Lens assembly, receiving module, detection apparatus, and terminal device

Abstract

A lens assembly, a receiving module, a detection apparatus and a terminal device, which relate to the technical field of radars and are used for improving the receiving efficiency of scanning-type LiDAR. The lens assembly comprises a first sub-lens-assembly, the first sub-lens-assembly comprises at least two lenses, and the at least two lenses are located between a scanning assembly and a detection module, and are used for performing, in a first direction, beam shrinking on light returned by the scanning assembly, wherein the first direction is orthogonal to the direction of a main optical axis. By means of performing beam shrinking on returned light in a first direction, the beam width of the returned light in the first direction can be reduced, and the returned light cannot be focused to one point. In this way, when the returned light is deflected in the first direction due to a walk-off angle, by means of beam shrinking, a walk-off distance in the first distance can be reduced, and then the probability that the returned light is irradiated onto the detection module is increased, thereby effectively improving the receiving efficiency of scanning-type LiDAR.

Description

Lens assembly, receiving module, detection device and terminal equipment

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of the People's Republic of China on November 2, 2023, with application number 202311458304.8 and application name "A lens assembly, receiving module, detection device and terminal equipment", all contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of radar technology, and in particular to a lens assembly, a receiving module, a detection device and a terminal device. Background Art

[0004] With the development of lidar technology, scanning lidar has gradually become a mainstream technology solution in the lidar field due to its advantages such as high power density, long range, high accuracy, rich information acquisition, and strong anti-interference ability. However, due to the high-speed rotation of the scanning component, there is usually an offset (walk-off) angle between the actual echo signal of this type of lidar and the ideal echo signal, as shown by θ in Figure 1a. This offset angle θ causes the actual echo signal to be offset by Δx in the x-direction shown in Figure 1a, which makes it impossible to accurately focus the actual echo signal on the center of the receiver. In severe cases, it may even prevent the receiver from receiving the echo signal, greatly reducing the receiver's reception efficiency.

[0005] At present, the receiving efficiency is usually improved by increasing the receiving aperture of the receiver or setting up multiple receivers. For example, the receiving aperture of the receiver in the x direction as shown in Figure 1a is increased, or multiple receivers are placed side by side in the x direction as shown in Figure 1a. However, due to process limitations, in some scenarios, even if the receiving aperture reaches the limit of process manufacturing, it is still impossible to make the receiving aperture cover the offset range of the actual echo signal, so the problem of low receiver receiving efficiency still exists. Or, due to process limitations, even if multiple receivers are set up, it is difficult to achieve zero gaps between multiple receivers. When detecting certain distances, if the echo signals corresponding to these distances happen to be transmitted to the gap between two receivers, the problem of low receiver receiving efficiency still exists. It can be seen that neither of the two existing solutions can effectively improve the receiving efficiency of scanning lidar.

[0006] In summary, how to effectively improve the receiving efficiency of scanning lidar is a technical problem that needs to be solved urgently.

[0007] Summary of the Invention

[0008] The present application provides a lens assembly, a receiving module, a detection device and a terminal device to improve the receiving efficiency of a scanning laser radar.

[0009] In a first aspect, the present application provides a lens assembly, including a first sub-lens assembly, the first sub-lens assembly including at least two lenses, the at least two lenses being located between a scanning assembly and a detection module, and being used to focus light returned by the scanning assembly in a first direction, wherein the first direction is orthogonal to the direction of the main optical axis.

[0010] In the above design, by converging the returned light in the first direction, the beam width of the returned light in the first direction can be reduced, and it will not be focused on one point. In this way, when the offset angle causes the returned light to deviate in the first direction, the offset distance in the first direction can be shortened by converging, thereby increasing the probability of the returned light irradiating the detection module, thereby effectively improving the receiving efficiency of the detection module.

[0011] In one possible design, the first direction is affected by an offset angle, such as the fast axis. The fast axis refers to the direction of fastest light vector propagation in an optical system, and is typically affected by an offset angle introduced by the high-speed rotation of the scanning assembly. By performing beam reduction along the fast axis, the effect of the offset angle on the returning light can be reduced.

[0012] In one possible design, the first sub-lens assembly has no optical power in a second direction, which is orthogonal to both the first direction and the principal optical axis. In other words, the first sub-lens assembly deflects light in the first direction while acting like flat glass in the second direction, leaving the light's propagation direction in the second direction unaffected.

[0013] In one possible design, at least two lenses are convex lenses, or a combination of a convex lens and a concave lens. The convex lens focuses light, while the concave lens diverges it. By combining focusing, or focusing and diverging, a simple optical path design can be used to achieve convergence of the return light in the first direction x, reducing the design difficulty of the lens assembly.

[0014] In one possible design, the at least two lenses include a first lens and a second lens. The first lens is located between the scanning assembly and the second lens. Both the first lens and the second lens are convex lenses, or the first lens is convex and the second lens is concave. By configuring the first sub-lens assembly as two lenses, light can be focused in the first direction with a minimum number of lenses, reducing the cost of manufacturing the lens assembly.

[0015] In one example of the above design, where both the first and second lenses are convex lenses, the distance between the first and second lenses is the sum of the focal lengths of the first and second lenses, with the focal length of the first lens being greater than the focal length of the second lens. In this way, light with a larger beam width incident on the first lens first passes through the first lens with a larger focal length before being focused between the first and second lenses. It then passes through the second lens with a smaller focal length before being converted into light with a smaller beam width and emitted from the second lens, thereby achieving light converging in the first direction.

[0016] In another example of the above design, where the first lens is a convex lens and the second lens is a concave lens, the distance between the first and second lenses is the difference between the focal lengths of the first and second lenses, with the focal length of the first lens being greater than the focal length of the second lens. In this way, light with a larger beam width emitted by the first lens first travels a distance less than the focal length of the first lens, becomes light with a smaller beam width, and then impinges on the second lens before being emitted from the second lens, thereby converging the light in the first direction.

[0017] In an example of the above design, the first lens and the second lens meet the following conditions: Where f1 is the focal length of the first lens, f2 is the focal length of the second lens, h is the object height, and h' is the image height. This configuration ensures that the focal length ratio of the first lens to the second lens satisfies the object-image ratio.

[0018] In one possible design, the lens assembly may further include a second sub-lens assembly, which is used to converge or focus the light returned by the scanning assembly in a second direction, wherein the second direction is a direction orthogonal to both the first direction and the main optical axis direction.

[0019] In the above design, the second direction can be understood as a direction that is not affected by the offset angle. By converging the returned light in the second direction, the returned light can be converged to a point, and the detection module is located at this point. In this way, the detection module can receive all the returned light. Alternatively, considering the influence of certain factors (such as the change in the position of the scanning component in the second direction due to the increase in usage), the light in the second direction that is not affected by the offset angle may also be deflected. Therefore, by also converging the light in the second direction, the offset distance of the returned light in the second direction due to the offset can be reduced, thereby reducing the degree to which the returned light is affected by the offset when it is transmitted in the second direction.

[0020] In one example of the above design, the second direction can be the slow axis direction, i.e., the direction in which the light vector propagates slowly in the optical system. By converging the returning light along the slow axis direction, the requirement that the returning light be transmitted to the detection module along the slow axis can be met. Furthermore, by converging the returning light along the slow axis direction, the effects of other factors on the light being transmitted along the slow axis can be reduced.

[0021] In one example of the above design, the second sub-lens assembly has no optical power in the first direction. In other words, the second sub-lens assembly can bend light in the second direction, while acting like a flat glass in the first direction, leaving the light transmission direction in the first direction unaffected.

[0022] In one example of the above design, the focal plane or exit pupil surface of the second sub-lens assembly coincides with the exit pupil surface of the first sub-lens assembly. For example, when the second sub-lens assembly is used to converge the light returned by the scanning assembly in the second direction, the focal plane of the second sub-lens assembly coincides with the exit pupil surface of the first sub-lens assembly, and when the second sub-lens assembly is used to focus the light returned by the scanning assembly in the second direction, the exit pupil surface of the second sub-lens assembly coincides with the exit pupil surface of the first sub-lens assembly. In this way, when the detection module is placed on the focal plane or exit pupil surface of the second sub-lens assembly, the position of the detection module in the direction of the principal optical axis can remain consistent in the first direction and the second direction, so that the detection module can receive the returned light in both the first direction and the second direction.

[0023] In one example of the above design, the second sub-lens assembly includes a third lens, which is a convex lens. The convex lens has a focusing function, which can converge the returning light in the first direction to the focal plane of the second sub-lens assembly so as to be received by the detection module placed on the focal plane.

[0024] In a further example, the focal length of the third lens is the distance between the third lens and the exit pupil of the first sub-lens assembly, so that the focal plane of the third lens coincides with the exit pupil of the first sub-lens assembly.

[0025] In one possible design, the first sub-lens assembly or the second sub-lens assembly includes a cylindrical lens. The cylindrical lens has the ability to deflect light in a single direction. Therefore, the cylindrical lens can be used to achieve the first sub-lens assembly to focus light in the first direction, and the second sub-lens assembly to converge or focus light in the second direction.

[0026] In the second aspect, the present application provides a receiving module, including a scanning component, a receiving optical system and a detection module. The receiving optical system is used to focus the light returned by the scanning component in a first direction, and the exit pupil position of the detection module coincides with that of the receiving optical system.

[0027] In the above design, the light incident on the receiving optical system will be emitted from the same area at the exit pupil position after being focused by the receiving optical system. Therefore, by placing the detection module at the exit pupil position, no matter how much the returned light has an offset in the first direction, it can be incident on the detection module in the same area at the exit pupil position, effectively reducing the degree to which the light received by the detection module is affected by the offset angle, so that the detection module can receive the returned light when detecting any detection distance, thereby improving the receiving efficiency of the detection module. In addition, because the returned light of different offset distances will be incident on the detection module in the same area, this method only requires the detection module to be assembled when the scanning assembly is stationary, and there is no need to adjust the position of the detection module when the scanning assembly is rotating, thereby reducing the difficulty of assembling the detection module.

[0028] In one possible design, the receiving optical system includes a lens assembly as described in the first aspect or any one of the designs of the first aspect, so that the receiving optical system has the beneficial effects described in any one of the designs of the first aspect.

[0029] In one possible design, the detection module includes one or more detectors. If multiple detectors are included, the detectors can be arranged along a second direction, which is orthogonal to both the first direction and the principal optical axis. This design supports multi-channel detection in the second direction, ensuring that light returned from any channel can be received by one or more detectors in the second direction. This increases the detection range while maintaining detection performance.

[0030] In one example of the above design, the detector includes a detection array, for example, the detection module includes a large detection array. In this way, the light emitted by the receiving optical system can be directly received by the detection array and converted into an electrical signal.

[0031] In one example of the above design, the detector includes an optical transmission medium and a detection array. For example, the detection module includes one set of optical transmission media and the detection array, or includes multiple sets of optical transmission media and the detection array, and the multiple sets of optical transmission media and the detection array are arranged along the second direction. The optical transmission medium is located between the receiving optical system and the detection array and is used to transmit received light to the detection array. The detection array is used to convert the received light into an electrical signal.

[0032] In a further possible design, the optical transmission medium is an optical fiber or a waveguide, which can be used to transmit light.

[0033] It should be noted that whether the detector consists of a detection array or a detection array and an optical transmission medium is determined by the radar's ranging principle. For example, when using the time-of-flight ranging principle, the speed and time of light propagation in air are used to measure distance. In this case, the detector may only include a detection array, which senses the arrival time of the return light. This is then combined with the emission time of the probe light to calculate the light's flight time in the air. This flight time, combined with the speed of light, is sufficient to complete the ranging. For another example, when using the frequency modulated continuous wave (FMCW) ranging principle, the frequency change (i.e., the Doppler effect) and time difference of the return light compared to the probe light are used to measure distance. In this case, the detector may include an optical transmission medium and a detection array. The optical transmission medium senses the frequency of the return light, while the detection array senses the arrival time of the return light. The frequency and arrival time of the return light can be combined with the frequency and emission time of the probe light to complete the ranging.

[0034] In one possible design, the scanning component is a polygonal rotating mirror, a micro electro-mechanical system (MEMS) galvanometer or oscillating mirror, or other mirror structures capable of achieving a scanning function.

[0035] In one possible design, the light is continuous light or pulsed light, such as light emitted in FMCM mode. The specific type of light used can be designed based on the actual application scenario to improve the flexibility and versatility of the receiving module.

[0036] In a third aspect, the present application provides a detection device, comprising a receiving module as in the above-mentioned second aspect or any one of the designs of the second aspect, wherein the receiving module is used to convert a received optical signal into an electrical signal.

[0037] In a possible design, the detection device may further include an emission module, which is used to emit light to the scanning component.

[0038] In one example of the above design, the detection device may further include an emission optical system located between the emission module and the scanning assembly for shaping the light emitted by the emission module. Exemplarily, the shaping may include beam collimation and beam homogenization.

[0039] In one example of the above design, the detection device may further include a separate transceiver assembly for transmitting light emitted by the transmitting module to the scanning assembly and for transmitting light returned from the scanning assembly to the detection module. This allows for separation of the transmitting module from the detection module, facilitating the separate configuration of the corresponding receiving optical system for the detection module.

[0040] In a possible design, the detection device may further include a control module, which is used to process the electrical signal from the receiving module to obtain relevant information of the target.

[0041] In a fourth aspect, the present application provides a terminal device, comprising a detection device as in the above-mentioned third aspect or any one of the designs of the third aspect.

[0042] The technical effects that can be achieved in the above-mentioned second to fourth aspects can refer to the description of the beneficial effects in the above-mentioned first aspect, and will not be repeated here one by one. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIG1a is a schematic diagram showing an exemplary offset angle;

[0044] FIG1b exemplarily shows a transmission light path diagram of a convex lens;

[0045] FIG1c exemplarily shows a transmission light path diagram of a concave lens;

[0046] FIG1d exemplarily shows a schematic diagram of a main optical axis;

[0047] FIG2 exemplarily shows a schematic diagram of a possible application scenario provided by the present application;

[0048] FIG3 a exemplarily shows a schematic diagram of optical transmission of a coaxial laser radar;

[0049] FIG3 b exemplarily shows a schematic diagram of the architecture of a detection device with separate transmission and reception;

[0050] FIG3 c exemplarily shows a schematic diagram of the architecture of a multi-receiver detection device;

[0051] FIG4a exemplarily shows a schematic structural diagram of a lens assembly provided by the present application;

[0052] FIG4b exemplarily shows a schematic diagram of possible locations of a detection module provided by the present application;

[0053] FIG5 exemplarily shows a schematic diagram of optical path transmission of an existing receiving optical system;

[0054] FIG6 exemplarily shows a schematic structural diagram of another lens assembly provided by the present application;

[0055] FIG7 exemplarily shows a specific structural diagram of a lens assembly provided by the present application;

[0056] FIG8a exemplarily shows a schematic diagram of a lens combination form of the first sub-lens assembly provided by the present application;

[0057] FIG8 b exemplarily shows a schematic diagram of another lens combination form of the first sub-lens assembly provided by the present application;

[0058] FIG9a exemplarily shows a schematic diagram of the arrangement order of a sub-lens assembly provided by the present application;

[0059] FIG9 b exemplarily shows a schematic diagram of the arrangement order of another sub-lens assembly provided by the present application;

[0060] FIG10a is a schematic diagram showing a distance relationship between lenses provided by the present application;

[0061] FIG10b exemplarily shows another schematic diagram of the distance relationship between lenses provided by the present application;

[0062] FIG10c is a schematic diagram showing another distance relationship between lenses provided by the present application;

[0063] FIG10d exemplarily shows a schematic diagram of the distance relationship between lenses provided in the present application;

[0064] FIG11 exemplarily shows a schematic diagram of the specific structure of another lens assembly provided by the present application;

[0065] FIG12 exemplarily shows a schematic diagram of the architecture of a receiving module provided by the present application;

[0066] FIG13a exemplarily shows a structural diagram of a detection module provided by the present application;

[0067] FIG13b exemplarily shows a schematic structural diagram of another detection module provided by the present application;

[0068] FIG14 exemplarily shows a schematic diagram of a design of a receiving module provided by the present application;

[0069] FIG15 exemplarily shows a simulation result diagram of a receiving light spot at an exit pupil position provided by the present application;

[0070] FIG16 exemplarily shows a schematic diagram of the architecture of a detection device provided in the present application. DETAILED DESCRIPTION

[0071] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0072] The following is an explanation of some of the terms used in this application. It should be noted that these explanations are for the purpose of facilitating understanding by those skilled in the art and do not limit the scope of protection claimed in this application.

[0073] 1. Walk-off Angle

[0074] Refer to Figure 1a. In a coaxial scanning lidar with coaxial transmission and reception, the probe light emitted by the scanning component is reflected back by the target. If the scanning component reflects the returned light at the scanning angle at which the probe light was emitted, the return light transmission path shown by the dotted line will be obtained. However, due to the high-speed rotation of the scanning component, the scanning angle of the scanning component changes. The scanning component reflects the returned light at this scanning angle, and the return light transmission path shown by the solid line will be obtained. The angle θ between the solid line return light transmission path and the dotted line return light transmission path is the offset angle. The offset angle θ is related to the angular velocity and flight time of the scanning component. The flight time can be understood as the time between the scanning component emitting the probe light and the scanning component receiving the returned light. When the speed of light is fixed, the flight time is proportional to the detection distance (i.e., the distance between the scanning component and the target). Therefore, it can also be understood that the offset angle θ is related to the angular velocity and detection distance of the scanning component. For example, by deduction, when the angular velocity of the scanning component is 3000 revolutions per minute (r / min) and the target is 150 meters from the scanning component, the offset angle θ is approximately 0.036°. This offset angle θ causes the returned light to deviate from the center of the receiver in the x-direction shown in Figure 1a when it is transmitted to the receiving side. This results in a certain offset distance between the returned light and the receiver, as shown by Δx in Figure 1a.

[0075] 2. Lens

[0076] A lens is a transparent optical device that affects the wavefront curvature of the light passing through it. Light enters from one side and exits from the other. The function of a lens is to change the wavefront curvature of light, that is, to focus or defocus the light. For example: a beam of collimated light with an approximately flat wavefront is converted into a beam with a curved wavefront, and the light is focused to a focal point. This type of lens acts as a focusing lens, also called a convex lens, see Figure 1b. The same lens as above can also convert divergent light into collimated light. In this case, the lens acts as a collimating lens, see Figure 1b, and the light is incident from the right. A lens with a concave surface can convert collimated or converging light into divergent light, see Figure 1c. This type of lens can also be used to convert a divergent light beam into a collimated light beam, see Figure 1c, and the light is incident from the right.

[0077] 3. Main optical axis

[0078] The principal optical axis is the line passing through the centers of the two spherical surfaces of a lens, also known as the principal axis (see Figure 1d). The plane perpendicular to the principal optical axis and passing through the focal point of a lens (for example, the front focal point of a convex lens, see focus F1 in Figure 1b, or the object focal point of a concave lens, see focus F2 in Figure 1c) is called the focal plane, also known as the front focal plane or object focal plane.

[0079] 4. Optical power

[0080] The optical power is equal to the difference between the image-side beam convergence and the object-side beam convergence, which can characterize the ability of optical elements to deflect light beams. Indicates. Generally, the focal length of the lens is expressed as the reciprocal of the focal length of the image side (assuming that the refractive index of air is approximately 1). The unit of focal length is diopter (D), 1 diopter (D) = 1m -1 .

[0081] Due to the different thicknesses of optical elements, non-uniformities such as refractive index, and different curvatures of the front and back surfaces (the curvature radius of the convex surface of the lens is a positive number, and the curvature radius of the concave surface is a negative number), these characteristics will cause the actual optical focal length of the optical element to differ from the theoretical optical focal length. Therefore, the actual optical focal length can also be called the equivalent optical focal length. Unless otherwise specified below, the optical focal length refers to the actual optical focal length of the optical element.

[0082] 5. Fast Axis and Slow Axis

[0083] The fast axis refers to the direction of the light vector with the fastest propagation speed in an optical system, and the slow axis refers to the direction of the light vector with the slowest propagation speed in an optical system. In radar systems, the fast axis, slow axis, and principal optical axis are orthogonal to each other. The light returned by the scanning component is usually affected by an offset angle on the fast axis, which is introduced by the high-speed rotation of the scanning component. For two-dimensional scanning components, which usually include rotating mirrors and swinging mirrors, the fast axis direction can be understood as the rotation direction of the rotating mirror, and the slow axis direction can be understood as the swing direction of the swinging mirror. For one-dimensional scanning components, which usually only include rotating mirrors, the fast axis direction can be understood as the rotation direction of the rotating mirror, and the slow axis direction can be understood as the normal direction of the plane formed by the fast axis and principal optical axis.

[0084] 6. Exit pupil position

[0085] In radar systems, the exit pupil position refers to the location of the common exit point where light beams emitted from various points on the object surface exit from the final aperture of the optical system after passing through it. Simply put, a virtual aperture exists in the radar's receiving optical system. This virtual aperture is located at a point where all incident light beams fill the corresponding aperture of the virtual aperture. Only light rays that pass through the corresponding aperture of the virtual aperture can exit the receiving optical system. The location of this virtual aperture is the exit pupil.

[0086] The previous text introduced some of the terms involved in this application. The following text introduces the possible application scenarios of this application.

[0087] In one possible implementation, the lens assembly provided by the present application can be integrated into a receiving module, the receiving module can be integrated into a detection device, and the detection device can be installed on a vehicle. The detection device may include, for example, but is not limited to, a laser radar. Please refer to Figure 2, which exemplarily shows a schematic diagram of a possible application scenario of the present application, in which the detection device is installed at the front bumper of the vehicle as an example. It can be understood that the detection device can also be installed at other locations of the vehicle, such as around the headlights, around the rearview mirrors, near the doors, at the rear bumper, behind the windshield or on the roof, etc., to capture information about the vehicle's surrounding environment. When the detection device is installed behind the windshield, it has a lower requirement for no gravel collision risk, will not affect the appearance of the vehicle, and the front windshield itself has window heating and demisting and wiper cleaning functions.

[0088] Taking the detection device installed on a vehicle as an example, refer to Figure 2. The working principle of the detection device is as follows: the detection device emits a light beam into the detection area. If there is a target in the detection area, the target can reflect the received light beam back to the detection device (also known as returned light or echo signal). The detection device then determines the target's related information based on the returned light. Specifically, the detection device can obtain the vehicle's latitude and longitude, speed, direction, or related information (such as the target's distance, speed, and / or posture) of targets within a certain range (such as other surrounding vehicles, pedestrians, or obstacles) in real time or periodically. Furthermore, optionally, the detection device can send this acquired information to a control device in the vehicle, so that the control device can perform vehicle path planning, braking, or starting based on this acquired information. For example, the vehicle's position can be determined using longitude and latitude, or the vehicle's direction and destination for a period of time in the future can be determined using speed and direction, or the number and density of obstacles around the vehicle can be determined using the distance of surrounding objects. Furthermore, optionally, the function of an advanced driving assistant system (ADAS) can be combined to achieve assisted driving or autonomous driving of the vehicle.

[0089] It should be understood that the above application scenarios are only examples, and the detection device provided in this application (the detection device includes the receiving optical system provided in this application) can also be applied to other possible scenarios, not limited to the scenarios exemplified above. For example, the detection device can also be installed in a roadside unit (RSU) as a roadside traffic detection device for realizing intelligent vehicle-road cooperative communication, etc. For another example, the detection device can also be applied to other means of transportation as an information collection source for path planning to assist the driver in achieving or automatically achieving safe driving. Other means of transportation may include but are not limited to ships, airplanes, drones, trains, subways, automated guided vehicles (AGVs) or unmanned transport vehicles, etc. For another example, the detection device can also be applied to a terminal device or a component provided in a terminal device. The terminal device may be, for example, a smartphone, smart home device, smart manufacturing equipment, medical equipment, industrial equipment, and a robot, etc. They are not listed here one by one. It should be noted that the application scenarios described in this application are for the purpose of more clearly illustrating the technical solution of this application and do not constitute a limitation on the technical solution provided in this application.

[0090] In addition, the above application scenarios can be applied to, for example, unmanned driving, assisted driving, intelligent driving, autonomous driving, connected vehicles, security monitoring, biomedicine, surveying and mapping (such as three-dimensional mapping, remote sensing mapping), meteorological research, biomass and vegetation research, air quality monitoring, and aviation and aerospace applications.

[0091] As described in the background technology, in a scanning laser radar, the returned light will have an offset angle after passing through the scanning component, resulting in the returned light not being efficiently received by the receiver, and this type of problem is particularly evident in a scanning laser radar with coaxial transmission and reception. For example, please refer to Figure 3a, which shows a schematic diagram of the optical path transmission of a coaxial laser radar, wherein Figure 3a (A) shows the optical path transmission diagram of the returned light on the xoz plane, and Figure 3a (B) shows the optical path transmission diagram of the returned light on the yoz plane, with the z direction being the main optical axis direction, the x direction being the fast axis direction, and the y direction being the slow axis direction. Referring to Figure 3a (A) and Figure 3a (B), whether in the x direction or the y direction, the receiving optical system will converge the light returned by the scanning component, thereby converging the returned light to a point, and the receiver is located in the plane where the point is located. However, referring to (A) in FIG3a , the high-speed rotation of the scanning component causes the returned light to be offset by an angle θ in the x-direction, thereby causing the position where the returned light is focused on the receiver to be offset by Δx in the x-direction. With a convergence method, the returned light will eventually converge to a single point in the x-direction. However, the presence of the offset Δx can easily cause this point to deviate directly from the receiver's position, resulting in the receiver being unable to receive the returned light, greatly reducing the receiver's receiving efficiency.

[0092] In response to the above problems, the industry has proposed some solutions, such as:

[0093] Solution 1 proposes a detection device architecture with separate transmitters and receivers, as shown in Figure 3b. Compared to Figure 3a, this architecture adds a polarization beamsplitter (PBS) and a quarter-wave plate. A smaller-aperture transmitter is placed on the left side of the PBS, while a larger-aperture receiver is placed above it. The light beam emitted by the transmitter (shown as a solid line) enters the PBS from the left side of the diagram, then passes through the PBS, the quarter-wave plate, and the transmitting optical system to the scanning component. It is scanned to the detection area in the scanning component's k1 state. The return light is scanned by the scanning component in the k2 state, then passes through the transmitting optical system, the quarter-wave plate, and the PBS, and is reflected to the upper area shown in the diagram, where it is received by the large-aperture receiver. This detection device architecture, by separating the transmitter and receiver, allows the receiver's receiving aperture to be increased independently, allowing it to cover the effect of the offset angle introduced by the difference between the scanning component's k2 and k1 states on the focus position of the return light, thereby improving the receiver's reception efficiency. However, increasing the receiving port diameter will not only increase the cost and process difficulty, but also, due to process limitations, in some cases, even if the receiving aperture reaches the process limit, it still cannot meet the range affected by the coverage offset angle, resulting in low receiving efficiency in these cases.

[0094] Solution 2 proposes a multi-receiver detection device architecture, see Figure 3c. Compared to Figure 3a, this architecture features multiple receivers on the receiving side. These receivers are arranged along the x-direction, which is affected by the offset angle. Specifically, they can be arranged in the area between the position unaffected by the offset angle and the position with the greatest offset angle effect. For example, assuming the transmitted light beam enters the scanning assembly horizontally as shown, the position unaffected by the offset angle can be understood as the position where the return light enters the receiving side horizontally, such as the position where the return light from the detection range corresponding to target 3 is focused onto detector 3. The position with the greatest offset angle effect can be understood as the position where the return light from the farthest detection range is reflected by the scanning assembly and enters the receiving side, such as the position where the return light from the detection range corresponding to target 1 is focused onto detector 1. In this architecture, multiple receivers can be arranged vertically between these two positions. Using this detection device architecture, when detecting targets at different distances, the light beams generated at different offset positions will always be received by one of the receivers, thus reducing the impact of the offset angle on the received beam. However, setting up multiple receivers not only increases the process difficulty, material cost, structural complexity and volume of the detection device on the receiving side, but also, due to existing process limitations, it is actually impossible to achieve an ideal zero gap between different receivers. Therefore, when detecting certain distances, if the corresponding return light is not exactly focused on the center position of a detector, the problem of low receiving efficiency will still exist.

[0095] In summary, neither of these two solutions offered by the industry effectively improves the receiving efficiency on the receiving side. Therefore, when assembling the receiver, it is typically necessary to first perform an initial assembly with the scanning assembly stationary. Then, when the scanning assembly is rotating, the position of the initially assembled receiver must be adjusted based on the resulting offset angle. This results in difficulties in assembling the receiver in existing detection devices. Furthermore, even if the receiver position is adjusted based on the different states of the scanning assembly, the adjusted receiver can only achieve balance at different detection distances, failing to resolve the aforementioned low receiving efficiency issue.

[0096] In view of this, the present application provides a lens assembly, which is placed between the receiving assembly and the detection module, and is used to focus the light returned by the scanning assembly in a first direction affected by the offset angle, so as to reduce the beam width (i.e., beam width) of the returned light in the first direction, thereby reducing the offset distance of the returned light in the first direction, increasing the probability of the returned light irradiating the detection module, and reducing the probability of the detection module not receiving the returned light, thereby effectively improving the receiving efficiency of the detection module. Optionally, the lens assembly can also be used to focus the light returned by the scanning assembly in a second direction that is not affected by the offset angle. Since the size of the focused light spot is larger than that of the focused light spot, even if the light is offset in the second direction due to some reasons (other reasons not affected by the offset angle), some light will still irradiate the detection module in the second direction, thereby reducing the degree to which the light beam received by the detection module in the second direction is affected by the offset in the second direction.

[0097] The lens assembly and receiving module proposed in this application are described in detail below with reference to specific drawings.

[0098] In the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0099] In addition, in this application, "position" does not refer to an absolute position and a certain engineering error is allowed. "Distance" does not refer to an absolute distance and a certain engineering error is allowed. "Focal length" does not refer to an absolute distance and a certain engineering error is allowed.

[0100] Please refer to Figure 4a, which is a schematic diagram of the structure of a lens assembly provided in this application. As shown in Figure 4a, the lens assembly 400 includes a first sub-lens assembly 410. The first sub-lens assembly 410 includes at least two lenses (not shown in the figure). The at least two lenses are located between the scanning assembly 500 and the detection module 600 and are used to focus the light returned by the scanning assembly 500 in a first direction (i.e., the x-direction, hereinafter referred to as the first direction x). The first direction x is orthogonal to the main optical axis (L in the figure), which is the z-direction in the figure.

[0101] In the foregoing, the first sub-lens assembly 410 focuses light in the first direction x, which can be understood as reducing the beam width of the light in the first direction x, while the beam shape can remain unchanged. For example, referring to FIG4a, assuming that the first sub-lens assembly 410 receives a collimated light beam, the two horizontal solid lines and the light beam in the middle area are the returned light without offset after being reflected by the scanning assembly 500, and the two inclined dotted lines and the light beam in the middle area are the returned light with offset after being reflected by the scanning assembly 500, and the returned light with offset is offset by Δx in the first direction x compared to the returned light without offset due to the existence of the offset angle θ. Then, using the lens assembly shown in FIG4a, the beam width of the collimated light beam incident on the first sub-lens assembly 410 in the first direction x is B1. After the collimated light beam passes through the first sub-lens assembly 410 and is focused in the first direction x, the beam width of the outgoing collimated light beam in the first direction x is reduced to B2. Compared with the existing receiving optical system shown in Figure 5, the existing receiving optical system directly focuses the light returned by the scanning component 500. Regardless of whether the returned light is offset or not, it will be focused to a point. Therefore, if the offset Δx is large, the focus position of the returned light with the offset will most likely deviate from the position of the detection module, resulting in the detection module not receiving the returned light. With the lens assembly shown in Figure 4a, the beam width of the returned light in the first direction x is reduced, but it is not focused to a point. Therefore, even if the returned light is offset, there is a high probability that at least part of the returned light will be irradiated onto the detection module. For example, referring to Figure 4b, for the returned light with an offset Δx, the detection module 600 is set at any position within the range U shown in the figure, and at least a part of the returned light with an offset Δx can be irradiated onto the detection module 600. In the existing receiving optical system shown in Figure 5, no matter where the detection module moves back or forth, the returned light cannot be received. It can be seen that compared with the existing receiving optical system, by performing beam reduction in the first direction, the probability of the returned light irradiating the detection module in the first direction can be increased, the probability of the detection module not receiving the returned light can be reduced, and the receiving efficiency of the detection module can be effectively improved.

[0102] Alternatively, the first direction x can be understood as a direction affected by an offset angle, such as the fast axis. The fast axis refers to the vector direction of light propagation speed within the lens assembly, and is typically affected by an offset angle introduced by the high-speed rotation of the scanning assembly, such as the high-speed rotation of a rotating mirror in a one-dimensional or two-dimensional scanning assembly. By performing beam reduction along the fast axis, the degree to which the offset angle affects the return light traveling along the fast axis can be reduced.

[0103] Furthermore, optionally, the first sub-lens assembly 410 can focus the light returned by the scanning assembly 500 in the first direction x to the exit pupil position of the first sub-lens assembly 410, such as the exit pupil position a1 shown in FIG4a . Exit pupil position a1 can be understood as the same position to which light returning from different directions exits after being deflected in the first direction x by the first sub-lens assembly 410. The centroid of the light spot of light returning from different directions exiting this position is the same. Optionally, at the exit pupil position, the plane perpendicular to the principal optical axis L is referred to as the exit pupil plane. In some scenarios, the detection module 600 can be placed at the exit pupil position a1, covering the area of ​​the centroid of the light spot, so that the receiving surface of the detection module 600 coincides with the exit pupil surface. In this way, no matter how much the light returned by the scanning assembly 500 deflects Δx in the first direction x, it can enter the detection module 600 in the same area at the exit pupil position a1. This can minimize the degree to which the light beam received by the detection module 600 is affected by the deflection angle, allowing the detection module 600 to receive the return light corresponding to any detection distance, thereby improving the reception efficiency of the detection module 600. In addition, because the return light with different deflection angles will all enter the detection module 600 in the same area, this method only requires the detection module 600 to be assembled when the scanning assembly 500 is stationary, and there is no need to adjust the position of the detection module 600 when the scanning assembly 500 is rotating, thereby reducing the difficulty of assembling the detection module 600.

[0104] Alternatively, please refer to FIG6 , which shows a schematic diagram of the structure of another lens assembly provided by the present application. In which, FIG6 (A) shows a transmission optical path diagram of the lens assembly 400 in the xoz direction, and FIG6 (B1) and FIG6 (B2) show transmission optical paths of the lens assembly 400 in the yoz direction. In this example, in addition to the aforementioned first sub-lens assembly 410, the lens assembly 400 may also include a second sub-lens assembly 420. The second sub-lens assembly 420 is used to converge or shrink the light returned by the scanning assembly 500 in the second direction y, wherein the second direction y refers to a direction orthogonal to both the first direction x and the main optical axis L. For example, please refer to FIG6 (B1), which shows a transmission optical path diagram corresponding to a scenario in which the second sub-lens assembly 420 converges the light returned by the scanning assembly 500 in the second direction y. In this scenario, the second sub-lens assembly 420 can focus the light returned by the scanning assembly 500 in the second direction y to the focal plane of the second sub-lens assembly 420. For another example, please refer to (B2) in Figure 6, which shows the transmission optical path diagram corresponding to the scenario in which the second sub-lens assembly 420 focuses the light returned by the scanning assembly 500 in the second direction y. In this scenario, the second sub-lens assembly 420 can focus the light returned by the scanning assembly 500 in the second direction y to the exit pupil position a2 of the second sub-lens assembly 420.

[0105] Optionally, whether the second sub-lens assembly 420 converges or converges the returned light can be determined specifically based on the offset of the returned light in the second direction y in the scene. For example, when the light returned by the scanning assembly 500 in the scene is not offset in the second direction y, the second sub-lens assembly 420 can be used to converge the returned light in the second direction y. Convergence has a simpler lens structure than convergence, thereby saving the complexity of the lens assembly while meeting the beam focusing requirements. Conversely, when the light returned by the scanning assembly 500 in the scene is offset in the second direction y, the second sub-lens assembly 420 can be used to converge the returned light in the second direction y to reduce the beam width of the light in the second direction y, thereby simultaneously reducing the offset distance of the returned light in the second direction y introduced due to the offset effect of other reasons, increasing the probability that the returned light in the second direction y will illuminate the detection module 600, and further improving the receiving efficiency of the detection module 600.

[0106] Further, optionally, the second direction y may be a slow axis direction. The slow axis direction refers to the direction of the light vector with a slow propagation speed in the lens assembly 400, which is not affected by the offset angle, but there may be a light beam offset due to certain reasons. For example, taking the two-dimensional scanning assembly as an example, when it is first used, the light returned by the two-dimensional scanning assembly will not usually be offset in the slow axis direction. In this case, the second sub-lens assembly 420 may be configured to converge the returned light in the slow axis direction to focus all of it on the detection module 600. However, as the use time increases, the position of the swing mirror in the two-dimensional scanning assembly may change, causing the returned light to also be offset in the slow axis direction. In this case, the second sub-lens assembly 420 may be configured to converge the returned light in the slow axis direction to reduce the degree to which the returned light is affected by the offset when it is transmitted in the slow axis direction.

[0107] The above content introduces the basic design of the lens assembly 400. The following will further describe in detail the various components involved in FIG. 6 to provide an exemplary specific implementation solution.

[0108] 1. First sub-lens assembly

[0109] Optionally, the first sub-lens assembly 410 has optical power in the first direction x and no optical power in the second direction y. In other words, the lens in the first sub-lens assembly 410 has curvature on one or both sides in the first direction x, thereby deflecting (contracting) the light returned from the scanning assembly 500 in the first direction x. In the second direction y, however, it acts like flat glass, transmitting the light straight out without deflection. In this way, the first sub-lens assembly 410 only affects the transmission direction of the light returned from the scanning assembly 500 in the first direction x and does not affect its transmission direction in the second direction y.

[0110] Furthermore, optionally, the first sub-lens assembly 410 includes at least two lenses, both of which are convex lenses, or a combination of a convex lens and a concave lens. The convex lens focuses light, while the concave lens diverges light. By combining focusing or focusing and diverging, a simple optical path design can be used to achieve convergence of the return light in the first direction x, thereby reducing the design difficulty of the lens assembly.

[0111] Taking the first sub-lens assembly 410 including two lenses as an example, please refer to Figure 7, which shows a specific structural schematic diagram of a lens assembly provided by the present application, wherein Figure 7 (A) shows the transmission light path of the lens assembly on the yoz plane, and Figure 7 (B) shows the transmission light path of the lens assembly on the xoz plane. In this example, the first sub-lens assembly 410 includes a first lens M1 and a second lens M2, and the first lens M1 is located between the scanning assembly 500 and the second lens M2. The figure takes the collimated light returned by the scanning assembly 500 as an example. Referring to Figure 7 (B), the first lens M1 can be used to converge the collimated light returned by the scanning assembly 500, and the second lens M2 can be used to collimate the converged light from the first lens M1. In this way, on the xoz plane, the light emitted and incident on the first sub-lens assembly 410 is both collimated light. By designing the parameters such as the focal length and position of the first lens M1 and the second lens M2 (see the introduction below), the beam width B2 of the emitted collimated light in the first direction x is made smaller than the beam width B1 of the incident collimated light in the first direction x, thereby achieving the reduction of the collimated light in the first direction x.

[0112] It will be appreciated that both the first lens M1 and the second lens M2 can be convex lenses, or a combination of a convex lens and a concave lens, for example, the first lens M1 can be a convex lens and the second lens M2 can be a concave lens. Please refer to Figures 8a and 8b for lens parameter diagrams illustrating these two possible combinations, which are described in detail below.

[0113] In lens combination form 1, as shown in Figure 8a , both the first lens M1 and the second lens M2 are convex lenses. The distance between the first lens M1 and the second lens M2 is the sum of the focal lengths f1 and f2 of the first lens M1, with the focal length f1 of the first lens M1 being greater than the focal length f2 of the second lens M2. Thus, the light beam (with a wide beam width B1) returned by the scanning assembly 500 first passes through the first lens M1 with a large focal length f1 before being focused between the first and second lenses M1 and M2 (as shown in the P plane, which can be understood as the focal plane of the first and second lenses M1 and M2). It then passes through the second lens M2 with a small focal length f2, converting it into light with a smaller beam width (B2), which is then emitted through the second lens M2. Optionally, the light returned by the scanning assembly 500 is parallel light. The first lens M1 focuses this parallel light onto the focal plane, which is then transmitted to the second lens M2. It is then collimated by the second lens M2 and emitted as parallel light. It can be seen that by designing the focal length of the convex second lens to be smaller than the focal length of the convex first lens, placing the convex first lens before the convex second lens, and designing the distance between the two to be the sum of their focal lengths, the incident light can be focused in the first direction.

[0114] In lens combination form 2, see Figure 8b . First lens M1 is a convex lens, and second lens M2 is a concave lens. The distance between first lens M1 and second lens M2 is the difference between the focal length f1 of first lens M1 and the focal length f2 of second lens M2. The focal length f1 of first lens M1 is greater than the focal length f2 of second lens M2. Thus, light beams (with a wide beam width B1) returned by scanning assembly 500 first pass through the large focal length f1 of first lens M1 before converging to second lens M2. Because the focal point F1 of first lens M1 is located to the right of second lens M2, the light beams converging to second lens M2 still have a certain beam width (B2), which is smaller than the beam width B1 of the incident light. Light beams with this width B2 are then deflected by second lens M2 before being emitted, for example, collimated into parallel light by second lens M2. It can be seen that by designing the focal length of the concave second lens to be smaller than the focal length of the convex first lens, placing the convex first lens before the convex second lens, and designing the distance between the two to be the difference between the focal lengths of the two, it is also possible to achieve beam reduction of the incident light.

[0115] Furthermore, optionally, in any of the above lens combinations, in order for the two lenses to achieve convergence of light in the first direction x, the focal length ratio of the two lenses must satisfy the object-image ratio. Specifically, the focal length f1 of the first lens M1 and the focal length f2 of the second lens M2 must satisfy the following formula (1.1):

[0116] Among them, h is the object height, which can be understood as the height of the detection target in the first direction x, or can be understood as the beam width of the light incident on the first sub-lens assembly 410 in the first direction x, that is, B1 shown in Figure 8a or 8b; h' is the image height, which can be understood as the height of the detection target imaged on the side of the detection module 600, or can be understood as the beam width of the light emitted from the first sub-lens assembly 410 in the first direction x, that is, B2 shown in Figure 8a or 8b.

[0117] Furthermore, optionally, the first lens M1 and the second lens M2 can both be cylindrical lenses. For example, both the first lens M1 and the second lens M2 are convex cylindrical lenses, or the first lens M1 is a convex cylindrical lens and the second lens M2 is a concave cylindrical lens. Cylindrical lenses have the ability to deflect light beams in a single direction. By configuring the first lens M1 and the second lens M2 as cylindrical lenses, and configuring these two cylindrical lenses to have curvature on one or both surfaces in the first direction x, light beam reduction in the first direction x can be achieved.

[0118] It should be noted that the above content is based on the example of the first sub-lens assembly 410 including two lenses, and introduces the lens parameters that the two lenses must meet. When the first sub-lens assembly 410 includes three or more lenses, the lens parameters of these lenses can be designed with reference to the design ideas of the above two lenses. For example, taking the first sub-lens assembly 410 including three lenses as an example:

[0119] In one possible lens combination, all three lenses are convex lenses, the focal length of the first lens is greater than the distance between the first and second lenses, the distance between the second and third lenses is equal to the sum of the focal lengths of the second and third lenses, and the focal length of the second lens is greater than the focal length of the third lens. In this way, light with a larger beam width first passes through the first lens and is focused onto the second lens. Since the focal point of the first lens is behind the second lens, the light focused on the second lens still has a certain beam width, which is smaller than the beam width of the light incident on the first lens. After passing through the second and third lenses (the second and third lenses are equivalent to the first lens M1 and second lens M2 in the above-mentioned lens combination form), the light with this beam width becomes light with an even smaller beam width and is emitted to the detection module 600. It can be seen that this lens combination form can achieve light beam reduction;

[0120] In another possible lens combination, the first two lenses are convex lenses, and the last lens is a concave lens. The focal length of the first lens is greater than the distance between the first and second lenses, the focal length of the second lens is greater than the focal length of the third lens, and the distance between the second and third lenses is equal to the difference between the focal lengths of the second and third lenses. In this way, light with a larger beam width first passes through the first lens and is focused onto the second lens. Since the focal point of the first lens is behind the second lens, the light focused on the second lens still has a certain beam width, which is smaller than the beam width of the light incident on the first lens. After passing through the second and third lenses (the second and third lenses are equivalent to the first and second lenses M1, M2 in the above-mentioned lens combination form two), the light with this beam width becomes light with a smaller beam width and is emitted to the detection module 600. It can be seen that this lens combination form can also achieve light converging.

[0121] It is understandable that there are many possible lens combinations, which will not be listed one by one in this application.

[0122] 2. Second sub-lens assembly

[0123] Optionally, the second sub-lens assembly 420 has optical power in the second direction y but no optical power in the first direction x. In other words, the lenses in the second sub-lens assembly 420 have curvature on one or both sides in the second direction y, thereby deflecting (converging or narrowing) the light returned from the scanning assembly 500 in the second direction y. In the first direction x, however, the lens acts like flat glass, transmitting the light straight out without deflection. In this way, the second sub-lens assembly 420 only affects the propagation direction of the light returned from the scanning assembly 500 in the second direction y, without affecting its propagation direction in the first direction x.

[0124] Furthermore, optionally, since the first sub-lens assembly 410 and the second sub-lens assembly 420 have optical power only in one of the two mutually orthogonal directions, any sub-lens assembly will not affect the beam deflection of the other sub-lens assembly, and thus, the positions of the first sub-lens assembly 410 and the second sub-lens assembly 420 between the scanning assembly 500 and the detection module 600 can be arbitrarily set. For example, taking the lens assembly shown in FIG7 as an example, it is taken as an example that the second sub-lens assembly 420 is placed between the scanning assembly 500 and the first sub-lens assembly 410, but the first sub-lens assembly 410 can also be placed between the scanning assembly 500 and the second sub-lens assembly 420, as shown in FIG9a, or the second sub-lens assembly 420 can also be placed between any two lenses of the first sub-lens assembly 410, as shown in FIG9b, or, in the case where the second sub-lens assembly 420 includes at least two lenses, the first sub-lens assembly 410 can also be placed between any two lenses of the second sub-lens assembly 420, and so on, without specific limitation.

[0125] It can be understood that (A) in Figure 9a and (A) in Figure 9b show the transmission light paths of the returned light corresponding to different arrangements on the yoz plane, and (B) in Figure 9a and (B) in Figure 9b show the transmission light paths of the returned light corresponding to different arrangements on the xoz plane. It can be seen that no matter how the first sub-lens assembly 410 and the second sub-lens assembly 420 are arranged, the first sub-lens assembly 410 will only deflect the returned light in the first direction x, and the change of the position of the second sub-lens assembly 420 will not affect the deflection result of the returned light in the first direction x. Similarly, the second sub-lens assembly 420 will only deflect the returned light in the second direction y, and the change of the position of the first sub-lens assembly 410 will not affect the deflection result of the returned light in the second direction y.

[0126] Furthermore, optionally, taking the arrangement of the sub-lens assemblies shown in FIG7 as an example, when the second sub-lens assembly 420 converges the light returned by the scanning assembly 500 in the second direction y, the detection module 600 may coincide with the focal plane of the second sub-lens assembly 420. The focal plane of the second sub-lens assembly 420 refers to a plane passing through the focal point of the second sub-lens assembly 420 (i.e., F3 shown in FIG7 ) and perpendicular to the principal optical axis L. Optionally, the receiving surface of the detection module 600 may be placed at the focal plane of the second sub-lens assembly 420 and cover the focal point F3 and the surrounding area, so that the detection module 600 can receive the returned light focused to the focal point F3 by the second sub-lens assembly 420 or focused near the focal point F3 due to factors such as errors.

[0127] Furthermore, optionally, referring to FIG. 7 , to ensure consistency of the position of the detection module 600 in the direction of the principal optical axis L in the xoz plane and the yoz plane, the focal plane of the second sub-lens assembly 420 can be configured to coincide with the exit pupil plane of the first sub-lens assembly 410 (i.e., the plane perpendicular to the principal optical axis L at the exit pupil position a1). In other words, the detection module 600 coincides with the focal plane of the second sub-lens assembly 420 and the exit pupil plane of the first sub-lens assembly 410. In this way, the second sub-lens assembly 420 can focus the light returned by the scanning assembly 500 in the second direction y to the focal plane of the second sub-lens assembly 420 (or the exit pupil surface of the first sub-lens assembly 410), so that the detection module 600 placed on the focal plane can receive the return light focused in the second direction y. At the same time, the first sub-lens assembly 410 can shrink the light returned by the scanning assembly 500 in the first direction x to the exit pupil surface of the first sub-lens assembly 410 (or the focal plane of the second sub-lens assembly 420), so that the detection module 600 placed on the exit pupil surface can receive the return light shrinked in the first direction x. In this way, the detection module 600 can receive more return light on the plane xoy formed by the first direction x and the second direction y, thereby effectively improving the receiving efficiency of the detection module 600.

[0128] It is understood that the second sub-lens assembly 420 includes at least one lens, which may be a convex lens, and the sum of the focal lengths of the at least one lens may be the distance from the at least one lens to the focal plane of the second sub-lens assembly 420. Thus, through the focusing capability of the at least one lens, the light returned by the scanning assembly 500 may be focused onto the detection module 600 placed at the focal plane.

[0129] Taking the second sub-lens assembly 420 as an example including a single lens, as shown in FIG7 , the second sub-lens assembly 420 may include a third lens M3. The focal length f3 of the third lens M3 is equal to the distance from the third lens M3 to the focal plane of the second sub-lens assembly 420. Since the focal plane of the second sub-lens assembly 420 coincides with the exit pupil plane of the first sub-lens assembly 410, the focal length f3 can also be considered to be equal to the distance from the third lens M3 to the exit pupil plane of the first sub-lens assembly 410.

[0130] It is understood that FIG7 shows an example in which the third lens M3 is located between the scanning assembly 500 and the first lens M1. However, the third lens M3 can also be located between the second lens M2 and the detection module 600, as shown in FIG9a, or between the first lens M1 and the second lens M2, as shown in FIG9b. When the placement of the third lens M3 is different, the relationship between the focal length f3 of the third lens M3 and the focal lengths of the other lenses is also different, for example:

[0131] In one example, referring to Figures 10a and 10b, when the third lens M3, the first lens M1, and the second lens M2 are arranged in this order, the focal length f3 of the third lens M3 is the sum of the distance between the third lens M3 and the first lens M1, the distance between the first lens M1 and the second lens M2, and the distance between the second lens M2 and the exit pupil plane of the first sub-lens assembly 410. For example, referring to Figure 10a, when the first lens M1, the second lens M2, and the third lens M3 are all convex lenses, the focal length f3 of the third lens M3 is the sum of the distance between the third lens M3 and the first lens M1, the focal length f1 of the first lens M1, the focal length f2 of the second lens M2, and the distance between the second lens M2 and the exit pupil plane of the first sub-lens assembly 410. Alternatively, referring to FIG10b , when the first lens M1 and the third lens M3 are convex lenses and the second lens M2 is a concave lens, the focal length f3 of the third lens M3 is the sum of the distance between the third lens M3 and the first lens M1, the focal length f1 of the first lens M1, and the distance between the focal point F1 of the first lens M1 and the exit pupil plane of the first sub-lens assembly 410; or the sum of the distance between the third lens M3 and the first lens M1, the distance between the first lens M1 and the second lens M2, the focal length f2 of the second lens M2, and the distance between the focal point F1 of the second lens M2 and the exit pupil plane of the first sub-lens assembly 410;

[0132] In another example, referring to FIG. 10 c , when the first lens M1, the second lens M2, and the third lens M3 are arranged in this order, the focal length f3 of the third lens M3 is the distance between the third lens M3 and the exit pupil plane of the first sub-lens assembly 410, and is unrelated to the focal length f1 of the first lens M1 and the focal length f2 of the second lens M2.

[0133] In another example, referring to FIG10d , when the first lens M1, the third lens M3, and the second lens M2 are arranged in this order, the focal length f3 of the third lens M3 is the sum of the distance between the third lens M3 and the second lens M2, and the distance between the second lens M2 and the exit pupil plane of the first sub-lens assembly 410, and is unrelated to the focal length f1 of the first lens M1.

[0134] Furthermore, optionally, the third lens M3 may be a cylindrical lens, such as a convex cylindrical lens. A cylindrical lens has the ability to deflect light beams in a single direction. Therefore, by configuring the third lens M3 as a convex cylindrical lens and configuring the convex cylindrical lens to have a curvature on one or both surfaces in the second direction y, light beam convergence in the second direction y can be achieved.

[0135] It should be noted that the above content is based on the example of the second sub-lens assembly 420 including one lens to introduce the lens parameters that the lens needs to meet. When the second sub-lens assembly 420 includes two or more lenses, the lens parameters of these lenses can be designed with reference to the design ideas of the above-mentioned one lens. For example, taking the lens placement order shown in Figure 7 as an example, please refer to Figure 11. When the second sub-lens assembly 420 includes two lenses M31 and M32, assuming that lens M31 is placed between lens M32 and scanning assembly 500, the focus F31 of lens M31 can be configured to be greater than the distance between lens M31 and lens M32, and the focus F32 of lens M32 is located at the focal plane of the second sub-lens assembly 420. In this way, light with a larger beam width first passes through lens M31 and is focused on lens M32. Since the focal length of lens M31 is located after lens M32, the light received by lens M32 still has a certain beam width, and the light with this beam width can then be focused by lens M32 to its focus F32, i.e., the focal plane. In this case, the distance between the lens M31 and the focal plane of the second sub-lens assembly 420 is the focal length f of the lens M31. 31 Focal length f of lens M32 32 There are many possible lens combinations, which will not be listed one by one in this application.

[0136] In addition, the above content only introduces the lens structure of the second sub-lens assembly 420 for realizing the convergence function of light in the second direction y. When the second sub-lens assembly 420 is used to realize the focusing function of light in the second direction y, the second sub-lens assembly 420 includes at least two lenses. The relevant design of the at least two lenses can refer to the above description of the first sub-lens assembly 410. The only difference is that the first direction x of the first sub-lens assembly 410 is replaced by the second direction y. This application will not repeat them one by one.

[0137] Furthermore, when the first sub-lens assembly 410 is used to realize the function of converging light in the first direction x, and the second sub-lens assembly 420 is used to realize the function of converging light in the second direction y, the exit pupil surface of the first sub-lens assembly 410 (the plane perpendicular to the main optical axis L at the exit pupil position a1 as shown in Figure 4a) coincides with the exit pupil surface of the second sub-lens assembly 420 (the plane perpendicular to the main optical axis L at the exit pupil position a2 as shown in (B2) in Figure 6), and the detection module 600 is placed on the exit pupil surface of the first sub-lens assembly 410 or the exit pupil surface of the second sub-lens assembly 420. In other words, the receiving surface of the detection module 600 coincides with the exit pupil surface of the first sub-lens assembly 410 and the exit pupil surface of the second sub-lens assembly 420. In this way, since the exit pupil surfaces of the two sub-lens assemblies coincide, the return light with different offsets in the first direction x and / or the second direction y will be focused to the position of the exit pupil surface after passing through the two sub-lens assemblies, thereby enabling the detection module 600 arranged on the exit pupil surface to receive the return light in the same area, effectively improving the receiving efficiency of the detection module 600 in either the first direction x or the second direction y.

[0138] Based on the structure of the lens assembly described above, the present application can also provide a receiving module.

[0139] Please refer to Figure 12, which shows a schematic diagram of the architecture of the receiving module provided by the present application. The receiving module includes a scanning component 1110, a receiving optical system 1120 and a detection module 1130. The receiving optical system 1120 is used to reduce the light returned by the scanning component 1110 in a first direction (as shown in the x direction), and the detection module 1130 coincides with the exit pupil position of the receiving optical system 1120. For example, the receiving surface of the detection module 1130 is located at the exit pupil position (or exit pupil surface) of the receiving optical system 1120. In this way, since the light incident on the receiving optical system 1120 is reduced in the first direction, it will be emitted from the same area at the exit pupil position. Therefore, by placing the detection module 1130 at the exit pupil position, no matter how much the returned light has an offset in the first direction x, it can be incident on the detection module 1130 in the same area at the exit pupil position, thereby effectively reducing the degree to which the light beam received by the detection module 1130 is affected by the offset angle, so that the detection module 1130 can receive the light returned when detecting any detection distance, thereby improving the receiving efficiency of the detection module 1130. In addition, since the return light with different offset distances will enter the detection module 1130 in the same area, this method only requires the detection module 1130 to be assembled when the scanning component 1110 is in a stationary state, and there is no need to adjust the position of the detection module 1130 when the scanning component 1110 is in a rotating state, thereby reducing the difficulty of assembling the detection module 1130.

[0140] The following describes in detail each component involved in FIG12 to provide an exemplary specific implementation solution.

[0141] 1. Scanning Components

[0142] For example, the scanning component 1110 can be a polyhedron (e.g., an octahedron, a hexahedron, or a tetrahedron) rotating mirror, a microelectromechanical system (MEMS) galvanometer, or an oscillating mirror. It should be noted that this application does not limit the type of scanning component 1110; any structure that can reflect the returned light to the receiving optical system 1120 is acceptable.

[0143] 2. Receiving Optical System

[0144] Optionally, the receiving optical system 1120 may include a lens assembly as described above, such as the lens assembly 400 described in any embodiment of Figures 4a to 11. Exemplarily, other optical elements may also be included, such as multiple lenses, and the lenses may be spherical lenses (such as concave lenses, or convex lenses, etc.), or may be aspherical lenses. The combination of multiple spherical lenses and / or aspherical lenses helps to improve the quality of receiving the returned light, thereby improving the imaging quality and reducing the aberration of the optical imaging system. It should be understood that there are many different types of convex lenses and concave lenses, for example, convex lenses include biconvex lenses, plano-convex lenses and concave-convex lenses, and concave lenses include biconcave lenses, plano-concave lenses and concave-convex lenses. The present application does not limit the types of convex lenses and concave lenses.

[0145] 3. Detection Module

[0146] Optionally, the detection module 1130 may include a detector for receiving an optical signal from the receiving optical system 1120 and converting the optical signal into an electrical signal to achieve target detection using the electrical signal.

[0147] Further, optionally, FIG13a shows a schematic structural diagram of a detection module provided by the present application. When the detection device operates in single-channel mode, it means that the detection device will only emit one beam of light in the same period of time, and the return light corresponding to the beam of light will be focused by the receiving optical system 1120 (such as the second sub-lens assembly described above) to a focal position in the second direction y, such as focus F0. In this case, the detection module 1130 may include only one detector (P), and the center position of the detector P is aligned with the focus F0 on the focal plane of the receiving optical system 1120. In this way, the return light can be focused to the center position of the detector P each time, so that the detector P can receive a relatively comprehensive return light.

[0148] Furthermore, optionally, FIG13b shows a schematic diagram of the structure of another detection module provided by the present application. When the detection device operates in a multi-channel mode, it means that the detection device will emit multiple beams of light in different directions at the same time. The figure takes two beams of light in different directions as an example. The beam shown by the solid line corresponds to the first channel detection, and the beam shown by the dotted line corresponds to the second channel detection. The return light corresponding to the first channel will be focused by the receiving optical system 1120 to a focal position in the second direction y, such as the focal point F 02 , and the return light corresponding to the second channel will be focused by the receiving optical system 1120 to another focal position in the second direction y, such as focus F 01 In this case, the detection module 1130 may include a plurality of detectors, which are sequentially arranged along the second direction y on the focal plane of the receiving optical system 1120. For example, with respect to the two beams of light shown in the figure, the detection module 1130 may include a detector P2 and a detector P1, the receiving surfaces of the detectors P2 and P1 both coincide with the focal plane of the receiving optical system 1120, and the center position of the detector P2 is aligned with the focus F on the focal plane of the receiving optical system 1120. 02 The center position of the detector P1 is aligned with the focus F on the focal plane of the receiving optical system 1120 01 In this way, the return light corresponding to each channel can be received by the center position of the corresponding detector, which can increase the detection range of the detection module in the second direction y while maintaining the detection performance of the detection module in the second direction y.

[0149] In one possible implementation, the detector may include a detection array and, in some scenarios, an optical transmission medium. The optical transmission medium is a medium capable of transmitting light, typically including an optical fiber or a waveguide. The optical transmission medium is located between the detection array and the receiving optical system 1120 and is used to transmit light from the receiving optical system 1120 to the detection array, where it is converted into an electrical signal.

[0150] It should be noted that the size of the detection array is generally large, while the size of the optical transmission medium is generally small. Therefore, when the detection device adopts single-channel detection, the range of the returned light focused to the focal plane is small. Therefore, the detection module 1130 may include only one detector, which may be a detection array with a relatively small aperture, or a combination of an optical transmission medium and a detection array with a relatively small aperture. Conversely, when the detection device adopts multi-channel detection, the range of the returned light focused to the focal plane is large. The detection module 1130 may include only one detector, which may be a detection array with a relatively large aperture. Alternatively, the detection module 1130 may include multiple detectors arranged along the second direction y, each detector being a combination of an optical transmission medium and a detection array with a relatively small aperture. Of course, it may also be multiple detection arrays with relatively small apertures, and there is no specific limitation.

[0151] As previously mentioned, whether the detector includes a detection array or a detection array and an optical transmission medium can be determined based on the radar's ranging principle. For example, when using the time-of-flight ranging principle, the speed and time of light propagation in air are used to measure distance. In this case, the detector may only include a detection array, which is used to sense the arrival time of the return light. This is then combined with the time the probe light is emitted to calculate the light's flight time in the air. This flight time, combined with the speed of light, is sufficient to complete the ranging. For another example, when using the FMCW ranging principle, the frequency change (i.e., the Doppler effect) and time difference of the return light compared to the probe light are used to measure distance. In this case, the detector may include an optical transmission medium and a detection array. The optical transmission medium senses the frequency of the return light, and the detection array senses the arrival time of the return light. The frequency and arrival time of the return light can be combined with the frequency and emission time of the probe light to complete the ranging.

[0152] Furthermore, when the detector includes only a detection array, the "receiving surface of the detection module" referred to above refers to the receiving surface of the detection array, such as the photosensitive surface of the detection array. When the detector includes both the detection array and an optical transmission medium, the "receiving surface of the detection module" referred to above refers to the receiving surface of the optical transmission medium, such as the surface of the optical transmission medium where the light aperture is located.

[0153] The preceding section describes the specific structure of a receiving module, which can be used to reduce the impact of the offset angle on the returned light when it is transmitted in the first direction. To more clearly illustrate the role of the receiving module in reducing the impact of the offset angle, the following provides a specific example of a receiving module design.

[0154] Please refer to Figure 14 and Table 1 below. Figure 14 shows the structure and transmission optical path of the receiving module in this design. Figure 14 (A) shows the transmission optical path of the receiving module in the xoz plane, and Figure 14 (B) shows the transmission optical path of the receiving module in the yoz plane. In this example, the receiving optical system 1120 in the receiving module takes the lens combination shown in Figure 7 as an example. This lens combination is used to narrow the light returned by the scanning component 1110 in the x direction and converge it in the y direction. Table 1 shows the relevant parameters of each lens (i.e., M1, M2, and M3) in this lens combination.

[0155] Table 1

[0156] In conjunction with Table 1 and Figure 14 , using the lens parameters shown in Table 1, assuming that due to the high-speed rotation of the scanning assembly 1110, the detection device has an x-direction offset angle range of 0° to 0.036° when detecting different distances, then by placing a detection module 1130 at the exit pupil plane, simulation can be performed to obtain information about the light spot transmitted to the exit pupil plane at different offset angles, such as the shape and size of the light spot. Assuming the simulation results are as shown in Figure 15 , then: Referring to Figure 15 , the blackened light spot can be understood as the light spot presented by the returned light transmitted to the exit pupil plane at an offset angle of 0°, and the large light spot outside the blackened light spot can be understood as the light spot presented by the returned light transmitted to the exit pupil plane at an offset angle greater than 0.036°. It can be seen that on the xoy plane, when the offset angle is 0°, the light spot size at the exit pupil position is 100 μm × 10 μm, while when the offset angle is 0.036°, the light spot size at the exit pupil position is 100 μm × 12 μm. It can be seen that although the returned light is offset in the x-direction, after optical processing by the receiving optical system 1120, the position (i.e., exit pupil position) and size of the returned light transmitted to the exit pupil plane are the same, regardless of whether the offset angle is 0° or 0.036°. Therefore, by predicting the exit pupil position and placing the receiving surface of the detection module 1130 at this exit pupil position, the returned light can be well received by the detection module 1130 regardless of the offset angle. This effectively reduces the degree to which the return light received by the detection module 1130 is affected by the offset angle, thereby improving the receiving efficiency of the detection module 1130.

[0157] It should be noted that in an ideal optical system, when converging in the y direction, light with different offset angles in the x direction should theoretically focus at the same position in the y direction. In other words, the light spot corresponding to 0° and the light spot corresponding to 0.036° should have the same spot width in the y direction. However, due to manufacturing errors or other factors, there may be deviations in the y direction. For example, when the focus of one or more lenses cannot be completely aligned with the designed focus due to manufacturing errors, the manufacturing error may cause the light spot at the position that should have been focused to become larger or smaller than the focused spot. For example, in the aforementioned example, there is a 2um deviation in the y direction between the light spot corresponding to 0° and the light spot corresponding to 0.036°. This 2um deviation is caused by manufacturing errors or other factors, is not related to the offset in the x direction, and can be ignored.

[0158] Based on the structure of the receiving module described above, the present application can also provide a detection device.

[0159] Please refer to Figure 16, which shows a schematic diagram of the architecture of the detection device provided by the present application. The detection device can be any optical device including a scanning component and a detection module, such as a laser radar or a projector. As shown in Figure 16, the detection device may include a receiving module 1510, and the receiving module 1510 may be any receiving module described in the above content, such as the receiving module in Figure 12, Figure 13a or Figure 13b. Exemplarily, the receiving module 1510 may include a scanning component 1511, a receiving optical system 1512 and a detection module 1513, the scanning component 1511 is used to scan the returned light to the receiving optical system 1512, the receiving optical system 1512 is used to transmit the received light to the detection module 1513 after converging in a first direction (x direction shown in the figure), and the detection module 1513 is used to convert the received light signal into an electrical signal for target detection. It is understandable that the receiving optical system 1512 can also converge or converging the received light in a second direction (y direction not shown in the figure), or perform other possible beam deflection, which is not specifically limited.

[0160] In one possible implementation, the detection device may further include a transmitting module 1520, configured to emit light toward the scanning component 1511. The scanning component 1511 may further scan the light from the transmitting module 1520 to a detection area. Optionally, the light emitted by the transmitting module 1520 may be continuous light or pulsed light, for example, continuous light emitted by the transmitting module 1520 in a frequency modulated continuous wave (FMCM) mode.

[0161] In a further possible implementation, the detection device may further include an emitting optical system 1530, which is located between the emitting module 1520 and the scanning component 1511, and is used to shape the light emitted by the emitting module 1520. Exemplarily, the emitting optical system 1530 may include micro-nano optical elements, such as a microlens array (MLA) or diffractive optical elements (DOE), etc., for shaping the light beam. The shaping method may include but is not limited to beam collimation and beam homogenization. Among them, beam collimation refers to converting the light beam into parallel light, and beam homogenization refers to homogenizing the energy of the light beam.

[0162] In a further possible implementation, the detection device may further include a transceiver separation component 1540, located at the intersection of the optical paths of the transmitting module 1520, the scanning component 1511, and the detection module 1513. The transceiver separation component 1540 is configured to transmit light emitted by the transmitting module 1520 to the scanning component 1511, and transmit light returned from the scanning component 1511 to the detection module 1513. By providing the transceiver separation component in the optical system, the transmitted light and the returned light can be separated, thereby allowing the transmitting module and the detection module to be provided separately, thereby supporting the addition of a receiving optical system 1512 for beam reduction on the detection module side.

[0163] Optionally, referring to FIG. 16 , the transmit / receive separation component 1540 may include a PBS and a quarter-wave plate. The PBS is located at the intersection of the optical paths of the transmitting module 1520, the scanning component 1511, and the detection module 1513. The quarter-wave plate is located between the PBS and the scanning component 1511, specifically, between the PBS and the transmitting optical system 1530. During operation of the detection device, linearly polarized P light emitted by the transmitting module 1520 is first transmitted to the PBS. After being converted by the PBS into circularly polarized P light, it is transmitted to the quarter-wave plate. After passing through the quarter-wave plate, it is transmitted to the scanning component 1511, where it is scanned into the detection space. When an object is present in the detection space, the object reflects the circularly polarized P light back to the scanning component 1511. The object then reflects the circularly polarized P light back to the quarter-wave plate, where it is converted by the quarter-wave plate into circularly polarized S light. The PBS then converts the light into linearly polarized S light, which is then reflected to the receiving optical system 1512, thereby separating the transmitted and received light.

[0164] In one possible implementation, the detection device may further include a control module (not shown) that processes the electrical signals from the detection module 1513 to obtain target-related information. Furthermore, based on the determined target-related information, the vehicle may plan a driving path, for example, to avoid obstacles along the route or to achieve autonomous driving.

[0165] Exemplarily, the control module may include one or more processors, and the processor may be a circuit with signal (or data) processing capabilities. In one implementation, the processor may be a circuit with instruction reading and execution capabilities, such as a central processing unit (CPU), a microprocessor, a graphics processing unit (GPU) (which can be understood as a microprocessor), or a digital signal processor (DSP); in another implementation, the processor may implement certain functions through the logical relationship of a hardware circuit, and the logical relationship of the hardware circuit is fixed or reconfigurable, such as a hardware circuit implemented by a processor as an application-specific integrated circuit (ASIC) or a programmable logic device (PLD), such as a field programmable gate array (FPGA). In a reconfigurable hardware circuit, the process of the processor loading a configuration document to implement the hardware circuit configuration can be understood as the process of the processor loading instructions to implement the functions of some or all of the above units. In addition, it can also be a hardware circuit designed for artificial intelligence, which can be understood as an ASIC, such as a neural network processing unit (NPU), a tensor processing unit (TPU), a deep learning processing unit (DPU), etc. For example, it can also be an application processor (AP), an image signal processor (ISP), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof.

[0166] It should be noted that the detection device architecture given in Figure 16 is only an example. In other examples, the detection device may include more, fewer or different structures, and each structure may include more, fewer or different components. The components shown or not shown may be combined or divided in any way, and this application does not make specific limitations on this.

[0167] Based on the structure and functional principle of the detection device described above, the application can also provide a terminal device. The terminal device may include the detection device in any of the above embodiments. Exemplarily, the terminal device can be, for example, a vehicle (such as a car, a truck, a motorcycle, a bus, a ship, an airplane, a helicopter, an amusement vehicle, an amusement park vehicle, a construction vehicle, a tram, a golf cart, a train, an unmanned vehicle, an intelligent vehicle and a digital vehicle, etc.), a robot, a surveying and mapping equipment, an intelligent home appliance (such as a TV, a sweeping robot, an intelligent desk lamp, a sound system, an intelligent lighting system, an electrical control system, a home background music, a home theater system, an intercom system, or a video surveillance system, etc.), an intelligent manufacturing equipment (such as an industrial equipment, a lawn mower, etc.), an intelligent transportation equipment (such as an AGV, an unmanned transport vehicle, or a truck, etc.), or an intelligent terminal (a mobile phone, a computer, a tablet computer, a handheld computer, a desktop computer, a headset, an audio system, a wearable device, an on-board device, a virtual reality device, an augmented reality device, etc.), etc.

[0168] In this application, "at least one" means one or more, and "more" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple. In the text description of this application, the character " / " generally indicates that the related objects before and after are in an "or" relationship. In the formula of this application, the character " / " indicates that the related objects before and after are in a "divided" relationship. In addition, in this application, the word "exemplarily" is used to indicate an example, illustration or description. Any embodiment or design described as an "example" in this application should not be interpreted as being more preferred or advantageous than other embodiments or designs. Alternatively, it can be understood that the use of the word "example" is intended to present concepts in a specific way and does not limit this application.

[0169] It will be appreciated that the various numerical numbers involved in this application are merely for the purpose of describing the distinctions made, and are not intended to limit the scope of the embodiments of the present application. The size of the sequence numbers of the above-mentioned processes does not imply the order of execution, and the order of execution of each process should be determined by its function and inherent logic. Terms such as "first", "second", and similar expressions are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, comprising a series of steps or units. Methods, systems, products, or devices are not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or that are inherent to these processes, methods, products, or devices.

Claims

1. A lens assembly, characterized in that: The first sub-lens assembly includes at least two lenses, and the at least two lenses are located between the scanning assembly and the detection module; The at least two lenses are used to focus the light returned by the scanning assembly in a first direction; Wherein, the first direction is orthogonal to the main optical axis direction.

2. The lens assembly according to claim 1, wherein: The first sub-lens assembly has no optical power in a second direction, and the second direction is a direction orthogonal to both the first direction and the main optical axis direction.

3. The lens assembly according to claim 1 or 2, characterized in that: The at least two lenses are both convex lenses, or a combination of a convex lens and a concave lens.

4. The lens assembly according to any one of claims 1 to 3, characterized in that: The at least two lenses include a first lens and a second lens, the first lens is located between the scanning component and the second lens, the first lens and the second lens are both convex lenses, or the first lens is a convex lens and the second lens is a concave lens.

5. The lens assembly according to claim 4, characterized in that The first lens and the second lens are both convex lenses, the distance between the first lens and the second lens is the sum of the focal length of the first lens and the focal length of the second lens, and the focal length of the first lens is greater than the focal length of the second lens.

6. The lens assembly according to claim 4, wherein: The first lens is a convex lens, and the second lens is a concave lens. The distance between the first lens and the second lens is the difference between the focal length of the first lens and the focal length of the second lens, and the focal length of the first lens is greater than the focal length of the second lens.

7. The lens assembly according to any one of claims 4 to 6, characterized in that: The first lens and the second lens meet the following conditions: Wherein, f1 is the focal length of the first lens, f2 is the focal length of the second lens, h is the object height, and h' is the image height.

8. The lens assembly according to any one of claims 1 to 7, characterized in that: Also included is a second sub-lens assembly; The second sub-lens assembly is used to converge or reduce the light returned by the scanning assembly in a second direction; The second direction is a direction orthogonal to both the first direction and the main optical axis direction.

9. The lens assembly according to claim 8, wherein: The second sub-lens assembly has no optical power in the first direction.

10. The lens assembly according to claim 8 or 9, characterized in that: The focal plane or exit pupil surface of the second sub-lens assembly coincides with the exit pupil surface of the first sub-lens assembly.

11. The lens assembly according to any one of claims 8 to 10, characterized in that: The second sub-lens assembly includes a third lens, and the third lens is a convex lens.

12. The lens assembly according to claim 11, wherein: The focal length of the third lens is the distance between the third lens and the exit pupil surface of the first sub-lens assembly.

13. The lens assembly according to any one of claims 8 to 12, characterized in that The first direction is a fast axis direction, and the second direction is a slow axis direction.

14. The lens assembly according to any one of claims 1 to 13, characterized in that: The first sub-lens assembly or the second sub-lens assembly includes a cylindrical lens.

15. A receiving module, characterized in that: It includes a scanning component, a receiving optical system and a detection module; The receiving optical system is used to focus the light returned by the scanning component in a first direction; The detection module coincides with the exit pupil position of the receiving optical system.

16. The receiving module according to claim 15, characterized in that: The receiving optical system includes the lens assembly according to any one of claims 1 to 14.

17. The receiving module according to claim 15 or 16, characterized in that: The detection module includes a plurality of detectors, and the plurality of detectors are arranged along a second direction, where the second direction is a direction orthogonal to both the first direction and the main optical axis direction.

18. The receiving module according to claim 17, characterized in that: The detector comprises an optical transmission medium and a detection array, wherein the optical transmission medium is located between the receiving optical system and the detection array; The optical transmission medium is used to transmit the received light to the detection array; The detection array is used to convert the received light into an electrical signal.

19. The receiving module according to claim 18, characterized in that: The optical transmission medium is an optical fiber or a waveguide.

20. The receiving module according to any one of claims 15 to 19, characterized in that: The scanning component is a polygonal rotating mirror, a micro electro-mechanical system (MEMS) vibrating mirror or a swinging mirror.

21. The receiving module according to any one of claims 15 to 20, characterized in that: The light is continuous light or pulsed light.

22. A detection device, characterized in that: comprising a receiving module as claimed in any one of claims 15 to 21; The receiving module is used to convert the received optical signal into an electrical signal.

23. The detection device according to claim 22, characterized in that Also includes launch module; The emission module is used to emit light to the scanning component.

24. The detection device according to claim 23, characterized in that It also includes an emission optical system, which is located between the emission module and the scanning component; The emission optical system is used to shape the light emitted by the emission module.

25. The detection device according to claim 23 or 24, characterized in that Also included is a send-receive separation component; The transmitting and receiving separation component is used to transmit the light emitted by the transmitting module to the scanning component, and transmit the light returned by the scanning component to the detection module.

26. The detection device according to any one of claims 22 to 25, characterized in that Also includes control modules; The control module is used to process the electrical signal from the receiving module to obtain the associated information of the target.

27. A terminal device, characterized in that: Comprising a detection device as claimed in any one of claims 22 to 26.

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