces the size of the entire scanning system and facilitates miniaturization.

[0057] It should be emphasized that the prisms described in this application are not limited to quadrangular or hexagonal prisms. In some other embodiments, the first multifaceted mirror and the second multifaceted mirror can be selected as triangular, quadrangular, pentagonal, hexagonal, heptagonal, octagonal, nonagonal, decimal, eleventh-sided prisms, etc., as long as the number of edges of the first multifaceted mirror is greater than the number of edges of the second multifaceted mirror.

[0058] Example 2

[0059] The difference between the laser scanning system in this embodiment and that in Embodiment 1 is that the second rotating mirror device 405 includes a second motor and a second multifaceted reflector 451 connected to the second motor. The second motor is used to drive the second multifaceted reflector 451 to rotate around its own central axis. That is, the first multifaceted reflector 421 and the second multifaceted reflector 451 no longer share the same motor (the first motor mentioned above).

[0060] Compared with Embodiment 1, its advantage is that it reduces the load on the first motor, and at the same time, it eliminates the need to control the rotation speed of the first multifaceted reflector 421 and the second multifaceted reflector 451 separately through a complex gear structure.

[0061] Example 3

[0062] The difference between the laser scanning system in this embodiment and that in Embodiment 1 is that the laser scanning system in this embodiment further includes a beam expander 407. For details, see [link to documentation]. Figure 4The laser scanning system includes a transmitting device 401, a first rotating mirror device 402, an optical path shaping device 404, a second rotating mirror device 405, a receiving device 406, and a beam expander 407. The transmitting device 401 emits a probe beam L0; the first rotating mirror device 402 receives and converts the single probe beam L0 emitted by the transmitting device 401 into multiple first scanning beams L1 propagating in the same horizontal plane, the multiple first scanning beams L1 forming a first beam surface S1; the optical path shaping device 404 receives and converts the multiple first scanning beams L1 propagating in the same horizontal plane into multiple third scanning beams L3 propagating in different horizontal planes, the multiple third scanning beams L3 forming a third beam surface S3; the second rotating mirror device 405 receives and converts the third beam surface S3 into multiple fourth beam surfaces S4; the beam expander 407 is arranged on the propagation path of the multiple fourth beam surfaces S4, and is used to receive and shape the fourth beam surfaces S4. A beam expansion process is performed to form a fifth beam surface S5 composed of multiple non-parallel fifth scanning rays L5; the multiple fifth beam surfaces S5 are projected onto the same vertical plane that simultaneously intersects with the multiple fifth beam surfaces S5 to form an illumination area IA, which is planar; the light reflected by an object in the illumination area IA after being illuminated by the fifth beam surface S5 includes a first echo ray L8 directed towards the beam expander 407; the first echo ray L8 is processed sequentially by the beam expander 407, the second rotating mirror device 405, the optical path shaping device 404, and the first rotating mirror device 402 before propagating towards the light transmission device 403; the first echo ray L8 is refracted by the light transmission device 403 to form a second echo ray L9; the receiving device 406 is used to receive multiple second echo rays L9.

[0063] It is worth mentioning that the diffusion angle of the corresponding fourth beam surface S4 formed by the third beam surface S3 after passing through the beam expander 407 is between 15° and 90° (preferably, 25° to 60°). The diffusion angle refers to the angle between the uppermost beam and the lowermost beam of the fourth beam surface S4. More specifically, the diffusion angle refers to the angle between the orthographic projections of the uppermost and lowermost fourth scanning rays L4 among the plurality of fourth scanning rays L4 contained in the fourth beam surface S4 onto the same vertical plane.

[0064] It should be understood that, compared with Embodiment 1, the effective scanning area of ​​the laser scanning system can be effectively expanded by adding the beam expander 407.

[0065] Example 4

[0066] The difference between the laser scanning system in this embodiment and that in Embodiment 1 is that, see [link to Embodiment 1]. Figure 5 The layout of each device is upside down.

[0067] Example 5

[0068] The difference between the laser scanning system in this embodiment and that in Embodiment 3 is that, see [link to Embodiment 3]. Figure 6 The layout of each device is upside down.

[0069] Example 6

[0070] The difference between the laser scanning system in this embodiment and that in Embodiment 1 is that the first multifaceted mirror 421 and the second multifaceted mirror 451 are not prisms. Specifically, see [link to embodiment]. Figure 7 and Figure 8 The first multi-faceted reflector 421 has a first top surface 4212 and a first bottom surface 4213 facing each other, and a first peripheral side surface connecting the first top surface and the first bottom surface. The first peripheral side surface includes a plurality of first light-reflecting surfaces 4211 connected in sequence. Crucially, at least one of the first light-reflecting surfaces 4211 is not perpendicular to the first top surface 4212 or the first bottom surface 4213. Here, each of the first light-reflecting surfaces 4211 is not perpendicular to the first top surface 4212 or the second bottom surface 4213, and the angle between each of the first light-reflecting surfaces 4211 and the first top surface 4212 (or the second bottom surface 4213) is the same. Similarly, see... Figure 10 The second multifaceted reflector 451 has a second top surface 4512 and a second bottom surface 4513 facing each other, and a second peripheral side surface connected between the second top surface 4512 and the second bottom surface 4513. The second peripheral side surface includes a plurality of second light-reflecting surfaces 4511 connected in sequence. Crucially, at least one of the second light-reflecting surfaces 4511 is not perpendicular to the second top surface 4512 or the second bottom surface 4513. Here, each of the second light-reflecting surfaces 4511 is not perpendicular to the second top surface 4512 or the second bottom surface 4513, and the angle between each of the second light-reflecting surfaces 4511 and the second top surface 4512 (or the second bottom surface 4513) is the same.

[0071] Example 7

[0072] The difference between the laser scanning system in this embodiment and that in Embodiment 1 is that the first multifaceted mirror 421 and the second multifaceted mirror 451 are not prisms. Specifically, see [link to embodiment]. Figure 9 and Figure 10The first multi-faceted reflector 421 has a first top surface 4212 and a first bottom surface 4213 facing each other, and a first peripheral side surface connecting the first top surface and the first bottom surface. The first peripheral side surface includes a plurality of first light-reflecting surfaces 4211 connected in sequence. Crucially, at least one of the first light-reflecting surfaces 4211 is not perpendicular to the first top surface 4212 or the first bottom surface 4213. Here, each of the first light-reflecting surfaces 4211 is not perpendicular to the first top surface 4212 or the second bottom surface 4213, and the angle between each of the first light-reflecting surfaces 4211 and the first top surface 4212 (or the second bottom surface 4213) is different. Specifically, in a clockwise direction, the angle between the first light-reflecting surface 4211 and the first top surface 4212 (or the second bottom surface 4213) gradually increases. Similarly, see... Figure 10 The second multifaceted reflector 451 has a second top surface 4512 and a second bottom surface 4513, and a second peripheral surface connected between the second top surface 4512 and the second bottom surface 4513. The second peripheral surface includes a plurality of second light-reflecting surfaces 4511 connected in sequence. Crucially, at least one of the second light-reflecting surfaces 4511 is not perpendicular to the second top surface 4512 or the second bottom surface 4513. Here, each of the second light-reflecting surfaces 4511 is not perpendicular to the second top surface 4512 or the second bottom surface 4513, and the angle between each of the second light-reflecting surfaces 4511 and the second top surface 4512 (or the second bottom surface 4513) is different. Specifically, in a clockwise direction, the angle between the second light-reflecting surface 4511 and the second top surface 4512 (or the second bottom surface 4513) gradually increases.

[0073] Example 8

[0074] The difference between the laser scanning system in this embodiment and that in Embodiment 1 is that the first light reflecting surface 4211 and the second light reflecting surface 4511 are curved surfaces instead of flat surfaces.

[0075] Example 9

[0076] The difference between the laser scanning system in this embodiment and that in Embodiment 1 is that the first multifaceted reflector 421 or the second multifaceted reflector 451 is selected as a pyramid, such as a triangular pyramid, a quadrangular pyramid, a pentagonal pyramid, a hexagonal pyramid, a heptagonal pyramid, an octagonal pyramid, a nonagonal pyramid, a decaangular pyramid, etc.

[0077] Example 10

[0078] The difference between the laser scanning system in this embodiment and that in Embodiment 1 is that, see [link to Embodiment 1]. Figure 11 and Figure 12The optical path shaping device 404 further includes a refractive surface 4043. The refractive surface 4043, the light reflecting surface 4041, and the beam adjustment part 4042 are an integral structure. The beam adjustment part 4042 is closer to the first rotating mirror device 402 relative to the light reflecting surface, and the light reflecting surface 4041 is higher than the beam adjustment part 4042, so that the beam adjustment part is not on the propagation path of the first scanning light. The refractive surface 4043 is closer to the first rotating mirror device 402 relative to the light reflecting surface, and the refractive surface 4043 is located on the propagation path of the first scanning light, so that the first scanning light L1 is refracted by the refractive surface 4043 before reaching the light reflecting surface 4041.

[0079] Thus, see Figure 11 The first scanning light L1 is refracted by the refractive surface 4043 before passing through the beam adjustment part to form a downward deflected intermediate scanning line L1'. After the intermediate scanning line L1' reaches the light reflection surface, the second scanning light L2 formed by reflection can enter the beam adjustment part 4042. Those skilled in the art should know that, in order to achieve the integrated design of the refractive surface 4043, the light-reflecting surface 4041, and the beam adjustment part, the optical path shaping device 404 can be made of plastic or glass. The optical path shaping device 404 is generally trapezoidal in shape. The surface of the optical path shaping device 404 facing away from the first rotating mirror device 402 is surface treated (e.g., etching, coating) to form the light-reflecting surface 4041. Then, the side of the optical path shaping device 404 near the first rotating mirror device 402 is designed as a semi-cylindrical shape to form the beam adjustment part 4042. The part located between the beam adjustment part 4042 and the light-reflecting surface 4041 is designed as a trapezoidal structure with a right-angled trapezoidal vertical cross-section. The inclined surface of the trapezoidal structure can serve as the refractive surface 4043. In this way, an integrated optical path shaping device 404 can be obtained.

[0080] Example 11

[0081] The difference between the laser scanning system in this embodiment and that in Embodiment 10 is that the optical path shaping device 404 is a split structure; that is, the refractive surface 4043, the light reflecting surface 4041, and the beam adjustment part 4042 are separate structures. Figure 13The light-reflecting surface 4041 is designed on a reflector, which can be made of plastic (coated with a reflective film), glass (coated with a reflective film), or metal. The beam adjustment part 4042 is a separate semi-cylindrical lens made of glass or plastic. The refractive surface 4043 is designed on a separate triangular prism made of glass or plastic. The triangular prism, the reflector, and the beam adjustment part are separated. Specifically, the reflector is positioned further away from the first rotating mirror device 402 relative to the beam adjustment part, and its height is higher than that of the beam adjustment part. Simultaneously, the reflector is positioned further away from the first rotating mirror device 402 relative to the triangular prism, and its height is lower than that of the triangular prism.

[0082] Thus, the first scanning light L1 is refracted by the refractive surface 4043 of the triangular prism before passing through the beam adjustment section, forming a downward deflected intermediate scanning line L1'. After the intermediate scanning line L1' reaches the light reflection surface 4041, the second scanning light L2 formed by reflection can enter the beam adjustment section 4042.

[0083] The embodiments of the invention have been described above with reference to the accompanying drawings. However, the invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the invention without departing from the spirit and scope of the claims. All of these are within the scope of protection of the invention.

Claims

1. A laser scanning system, characterized by The laser scanning system comprises a transmitting device (401), a light-transmitting device (403), a first rotating mirror device (402), a light path shaping device (404), a second rotating mirror device (405) and a receiving device (406); The transmitting device (401) is used for transmitting a probe light ray (L0); The light-transmitting device (403) is arranged on the propagation path of the probe light ray (L0) so that the probe light ray (L0) penetrates through the light-transmitting device (403) and reaches the first rotating mirror device (402); The first rotating mirror device (402) is used for receiving and converting the single probe light ray (L0) emitted by the transmitting device (401) into a plurality of first scanning light rays (L1) propagating in the same horizontal plane, and the plurality of first scanning light rays (L1) form a first light beam plane (S1); The light path shaping device (404) is used for receiving and converting the plurality of first scanning light rays (L1) propagating in the same horizontal plane into a plurality of third scanning light rays (L3) not propagating in the same horizontal plane, and the plurality of third scanning light rays (L3) form a third light beam curved surface (S3), and any two third scanning light rays (L3) in the plurality of third scanning light rays (L3) have a second included angle between the orthogonal projections of the two third scanning light rays (L3) in the same horizontal plane; The second rotating mirror device (405) is used for receiving and converting the third light beam curved surface (S3) into a plurality of fourth light beam curved surfaces (S4), and the plurality of fourth light beam curved surfaces (S4) form a light irradiation area (IA) in a planar shape on the same vertical plane intersecting the plurality of fourth light beam curved surfaces (S4); The light rays reflected by the objects in the light irradiation area (IA) after being irradiated by the fourth light beam curved surfaces (S4) include first echo light rays (L8) directed to the second rotating mirror device (405); The first echo light rays (L8) are sequentially processed by the second rotating mirror device (405), the light path shaping device (404) and the first rotating mirror device (402) and then propagate towards the light-transmitting device (403); The first echo light rays (L8) are refracted by the light-transmitting device (403) to form second echo light rays (L9); The receiving device (406) is used for receiving the plurality of second echo light rays (L9); The central axis of the first rotating mirror device (402) is collinear with the central axis of the second rotating mirror device (405).

2. A laser scanning system, characterized by The laser scanning system comprises a transmitting device (401), a light-transmitting device (403), a first rotating mirror device (402), a light path shaping device (404), a second rotating mirror device (405), a receiving device (406) and a beam expanding device (407); The transmitting device (401) is used for transmitting a probe light ray (L0); The light-transmitting device (403) is arranged on the propagation path of the probe light ray (L0) so that the probe light ray (L0) penetrates through the light-transmitting device (403) and reaches the first rotating mirror device (402); The first mirror device (402) is configured to receive and convert the single probe light beam (L0) emitted by the emitting device (401) into a plurality of first scanning light beams (L1) propagating in the same horizontal plane, and the plurality of first scanning light beams (L1) form a first light beam plane (S1). The light path shaping device (404) is configured to receive and convert the plurality of first scanning light beams (L1) propagating in the same horizontal plane into a plurality of third scanning light beams (L3) not propagating in the same horizontal plane, and the plurality of third scanning light beams (L3) form a third light beam curved surface (S3), and the second included angle between the orthogonal projections of any two third scanning light beams (L3) in the same horizontal plane is formed. The second mirror device (405) is configured to receive and convert the third light beam curved surface (S3) into a plurality of fourth light beam curved surfaces (S4). The beam expanding device (407) is arranged in the propagation path of the plurality of fourth light beam curved surfaces (S4) and is configured to receive and expand the fourth light beam curved surfaces (S4) to form a fifth light beam curved surface (S5) composed of a plurality of fifth scanning light beams (L5) which are not parallel to each other; and the plurality of fifth light beam curved surfaces (S5) project on the illumination area (IA) formed by the vertical plane intersecting the plurality of fifth light beam curved surfaces (S5) to form a planar illumination area (IA). The light reflected by the object in the illumination area (IA) after being illuminated by the fifth light beam curved surface (S5) includes a first echo light beam (L8) directed to the second mirror device (405). The first echo light beam (L8) is sequentially processed by the beam expanding device (407), the second mirror device (405), the light path shaping device (404) and the first mirror device (402) and then propagates towards the light-transmitting device (403). The first echo light beam (L8) is refracted by the light-transmitting device (403) to form a second echo light beam (L9). The receiving device (406) is configured to receive a plurality of second echo light beams (L9).

3. The laser scanning system according to any of claims 1-2, characterized in that, The first mirror device (402) comprises a first motor and a first multi-faceted mirror (421) connected to the first motor, the first multi-faceted mirror (421) is a prism or a pyramid, a first light reflection surface (4211) of the first multi-faceted mirror (421) is arranged on a side surface, and the first motor is configured to drive the first multi-faceted mirror (421) to rotate around a central axis thereof.

4. The laser scanning system of claim 3, wherein, The second mirror device (405) comprises a second multi-faceted mirror (451) arranged above or below the first multi-faceted mirror (421) and connected to the first motor, and the first motor is further configured to drive the second multi-faceted mirror (451) to rotate around a central axis thereof.

5. The laser scanning system of claim 2, wherein, The diffusion angle of the corresponding fourth light beam curved surface (S4) formed after the third light beam curved surface (S3) passes through the beam expanding device (407) is between 15° and 90°.

6. The laser scanning system of any of claims 1-2, wherein, The second included angle between the orthogonal projections of any two of the third scanning light rays (L3) on the same horizontal plane is in the range of 0°-30°.

7. The laser scanning system of claim 1, wherein, The light path shaping device (404) comprises a light reflection curved surface (4041) and a light beam adjusting part (4042). The light reflection curved surface (4041) is configured to receive and convert the first scanning light rays (L1) propagating in the same horizontal plane into the second scanning light rays (L2) not propagating in the same horizontal plane, and any two of the second scanning light rays (L2) have a first included angle between the orthogonal projections on the same horizontal plane. The light beam adjusting part (4042) is configured to receive and convert the second scanning light rays (L2) into the third scanning light rays (L3) not propagating in the same horizontal plane, and any two of the third scanning light rays (L3) have a second included angle between the orthogonal projections on the same horizontal plane. The angle value of the second included angle is smaller than that of the first included angle.

8. The laser scanning system of claim 1, wherein, The light path shaping device (404) comprises a refractive surface (4043), a light reflection curved surface (4041) and a light beam adjusting part (4042). The refractive surface (4043) is configured to receive and refract the first scanning light rays (L1) propagating in the same horizontal plane into the intermediate scanning light rays (L1') propagating in the same inclined plane. The light reflection curved surface (4041) is configured to receive and convert the intermediate scanning light rays (L1') propagating in the same inclined plane into the second scanning light rays (L2) not propagating in the same horizontal plane, and any two of the second scanning light rays (L2) have a first included angle between the orthogonal projections on the same horizontal plane. The light beam adjusting part (4042) is configured to receive and convert the second scanning light rays (L2) into the third scanning light rays (L3) not propagating in the same horizontal plane, and any two of the third scanning light rays (L3) have a second included angle between the orthogonal projections on the same horizontal plane. The angle value of the second included angle is smaller than that of the first included angle.

9. The laser scanning system according to any of claims 7-8, characterized in that, The light reflection curved surface and the light beam adjusting part are in an integrated structure or a split structure, and the light beam adjusting part is not on the propagation path of the first scanning light rays (L1).

10. The laser scanning system according to claim 4, wherein The first polygon mirror (421) has opposite first top and bottom surfaces (4212, 4213) and a first peripheral surface connected between the first top and bottom surfaces, the first peripheral surface comprising a plurality of first light reflection surfaces (4211) connected in sequence; each first light reflection surface (4211) is not perpendicular to the first top or bottom surface (4212, 4213), and each first light reflection surface (4211) has a different included angle with the first top surface (4212). The second multi-faceted mirror (451) has opposite second top and bottom surfaces (4512, 4513) and a second peripheral side surface connecting between the second top and bottom surfaces (4512, 4513), the second peripheral side surface comprising a plurality of second light reflection surfaces (4511) connected in sequence, each of the second light reflection surfaces (4511) being non-perpendicular to the second top or bottom surface (4512, 4513), and each of the second light reflection surfaces (4511) having a different angle with the second top surface (4512); Or, The first multi-faceted mirror (421) has opposite first top and bottom surfaces (4212, 4213) and a first peripheral side surface connecting between the first top and bottom surfaces, the first peripheral side surface comprising a plurality of first light reflection surfaces (4211) connected in sequence, each of the first light reflection surfaces (4211) being non-perpendicular to the first top or bottom surface (4212, 4213), and each of the first light reflection surfaces (4211) having a same angle with the first top surface (4212); The second multi-faceted mirror (451) has opposite second top and bottom surfaces (4512, 4513) and a second peripheral side surface connecting between the second top and bottom surfaces (4512, 4513), the second peripheral side surface comprising a plurality of second light reflection surfaces (4511) connected in sequence, each of the second light reflection surfaces (4511) being non-perpendicular to the second top or bottom surface (4512, 4513), and each of the second light reflection surfaces (4511) having a same angle with the second top surface (4512).

Images