Laser radar and mobile device

Abstract

The embodiment of the invention discloses a laser radar and a mobile device. The laser radar comprises a transmitting module, a receiving module, a beam splitter and a scanning module. The receiving lens satisfies the following conditions: 40mm < = fRX < = 80mm; wherein fRX is the effective focal length of the receiving lens; the beam splitter comprises a light-transmitting part and a light-reflecting part, the light-reflecting part is arranged on the periphery of the light-transmitting part, the light-transmitting part is used for transmitting the detection light, and the light-reflecting part is used for reflecting the echo light; the scanning module is used for emitting the detection light to a target object and transmitting the echo light to the receiving module. According to the invention, the effective focal length fRX of the receiving lens is reduced, so that all or more of the light spots reaching the receiver can be received by the receiving surface, the echo light energy received by the receiver is improved, and the short-distance detection performance of the laser radar is improved.

Description

Technical Field

[0001] This application relates to the field of laser detection equipment technology, and in particular to a lidar and a mobile device. Background Technology

[0002] Due to the widespread use of LiDAR systems in autonomous driving and other advanced applications, their design must accurately detect both distant and near-range targets simultaneously. In LiDAR systems, the receiving system typically employs a telescope configuration to optimize detection performance for distant targets. In this configuration, the object distance is usually assumed to be close to infinity during design, meaning the system is primarily optimized for achieving the best long-range imaging performance.

[0003] However, this design configuration, which is primarily designed for long-range operations, has a significant limitation: it may cause defocusing when detecting close-range targets. Summary of the Invention

[0004] This application provides a lidar and a mobile device that can improve the problem of defocusing when detecting close-range targets in detection systems with large variations in target distance and size, which is designed primarily for long-range detection.

[0005] In a first aspect, embodiments of this application provide a lidar, including a transmitting module, a receiving module, a beam splitter, and a scanning module. The transmitting module is used to transmit detection light; the receiving module is used to receive the echo light formed by the detection light reflected from the target object. The receiving module includes a receiving lens and a receiver, with the receiving lens located on the incident light side of the receiver. The receiving lens satisfies: 40mm ≤ f RX ≤80mm; where f RX The effective focal length of the receiving lens is specified; the beam splitter includes a light-transmitting part and a light-reflecting part, with the light-reflecting part located around the light-transmitting part. The light-transmitting part is used to transmit the probe light, and the light-reflecting part is used to reflect the echo light; the scanning module is used to emit the probe light to the target object and to transmit the echo light to the receiving module.

[0006] The lidar in this embodiment sets the effective focal length f of the receiving lens. RX For lenses with a focal length greater than or equal to 40mm and less than or equal to 80mm, reduce the effective focal length f of the receiving lens. RX Combining the geometric optics formula h = f * tanθ, we can know that the effective focal length f of the receiving lens is... RX Reducing the size of the light spot received on the receiving surface can reduce the size of the light spot, allowing the receiving surface to receive all or more of the light spot, thereby increasing the energy of the echo light received by the receiver.

[0007] In some embodiments, the interface between the light-transmitting part and the reflective part is a cylindrical surface;

[0008] The beam splitter satisfies:

[0009] 10mm≤R≤12mm;

[0010] Where R is the radial dimension of the interface between the light-transmitting part and the reflective part.

[0011] Based on the above embodiments, while ensuring a certain emission efficiency, reducing the size of the light-transmitting part in the middle of the beam splitter is equivalent to reducing the object height of the beam splitter relative to its rear mirror group, thereby reducing the size of the hole (corresponding to the light-transmitting part) in the middle of the light spot hitting the receiver, increasing the area of ​​the light spot hitting the receiver, and realizing the improvement of the echo energy on the receiver.

[0012] In some embodiments, the light-transmitting part is a light-transmitting hole on a beam splitter, and the cross-section of the light-transmitting hole along the radial direction is circular.

[0013] Based on the above embodiments, directly opening a light-transmitting hole on the beam splitter to allow the probe light to pass through can reduce light loss and processing costs compared to setting a portion of the beam splitter as a light-transmitting material to transmit the probe light.

[0014] In some embodiments, the receiver has a receiving surface that satisfies:

[0015] 0.05mm≤H1≤0.2mm;

[0016] Wherein, H1 is the distance between the center of the first light spot and the center of the receiving surface in the first direction, the first light spot is the light spot of the echo light incident on the receiving surface, and the first direction is the dimensional direction of the receiving surface.

[0017] The above design can offset the central hole of the first light spot relative to the center of the receiving surface, so that at least part of the central hole moves out of the receiving surface, while the first light spot is more on the receiving surface, thereby increasing the area of ​​the light spot hitting the receiving surface and thus improving the echo energy on the receiver.

[0018] In some embodiments, the transmitting module includes:

[0019] The emitting unit includes multiple lasers, which are used to generate probe light;

[0020] The transmitting lens, located on the light-emitting side of the transmitting unit, is used to emit probe light;

[0021] Among them, multiple lasers are arranged linearly or in a two-dimensional array.

[0022] Based on the above embodiments, setting multiple lasers within the transmitting unit to correspond to the same receiver allows the receiver to receive the echo light corresponding to all lasers within the transmitting unit. That is, the receiver receives the composite echo light formed by all lasers within the transmitting unit, achieving multi-transmitter-one-receiver. Compared to single-transmitter-one-receiver, multi-transmitter-one-receiver is beneficial for increasing the energy of the echo light received by the receiver, thereby optimizing the transmission and reception efficiency of the lidar.

[0023] In some embodiments, the scanning module includes:

[0024] A rotating mirror is used to rotate about a first straight line as an axis. The rotating mirror has multiple second reflective surfaces arranged around the first straight line. The first straight line is perpendicular to the plane where the optical axis of the lidar is located.

[0025] A galvanometer is used to rotate about a second straight line as an axis. The galvanometer has a second reflective surface, and the second straight line is perpendicular to the first straight line.

[0026] In some embodiments, adjacent second reflective surfaces are connected by a transition surface.

[0027] Based on the above embodiments, diffuse reflection is easily formed at the sharp corners formed by the direct connection of two adjacent second reflective surfaces, and the setting of the transition surface is conducive to achieving controllable reflection of the light beam.

[0028] In some embodiments, the lidar further includes a first extinction unit and a second extinction unit; the first extinction unit is located between the transmitting unit and the transmitting lens; and the second extinction unit is located between the receiving surface and the receiving lens.

[0029] Based on the above embodiments, the first extinction unit is used to eliminate stray light between the transmitting unit and the transmitting lens. The second extinction unit is used to eliminate stray light between the receiving surface of the receiver and the beam splitter.

[0030] In some embodiments, the lidar further includes a housing, which includes a mounting cavity and a window; the transmitting module, receiving module, beam splitter, and scanning module are all disposed within the mounting cavity; the angle between the normal vector at the first point on the window and the probe light is greater than a preset value, wherein the first point is the intersection of the probe light and the surface of the window near the mounting cavity, and the preset value is determined based on the energy of the probe light.

[0031] Based on the above embodiments, by performing targeted surface optimization on the window of the lidar, the angle between the normal vector at the intersection of the probe light and the inner surface of the window is increased by using a non-uniform curved surface on the inner surface of the window. Ultimately, the angle between the normal vector at the intersection of the probe light and the window at different fields of view is greater than a preset angle. This design aims to minimize the generation of reflected light perpendicular to the window and reduce the impact of the leader phenomenon as much as possible.

[0032] Secondly, embodiments of this application provide a mobile device, including a device body and a lidar of any of the above embodiments, wherein the lidar is connected to the device body.

[0033] The mobile device in this application embodiment sets the effective focal length f of the receiving lens. RX For lenses with a focal length greater than or equal to 40mm and less than or equal to 80mm, reduce the effective focal length f of the receiving lens. RX Combining the geometric optics formula h = f * tanθ, we can know that the effective focal length f of the receiving lens is... RX Reducing the size of the light spot received on the receiving surface can reduce the size of the light spot, allowing the receiving surface to receive all or more of the light spot, thereby increasing the energy of the echo light received by the receiver. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a partial structural schematic diagram of the lidar provided in an embodiment of this application;

[0036] Figure 2 This is a schematic diagram of the structure of the transmitting module in the lidar provided in the embodiments of this application;

[0037] Figure 3 yes Figure 2 A schematic diagram of the structure of the light spot received on the receiving surface of a lidar is shown;

[0038] Figure 4 This is a schematic diagram of the receiving module in the lidar provided in the embodiments of this application;

[0039] Figure 5 yes Figure 4 The diagram shows the structure of the light spot received on the receiving surface of a lidar for near-range or very near-range detection.

[0040] Figure 6 yes Figure 4 A schematic diagram of the structure of the long-range detection light spot received on the receiving surface of a lidar is shown;

[0041] Figure 7 This is a schematic diagram of the beam splitter in the lidar provided in the embodiments of this application;

[0042] Figure 8This is a schematic diagram of another beam splitter provided in an embodiment of this application;

[0043] Figure 9 This is a graph showing the changes in emission efficiency and near-range echo energy of the lidar provided in the embodiments of this application as a function of the radial dimension of the interface between the light-transmitting part and the reflective part;

[0044] Figure 10 This is a graph showing the change in transceiver efficiency of the lidar provided in the embodiments of this application as a function of the radial dimension of the interface between the light-transmitting part and the reflective part;

[0045] Figure 11 This is a partial structural schematic diagram of the lidar provided in an embodiment of this application;

[0046] Figure 12 This is a schematic diagram of the structure of the mobile device provided in the embodiments of this application.

[0047] Explanation of reference numerals in the attached figures:

[0048] 1. LiDAR; 2. Mobile device; 3. Main body of the device;

[0049] 10. Transmitting module; 11. Transmitting unit; 111. Laser; 111a. Laser; 111b. Laser; 12. Transmitting lens;

[0050] 20. Receiver module; 21. Receiver lens; 22. Receiver; 221. Receiver surface; 2211. Spot; 2211a. Spot; 2211b. Spot;

[0051] 30. Beam splitter; 31. Transmitting part; 32. Reflecting part; 33. First surface; 34. Second surface; 35. Light-transmitting aperture;

[0052] 40. Scanning module; 41. Galvanometer; 411. First reflective surface; 42. Rotating mirror; 421. Second reflective surface; 422. Transition surface;

[0053] 50. First matting unit; 51. First light-transmitting hole; 511. Matting groove; 52. First end face; 53. Second end face; 531. Second mounting groove;

[0054] 60. Second matting unit; 61. First matting device; 611. First matting section; 62. Second matting device; 621. Matting unit; 6211. Matting teeth;

[0055] 70. Housing; 71. Mounting cavity; 72. Window piece;

[0056] x, the first line; y, the second line. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application, as detailed in the appended claims.

[0058] In lidar, the receiving system typically employs a telescope configuration to optimize detection performance for distant targets. However, this design, primarily focused on long-range operations, introduces a significant limitation: defocusing may occur when detecting close-range targets.

[0059] Defocusing occurs when the object's position mismatches with the system's focal length setting, preventing the imaging system from forming a sharp focus on the detector, thus affecting image clarity and target recognition capabilities. For lidar systems, when a close-range target is within the system's minimum focal length, the beam may not be accurately focused on the detector, resulting in blurred images and reduced detection performance. Furthermore, for radar optical systems with coincident optical axes (coaxial systems), a planar lens called a beam splitter is used to separate the optical paths. When the close-range beam is blurred, the center of the received beam is missing. This leads to an increase in the energy of the close-range beam incident at the entrance pupil of the optical system, but a decrease in the energy received by the detector.

[0060] Please see Figure 1 This application provides a lidar 1, which includes a transmitting module 10, a receiving module 20, a beam splitter 30, and a scanning module 40. The transmitting module 10 is used to emit detection light; the receiving module 20 is used to receive the echo light formed by the detection light reflected from the target object, and the receiving module 20 includes a receiving lens 21 and a receiver 22, with the receiving lens 21 located on the light-incident side of the receiver 22; the beam splitter 30 includes a light-transmitting part 31 and a reflective part 32, with the reflective part 32 disposed around the light-transmitting part 31, the light-transmitting part 31 for transmitting the detection light, and the reflective part 32 for reflecting the echo light; the scanning module 40 is used to emit the detection light to the target object and transmit the echo light to the receiving module 20.

[0061] Next, see Figure 2 and Figure 3 Further explanation is provided regarding the aforementioned launch module 10.

[0062] See Figure 2The emitting module 10 includes an emitting unit 11 and an emitting lens 12. The emitting unit 11 includes a laser 111, which is used to generate probe light; the emitting lens 12 is located on the light-emitting side of the emitting unit 11 and is used to emit probe light. The laser 111 can be of various types; for example, it can be a vertical-cavity surface-emitting laser (VCSEL), an edge-emitting laser (EEL), an LD light source, etc., and is not limited thereto.

[0063] See Figure 2 and Figure 3 In some embodiments, the transmitting unit 11 includes multiple lasers 111. Each laser 111 within the transmitting unit 11 corresponds to the same receiver 22. Since each laser 111 in the transmitting unit 11 generates a probe light that corresponds to an echo light, assigning multiple lasers 111 within the transmitting unit 11 to the same receiver 22 allows the receiver 22 to receive the echo light corresponding to all lasers 111 within the transmitting unit 11. That is, the receiver 22 receives the composite echo light formed by all lasers 111 within the transmitting unit 11, achieving multiple transmissions to one receiver. Compared to single transmission and single reception, multiple transmissions to one receiver are beneficial for increasing the energy of the echo light received by the receiver 22, thereby optimizing the transmission and reception efficiency of the lidar 1.

[0064] It is understood that each echo beam incident on the receiving surface 221 of the receiver 22 will form a light spot 2211. In some embodiments, at least two lasers 111 in the transmitting unit 11 correspond to at least two light spots 2211 on the receiving surface 221, which at least partially overlap. For example, the transmitting unit 11 includes lasers 111a and 111b, where laser 111a corresponds to light spot 2211a on the receiving surface 221, and laser 111b corresponds to light spot 2211b on the receiving surface 221, with light spots 2211a and 2211b at least partially overlapping.

[0065] Since the light-transmitting part 31 of the beam splitter 30 is used to transmit the probe light and the reflective part 32 is used to reflect the echo light, and the reflective part 32 is located around the light-transmitting part 31, the light spot 2211 formed on the receiving surface 221 by the echo light reflected by the reflective part 32 after the probe light produced by each laser 111 is generated by the probe light 111 is generated by the probe light 111 being generated by the laser ...

[0066] In some embodiments, the multiple lasers 111 within the emitting unit 11 can be arranged randomly or regularly. For example, the multiple lasers 111 within the emitting unit 11 can be arranged linearly or in a two-dimensional array, without limitation. It should be noted that the multiple lasers 111 within the emitting unit 11 can be lit simultaneously or in a time-sequenced manner.

[0067] Next, see Figures 4 to 6 The receiving module 20 described above will be further explained.

[0068] See Figure 4 The receiving module 20 includes a receiving lens 21 and a receiver 22. The receiving lens 21 is located on the light-incident side of the receiver 22 and is used to transmit the echo light to the receiver 22. The receiver 22 can be a silicon photomultiplier (SiPM), an avalanche photodiode (APD), a single-photon avalanche photodiode (SPAD), etc., and there is no limitation on it.

[0069] In some embodiments, the receiving lens 21 satisfies: 40mm ≤ f RX ≤80mm; where f RX The effective focal length f of the receiving lens 21 is determined. RX A focal length f of receiving lens 21 that is greater than or equal to 40mm and less than or equal to 80mm can be achieved. RX The reduction in focal length (the effective focal length of the receiving lens in related technologies is usually between 110mm and 120mm), combined with the geometric optics formula h = f * tanθ, shows that the effective focal length f of the receiving lens 21 is... RX As the focal length of the receiving lens 21 decreases, the size of the light spot received on the receiving surface 221 decreases accordingly. This allows the receiving surface 221 to receive all or most of the light spot, thereby increasing the energy of the echo light received by the receiver 22. In some embodiments, the effective focal length f of the receiving lens 21 is... RX Available sizes include 56mm, 59.5mm, 63mm, 66.5mm, and 70mm.

[0070] See Figure 5In some embodiments, the receiver 22 has a receiving surface 221, which satisfies the following condition: 0.05mm ≤ H1 ≤ 0.2mm; where H1 is the distance between the center of the first light spot and the center of the receiving surface 221 in a first direction, the first light spot is the spot of the echo light incident on the receiving surface 221, and the first direction is the dimensional direction of the receiving surface 221. The receiving surface 221 may be approximately rectangular, and the first direction may be the length or width direction of the rectangle.

[0071] Since the light-transmitting part 31 of the beam splitter 30 is used to transmit probe light and the reflective part 32 is used to reflect echo light, and the reflective part 32 is disposed around the light-transmitting part 31, the first light spot formed on the receiving surface 221 by the echo light reflected by the reflective part 32 is approximately ring-shaped. The distance H1 between the center of the first light spot and the center of the receiving surface 221 in the first direction is greater than or equal to 0.05 mm and less than or equal to 0.2 mm, which can offset the central hole of the first light spot relative to the center of the receiving surface 221, so that at least a part of the central hole moves out of the receiving surface 221, and the first light spot is more on the receiving surface 221, increasing the area of ​​the light spot hitting the receiving surface 221, thereby increasing the echo energy on the receiver 22. In some embodiments, the distance H1 between the center of the first light spot and the center of the receiving surface 221 in the first direction can be 0.05 mm, 0.0625 mm, 0.075 mm, 0.0875 mm, 0.1 mm, etc.

[0072] It should be noted that during long-range detection, the size of the light spot formed by the echo light on the receiving surface 221 is relatively small, ensuring that the entire light spot is on the receiving surface 221, with few instances of the light spot falling outside the area of ​​the receiving surface 221. However, for short-range or very short-range detection, the size of the light spot formed by the echo light on the receiving surface 221 is larger, and the central hole of the light spot is also larger, even exceeding the size of the receiving surface 221. In this case, if the center of the light spot coincides with the center of the receiving surface 221, a large portion of the annular light spot will not fall on the receiving surface 221, resulting in a loss of echo energy. The above design ensures that the light spot does not deviate from the receiving surface 221 during long-range detection (see [reference needed]). Figure 6 This allows at least a portion of the central hole of the light spot used for close-range or extremely close-range detection to be moved out of the receiving surface 221, while the outer ring of the light spot used for close-range or extremely close-range detection is moved into the receiving surface 221 (see reference). Figure 5 This effectively enhances the echo energy received on the receiving surface 221 during close-range or very close-range detection. Specifically, the distance H1 between the center of the first light spot and the center of the receiving surface 221 in the first direction is greater than or equal to 0.05 mm and less than or equal to 0.2 mm, thus optimizing the detection performance of the lidar 1 across the entire range.

[0073] Next, see Figures 7 to 10 The beam splitter 30 described above will be further explained.

[0074] See Figure 7 and Figure 8 The beam splitter 30 includes a light-transmitting part 31 and a light-reflecting part 32. The light-reflecting part 32 is disposed around the light-transmitting part 31. The light-transmitting part 31 is used to transmit probe light, and the light-reflecting part 32 is used to reflect echo light.

[0075] In one exemplary solution, see [reference] Figure 7 The light-transmitting portion 31 of the beam splitter 30 can be recessed relative to the reflective portion 32 to reduce the thickness of the medium through which light passes, thereby reducing losses. Specifically, the beam splitter 30 has opposing first surfaces 33 and second surfaces 34. The probe light can pass through along the direction from the first surface 33 to the second surface 34. The recess of the light-transmitting portion 31 relative to the reflective portion 32 can be a partial area of ​​the light-transmitting portion 31 corresponding to the first surface 33 being recessed relative to a partial area of ​​the reflective portion 32 corresponding to the first surface 33, or a partial area of ​​the light-transmitting portion 31 corresponding to the second surface 34 being recessed relative to a partial area of ​​the reflective portion 32 corresponding to the second surface 34. The reflective portion 32 can be made of a material with reflective properties, or a reflective film can be provided in a partial area of ​​the reflective portion 32 corresponding to the first surface 33 or a partial area of ​​the reflective portion 32 corresponding to the second surface 34, giving the reflective portion 32 a reflective function. The light-transmitting portion 31 can be made of a material with light-transmitting properties. In some embodiments, an anti-reflective film may be provided on a portion of the light-transmitting portion 31 corresponding to the first surface 33 or a portion of the light-transmitting portion 31 corresponding to the second surface 34 to improve the light transmission performance of the light-transmitting portion 31.

[0076] In another exemplary solution, see [reference] Figure 8 The light-transmitting portion 31 is a light-transmitting aperture 35 on the beam splitter 30, which is used to transmit probe light. Directly opening the light-transmitting aperture 35 on the beam splitter 30 to transmit probe light reduces light loss and processing costs compared to using a portion of the beam splitter 30 as a light-transmitting material. In one embodiment, the radial cross-section of the light-transmitting aperture 35 is circular.

[0077] In some embodiments, the interface between the light-transmitting portion 31 and the reflective portion 32 can be approximately cylindrical. For example, the interface can be a prismatic surface, a cylindrical surface, or the like.

[0078] In some embodiments, the interface between the light-transmitting part 31 and the reflective part 32 is a cylindrical surface, and the beam splitter 30 satisfies: 10mm ≤ R ≤ 12mm; where R is the radial dimension of the interface between the light-transmitting part 31 and the reflective part 32. Designing the radial dimension R of the interface between the light-transmitting part 31 and the reflective part 32 to be greater than or equal to 10mm and less than or equal to 12mm reduces the size of the light-transmitting part 31 in the middle of the beam splitter 30 (in related technologies, the radial dimension of the interface between the light-transmitting part 31 and the reflective part 32 is typically 13mm-15mm). While ensuring a certain emission efficiency, reducing the size of the light-transmitting part 31 in the middle of the beam splitter 30 is equivalent to reducing the object height of the beam splitter 30 relative to its rear lens group, thereby reducing the size of the central hole (corresponding to the light-transmitting part 31) of the light spot hitting the receiver 22, increasing the area of ​​the light spot hitting the receiver 22, and thus improving the echo energy on the receiver 22.

[0079] It should be noted that the radial dimension R of the interface between the light-transmitting part 31 and the reflective part 32 in the above design, which is greater than or equal to 10 mm and less than or equal to 12 mm, was determined after comprehensively considering transmission efficiency, short-range echo energy, and transmission and reception efficiency. For details, please refer to... Figure 9 and Figure 10 The diagram shows the following curves: M, the variation curve of emission efficiency with the radial dimension R of the interface between the light-transmitting part 31 and the reflective part 32; W, the variation curve of near-range echo energy with the radial dimension R of the interface between the light-transmitting part 31 and the reflective part 32; and T, the variation curve of transceiver efficiency with the radial dimension R of the interface between the light-transmitting part 31 and the reflective part 32. Since ensuring the long-range ranging capability of the lidar 1 requires high transceiver efficiency, it is necessary to determine the position of the near-intersection point of these three curves to determine the radial dimension R of the interface between the light-transmitting part 31 and the reflective part 32. Furthermore, to avoid problems such as lead-in light and stray light caused by excessive reduction in emission efficiency, the radial dimension R of the interface between the light-transmitting part 31 and the reflective part 32 should also satisfy that the corresponding emission efficiency is not less than 80%. Based on the intersection of the three curves and the emission efficiency, this embodiment of the application determines that the radial dimension R of the interface between the light-transmitting part 31 and the reflective part 32 is greater than or equal to 10 mm and less than or equal to 12 mm, so as to achieve the improvement of near-range light efficiency and the balance of emission efficiency, near-range echo energy and transmission and reception efficiency.

[0080] Next, see Figure 1 Further explanation is provided for the aforementioned scanning module 40.

[0081] In some embodiments, see Figure 1The scanning module 40 includes a rotating mirror 42 and a galvanometer 41. The rotating mirror 42 is used to rotate about a first straight line x as an axis. The rotating mirror 42 has multiple second reflective surfaces 421 arranged around the first straight line x. The first straight line x is perpendicular to the plane containing the optical axis of the lidar 1. The galvanometer 41 is used to rotate about a second straight line y as an axis. The galvanometer 41 has a first reflective surface 411. The second straight line y is perpendicular to the first straight line x. One of the first straight line x and the second straight line y is horizontal, and the other is vertical, to achieve field-of-view scanning along the vertical and horizontal directions, respectively.

[0082] In some embodiments, adjacent second reflective surfaces 421 of the rotating mirror 42 are connected by a transition surface 422. Compared to the direct connection of adjacent second reflective surfaces 421 forming a sharp corner, where diffuse reflection is easily formed, the transition surface 422 facilitates controllable beam reflection. The second reflective surfaces 421 are used to reflect probe light and echo light, while the transition surface 422 can be used to balance the radar volume, reduce the load on the rotating mirror 42 motor, and reduce stray light risk, etc. The transition surface 422 can be a plane, an arc surface, or a combination of a plane and an arc surface, and its size is related to the spot size of the probe light.

[0083] In some embodiments, see Figure 1 The lidar 1 also includes a first extinction unit 50, which is located between the transmitting unit 11 and the transmitting lens 12. The first extinction unit 50 is used to eliminate stray light between the transmitting unit 11 and the transmitting lens 12.

[0084] Next, see Figure 1 The first extinction unit 50 described above will be further explained.

[0085] In some embodiments, see Figure 1 The first extinction unit 50 is provided with a first light-transmitting hole 51 for detecting the passage of light, and the inner wall surface of the first light-transmitting hole 51 is provided with at least one extinction groove 511. When multiple extinction grooves 511 are provided on the inner wall surface of the first light-transmitting hole 51, the multiple extinction grooves 511 can be arranged sequentially along the extending direction of the first light-transmitting hole 51. The extinction groove 511 can be an annular groove, and the cross-section of the extinction groove 511 can be arc-shaped, polygonal, etc., wherein the polygon can be rectangular, triangular, etc.

[0086] In some embodiments, the first extinction unit 50 has a first end face 52 and a second end face 53 disposed opposite to each other along the transmission path of the probe light. The first end face 52 is provided with a first mounting groove (not shown) communicating with the first light-transmitting hole 51, and at least a portion of the transmitting unit 11 is located in the first mounting groove. The first mounting groove can position the transmitting unit 11, improving the assembly accuracy, assembly efficiency, and assembly stability of the transmitting unit 11 and the first extinction unit 50. The second end face 53 is provided with a second mounting groove 531 communicating with the first light-transmitting hole 51, and at least a portion of the transmitting lens 12 is located in the second mounting groove 531. The second mounting groove 531 can position the transmitting lens 12, improving the assembly efficiency, assembly stability, and assembly stability of the transmitting lens 12 and the first extinction unit 50. In some embodiments, the first extinction unit 50 may also be provided with weight-reducing holes, etc., to reduce the weight of the first extinction unit 50.

[0087] In some embodiments, see Figure 1 The lidar 1 also includes a second extinction unit 60, which is located between the receiving surface 221 of the receiver 22 and the beam splitter 30. The second extinction unit 60 is used to eliminate stray light between the receiving surface 221 of the receiver 22 and the beam splitter 30.

[0088] Next, see Figure 1 The second extinction unit 60 described above will be further explained.

[0089] In some embodiments, the second extinction unit 60 is used to block the light signal emitted from the non-main ray region to the receiving surface 221 of the receiver 22. In the light signal from the non-main ray region, the energy proportion of the echo light is less than a first preset value. It should be noted that the first preset value can be selected according to actual needs; for example, the first preset value can be 6%, 8%, 10%, 12%, 14%, etc., and is not limited thereto.

[0090] See Figure 11In some embodiments, the second extinction unit 60 includes a first extinction element 61 located between the beam splitter 30 and the receiving lens 21. The first extinction element 61 blocks light signals from non-primary light regions from being emitted to the receiver 22, preventing stray light (e.g., lead light) from being received by the receiver 22, thus reducing the impact of stray light on the detection results of the lidar 1 and improving the detection accuracy of the lidar 1. Furthermore, since the energy proportion of echo light in non-primary light regions is relatively small, even if the receiving surface 221 of the receiver 22 does not receive this portion of echo light energy, it will hardly affect the detection performance of the lidar 1. It is understood that when determining the specific installation position of the first extinction element 61, it is first necessary to determine the non-primary light region between the receiving surface 221 of the receiver 22 and the beam splitter 30. The non-primary ray region can be obtained by fitting the optical path using a simulation system. Specifically, the optical path between the receiving surface 221 of the receiver 22 and the beam splitter 30 can be fitted using a simulation system to obtain the energy proportion of the echo light in each region of the optical path between the receiving surface 221 of the receiver 22 and the beam splitter 30. Based on this energy proportion of the echo light, the primary ray region and the non-primary ray region are divided. Within the primary ray region, the energy proportion of the echo light in the optical signal is greater than or equal to a second pre-value. The second pre-value can be selected according to actual needs; for example, the second pre-value can be 86%, 88%, 90%, 92%, 94%, etc.

[0091] The aforementioned first extinction device 61 can not only block light signals from non-main ray regions from being emitted to the receiver 22, but also block light signals from the edge of the main ray region near the non-main ray region from being emitted to the receiver 22, thereby achieving a better effect in eliminating optical crosstalk. It should be noted that if the first extinction device 61 is also used to block light signals from the edge of the main ray region from being emitted to the receiver 22, the area ratio of this edge of the main ray region to the main ray region should be less than or equal to a third pre-value, so as to ensure sufficient echo light energy received by the lidar 1 while achieving a better effect in eliminating optical crosstalk. The third pre-value can be selected according to actual needs; for example, the third pre-value can be 26%, 28%, 30%, 32%, 34%, etc.

[0092] See Figure 11In some embodiments, the first extinction device 61 includes a first extinction section 611, which is used to block the light signal emitted to the receiver 22 via the light-transmitting section 31 of the beam splitter 30. Since the light signal emitted to the receiver 22 via the light-transmitting section 31 is not echo light, designing the first extinction section 611 to block the light signal emitted to the receiver 22 via the light-transmitting section 31 can eliminate crosstalk between the light signal emitted to the receiver 22 and the echo light. It should be noted that in the actual manufacturing process, light-transmitting devices (such as the light-transmitting section 31 of the beam splitter 30 and the window 72) are difficult to achieve 100% transmittance and will always have a certain reflectivity. As a result, the emitted light will not leave the housing 70 but will reach the receiver 22 after a certain transmission inside the housing 70, that is, a leading light will be generated, which will cause crosstalk to the echo light received by the receiver 22. The lead-in light is mainly transmitted inside the housing 70. The transmission time is similar to the detection time of the near-distance target object, which can easily affect the detection accuracy of the near-distance target object and cause a detection blind zone of the near-distance target object.

[0093] In other embodiments, see Figure 1 A second extinction unit 62 is disposed between the beam splitter 30 and the receiving lens 21. The second extinction unit 62 includes at least one extinction unit 621, which includes a plurality of extinction teeth 6211 spaced apart along the transmission path of the echo light. The extinction teeth 6211 can generate at least one reflection of at least part of the stray light, causing the stray light to be transmitted in a direction away from the receiver 22 or reducing the intensity of the stray light, thereby reducing the interference of stray light on the echo light and improving the detection accuracy of the lidar 1.

[0094] Next, see Figure 1 Further explanation is provided for the aforementioned lidar 1.

[0095] In some embodiments, see Figure 1 The lidar 1 also includes a housing 70, which includes a mounting cavity 71 and a window 72; the transmitting module 10, the receiving module 20, the beam splitter 30 and the scanning module 40 are all disposed in the mounting cavity 71.

[0096] In some embodiments, the angle between the normal vector at the first point on the window 72 and the probe light is greater than a preset value, wherein the first point is the intersection of the probe light and the surface of the window 72 near the mounting cavity 71, and the preset value is determined based on the energy of the probe light.

[0097] The pre-leading phenomenon caused by window 72 is mainly due to the different exit angles and positions of the probe light. Some probe light may be perpendicular to a local surface of window 72, thus failing to transmit and generating strong reflected light inside the lidar 1. The receiver receives strong internal echo energy for a short period, causing receiver saturation and rendering the lidar unable to detect within that timeframe. It is understood that the larger the angle between the normal vector at the first point on window 72 and the probe light, the lower the probability of the reflected light being detected by the receiver. In this embodiment, by optimizing the surface shape of window 72 of lidar 1, the angle between the normal vector at the intersection of the probe light and the inner surface of window 72 is increased using a non-uniform curved surface. This ensures that the angle between the surface normal vector at the intersection of the probe light and window 72 at different fields of view is greater than a preset angle, minimizing the generation of reflected light perpendicular to window 72 from the design perspective and reducing the impact of the pre-leading phenomenon.

[0098] The specific value of the preset value relates to the lead saturation energy and ranging requirements of different types of radar. In some embodiments, the preset value ranges from 3° to 10°. For example, the preset value can be 5°, 8°, etc. Setting the angle between the normal vector at the first point on the window 72 and the probe light to be greater than the preset value can effectively reduce the lead phenomenon caused by the refraction and reflection of the light path due to the window 72, and reduce the blind zone of the entire radar.

[0099] Based on the same inventive concept, see [reference] Figure 12 This application also provides a mobile device 2, which includes a device body 3 and the aforementioned lidar 1, with the lidar 1 connected to the device body 3. In some embodiments, the mobile device 2 can be any mobile tool capable of carrying the lidar 1, such as a car, electric vehicle, drone, or robot.

[0100] In the description of this application, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Furthermore, in the description of this application, unless otherwise stated, "multiple" means at least two, for example, two, three, four, etc. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0101] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with the claims of this application shall still fall within the scope of this application.

Claims

1. A lidar, comprising: The application relates to a laser radar, comprising: a transmitting module for transmitting probe light; A receiving module is configured to receive echo light formed by reflection of the probe light on the target object, and the receiving module comprises a receiving lens and a receiver, the receiving lens is located on the light-in side of the receiver, and the receiving lens satisfies: 40mm≤f RX ≤80mm; wherein, f RX is the effective focal length of the receiving lens. a beam splitter comprising a light-transmitting part and a light-reflecting part, the light-reflecting part being arranged at the periphery of the light-transmiting part, the light-transmitting part being used for transmitting the probe light, and the light-reflecting part being used for reflecting echo light; a scanning module for emitting the probe light to a target object and transmitting the echo light to the receiving module.

2. The lidar of claim 1, wherein, The interface between the light-transmitting part and the light-reflecting part is a cylindrical surface; The beam splitter satisfies: 10mm<=R<=12mm; wherein R is the radial dimension of the interface between the light-transmitting part and the light-reflecting part.

3. The lidar of claim 1, wherein, The light-transmitting part is a light-transmitting hole on the beam splitter, and the cross section of the light-transmitting hole along the radial direction is circular.

4. The lidar of claim 1, wherein, The receiver has a receiving surface, and the receiving surface satisfies: 0.05mm<=H1<=0.2mm; wherein H1 is the distance between the center of a first light spot and the center of the receiving surface in a first direction, the first light spot being a light spot of the echo light incident to the receiving surface, and the first direction being a dimension direction of the receiving surface.

5. The lidar of claim 4, wherein, The transmitting module comprises: a transmitting unit comprising a plurality of lasers, the lasers being used for generating the probe light; a transmitting lens located on the light-emitting side of the transmitting unit and used for transmitting the probe light; wherein the plurality of lasers are arranged linearly or in a two-dimensional array.

6. The lidar of claim 1, wherein, The scanning module comprises: a rotating mirror for rotating around a first straight line, the rotating mirror having a plurality of second reflecting surfaces arranged around the first straight line, and the first straight line being perpendicular to the plane in which the optical axis of the laser radar is located; a vibrating mirror for rotating around a second straight line, the vibrating mirror having a second reflecting surface, and the second straight line being perpendicular to the first straight line.

7. The lidar of claim 6, wherein, Adjacent two second reflecting surfaces are connected by a transition surface.

8. The lidar of claim 5, wherein, The laser radar further comprises a first light-eliminating unit and a second light-eliminating unit; the first light-eliminating unit is located between the transmitting unit and the transmitting lens; the second light-eliminating unit is located between the receiving surface and the receiving lens.

9. The lidar of claim 1, wherein, The laser radar further comprises a housing, the housing comprising a mounting cavity and a window sheet; the transmitting module, the receiving module, the beam splitter and the scanning module are all arranged in the mounting cavity; the angle between the normal vector of a first site on the window sheet and the probe light is greater than a preset value, wherein the first site is the intersection of the probe light and the surface of the window sheet close to the mounting cavity, and the preset value is determined according to the energy of the probe light.

10. A mobile device, comprising: The application relates to a device main body and the laser radar of any one of claims 1 to 9, wherein the laser radar is connected to the device main body.

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