lidar

Abstract

Provided in the present disclosure is a LiDAR. The LiDAR comprises a base, a transmitting module and a receiving module, wherein the base rotates around an axis of rotation when the LiDAR operates; the transmitting module emits emergent laser light during operation; and the receiving module receives reflected laser light formed after the emergent laser light encounters an obstacle during operation. The transmitting module comprises a transmitting lens unit and a plurality of transmitting units, wherein the transmitting lens unit has a transmitting optical axis, and the projection of the transmitting optical axis on a reference plane and the transmitting optical axis form a first target plane, the reference plane being perpendicular to the axis of rotation; and the plurality of transmitting units emit the emergent laser light during operation, the emergent laser light is emitted to the outside of the LiDAR through the transmitting lens unit, the plurality of transmitting units comprise a target transmitting unit, and target emergent laser light emitted by the target transmitting unit is located on the first target plane.

Description

A laser radar

[0001] This disclosure claims priority to a Chinese patent application entitled “A Laser Radar” and application number 202410178003.8 filed on February 8, 2024, and the contents of the priority application are incorporated herein by reference in their entirety. Technical Field

[0002] This specification relates to the field of laser detection technology, and in particular to a laser radar. Background Art

[0003] LiDAR (light detection and ranging) is a radar system that detects targets by emitting a laser beam and receiving the echo signal when the laser beam is reflected back by the target object. LiDAR generally consists of a transmitting module and a receiving module. Its main working principle is as follows: the transmitting module emits an outgoing laser. The outgoing laser is reflected back by the object and the reflected laser returns to the LiDAR. The LiDAR compares the reflected laser with the outgoing laser and, after appropriate processing, obtains relevant information about the object, such as the object's distance, direction, height, speed, attitude, reflectivity, shape and other parameters. LiDAR acquires numerous data points in the process of scanning the surrounding environment. These data points contain relevant information about the object and are called point clouds. Summary of the Invention

[0004] In a first aspect, the present specification provides a laser radar. The laser radar includes a base, a transmitting module, and a receiving module. The base rotates around a rotation axis when the laser radar is in operation. The transmitting module is mounted on the base and transmits an outgoing laser when in operation. The receiving module is mounted on the base and receives reflected laser light formed when the outgoing laser encounters an object when in operation. The transmitting module includes: a transmitting lens unit having an emission optical axis, the projection of the emission optical axis on a reference plane and the emission optical axis defining a first target plane, wherein the reference plane is perpendicular to the rotation axis, and a plurality of transmitting units that transmit the outgoing laser light when in operation. The outgoing laser light is emitted outside the laser radar through the transmitting lens unit. The plurality of transmitting units include a target transmitting unit, and the target outgoing laser light emitted by the target transmitting unit is located on the first target plane.

[0005] In some embodiments, the laser radar also includes a circuit board, the multiple transmitting units are arranged on the circuit board, the projection of the first target plane on the circuit board includes a transmitting central axis; and the multiple transmitting units form a plurality of transmitting arrays, at least one of the multiple transmitting arrays includes the target transmitting unit, and the target transmitting unit is located on the transmitting central axis.

[0006] In some embodiments, the multiple transmitting arrays include multiple first transmitting arrays, multiple second transmitting arrays and at least one third transmitting array, the multiple first transmitting arrays are distributed on the first side of the transmitting axis to form a first queue, the multiple second transmitting arrays are distributed on the second side of the transmitting axis to form a second queue, the first queue and the second queue are arranged equidistant and parallel to the transmitting axis, and the third transmitting array is connected to the first queue and includes the target transmitting unit.

[0007] In some embodiments, the emission optical axis is at a first preset angle to the rotation axis; the distance between the target emission unit and the emission optical axis is a first preset value, and the target emitted laser is parallel to the rotation axis after being deflected by the emission lens unit.

[0008] In some embodiments, the circuit board coincides with a first focal plane, wherein the first focal plane is a plane passing through the focus of the emission lens unit and perpendicular to the emission optical axis.

[0009] In some embodiments, the receiving module includes a receiving lens unit and a plurality of receiving units; the receiving module has a receiving optical axis, the projection of the receiving optical axis on the reference plane and the receiving optical axis form a second target plane, and the reflected laser is incident into the receiving module through the receiving lens unit; and a plurality of receiving units, corresponding to the plurality of transmitting units, are located on the optical path of the reflected laser to receive the reflected laser, wherein the plurality of receiving units include a target receiving unit, the reflected laser includes a target reflected laser, and the target reflected laser propagates along the second target plane and is incident on the target receiving unit.

[0010] In some embodiments, the multiple receiving units are arranged on the circuit board and facing the receiving lens unit, the projection of the second target plane on the circuit board includes a receiving central axis; and the multiple receiving units form a plurality of receiving arrays, at least one of the multiple receiving arrays includes the target receiving unit, and the target receiving unit is located on the receiving central axis.

[0011] In some embodiments, the transmitting module and the receiving module are arranged side by side and face the same direction, the rotation axis is equidistant from the transmitting optical axis and the receiving optical axis, and the multiple receiving units and the multiple transmitting units have the same distribution.

[0012] In some embodiments, the plurality of receiving units include single photon avalanche diodes.

[0013] In some embodiments, the multiple receiving units are arranged on the circuit board and facing the receiving lens unit, the multiple receiving units form a plurality of receiving arrays, at least one of the multiple receiving arrays includes the target receiving unit, and the target receiving unit is arranged on one side of the second target plane; and a receiving light path guiding module guides the target reflected laser propagating along the second target plane out of the second target plane to be incident on the target receiving unit.

[0014] In some embodiments, the circuit board includes a transmitting circuit board and a receiving circuit board, the plurality of transmitting units are arranged on the transmitting circuit board, and the plurality of receiving units are arranged on the receiving circuit board.

[0015] In some embodiments, the vertical field of view of the multiple emission units is greater than or equal to 100 degrees, and the number of the emitted laser beams is greater than or equal to 128 beams.

[0016] In some embodiments, the first preset angle is greater than 10 degrees and less than 80 degrees, so that the emitted laser is close to the zenith area pointed by the rotation axis.

[0017] In some embodiments, the plurality of emitting units include vertical cavity surface emitting lasers.

[0018] In some embodiments, the laser radar also includes a circuit board, the multiple transmitting units are arranged on the circuit board, the multiple transmitting units form multiple transmitting arrays, at least one of the multiple transmitting arrays includes the target transmitting unit, and the target transmitting unit is arranged on one side of the first target plane; and the transmitting module also includes a transmitting light path guiding module, which guides the target emitted laser to the first target plane.

[0019] In a second aspect, the present application provides a laser radar. The laser radar includes a base, a transmitting module, and a receiving module; the base rotates around a rotation axis when the laser radar is in operation; the transmitting module is mounted on the base and emits an outgoing laser when in operation; the receiving module is mounted on the base and receives a reflected laser formed when the outgoing laser encounters an object when in operation, wherein the receiving module includes a receiving lens unit and a plurality of receiving units, the receiving lens unit having a receiving optical axis, the projection of the receiving optical axis on a reference plane and the receiving optical axis forming a second target plane, the reflected laser is incident on the receiving module through the receiving lens unit, wherein the reference plane is perpendicular to the rotation axis, and the plurality of receiving units face the receiving lens unit and are located on the optical path of the reflected laser to receive the reflected laser, wherein the plurality of receiving units include a target receiving unit, the reflected laser includes a target reflected laser, and the target reflected laser propagates along the second target plane and is incident on the target receiving unit.

[0020] In some embodiments, the laser radar also includes a circuit board, the multiple receiving units are arranged on the circuit board and face the receiving lens unit, the projection of the second target plane on the circuit board is the receiving central axis; and the multiple receiving units form a plurality of receiving arrays, at least one of the multiple receiving arrays includes the target receiving unit, and the target receiving unit is located on the receiving central axis.

[0021] In some embodiments, the multiple receiving arrays include multiple first receiving arrays, multiple second receiving arrays and at least one third receiving array, the multiple first receiving arrays are distributed on the first side of the receiving central axis to form a fourth queue, the multiple second receiving arrays are distributed on the second side of the receiving central axis to form a fifth queue, the fourth queue and the fifth queue are arranged equidistant and parallel to the receiving central axis, and the third receiving array is connected to the fourth queue and includes the target receiving unit.

[0022] In some embodiments, the receiving optical axis is at a second preset angle to the rotation axis; the distance between the target receiving unit and the receiving optical axis is a second preset value, and the target receiving unit receives the target reflected laser parallel to the rotation axis.

[0023] In some embodiments, the circuit board and a second focal plane coincide with each other, wherein the second focal plane is a plane passing through the focus of the receiving lens unit and perpendicular to the receiving optical axis.

[0024] In some embodiments, the transmitting module includes a transmitting lens unit and multiple transmitting units; the transmitting lens has an transmitting optical axis, and the vertical projection of the transmitting optical axis on the reference plane forms a first target plane with the transmitting optical axis; the multiple transmitting units correspond to the multiple receiving units, and transmit the outgoing laser to the transmitting lens unit during operation, wherein the multiple transmitting units include a target transmitting unit, and the target outgoing laser emitted by the target transmitting unit is located on the first target plane.

[0025] In some embodiments, the multiple transmitting units are arranged on the circuit board, the projection of the first target plane on the circuit board includes the transmitting central axis; and the multiple transmitting units form a plurality of transmitting arrays, at least one of the multiple transmitting arrays includes the target transmitting unit, and the target transmitting unit is located on the transmitting central axis.

[0026] In some embodiments, the transmitting module and the receiving module are arranged side by side and face the same direction, the rotation axis is equidistant from the transmitting optical axis and the receiving optical axis, and the multiple receiving units and the multiple transmitting units have the same distribution.

[0027] In some embodiments, the plurality of emitting units include vertical cavity surface emitting lasers.

[0028] In some embodiments, the multiple emitting units are arranged on the circuit board, and the multiple emitting units form multiple emitting arrays. At least one of the multiple emitting arrays includes the target emitting unit, and the target emitting unit is arranged on one side of the first target plane; and the emitting module emitting light path guiding module, and the emitting light path guiding module guides the laser emitted by the target emitting unit to the first target plane.

[0029] In some embodiments, the vertical field of view of the multiple receiving units is greater than or equal to 100 degrees.

[0030] In some embodiments, the second preset angle is greater than 10 degrees and less than 80 degrees, so that the plurality of receiving units receive the reflected laser light in a zenith area close to the rotation axis.

[0031] In some embodiments, the plurality of receiving units include single photon avalanche diodes.

[0032] In some embodiments, the laser radar also includes a circuit board, the multiple receiving units are arranged on the circuit board and facing the receiving lens unit, the multiple receiving units form a plurality of receiving arrays, and at least one of the multiple receiving arrays includes the target receiving unit; the receiving module also includes a receiving light path guiding module, and the receiving light path guiding module guides the target reflected laser propagating along the second target plane out of the second target plane to be incident on the target receiving unit.

[0033] In the third aspect, the present application provides a laser radar. The laser radar includes a base, a transmitting module and a receiving module. The base rotates around the rotation axis when the laser radar is in operation; the transmitting module is installed on the base and transmits an outgoing laser when in operation; the receiving module is installed on the base and receives the reflected laser formed when the outgoing laser encounters an object when in operation, wherein the transmitting module includes a transmitting lens unit and a plurality of transmitting units, the transmitting lens unit has an transmitting optical axis, the projection of the transmitting optical axis on the reference plane forms a first target plane with the transmitting optical axis, wherein the reference plane is perpendicular to the rotation axis, and the plurality of transmitting units transmit the outgoing laser when in operation, and the outgoing laser is emitted outside the laser radar through the transmitting lens unit, wherein the plurality of transmitting units include a target The transmitting unit comprises a target outgoing laser emitted by the target transmitting unit and located on the first target plane. The receiving module comprises a receiving lens unit and a plurality of receiving units. The receiving lens unit has a receiving optical axis. The projection of the receiving optical axis on the reference plane and the receiving optical axis form a second target plane. The reflected laser is incident on the receiving module through the receiving lens unit, wherein the reference plane is perpendicular to the rotation axis. The plurality of receiving units face the receiving lens unit and are located on the optical path of the reflected laser to receive the reflected laser. The plurality of receiving units include a target receiving unit. The reflected laser includes a target reflected laser. The target reflected laser propagates along the second target plane and is incident on the target receiving unit.

[0034] As can be seen from the above technical solution, this specification provides a laser radar comprising a target transmitting unit located within a first target plane and a target receiving unit located within a second target plane. The target-emitting laser light emitted by the target transmitting unit can be emitted parallel to the rotation axis after passing through the transmitting lens unit and then emitted to the exterior of the laser radar, thereby enabling detection of the zenith region. The target receiving unit can receive the target-reflected laser light parallel to the rotation axis. The laser radar can obtain point cloud data of the zenith region, thereby enabling the stitching of the point cloud data of the zenith region. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of this specification, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0036] FIG1 shows a working scenario of a laser radar according to some embodiments of this specification;

[0037] FIG2A shows a cross-sectional view of a laser radar according to some embodiments of the present specification;

[0038] FIG2B is a schematic diagram showing a laser radar emitting multiple laser beams during operation according to some embodiments of this specification;

[0039] FIG3A shows a schematic diagram of a transmitting module in operation according to some embodiments of this specification;

[0040] FIG3B is a schematic diagram showing how the emitted laser forms a scanning blind zone in the zenith area;

[0041] FIG3C shows a schematic diagram of the optical path of an outgoing laser according to some embodiments of this specification;

[0042] FIG4A shows a schematic diagram of a transmitting module including a target transmitting unit in operation according to some embodiments of the present specification;

[0043] FIG4B shows a schematic diagram of a transmitting module in operation according to some embodiments of this specification;

[0044] FIG4C shows a schematic diagram of the arrangement of multiple transmitting units according to some embodiments of this specification;

[0045] FIG5 shows a schematic diagram of target-emitting laser scanning according to some embodiments of this specification;

[0046] FIG6A shows a schematic diagram of a receiving module in operation according to some embodiments of this specification;

[0047] FIG6B shows a schematic diagram of the distribution of receiving units according to some embodiments of this specification;

[0048] FIG7 shows a schematic diagram of the distribution of transmitting units and receiving units according to some embodiments of this specification;

[0049] FIG8A shows an installation method of a laser radar according to some embodiments of the present application; and

[0050] FIG8B shows another installation method of a laser radar according to some embodiments of the present application. DETAILED DESCRIPTION

[0051] The following description provides specific application scenarios and requirements for this specification, with the goal of enabling those skilled in the art to make and use the contents of this specification. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of this specification. Therefore, this specification is not limited to the embodiments shown, but is intended to be accorded the broadest scope consistent with the claims.

[0052] The terms used herein are for the purpose of describing specific example embodiments only and are not intended to be limiting. For example, as used herein, the singular forms "a," "an," and "the" may also include the plural forms unless the context clearly indicates otherwise. When used in this specification, the terms "comprise," "include," and / or "contain" are intended to refer to the presence of the associated integers, steps, operations, elements, and / or components, but do not preclude the presence of one or more other features, integers, steps, operations, elements, components, and / or groups or the addition of other features, integers, steps, operations, elements, components, and / or groups in the system / method.

[0053] In this specification, "X includes at least one of A, B, or C" means that X includes at least A, or X includes at least B, or X includes at least C. In other words, X may include only any one of A, B, and C, or any combination of A, B, and C, as well as other possible contents / elements. Any combination of A, B, and C may be A, B, C, AB, AC, BC, or ABC.

[0054] In this specification, unless otherwise specified, the association relationship between structures can be a direct association relationship or an indirect association relationship. For example, when describing "A is connected to B", unless it is clearly stated that A is directly connected to B, it should be understood that A can be directly connected to B or indirectly connected to B; for another example, when describing "A is above B", unless it is clearly stated that A is directly above B (AB are adjacent and A is above B), it should be understood that A can be directly above B or indirectly above B (AB is separated by other elements and A is above B). And so on.

[0055] These and other features of this specification, as well as the operation and function of the associated elements of the structure, and the economical assembly and manufacture of the components, can be significantly improved with consideration of the following description. Reference is made to the accompanying drawings, all of which form a part of this specification. However, it should be expressly understood that the drawings are for illustration and description purposes only and are not intended to limit the scope of this specification. It should also be understood that the drawings are not drawn to scale.

[0056] The flowcharts used in this specification illustrate operations implemented by systems according to some embodiments of the present specification. It should be clearly understood that the operations of the flowcharts may not be implemented in sequence. Rather, the operations may be implemented in reverse order or simultaneously. Furthermore, one or more additional operations may be added to the flowcharts. One or more operations may be removed from the flowcharts.

[0057] Before describing the specific embodiments of this specification, the structure and working process of the laser radar are briefly described with reference to FIG1 .

[0058] Figure 1 shows an operating scene 001 of a laser radar 10 provided according to some embodiments of this specification. Scene 001 includes the laser radar 10 and an obstacle (or target object) 20. The laser radar 10 may include a transmitting system and a receiving system. The transmitting system may include a transmitting module 100. The transmitting module 100 may transmit an outgoing laser beam toward the object 20. The receiving system may include a receiving module 200. The receiving module 200 may receive reflected laser beams formed after the outgoing laser beams are reflected by the object 20. Based on the reflected laser beams, the laser radar 10 may obtain detection information of the object 20, such as the distance, position, height, shape, attitude, and speed of the object 20 relative to the laser radar 10. The transmitting module 100 may include multiple transmitting units 110 and a transmitting lens unit 120. The transmitting unit 110 may transmit an outgoing laser beam. The outgoing laser beams are then emitted outside the laser radar after passing through the transmitting lens unit 120. The receiving module 200 may include multiple receiving units 210 (receiving unit group 210) and a receiving lens unit 220. The receiving unit 210 may receive reflected laser light generated when the emitted laser light is reflected by the object 20 .

[0059] In some embodiments, the transmitting module 100 may include a transmitting circuit board. Multiple transmitting units are disposed on the transmitting circuit board. The receiving module includes a receiving circuit board. Multiple receiving units 210 are disposed on the receiving circuit board. In other embodiments, the laser radar 10 may include a circuit board. Multiple transmitting units 110 and multiple receiving units 210 may be disposed on the same circuit board. This facilitates alignment of the transmitter and receiver. For example, the transmitting module 100 may also include a driver circuit. The driver circuit may be integrated on a chip. The laser radar 10 includes a driver chip. The receiving module 200 may also include a readout circuit. The readout circuit may be integrated on a chip. The receiving module 200 includes a readout chip. The driver chip and the receiving chip may be soldered to the circuit board. A single circuit board can be used to control the transmitting and receiving modules, reducing signal time difference offset and improving ranging accuracy. The following description uses the example of the transmitting and receiving units being disposed on the same circuit board.

[0060] Figure 2A shows a cross-sectional view of a laser radar 10 according to some embodiments of this specification. Due to obstruction, only the cross-sectional view of the transmitting module 100 structure is shown in Figure 2A. The receiving module 200 is obscured behind the transmitting module 100. Figure 2B shows a schematic diagram of the laser radar 10 according to some embodiments of this specification emitting multiple laser beams during operation. As shown in Figure 2A, the transmitting module 100 also includes a lens barrel 300. The laser radar 10 also includes a control circuit board 400 and a base 500. The transmitting module 100 and the receiving module 200 can be connected to the control circuit board 400. The transmitting lens unit 120 of the transmitting module 100 is disposed within the lens barrel 300. The transmitting module 100 and the receiving module 200 are fixed to the base 500. When the laser radar 10 is in operation, the transmitting module 100 and the receiving module 200 can rotate 360° around the rotation axis R along with the base 500. Simultaneously, the transmitting module 100 emits outgoing laser light. The receiving module 200 receives the reflected laser light generated when the outgoing laser light encounters an object, thereby detecting the surrounding environment of the laser radar 10 .

[0061] For the convenience of the following description, in this application, the direction of the rotation axis R in Figure 2A is defined as the zenith direction of the laser radar. If the orientation of the plane in which the base 500 is located is horizontal, the rotation axis R in Figure 2A points to the sky. At this time, the zenith direction points to the sky. If the laser radar is rotated 90° clockwise, the rotation axis R points to the right (-X direction of Figure 2A). At this time, the zenith direction of the laser radar 10 points to the right. Continue to rotate the laser radar 90° clockwise, and the rotation axis R points to the ground (the direction opposite to the direction indicated by the R arrow in Figure 2A). At this time, the zenith direction of the laser radar 10 points to the ground. Rotate the laser radar 90° clockwise again, and the rotation axis R points to the left (X direction of Figure 2A), then the zenith direction of the laser radar 10 points to the left.

[0062] For this description, the plane where the base 500 is located is horizontal, with the rotation axis R in FIG2A pointing toward the sky. In this case, the sky direction is the zenith direction. In this case, the field of view of the laser radar 10 perpendicular to the horizontal plane is the vertical field of view. The situation where the plane where the base 500 is located is located in other orientations will be described later.

[0063] Different transmitting units have different relative positions to the transmitting optical axes of the transmitting lens unit 120, so the transmitting lens unit 120 has different degrees of deflection of the emitted lasers of different transmitting units. When working, the laser radar 10 can emit outgoing lasers to different azimuths within the vertical field of view angle range, and receive reflected lasers reflected back by objects at corresponding azimuths, thereby obtaining point cloud data within the vertical field of view angle range. For example, in Figure 2B, the total number of beams emitted by the laser radar 10 is 40 (part of the beams is shown in Figure 2B). The vertical field of view angle of the laser radar 10 is 23°. The scanning angle of the upper edge of the vertical field of view relative to the horizontal direction X is 7°, and the scanning angle of the lower edge relative to the horizontal direction X is -16°. In the case of the vertical field of view angle shown in Figure 2B, it is difficult for the laser radar 10 to detect the space above the radar. In one or more embodiments of the present disclosure, a laser radar is provided that can increase the pitch angle of the transmitting module 100 and the receiving module 200. By orienting the transmitting optical axis A1 (shown in Figures 3A and 4A) of the transmitting lens unit 120 and the receiving optical axis A2 (shown in Figure 6A) of the receiving lens unit 220 relative to the base 500 toward the direction of the rotation axis R, the emitted laser light can be directed toward the zenith of the laser radar 10 in the vertical field of view. This increases the detection range of the laser radar 10 between the horizontal direction X and the rotation axis R (zenith direction). The area in the zenith direction of the laser radar 10 and the adjacent area can be represented as the zenith area.

[0064] In the actual use of the laser radar 10, in order to further eliminate the transmission and reception blind spots in the zenith area, this application takes the transmitting end as an example to describe the detection blind spot problem of the existing laser radar 10. The blind spot problem of the receiving end is similar.

[0065] For ease of description, we first define the direction indicated by the rotation axis R of the laser radar 10 as the zenith direction. For example, if the rotation axis R of the laser radar 10 points directly upward, then the direction directly upward is the zenith direction. If the laser radar is rotated 90°, with the rotation axis R pointing to the right, then the right direction is the zenith direction of the laser radar 10. The blind spot that exists during the detection process of the laser radar 10 is the detection blind spot in the zenith area.

[0066] Specifically, Figure 3A shows a schematic diagram of the operation of the transmitting module 100 according to some embodiments of this specification. Figure 3B shows a schematic diagram of how the output laser L1 forms a scanning blind zone in the zenith area. Figure 3C shows a schematic diagram of the optical path of the output laser L1 according to some embodiments of this specification.

[0067] As shown in Figure 3A, multiple transmitting units 110 can be distributed on the control circuit board 400. According to some embodiments of the present application, multiple transmitting units 110 can be arranged in an array on the control circuit board 400. For example, multiple transmitting units 110 form several one-dimensional arrays (for example, linear arrays). These linear arrays are symmetrically distributed along the transmitting central axis C1. The control circuit board 400 is located on one side of the rotation axis R, that is, the multiple transmitting units 110 are all located on one side of the rotation axis R. There is a distance between the linear array formed by the multiple transmitting units 110 and the rotation axis R. Furthermore, the transmitting lens unit 120 is configured so that its optical axis passes perpendicularly through the transmitting central axis C1. The posture of the transmitting module 100 is configured so that the plane determined by the transmitting optical axis A1 and the transmitting central axis C1 (referred to as the first target plane) is parallel to the rotation axis R. Exemplarily, the first target plane is perpendicular to the plane where the control circuit board 400 is located.

[0068] Along the emission direction of the laser, assuming that the outgoing laser light L1 emitted by a certain emitting unit 110P on one side of the emission center axis C1 is parallel to the optical axis A1, the laser light L1 will be refracted by the emitting lens unit 120 toward the focus O located on the optical axis A1. In FIG3A , from the direction from the control circuit board 400 to the emitting lens unit 120, the emitting unit 110P and the outgoing laser light L1 are located at the lower left of the optical axis A1, so the refraction direction of L1 is to the upper right. As shown in FIG3C , assuming that each emitting unit 110 emits an outgoing laser light parallel to the optical axis A1, the outgoing laser light will converge at the focus O of the emitting lens unit 120. However, because no emitting unit 110 is located on the emission center axis C1, the outgoing laser light emitted by the emitting unit 110 will be refracted to the right, upper right, or lower right after passing through the emission lens unit 120, or will be refracted to the left, upper left, or lower left. In other words, the outgoing laser light emitted by the transmitting unit assembly 110 along the optical axis A1 cannot be parallel to the first target plane after being refracted by the output lens unit 120. Because the rotation axis R is parallel to the target plane, even if the pitch angle of the transmitting module 100 is adjusted so that the upper edge of its vertical field of view is parallel to the rotation axis R, all outgoing laser light emitted by the transmitting unit 110 along the optical axis A1 cannot be parallel to the rotation axis R.

[0069] When the laser radar 10 rotates about the rotation axis R, the outgoing laser light L1 rotates about the rotation axis R. Since the outgoing laser light L1 always forms a non-zero angle with the rotation axis R, the rotation of L1 about R produces a scanning surface with the outer contour of a single-leaf hyperboloid, as shown in Figure 3B . As can be seen in Figure 3B , the characteristic of a single-leaf hyperboloid is that the radius of the opening of the surface decreases and then gradually increases upward along the rotation axis R. The laser radar 10 will not be able to detect objects 20 in the zenith or nearby areas through which the outgoing laser light L1 passes. Consequently, the laser radar 10 will not be able to obtain information about objects 20 in the zenith area. As the distance from which the outgoing light beam L1 is emitted increases (the detection range of the laser radar 10 is several hundred meters), the detection blind spot in the zenith area becomes larger and larger. As long as no transmitting unit 110 is on the transmitting central axis C1, each outgoing laser beam L1 cannot be parallel to the rotation axis R. Therefore, no matter how the elevation angle of the transmitting module 100 is adjusted, the laser radar 10 will always have a blind spot in its zenith area.

[0070] In order to solve the problem of detection blind spots in the zenith area, the laser radar 10 must first prevent the detection blind spots from becoming larger and larger in the zenith area. In order to prevent the detection blind spots of the laser radar 10 from becoming larger and larger in the zenith area, at least one beam of the outgoing laser light emitted from the laser radar 10 must be parallel to the rotation axis R. This is because the scanning trajectory formed by the outgoing laser light parallel to the rotation axis R after rotating around the rotation axis R is cylindrical. The transmitting module 100 is close to the rotation axis R, and the distance between the multiple transmitting units 110 and the rotation axis R is in the millimeter order, which is less than the detection accuracy of the laser radar point cloud. Therefore, the cylindrical detection blind spot will not affect the accuracy of the point cloud image obtained by the laser radar, so the blind spot can be ignored. The outgoing laser light parallel to the rotation axis R is a laser light that is only deflected in the up and down directions after passing through the transmitting lens unit 120. As can be seen from the structures in Figures 3A-3C, because the rotation axis R is parallel to the first target plane (i.e., the plane where the optical axis A1 and the emission center axis C1 are located), only the laser light beam emitted along the target plane can be parallel to the rotation axis R after being refracted by the emission lens unit 120.

[0071] Based on the above analysis, this specification provides a laser radar 10 that can address the aforementioned issues. Figure 4A shows a schematic diagram of a transmitter module 100 including a target transmitting unit 211, according to some embodiments of this specification, in operation. Figure 4B shows a schematic diagram of a transmitter module 100 in operation, according to some embodiments of this specification. Figure 4C shows a schematic diagram of the arrangement of multiple transmitter units 110, according to some embodiments of this specification. In Figure 4A, reference plane Rf is perpendicular to the rotation axis R. For example, reference plane Rf can be the plane on which the base 500 is located, or any plane perpendicular to the rotation axis R. The transmitting lens unit 120 has a transmitting optical axis A1. The perpendicular projection of the transmitting optical axis A1 onto the reference plane Rf and the transmitting optical axis A1 form a first target plane D1. The line on the transmitting lens unit 120 that intersects the first target plane D1 is the transmitting lens centerline m1. As shown in Figure 4A, the first target plane D1 is parallel to the rotation axis R. The transmitting lens centerline m1 passes through the transmitting optical axis A1. The transmitting module 100 includes multiple transmitting units 110 and a transmitting lens unit 120. The transmitting lens unit 120 may include a single lens or a combination of multiple lenses. As shown in FIG4A , the multiple transmitting units 110 can emit outgoing laser light when in operation. The outgoing laser light passes through the transmitting lens unit 120 and exits the laser radar 10. The multiple transmitting units 110 include a target transmitting unit 111. The target outgoing laser light L4 emitted by the target transmitting unit 111 is located on the first target plane D1.

[0072] In some embodiments, the target outgoing laser light L2 is located on the first target plane D1 because the target transmitting unit 111 is located on the first target plane D1. Therefore, the target outgoing laser light L2 emitted by the target transmitting unit 11 is located on the first target plane D1. In some embodiments, the target transmitting unit 111 may also be located to one side of the first target plane D1. That is, the target transmitting unit 111 is not located on the first target plane D1. In this case, the laser radar 10 also includes a transmission light path guidance module. The transmission light path guidance module guides the outgoing laser light emitted by the at least one target transmitting unit 111 onto the first target plane D1 so that the outgoing laser light is incident on the transmitting lens unit 120 along the first target plane D1. For example, the transmission light path guidance module may include a reflector. The outgoing laser light emitted by the target transmitting unit 111 is located within the first target plane D1 after passing through the reflector, and then is emitted outside the laser radar 10 after passing through the transmitting lens unit 120. All situations in which the outgoing laser light incident on the transmitting lens unit 120 is located within the first target plane D1 are within the scope of protection of this specification. The following description will be made by taking an example where the target emitting unit 111 is located on the first target plane D1 and the target outgoing laser light L2 emitted by the target emitting unit 111 is located on the first target plane D1 .

[0073] The target emitting unit 111 is located on the first target plane D1, and the target outgoing laser light L2 it emits is parallel to the optical axis A1. Therefore, the target outgoing laser light L2 is also on the first target plane D1 and can pass through the transmitting lens centerline m1 of the transmitting lens unit 120. Regardless of how the transmitting lens unit 120 refracts the target outgoing laser light L2, the target outgoing laser light L2 will only be refracted in the vertical direction relative to the transmitting lens centerline m1, and will not be deflected in the left-right direction relative to the transmitting lens centerline m1. After being refracted by the transmitting lens unit 120, the target outgoing laser light L2 will always be located on the first target plane D1 and will not be located outside the first target plane D1. The target outgoing laser light L2 emitted by the emitting unit 110 (target emitting unit 111) located on the first target plane D1 passes through the transmitting lens centerline m1 of the transmitting lens unit 120 when it enters the transmitting lens unit 120. After being deflected by the transmitting lens unit 120, the target outgoing laser light L2 is located within the first target plane D1. The first target plane D1 is parallel to the rotation axis R. Therefore, the emission direction of the target emitted laser L2 after passing through the emission lens unit 120 can be adjusted to be parallel to the rotation axis R by adjusting the pitch angle of the emission module 100 .

[0074] It should be noted that the illustration of only one lens in FIG4A is merely an example. In a specific implementation, the laser radar 10 may include one or more lenses or lens groups. As shown in FIG4B , the transmitting lens unit 120 includes four lenses. After being deflected multiple times by the transmitting lens unit 120, the emitted laser light is emitted outside the laser radar 10. The direction of the target emitted laser light L2 after exiting the transmitting lens unit 120 is adjusted to be parallel to the rotation axis R.

[0075] By setting at least one target emitting unit 111 on the first target plane D1, it is ensured that there is at least one target outgoing laser L2 in the multiple target units 110. The target outgoing laser L2 is still within the first target plane after being refracted by the emitting lens unit 120. In this way, the target outgoing laser L2 can be adjusted to be parallel to the rotation axis R by adjusting the pitch angle of the transmitting module 100, that is, emitted in the zenith direction. In this way, the scanning trajectory formed by the target outgoing laser L2 after rotating around the rotation axis R is a cylinder. The transmitting module 100 is close to the rotation axis R, and the diameter of the cylinder is in the millimeter level, which is smaller than the detection accuracy of the laser radar point cloud. In this way, the cylindrical scanning blind area will not affect the accuracy of the point cloud image obtained by the laser radar. The laser radar 10 with the above structure is equivalent to having no scanning blind area in its zenith area within the preset distance range.

[0076] Accordingly, multiple transmitting units 110 can be disposed on the control circuit board 400. The control circuit board 400 can overlap with the first focal plane. In some embodiments, the overlap can be achieved by ensuring that the distance between the control circuit board 400 and the first focal plane does not exceed a first threshold. The first threshold can be any value between 0.01 mm and 1 mm, such as 1 mm, 0.5 mm, 0.1 mm, or 0.05 mm. The first focal plane is the plane that passes through the focal point of the transmitting lens unit 120 near the base 500 and is perpendicular to the transmitting optical axis A1. After passing through the transmitting lens unit 120, the emitted laser beam is emitted from the lidar 10 to the outside. The projection of the first target plane D1 onto the control circuit board 400 can be the transmitting central axis C1. It should be noted that the transmitting central axis C1 here is determined by projecting the first target plane D1 onto the control circuit board 400, as opposed to determining it based on the axis of symmetry between two rows of transmitting units 110. Therefore, the arrangement of the multiple transmitting units 110 can be symmetrical or asymmetrical with respect to the transmitting central axis C1.

[0077] For example, as shown in FIG4C , a plurality of transmitting units 110 can be arranged into an array 10A. A plurality of transmitting units 110 can be divided into multiple groups. A group of transmitting units 110 forms a transmitting array. A transmitting array may include multiple transmitting units 110. A transmitting array may be a chip (die). A certain number of transmitting units 110 may be set on the chip to emit outgoing laser light. For example, the laser radar 10 shown in FIG4C includes 8 transmitting chips, die1 to die8. A transmitting array is formed on a transmitting chip. A transmitting chip (a transmitting array) may include 32 transmitting units 110. The transmitting units 110 of the transmitting array may be divided into 4 columns, and arranged in a form in which each column includes 8 transmitting units.

[0078] To enable the laser radar 10 to achieve a predetermined vertical field of view, multiple transmitting arrays can be arranged in a row. For example, multiple first transmitting arrays can be arranged on the first side of the transmitting axis C1, forming a first row 10A1. Multiple second transmitting arrays can be arranged on the second side of the transmitting axis C1, forming a second row 10A2. The first and second rows are arranged parallel and equidistant from the transmitting axis C1. Neither the first nor the second row lies on the transmitting axis C1. The first and second rows can also be arranged symmetrically about the transmitting axis C1. The transmitting arrays in the first and second rows can also be staggered about the transmitting axis C1. As shown in Figure 4C, the first row 10A1 includes die 2, die 4, and die 6. The second row 10A2 includes die 1, die 3, die 5, and die 7. The multiple first transmitting arrays in the first row 10A1 and the multiple second transmitting arrays in the second row 10A2 are staggered about the transmitting axis C1. The third row 10A3 includes die 8. The multiple transmitting units 110 can also include a set of third transmitting arrays. The third transmitting row forms a third row 10A3. The third queue A3 is connected to the first queue and includes a target emitting unit 111. The connection can be that the straight line where the first queue A1 is located intersects the straight line where the third queue A3 is located. The target emitting unit 111 is located on the emission center axis C1. The third queue A3 in Figure 4C includes die8. The straight line where die8 is located is connected to the straight line where die6 of the first queue is located. Die1-die7 are all parallel to the emission center axis C1. Chip die8 is tilted at an angle that is not 0 relative to the emission center axis C1. This makes one of the target emitting units 111 in the third queue 10A3 located on the emission center axis C1. In this way, the target emission laser L2 emitted by the target emission unit 111 can be located in the first target plane D1, so that there is a possibility of parallelism between the target emission laser L2 and the rotation axis R.

[0079] As previously mentioned, to prevent the laser radar 10 from experiencing an increasingly large detection blind spot in the zenith region, at least one target laser beam L2 emitted from the laser radar 10 must be parallel to the rotation axis R. The laser radar 10's emission optical axis A1 and the rotation axis R form a first preset angle. The distance between the target emission unit 111 and the emission optical axis A1 is a first preset value. This ensures that the emission direction of the target laser beam L2 emitted by at least one target emission unit 111, after being deflected by the emission lens unit 120, is parallel to the rotation axis R.

[0080] The distance between the target emitting unit 111 and the emission optical axis A1 is a first preset value. The first preset value can be obtained based on a first preset angle between the emission optical axis A1 and the rotation axis R. When the angle between the emission optical axis A1 and the rotation axis R and the focal length of the emission lens unit 120 are determined, the distances between the emission units 110 at different positions and the emission optical axis A1 are different, so that the degree to which the emitted laser is deflected by the emission lens unit 120 is also different. For example, the emitted laser emitted by the emission unit 110 close to the emission optical axis A1 is deflected to a small extent. The emitted laser emitted by the emission unit 110 far from the emission optical axis A1 is deflected to a large extent. When the angle between the emission optical axis A1 and the rotation axis R is determined, the distance between the target emitting unit 111 and the emission optical axis A1 can be selected so that the target emitted laser L2 emitted by the target emitting unit 111 is parallel to the rotation axis R.

[0081] 4A , the target emitting unit 111 may include the emitting unit that is farthest from the emitting optical axis A1 among all the emitting units. For example, when the reference plane Rf is the plane where the base 500 is located, or is located below the control circuit board 400, the target emitting unit 111 may be located on the control circuit board 400 at a position close to the reference plane Rf. The emitting lens unit 120 deflects the target outgoing laser L2. After deflection, the target outgoing laser L2 located at the bottom can become the target outgoing laser L2 closest to the rotation axis R. As a result, the target outgoing laser L2 is closer to the zenith area, allowing detection of the zenith area. By selecting a suitable focal length of the emitting lens unit 120 and a combination of lenses included in the emitting lens unit 120, the target outgoing laser L2 closest to the rotation axis R can also be made parallel to the rotation axis R. This solves the problem of the laser radar 10 having an increasingly larger detection blind spot in the zenith area and reduces the range of the laser radar 10's detection blind spot in the zenith area.

[0082] Figure 5 illustrates a schematic diagram of scanning a target outgoing laser light L2, according to some embodiments of the present disclosure. Figure 5 illustrates the scanning of the target outgoing laser light L2 (parallel to the rotation axis R) emitted by the target emitting unit 111 after one rotation about the rotation axis R, as well as the scanning of the outgoing laser light L1 (non-parallel to the rotation axis R) emitted by an emitting unit not located on the emission center axis C1 after one rotation about the rotation axis R. The target outgoing laser light L2 forms a cylinder with a radius r after rotating about the rotation axis R. The outgoing laser light L1 (not in the same plane as the target outgoing laser light L2) forms a single-leaf hyperboloid with a gradually changing opening radius (not shown in Figure 5). Figure 5 shows two cross-sections of the single-leaf hyperboloid with opening radii r1 and r2, respectively, marked on the single-leaf hyperboloid (indicated by dashed lines in Figure 5). It can be seen that the target outgoing laser light L2 is closest to the cylinder, so the cylinder's radius r is smaller than the cross-sectional radii r1 and r2 of the single-leaf hyperboloid. As the outgoing laser light travels farther toward the zenith region, r1 and r2 become much larger than r. In a laser radar, the distance between the transmitting unit 110 and the rotation axis R can be very small, for example, on the order of millimeters (mm). Therefore, the radius r of the cylinder obtained by rotating the target emitting laser L2 closest to the rotation axis R is also very small, also on the order of millimeters (mm). Such a large scanning blind area is smaller than the point cloud accuracy of the laser radar 10 and can be ignored. Therefore, it can be considered that the target emitting laser L2 can complete the scanning of the zenith or the zenith area. Combined with the scanning of other transmitting units 110, it is equivalent to the laser radar 10 being able to fully cover the zenith and the surrounding areas. The "stitching" of the point cloud in the zenith blind area is achieved. The laser radar 10 will not miss objects in the zenith and the surrounding areas when scanning.

[0083] In some embodiments, the plurality of emitting units may include a plurality of target emitting units 111. The plurality of target emitting units 111 emit multiple target laser beams located on a first target plane D1. For example, the plurality of target emitting units 111 are disposed on an emission central axis C1. The plurality of target emitting units 111 are located at different distances from the emission optical axis A1.

[0084] In some embodiments, the laser radar 10 can set a transmitting unit 110 at a position close to the base 500 on the control circuit board 400, under the condition that there is a target outgoing laser L2 parallel to the rotation axis R. This makes the outgoing laser of the transmitting unit 110 closer to the rotation axis R after being deflected. The outgoing laser L1 of the transmitting unit 110 is not on the first target plane D1, and a single-leaf hyperboloid is still obtained during the rotation scanning process, and a larger opening will appear at a farther distance. However, after the outgoing laser L1 is deflected by the transmitting lens unit 120, the distance from the rotation axis R is very close, for example, on the order of cm. The smallest radius of the opening radius of the single-leaf hyperboloid is also on the order of cm. At the smallest opening, the laser radar 10 can be regarded as having achieved "stitching" in the zenith area.

[0085] Figure 6A shows a schematic diagram of the receiving module 200 in operation according to some embodiments of the present specification. Figure 6B shows a schematic diagram of the distribution of the receiving unit 210 according to some embodiments of the present specification.

[0086] Similar to the principle that the transmitting end has a blind spot, the original laser radar also has a receiving blind spot when receiving. In order to be able to receive the reflected laser from the zenith area, this specification provides a laser radar 10, in which the receiving module 200 is installed on the base 500 and rotates around the rotation axis R together with the base 500 during operation. The receiving module 200 can receive the reflected laser formed after the outgoing laser encounters the object 20. The overall structure of the laser radar 10 can adopt the structure described earlier in this specification. The arrangement of the transmitting unit 110 in the transmitting module 100 can adopt the arrangement of the above embodiment, so that the target outgoing laser L2 is parallel to the rotation axis R and emitted outside the laser radar 10.

[0087] The receiving lens unit 220 has a receiving optical axis A2. The projection of the receiving optical axis A2 onto the reference plane Rf forms a second target plane D2 with the receiving optical axis A2. The line on the receiving lens unit 220 that intersects the second target plane D2 is the receiving lens centerline m2. As shown in FIG6A , the second target plane D2 is parallel to the rotation axis R. The second target plane D2 is perpendicular to the plane where the control circuit board 400 is located. The receiving lens centerline m2 passes through the receiving optical axis A2. The receiving module 200 includes multiple receiving units 210 and a receiving lens unit 220. The receiving lens unit 220 can include a single lens or a combination of multiple lenses. Reflected laser light passes through the receiving lens unit and enters the receiving module 200. As shown in FIG6A , the multiple receiving units 210 face the receiving lens unit 220 and are located in the optical path of the reflected laser light. When in operation, the multiple receiving units 210 can receive reflected laser light. The reflected laser light includes target reflected laser light L4. The target reflected laser light L4 propagates along the second target plane D2 and is incident on the target receiving unit 211.

[0088] In some embodiments, the target receiving unit 211 can receive the target reflected laser light L4 propagating along the second target plane D2 because the target receiving unit 211 is located on the second target plane D2, thereby being able to receive the target reflected laser light L4. In other embodiments, the target receiving unit 211 can also be located on one side of the second target plane D2. The target receiving unit 211 is not located on the second target plane D2. In this case, the laser radar 10 also includes a receiving light path guidance module. The at least one target reflected laser light L4 propagates along the second target plane D2. The receiving light path guidance module can guide the at least one target reflected laser light L4 out of the second target plane D2 so that it is incident on the target receiving unit 211. For example, the receiving light path guidance module includes a reflector. The target reflected laser light L4 propagates along the second target plane D2, is deflected by the receiving lens unit 220, and then reflected by the reflector to the target receiving unit 211. All situations in which the laser light incident on the receiving lens unit 220 is located within the second target plane D2 are within the scope of protection of this specification. The following description will be made by taking the case where the target receiving unit 211 is located on the second target plane D2 as an example.

[0089] The target receiving unit 211 is located on the second target plane D2. The target reflected laser light L4 can be reflected by an object 20 in the zenith region. For example, the target reflected laser light L4 can be obtained by reflecting the target outgoing laser light L2 from the object 20. The target reflected laser light L4 can be parallel to the rotation axis R. The target reflected laser light L4 propagates along the second target plane D2. The target reflected laser light L4 is incident on the receiving lens centerline m2 of the receiving lens unit 210. After being refracted in the vertical direction at the receiving lens centerline m2 by the receiving lens unit 210, the target reflected laser light L4 is incident on the target receiving unit 211. The specific analysis process is similar to that of the transmitting end. After being refracted by the receiving lens unit 220, the target reflected laser light L4 is located within the second target plane D2. Since the second target plane D2 is parallel to the rotation axis R, by adjusting the pitch angle of the receiving module 200, the target reflected laser light L4 parallel to the rotation axis R can be received by the target receiving unit 211.

[0090] At least one target receiving unit 211 is disposed on the second target plane D2. The at least one target receiving unit 211 is capable of receiving the target reflected laser light L4 propagating along the second target plane D2. This allows the receiving module 200 to receive the target reflected laser light L4 parallel to the rotation axis R and reflected by the object 20 in the zenith region by adjusting the elevation angle. The laser radar 10 having the above-described structure has no blind spot in its zenith region.

[0091] In actual products, the plurality of receiving units 210 are often arranged on a second focal plane of the receiving lens unit 220. The second focal plane is a plane passing through the focus of the receiving lens unit 220 and perpendicular to the receiving optical axis A2.

[0092] A plurality of receiving units 210 may be provided on the control circuit board 400. The control circuit board 400 may coincide with the second focal plane. In some embodiments, the coincidence may be such that the distance between the control circuit board 400 and the second focal plane does not exceed a first threshold value. The first threshold value may be any value within the range of 0.01 mm to 1 mm. For example, any value such as 1 mm, 0.5 mm, 0.1 mm, or 0.05 mm. The second focal plane is a plane passing through the focal point of the receiving lens unit 220 close to the base 500 and perpendicular to the receiving optical axis A2. The reflected laser light L3 is received by the receiving unit 210 after passing through the receiving lens unit 220. The projection of the second target plane D2 on the control circuit board 400 may be the receiving central axis C2. The arrangement of the plurality of receiving units 210 may be symmetrical or asymmetrical relative to the receiving central axis C2.

[0093] For example, as shown in FIG6B , a plurality of receiving units 210 are arranged into an array 20A. The plurality of receiving units 210 are divided into a plurality of groups. One group forms a receiving array. A receiving array includes a plurality of receiving units 210. A receiving array can be a chip (die). A certain number of receiving units 210 can be set on a chip to receive reflected laser light. For example, the laser radar 10 shown in FIG6B includes 8 receiving chips, namely die1' to die8'. One receiving chip forms a receiving array. A receiving chip (including a receiving array) includes 32 receiving units 210. The receiving units 210 of the receiving array are divided into 4 columns, and are arranged in the form of 8 receiving units 210 in each column.

[0094] To enable the laser radar 10 to achieve a preset field of view in the vertical direction, the receiving arrays can be arranged in a row. For example, multiple first receiving arrays can be arranged on the first side of the receiving axis C2 to form a fourth row 20A1. Multiple second receiving arrays can be arranged on the second side of the receiving axis C2 to form a fifth row 20A2. The fourth row 20A1 and the fifth row 20A2 are arranged parallel and equidistant from the receiving axis C2. Neither the fourth row nor the fifth row lies on the receiving axis C2. The multiple first receiving arrays of the fourth row and the multiple second receiving arrays of the fifth row can be arranged symmetrically about the transmitting axis C1 or staggered about the transmitting axis C1. As shown in Figure 6B, the fourth row 20A1 can include die2', die4', and die6'. The fifth row 20A2 can include die1', die3', die5', and die7'. The first receiving arrays in the fourth row 20A1 and the second receiving arrays in the fifth row 20A2 are staggered about the receiving axis C2. The sixth row 20A3 includes die8'. The multiple receiving units 210 may also include a third receiving array. The third receiving array forms a sixth queue 20A3. The sixth queue is connected to the fourth queue and includes a target receiving unit 211. The connection can be that the straight line where the sixth queue 20A3 is located intersects the straight line where the fourth queue 20A1 is located. The target receiving unit 211 is located on the receiving central axis C3. The sixth queue 20A3 in Figure 6B includes die8'. The straight line where die8' is located is connected to the straight line where die6' of the fourth queue is located. The receiving chips die1'-die7' are all parallel to the receiving central axis C2. The receiving chip die8' is tilted at an angle that is not zero relative to the receiving central axis C2. This allows one of the receiving units 211 in the sixth queue 10A3 to be located on the receiving central axis C2. In this way, the target receiving unit 211 can receive the target reflected laser L4 propagating along the second target plane D2, so that the laser radar 10 has the possibility of receiving the target reflected laser L4 parallel to the rotation axis R.

[0095] As mentioned above, in order for the laser radar 10 to receive the target reflected laser light L4 reflected by the object 20 in the zenith area and parallel to the rotation axis R, the receiving module 200 can be adjusted to an appropriate pitch angle. The receiving optical axis A2 of the laser radar 10 and the rotation axis R can be at a second preset angle. There is also a preset distance (second preset value) between at least one receiving unit 210 and the receiving optical axis A2. The target reflected laser light L4 parallel to the rotation axis R is incident on the receiving lens unit 220, and after being refracted by the receiving lens unit 220, it can be received by the target receiving unit 211.

[0096] 6A , the target receiving unit 211 can be the receiving unit farthest from the receiving optical axis A2 among all the receiving units. For example, when the reference plane Rf is the plane where the base 500 is located, or is located on the plane below the control circuit board 400, the target receiving unit 211 can be located on the control circuit board 400 at a position close to the reference plane Rf. The receiving lens unit 220 will deflect the target receiving laser L4. The target receiving laser L4 that is closest to the rotation axis R and closest to the zenith area will be located at the bottom of all the transmitted lasers after deflection. By selecting a suitable focal length of the receiving lens unit 220 and a combination of lenses included in the receiving lens unit 220, the target reflected laser L4 that is closest to the rotation axis R can also be made to enter the target receiving unit 211. This solves the problem of the laser radar 10 having a receiving blind spot in the zenith area.

[0097] The transmitting module 100 and the receiving module 200 can be arranged side by side and oriented in the same direction. The transmitting module 100 and the receiving module 200 can be distributed on both sides of the rotation axis R. The distance between the rotation axis R and the transmitting optical axis A1 is equal to the distance between the rotation axis R and the receiving optical axis A2. The transmitting unit 110 in the transmitting module 100 and the receiving unit 210 in the receiving module 200 can have a corresponding relationship. For example, the above-mentioned corresponding relationship can be a one-to-one relationship, a one-to-many relationship, or a many-to-one relationship. For example, Figure 7 shows a schematic diagram of the distribution of the transmitting unit 110 and the receiving unit 210 provided according to some embodiments of this specification. As shown in Figure 7, a plurality of transmitting units 110 and a plurality of receiving units 210 are provided on the control circuit board 400. The plurality of receiving units 210 and the plurality of transmitting units 110 can have the same distribution pattern, so that the plurality of transmitting units 110 can correspond one-to-one with the plurality of receiving units 210. The outgoing laser light L1 emitted by a transmitting unit 110 can be received by the corresponding receiving unit 210 after being reflected by the object 20. For example, when the target transmitting unit 111 is the transmitting unit farthest from the transmitting optical axis A1 among all transmitting units, the target receiving unit 211 is the receiving unit farthest from the receiving optical axis A2 among all receiving units. The lidar 10 may also include a driver chip and a readout chip. The driver chip can be used to drive the transmitting unit 110 to emit laser pulses (emitted laser light). The readout chip can collect and read the electrical signal converted by the echo signal (reflected laser light) by the receiving unit 210.

[0098] In some embodiments, the plurality of receiving units 210 includes a plurality of target receiving units 211. The plurality of target receiving units 211 can receive a plurality of target-reflected laser beams propagating along the second target plane D2. For example, the plurality of target receiving units 211 are disposed on the receiving central axis C3. The plurality of target receiving units 211 are located at different distances from the receiving optical axis.

[0099] It should be noted that the arrangement of multiple transmitting units and multiple receiving units on a single circuit board (transmitting and receiving on a common board) shown in FIG7 is for illustration only. In some embodiments of the present disclosure, the circuit board of the lidar may include a transmitting circuit board and a receiving circuit board. Multiple transmitting units may be arranged on the transmitting circuit board. Multiple receiving units may be arranged on the receiving circuit board. The arrangement of the multiple transmitting units and the multiple receiving units may be the same or similar to the embodiment shown in FIG7.

[0100] In some embodiments, the laser radar 10 may include multiple transmitting units 110. For example, the multiple transmitting units 110 may include vertical-cavity surface-emitting lasers (VCSELs). The VCSEL laser may include multiple VCSEL transmitting units. Multiple VCSEL transmitting units may be driven to emit light at the same time to generate a beam of outgoing laser light. The multiple transmitting units 110 may also include edge emitting lasers (EELs). The EEL laser may emit a laser beam in a direction parallel to the surface of the substrate. The laser may also include a Fabry-Perot (FP) laser, a distributed feedback laser (DFB), and a distributed Bragg reflector (DBR), etc. The multiple transmitting units 110 may also include fiber lasers, solid-state lasers, etc., which are not limited in the embodiments of this specification.

[0101] In some embodiments, the laser radar 10 may include multiple receiving units 210. For example, the multiple receiving units 210 may include single photon avalanche diodes (SPADs). For example, the SPAD may include multiple sub-pixels. Each sub-pixel may sense a light signal and output an electrical signal. The light signal may be an echo signal or an ambient light signal. The multiple receiving units 210 may also include avalanche photodiodes (APDs) or silicon photomultipliers (SiPMs), etc.

[0102] In some embodiments, the vertical field of view of the multiple transmitting units 110 may be greater than or equal to 90 degrees (for example, greater than or equal to 100 degrees). The beam of the outgoing laser may be greater than 128 beams. The vertical field of view of the laser radar 10 is greater than or equal to 90 degrees (for example, greater than or equal to 100 degrees) so that the laser radar 10 can scan the surrounding environment with a wider coverage. The target outgoing laser L2 of the laser radar 10 can be closer to the zenith area. The beam of the outgoing laser is greater than 128 beams so that the laser radar 10 can capture richer details of the object 20. The laser radar has a higher resolution and the point cloud map formed is significantly clearer. The vertical field of view of the multiple receiving units 210 may be greater than or equal to 90 degrees (for example, greater than or equal to 100 degrees) so as to receive the reflected laser emitted by the transmitting unit 110 and reflected by the object 20 over a larger range.

[0103] In some embodiments, the pitch angle (tilt angle) of the emission optical axis A1 of the emitting lens unit 120 relative to the rotation axis R can be greater than 10 degrees and less than 80 degrees. The first preset angle is greater than 10 degrees and less than 80 degrees. The emitted laser can be close to the zenith area pointed by the rotation axis R. By raising the inclination of the emission optical axis A1 relative to the base 500, the target emission laser L2 emitted by the target emission unit 111 can be made closer to the rotation axis R. The radius r of the cylinder obtained by the target emission laser L2 around the rotation axis R is smaller, achieving a scan that almost covers the zenith. The pitch angle (tilt angle) of the receiving optical axis A2 of the receiving lens unit 220 relative to the rotation axis R can be greater than 10 degrees and less than 80 degrees. The second preset angle is greater than 10 degrees and less than 80 degrees. The receiving unit 210 can receive reflected laser light close to the zenith area pointed by the rotation axis R.

[0104] As mentioned above, the rotation axis R pointing upwards is only one way to install the laser radar 10. In order to adapt to different usage scenarios and usage requirements, the laser radar 10 can be installed in different ways. For example, in the scenario of autonomous driving, in order to detect the road conditions on the left or right, the laser radar 10 is installed horizontally on the vehicle body. The rotation axis R points to the left or right to obtain the conditions of objects on the left or right. For another example, in the scenario of a smart home, in order to monitor the indoor conditions, the laser radar 10 is installed upside down on the roof. The rotation axis of the laser radar 10 points downward to obtain the conditions of objects inside the house.

[0105] Figure 8A illustrates one installation method for a laser radar 10 provided in accordance with some embodiments of the present application. Figure 8B illustrates another installation method for a laser radar 10 provided in accordance with some embodiments of the present application. For example, the laser radar 10 in Figure 8A utilizes an inverted installation method. The base of the laser radar 10 is located above the transmitting and receiving modules. The rotation axis R points directly downward. The laser radar 10 has a vertical field of view of 105 degrees. The laser emitted by the laser radar 10 has an upward scanning range of 15 degrees horizontally and a downward scanning range of 90 degrees horizontally. The inverted laser radar 10 can scan the area directly below and acquire relevant information. To accommodate the field of view distribution of the laser radar 10 when inverted, the top corner of the light shield 600 is designed to be curved. This allows light to be emitted from both the side and top of the light shield 600. This design reduces the incident angle of the emitted laser on the light shield 600 and reduces internal reflections. This results in a more streamlined appearance and improved mechanical properties. The top of the light shield is less likely to collapse under stress. The corners of the mask are less likely to generate stress. The mask 600 also has the advantages of being easier to process, easier to demould, less consumables, and lower cost.

[0106] The laser radar 10 in Figure 8B uses a horizontal installation method. The base of the laser radar 10 is on the left side of the transmitting module and the receiving module. The rotation axis R points to the right. The laser radar 10 has a field of view of 103 degrees. When the laser radar 10 rotates, it can form a complete hemisphere, so that the laser radar 10 has almost no scanning blind spots in the vertical direction. And when the laser radar 10 is installed horizontally on the vehicle body, only the head of the light cover 600 needs to be exposed from the side of the vehicle body. The exposed part of the laser radar is very small, such as only 2 cm. It has good concealment and little impact on the appearance of the entire vehicle. The laser radar 10 in this application supports various tilt installation angles of the rotation axis R from vertical to horizontal, balancing the detection area and the protruding volume, so that users can choose the installation method according to the vehicle model.

[0107] This specification provides a laser radar 10, including a target transmitting unit 111 and a target receiving unit 211. The target transmitting unit 111 is located in a first target plane D1. The target receiving unit 211 is located in a second target plane D2. The target outgoing laser L2 emitted by the target transmitting unit 111 can be parallel to the rotation axis R after passing through the transmitting lens unit 120. The target outgoing laser L2 is emitted to the outside of the laser radar 10, thereby realizing the detection of the zenith area. The target receiving unit 211 can receive the target reflected laser L4 parallel to the rotation axis R. The laser radar 10 can obtain point cloud data of the zenith area, thereby realizing the stitching of point cloud data of the zenith area. Solve the problem of scanning blind spots in the zenith area in the prior art.

[0108] It should be understood that each module or unit in the embodiments described in this disclosure may include one or more physical components in whole or in part. For example, a module may include an optoelectronic device, an optical device (e.g., one or more lenses, reflectors, scanning mirrors, etc.), or a circuit, etc. A module may also include a mechanical frame for mounting the optoelectronic device, optical device, or circuit, etc. For another example, a module or unit may be implemented as a processor, a controller, a computer, or any form of hardware component. For another example, a module or unit may include one or more hardware components and one or more software components. Hardware components include, for example, a processor (e.g., a digital signal processor, a microcontroller, a field programmable gate array, a central processing unit, an application-specific integrated circuit, etc.). Software components include, for example, a computer program. When the computer program is executed on the processor, the functionality of the module can be realized. The computer program may be stored in a memory (e.g., a random access memory, a flash memory, a read-only memory, a programmable read-only memory, a register, a hard disk, a removable hard disk, or any other form of storage medium) or a server.

[0109] It should be understood that each unit in the embodiments described in the present disclosure may include one or more physical components in whole or in part. For example, a unit may be implemented as a transmitter, detector, optical device, processor, circuit, or any form of hardware component. For another example, a unit may include one or more hardware components and one or more software components. For example, the transmitting unit may include a light-emitting circuit, a VCSEL, an EEL, a DFB, or a fiber laser, etc. For another example, the receiving unit may include a detection circuit, a photoelectric conversion circuit, a SPAD, an APD, or a SiPM, etc. The above describes specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps described in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require showing a specific order or a continuous order to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0110] In summary, after reading this detailed disclosure, those skilled in the art will appreciate that the foregoing detailed disclosure may be presented by way of example only and may not be limiting. Although not expressly stated herein, those skilled in the art will understand that this specification encompasses various reasonable changes, improvements, and modifications to the embodiments. Such changes, improvements, and modifications are intended to be suggested by this specification and are within the spirit and scope of the exemplary embodiments of this specification.

[0111] Furthermore, certain terms in this specification have been used to describe embodiments of this specification. For example, “one embodiment,” “an embodiment,” and / or “some embodiments” mean that a particular feature, structure, or characteristic described in connection with that embodiment may be included in at least one embodiment of this specification. Therefore, it is emphasized and should be understood that two or more references to “an embodiment,” “one embodiment,” or “an alternative embodiment” in various parts of this specification do not necessarily refer to the same embodiment. Furthermore, particular features, structures, or characteristics may be appropriately combined in one or more embodiments of this specification.

[0112] It should be understood that in the foregoing descriptions of the embodiments of this specification, to facilitate understanding of a feature and to simplify this specification, various features are combined in a single embodiment, figure, or description thereof. However, this does not necessarily mean that these features are combined. When reading this specification, a person skilled in the art may label some of the devices as separate embodiments. In other words, the embodiments of this specification can also be understood as the integration of multiple sub-embodiments. This also applies when each sub-embodiment contains fewer than all the features of a single previously disclosed embodiment.

[0113] Each patent, patent application, patent application publication, and other materials, such as articles, books, specifications, publications, documents, articles, etc., cited herein is hereby incorporated by reference, except for any content that appears in the patent-related documents that may be inconsistent or conflicting with this document or that may have a limiting effect on the broadest scope of the claims. In addition, if there is any inconsistency or conflict between the description, definition, and / or use of terms associated with any incorporated material and the terminology, description, definition, and / or use associated with this document, the terminology in this document shall control.

[0114] Finally, it should be understood that the embodiments of the application disclosed herein are illustrative of the principles of the embodiments of this specification. Other modified embodiments are also within the scope of this specification. Therefore, the embodiments disclosed in this specification are merely examples and not limitations. Those skilled in the art can adopt alternative configurations based on the embodiments in this specification to implement the application in this specification. Therefore, the embodiments of this specification are not limited to the embodiments precisely described in the application.

Claims

1. A laser radar comprising: a base, which rotates around a rotation axis when the laser radar is in operation; A transmitting module is mounted on the base and emits an outgoing laser when in operation; as well as The receiving module is installed on the base and receives the reflected laser light generated when the outgoing laser hits an object during operation. The transmitting module comprises: an emission lens unit having an emission optical axis, a projection of the emission optical axis on a reference plane and the emission optical axis defining a first target plane, wherein the reference plane is perpendicular to the rotation axis, and Multiple transmitting units transmit the outgoing laser when in operation, and the outgoing laser is emitted outside the laser radar through the transmitting lens unit, wherein the multiple transmitting units include a target transmitting unit, and the target outgoing laser emitted by the target transmitting unit is located on the first target plane.

2. The laser radar according to claim 1, wherein The system further comprises a circuit board, wherein the plurality of transmitting units are arranged on the circuit board, and a projection of the first target plane on the circuit board comprises a transmitting central axis; and The plurality of launch units form a plurality of launch arrays, at least one of the plurality of launch arrays includes the target launch unit, and the target launch unit is located on the launch central axis.

3. The laser radar according to claim 2, wherein: The plurality of transmit arrays include a plurality of first transmit arrays, a plurality of second transmit arrays and at least one third transmit array, The plurality of first transmitting arrays are distributed on the first side of the transmitting central axis to form a first queue. The plurality of second transmitting arrays are distributed on the second side of the transmitting central axis to form a second queue, and the first queue and the second queue are arranged in parallel with the transmitting central axis at equal distances, and The third firing array is connected to the first queue and includes the target firing unit.

4. The laser radar according to claim 3, wherein The emission light axis and the rotation axis form a first preset angle; The distance between the target emitting unit and the emitting optical axis is a first preset value, and the target emitted laser is parallel to the rotation axis after being deflected by the emitting lens unit.

5. The laser radar according to claim 2, wherein: The circuit board and the first focal plane coincide with each other, The first focal plane is a plane passing through the focus of the emission lens unit and perpendicular to the emission optical axis.

6. The laser radar according to claim 2, wherein: The receiving module includes: a receiving lens unit having a receiving optical axis, wherein a projection of the receiving optical axis on the reference plane and the receiving optical axis form a second target plane, and the reflected laser light is incident into the receiving module through the receiving lens unit; and A plurality of receiving units, corresponding to the plurality of transmitting units, are located on the optical path of the reflected laser to receive the reflected laser, The plurality of receiving units include a target receiving unit, the reflected laser includes a target reflected laser, and the target reflected laser propagates along the second target plane and is incident on the target receiving unit.

7. The laser radar according to claim 6, wherein: The plurality of receiving units are arranged on the circuit board and face the receiving lens unit, and the projection of the second target plane on the circuit board includes a receiving central axis; and The plurality of receiving units form a plurality of receiving arrays, at least one of the plurality of receiving arrays includes the target receiving unit, and the target receiving unit is located on the receiving central axis.

8. The laser radar according to claim 7, wherein: The transmitting module and the receiving module are arranged side by side and face the same direction. The rotation axis is equidistant from the transmitting optical axis and the receiving optical axis, and The multiple receiving units and the multiple transmitting units have the same distribution method.

9. The laser radar according to claim 6, wherein: The plurality of receiving units include single photon avalanche diodes.

10. The laser radar according to claim 6, wherein: The plurality of receiving units are arranged on the circuit board and face the receiving lens unit, the plurality of receiving units form a plurality of receiving arrays, at least one receiving array of the plurality of receiving arrays includes the target receiving unit, and the target receiving unit is arranged on one side of the second target plane; as well as The receiving light path guiding module guides the target reflected laser light propagating along the second target plane out of the second target plane so as to be incident on the target receiving unit.

11. The laser radar according to claim 6, wherein: The circuit board includes a transmitting circuit board and a receiving circuit board. The plurality of transmitting units are arranged on the transmitting circuit board, and the plurality of receiving units are arranged on the receiving circuit board.

12. The laser radar according to claim 1, wherein The vertical field of view angles of the multiple emitting units are greater than or equal to 100 degrees, and the number of the emitted laser beams is greater than or equal to 128 beams.

13. The laser radar according to claim 12, wherein: The first preset angle is greater than 10 degrees and less than 80 degrees, so that the emitted laser is close to the zenith area pointed by the rotation axis.

14. The laser radar according to claim 1, wherein The plurality of emission units include vertical cavity surface emitting lasers.

15. The laser radar according to claim 1, wherein The system further includes a circuit board, the plurality of transmitting units are arranged on the circuit board, the plurality of transmitting units form a plurality of transmitting arrays, at least one transmitting array of the plurality of transmitting arrays includes the target transmitting unit, and the target transmitting unit is arranged on one side of the first target plane; and The emission module further includes an emission light path guiding module, which guides the target-emitted laser light onto the first target plane.

16. A laser radar comprising: a base, which rotates around a rotation axis when the laser radar is in operation; A transmitting module is mounted on the base and emits an outgoing laser when in operation; as well as The receiving module is installed on the base and receives the reflected laser light generated when the outgoing laser hits an object during operation. The receiving module includes: a receiving lens unit having a receiving optical axis, wherein a projection of the receiving optical axis on a reference plane and the receiving optical axis form a second target plane, and the reflected laser is incident into the receiving module through the receiving lens unit, wherein the reference plane is perpendicular to the rotation axis, and A plurality of receiving units are located on the optical path of the reflected laser and receive the reflected laser, facing the receiving lens unit, wherein the plurality of receiving units include a target receiving unit, the reflected laser includes a target reflected laser, and the target reflected laser propagates along the second target plane and is incident on the target receiving unit.

17. The laser radar according to claim 16, wherein: It also includes a circuit board, the plurality of receiving units are arranged on the circuit board and face the receiving lens unit, and the projection of the second target plane on the circuit board includes a receiving central axis; and The plurality of receiving units form a plurality of receiving arrays, at least one of the plurality of receiving arrays includes the target receiving unit, and the target receiving unit is located on the receiving central axis.

18. The laser radar according to claim 17, wherein: The plurality of receiving arrays include a plurality of first receiving arrays, a plurality of second receiving arrays and at least one third receiving array. The plurality of first receiving arrays are distributed on the first side of the receiving central axis to form a fourth queue. The plurality of second receiving arrays are distributed on the second side of the receiving central axis to form a fifth queue, and the fourth queue and the fifth queue are arranged equidistantly and parallel to the receiving central axis, and The third receiving array is connected to the fourth queue and includes the target receiving unit.

19. The laser radar according to claim 18, wherein The receiving light axis and the rotation axis form a second preset angle; The distance between the target receiving unit and the receiving optical axis is a second preset value, and the target receiving unit receives the target reflected laser parallel to the rotation axis.

20. The laser radar according to claim 17, wherein: The circuit board and the second focal plane coincide with each other, The second focal plane is a plane passing through the focus of the receiving lens unit and perpendicular to the receiving optical axis.

21. The laser radar according to claim 17, wherein: The transmitting module includes: an emitting lens unit having an emitting optical axis, wherein a perpendicular projection of the emitting optical axis on a reference plane and the emitting optical axis form a first target plane; and A plurality of transmitting units, corresponding to the plurality of receiving units, transmit the outgoing laser to the transmitting lens unit during operation, The plurality of emission units include a target emission unit, and the target emission laser emitted by the target emission unit is located on the first target plane.

22. The laser radar according to claim 21, wherein The plurality of transmitting units are arranged on the circuit board, and the projection of the first target plane on the circuit board includes a transmitting central axis; and The multiple launch units form a plurality of launch arrays, at least one of the multiple launch arrays includes the target launch unit, and the target launch unit is located on the launch central axis.

23. The laser radar according to claim 22, wherein: The transmitting module and the receiving module are arranged side by side and face the same direction. The rotation axis is equidistant from the transmitting optical axis and the receiving optical axis, and The multiple receiving units and the multiple transmitting units have the same distribution method.

24. The laser radar according to claim 21, wherein The plurality of emission units include vertical cavity surface emitting lasers.

25. The laser radar according to claim 21, wherein The plurality of transmitting units are disposed on the circuit board, the plurality of transmitting units forming a plurality of transmitting arrays, at least one transmitting array of the plurality of transmitting arrays includes the target transmitting unit, and the target transmitting unit is disposed on one side of the first target plane; and The emission module includes an emission light path guiding module, which guides the target-emitted laser onto the first target plane.

26. The laser radar according to claim 16, wherein: The vertical viewing angle of the multiple receiving units is greater than or equal to 100 degrees.

27. The laser radar according to claim 26, wherein: The second preset angle is greater than 10 degrees and less than 80 degrees, so that the multiple receiving units receive the reflected laser light in the zenith area close to the rotation axis.

28. The laser radar according to claim 16, wherein: The plurality of receiving units include single photon avalanche diodes.

29. The laser radar according to claim 16, wherein: Also included is a circuit board, the plurality of receiving units are arranged on the circuit board and face the receiving lens unit, the plurality of receiving units form a plurality of receiving arrays, at least one receiving array of the plurality of receiving arrays includes the target receiving unit; as well as The receiving module includes a receiving light path guiding module, which guides the target reflected laser propagating along the second target plane out of the second target plane to be incident on the target receiving unit.

30. A laser radar, characterized in that: include: a base, which rotates around a rotation axis when the laser radar is in operation; A transmitting module is mounted on the base and emits an outgoing laser when in operation; as well as The receiving module is installed on the base and receives the reflected laser light generated when the outgoing laser hits an object during operation. The transmitting module comprises: an emission lens unit having an emission optical axis, a projection of the emission optical axis on a reference plane forming a first target plane with the emission optical axis, wherein the reference plane is perpendicular to the rotation axis, and a plurality of transmitting units, which transmit the outgoing laser when in operation, wherein the outgoing laser is emitted outside the laser radar through the transmitting lens unit, wherein the plurality of transmitting units include a target transmitting unit, and the target outgoing laser emitted by the target transmitting unit is located on the first target plane; and The receiving module includes: a receiving lens unit having a receiving optical axis, a projection of the receiving optical axis on the reference plane and the receiving optical axis forming a second target plane, the reflected laser light is incident into the receiving module through the receiving lens unit, wherein the reference plane is perpendicular to the rotation axis, and A plurality of receiving units are located on the optical path of the reflected laser and receive the reflected laser, facing the receiving lens unit, wherein the plurality of receiving units include a target receiving unit, the reflected laser includes a target reflected laser, and the target reflected laser propagates along the second target plane and is incident on the target receiving unit.

Images