Lens assembly, receiving module, detection device and terminal equipment

Abstract

The invention discloses a lens assembly, a receiving module, a detection device and terminal equipment, relates to the technical field of radars, and is used for improving the receiving efficiency of a scanning laser radar. Wherein the lens assembly comprises a first sub-lens assembly, the first sub-lens assembly comprises at least two lenses, the at least two lenses are located between the scanning assembly and the detection module and used for carrying out beam shrinkage on light returned by the scanning assembly in the first direction, and the first direction is orthogonal to the main optical axis direction. The beam width of the returned light in the first direction can be reduced by reducing the beam width of the returned light in the first direction, and the returned light cannot be focused to a point, so that when the returned light deviates in the first direction due to the influence of the deviation angle, the deviation distance in the first direction can be reduced by reducing the beam width of the returned light in the first direction; therefore, the probability that the returned light irradiates the detection module can be increased, and the receiving efficiency of the scanning type laser radar is effectively improved.

Description

Technical Field

[0001] 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

[0002] With the development of LiDAR technology, scanning LiDAR has gradually become a mainstream technical solution in the field of LiDAR due to its advantages such as high power density, long distance measurement, 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, such as Figure 1a The offset angle θ will cause the actual echo signal to Figure 1a There is an offset Δx in the x direction shown, which makes it impossible for the actual echo signal to be accurately focused on the center of the receiver. In severe cases, the receiver may not even receive the echo signal, greatly reducing the receiving efficiency of the receiver.

[0003] At present, the receiving efficiency is usually improved by increasing the receiving aperture of the receiver or setting up multiple receivers. Figure 1a The receiving aperture in the x direction shown, or Figure 1a As shown, multiple receivers are placed side by side in the x direction. However, due to the limitations of the process, in some scenarios, even if the receiving aperture reaches the limit of the process manufacturing, it is still impossible to make the receiving aperture cover the offset range of the actual echo signal, so there is still a problem of low receiving efficiency of the receiver. Alternatively, due to the limitations of the process, 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, there is still a problem of low receiving efficiency of the receiver. It can be seen that neither of the two existing solutions can effectively improve the receiving efficiency of scanning lidars.

[0004] In summary, how to effectively improve the receiving efficiency of scanning lidar is a technical problem that needs to be solved urgently. Summary of the invention

[0005] 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.

[0006] 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 are located between a scanning assembly and a detection module, and are used to focus light returned by the scanning assembly in a first direction, wherein the first direction is orthogonal to the main optical axis direction.

[0007] In the above design, by focusing the returned light in the first direction, the beam width of the returned light in the first direction can be reduced, and the returned light will not be focused to one point. Thus, when the offset angle causes the returned light to deviate in the first direction, the offset distance in the first direction can be reduced by focusing, thereby increasing the probability that the returned light will irradiate the detection module, thereby effectively improving the receiving efficiency of the detection module.

[0008] In a possible design, the first direction is a direction affected by the deviation angle, such as the fast axis direction. The fast axis direction refers to the direction in which the light vector propagates at a fast speed in an optical system, and is usually affected by the deviation angle, which is introduced by the high-speed rotation of the scanning component. By performing beam reduction in the fast axis direction, the degree to which the returned light is affected by the deviation angle when it is transmitted in the fast axis direction can be reduced.

[0009] In a possible design, the first sub-lens assembly has no optical power in the second direction, and the second direction is a direction orthogonal to both the first direction and the main optical axis direction. In other words, the first sub-lens assembly can bend light in the first direction, and is equivalent to a flat glass in the second direction, so that the transmission direction of light in the second direction is not affected.

[0010] In a possible design, at least two lenses are convex lenses, or a combination of a convex lens and a concave lens. The convex lens has a focusing effect on light, and the concave lens has a diverging effect on light. By combining focusing or focusing and diverging, the return light can be reduced in the first direction x through a simple optical path design, reducing the difficulty of designing the lens assembly.

[0011] In a 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, 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. By configuring the first sub-lens assembly as two lenses, the light can be focused in the first direction by using a minimum number of lenses, thereby saving the manufacturing cost of the lens assembly.

[0012] In an example of the above design, when both the first lens and the second lens are 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. In this way, the light with a larger beam width incident on the first lens first passes through the large focal length of the first lens and is focused between the first lens and the second lens, and then passes through the small focal length of the second lens and is converted into light with a smaller beam width and then emitted from the second lens, so as to achieve the reduction of the light in the first direction.

[0013] In another example of the above design, when 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. In this way, the light with a larger beam width emitted by the first lens first passes through a distance less than the focal length of the first lens and then becomes light with a smaller beam width, and then irradiates the second lens, and then is emitted from the second lens, so as to achieve the reduction of the light in the first direction.

[0014] In an example of the above design, the first lens and the second lens satisfy 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. With such configuration, the focal length ratio of the first lens and the second lens can satisfy the object-image ratio.

[0015] 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.

[0016] In the above design, the second direction can be understood as a direction that is not affected by the deviation 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 as the use time increases, etc.), the light in the second direction that is not affected by the deviation angle may also be deflected. Therefore, by also converging in the second direction, the deviation distance of the returned light in the second direction due to the deviation can be reduced, and the degree of influence of the deviation on the returned light when it is transmitted in the second direction can be reduced.

[0017] In an example of the above design, the second direction may be a slow axis direction, that is, a direction in which the light vector propagates slowly in the optical system. By converging the returned light in the slow axis direction, the requirement that the returned light is transmitted to the detection module in the slow axis direction can be met. By converging the returned light in the slow axis direction, the influence of other factors on the light being transmitted in the slow axis direction can be reduced.

[0018] 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, and is equivalent to a flat glass in the first direction, so that the transmission direction of light in the first direction is not affected.

[0019] 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 converge 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 main optical axis can be kept 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.

[0020] 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, and can converge the returned light in the first direction to the focal plane of the second sub-lens assembly to be received by the detection module placed on the focal plane.

[0021] In a further example, 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, so that the focal plane of the third lens coincides with the exit pupil surface of the first sub-lens assembly.

[0022] In a 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, by using the cylindrical lens, the first sub-lens assembly can focus the light in the first direction, and the second sub-lens assembly can converge or focus the light in the second direction.

[0023] In a 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.

[0024] 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 beam-contracted 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, since the returned light of different offset distances will be incident on the detection module in the same area, this method only needs to assemble the detection module when the scanning component is stationary, and there is no need to adjust the position of the detection module when the scanning component is rotating, thereby reducing the difficulty of assembling the detection module.

[0025] 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.

[0026] In a possible design, the detection module includes one or more detectors. In the case of including multiple detectors, the multiple detectors can be arranged along the second direction, and the second direction is a direction orthogonal to both the first direction and the main optical axis direction. This design can support multi-channel detection for the second direction, and can enable light returned from any channel to be received by one or more detectors in the second direction, thereby increasing the detection range while maintaining the detection performance.

[0027] In an example of the above design, the detector includes a detection array, such as a detection module including 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.

[0028] In an example of the above design, the detector includes an optical transmission medium and a detection array, such as a detection module including a group of optical transmission media and a detection array, or including multiple groups of optical transmission media and detection arrays, and the multiple groups of optical transmission media and detection arrays 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 the received light to the detection array, and the detection array is used to convert the received light into an electrical signal.

[0029] In a further possible design, the optical transmission medium is an optical fiber or a waveguide, which can be used to transmit light.

[0030] It should be noted that whether the detector includes a detection array or includes a detection array and an optical transmission medium can be determined according to the ranging principle of the radar. For example, when the time-of-flight ranging principle is adopted, the speed and time of light propagation in the air are used to measure the distance. In this case, the detector may only include a detection array, which is used to sense the time when the return light arrives, and then the flight time of the light in the air can be calculated in combination with the time when the detection light is emitted. The flight time combined with the speed of light is sufficient to complete the ranging. For another example, when the frequency modulated continuous wave (FMCW) ranging principle is adopted, the frequency change (i.e., Doppler effect) and time difference of the return light compared to the detection light are used to measure the distance. In this case, the detector may include an optical transmission medium and a detection array, the optical transmission medium is used to sense the frequency of the return light, and the detection array is used to sense the time when the return light arrives. The frequency of the return light and the time when the return light arrives can be combined with the frequency of the detection light and the time when the detection light is emitted to complete the ranging.

[0031] In one possible design, the scanning component is a polygonal rotating mirror, a micro electro-mechanical system (MEMS) galvanometer or swing mirror, or other mirror structures capable of realizing a scanning function.

[0032] In a 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 according to the actual application scenario to improve the flexibility and versatility of the receiving module.

[0033] 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.

[0034] In a possible design, the detection device may further include an emission module, which is used to emit light to the scanning component.

[0035] In an example of the above design, the detection device may further include an emission optical system, which is located between the emission module and the scanning component and is used to shape the light emitted by the emission module. Exemplarily, the shaping may include beam collimation and beam homogenization.

[0036] In one example of the above design, the detection device may further include a transceiver separation component, which 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. In this way, the separation of the transmitting module and the detection module can be achieved, which facilitates the separate setting of the receiving optical system corresponding to the detection module.

[0037] 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.

[0038] 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.

[0039] The technical effects that can be achieved by the second to fourth aspects mentioned above can refer to the description of the beneficial effects in the first aspect mentioned above, and will not be repeated here one by one. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1a A schematic diagram showing an exemplary offset angle;

[0041] Figure 1b An exemplary transmission light path diagram of a convex lens is shown;

[0042] Figure 1cAn exemplary transmission optical path diagram of a concave lens is shown;

[0043] Figure 1d A schematic diagram exemplarily showing a main optical axis;

[0044] Figure 2 A schematic diagram of a possible application scenario provided by the present application is exemplified;

[0045] Figure 3a An optical transmission schematic diagram of a coaxial laser radar is shown as an example;

[0046] Figure 3b A schematic diagram of the architecture of a detection device with separate transmission and reception is exemplarily shown;

[0047] Figure 3c A schematic diagram showing an architecture of a multi-receiver detection device is exemplified;

[0048] Figure 4a A schematic diagram showing the structure of a lens assembly provided by the present application is exemplified;

[0049] Figure 4b A schematic diagram showing exemplarily the possible positions of a detection module provided by the present application;

[0050] Figure 5 An optical path transmission schematic diagram of an existing receiving optical system is shown as an example;

[0051] Figure 6 A schematic diagram showing the structure of another lens assembly provided by the present application is exemplified;

[0052] Figure 7 A specific structural schematic diagram of a lens assembly provided by the present application is exemplarily shown;

[0053] Figure 8a A schematic diagram showing a lens combination form of the first sub-lens assembly provided by the present application is exemplified;

[0054] Figure 8b A schematic diagram showing another lens combination form of the first sub-lens assembly provided by the present application;

[0055] Figure 9a A schematic diagram showing the arrangement order of a sub-lens assembly provided by the present application is exemplified;

[0056] Figure 9b A schematic diagram showing an arrangement sequence of another sub-lens assembly provided by the present application is exemplified;

[0057] Fig.10a A schematic diagram showing the distance relationship between lenses provided by the present application is exemplified;

[0058] Fig.10b Another schematic diagram of the distance relationship between lenses provided by the present application is exemplified;

[0059] Fig.10c A schematic diagram showing another distance relationship between lenses provided by the present application is exemplified;

[0060] Fig.10d A schematic diagram showing a distance relationship between another lens provided by the present application is exemplified;

[0061] Fig.11 A schematic diagram showing the specific structure of another lens assembly provided by the present application is exemplified;

[0062] Fig.12 A schematic diagram of the architecture of a receiving module provided by the present application is exemplified;

[0063] Fig.13a A schematic diagram of the structure of a detection module provided by the present application is exemplified;

[0064] Fig.13b A schematic diagram showing the structure of another detection module provided by the present application is exemplified;

[0065] Fig.14 A schematic diagram of a receiving module provided by the present application is exemplarily shown;

[0066] Fig.15 An exemplary diagram showing a simulation result of a receiving light spot at an exit pupil position provided by the present application;

[0067] Fig.16 A schematic diagram of the architecture of a detection device provided in the present application is exemplified. DETAILED DESCRIPTION

[0068] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0069] Below, some terms in this application are explained. It should be noted that these explanations are for the convenience of understanding by those skilled in the art and do not constitute a limitation on the scope of protection claimed in this application.

[0070] 1. Walk off angle

[0071] See also Figure 1aIn a scanning laser radar with coaxial transmission and reception, after the detection light emitted by the scanning component is reflected back to the scanning component by the target, if the scanning component reflects the returned light at the scanning angle when the detection light is emitted, the return light transmission path shown by the dotted line in the figure will be obtained. However, due to the high-speed rotation of the scanning component, the scanning angle of the scanning component has changed. The scanning component reflects the returned light at this scanning angle, and the return light transmission path shown by the solid line in the figure will be obtained. The angle θ between the return light transmission path of the solid line and the return light transmission path of the dotted line 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 detection 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 150m away from the scanning component, the offset angle θ is approximately 0.036°. The offset angle θ causes the returned light to deviate from the center of the receiver in the x direction as shown in the figure when it is transmitted to the receiving side, thereby causing a certain offset distance between the returned light and the receiver, such as Figure 1a Δx shown.

[0072] 2. Lens

[0073] A lens is a transparent optical device that affects the curvature of the wavefront of light passing through it. Light enters from one side and exits from the other side. The function of a lens is to change the curvature of the wavefront of light, that is, to focus or defocus the light. For example: a beam of collimated light with a wavefront of approximately a plane is transformed into a beam of light with a curved wavefront, and the light is focused to a focal point. This type of lens is 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 , in this case, the light is incident from the right. A lens with a concave surface can turn collimated or converging light into divergent light, see Figure 1c , this type of lens can also be used to convert a diverging beam into a collimated beam, see Figure 1c , at this time the light beam is incident from the right side.

[0074] 3. Main optical axis

[0075] The principal optical axis is the straight line passing through the centers of the two spherical surfaces of the lens, also called the principal axis. Figure 1d Through the focus of the lens (such as the front focus of a convex lens, see Figure 1b The focal point F1 in the image, or the object focus of a concave lens, see Figure 1cThe plane perpendicular to the principal optical axis and the focal point F2 in the image is called the focal plane, also known as the front focal plane or the object focal plane.

[0076] 4. Optical power

[0077] The focal power is equal to the difference between the image-side beam convergence and the object-side beam convergence, and can characterize the ability of an optical element to deflect a beam. Indicated. Generally, the focal length of the lens is expressed as the reciprocal of the focal length of the image side (the refractive index of air is assumed to be 1). The unit of focal length is diopter (D), 1 diopter (D) = 1m -1 .

[0078] Due to the different thicknesses of optical elements, non-uniformities such as refractive index, and different curvatures of the front and back surfaces (the radius of curvature of the convex surface of the lens is a positive number, and the radius of curvature of the concave surface is a negative number), these characteristics will cause the actual optical focal length of the optical element to be different from the theoretical optical focal length. Therefore, the actual optical focal length can also be called equivalent optical focal length. Unless otherwise specified in the following text, the optical focal length refers to the actual optical focal length of the optical element.

[0079] 5. Fast Axis and Slow Axis

[0080] The fast axis refers to the direction of the light vector with a fast propagation speed in an optical system, and the slow axis refers to the direction of the light vector with a slow propagation speed in an optical system. In a radar system, the fast axis, slow axis and main optical axis are orthogonal to each other. The light returned by the scanning component is usually affected by the deviation angle on the fast axis, which is introduced by the high-speed rotation of the scanning component. For a two-dimensional scanning component, which usually includes a rotating mirror and a swinging mirror, 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 swinging direction of the swinging mirror. For a one-dimensional scanning component, which usually only includes a rotating mirror, 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 the main optical axis.

[0081] 6. Exit pupil position

[0082] In the radar system, the exit pupil position refers to the location of the common exit of the light beams emitted from various points on the object surface after passing through the optical system and exiting from the last light hole. Simply put, there is a virtual aperture in the receiving optical system of the radar, which is located at the position where all incident light beams fill the corresponding aperture of the virtual aperture. Only light that passes through the corresponding aperture of the virtual aperture can leave the receiving optical system. The position of the virtual aperture is the exit pupil position.

[0083] The foregoing text introduces some of the terms involved in this application. The following text introduces possible application scenarios of this application.

[0084] In a possible implementation, the lens assembly provided by the present application may be integrated into a receiving module, the receiving module may be integrated into a detection device, and the detection device may be installed on a vehicle. The detection device may include, but is not limited to, a laser radar. Figure 2 , exemplarily shows 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 is understandable 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 the vehicle's surrounding environment information. When the detection device is installed behind the windshield, it has a lower requirement for no risk of gravel collision, and will not affect the appearance of the vehicle. In addition, the front windshield itself has the functions of window heating, demisting, and wiper cleaning.

[0085] For example, the detection device is installed on a vehicle. Figure 2 The working principle of the detection device is as follows: the detection device emits a light beam to 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 called returned light or echo signal), and the detection device determines the associated information of the target based on the returned light. Specifically, the detection device can obtain the latitude and longitude, speed, direction of the vehicle, or the associated information of targets within a certain range (such as other surrounding vehicles, pedestrians, or obstacles, etc.) in real time or periodically (such as the distance of the target, the speed of the target, and / or the posture of the target, etc.). Further, optionally, the detection device can send the acquired information to the control device in the vehicle, so that the control device can perform path planning, braking or starting of the vehicle based on the acquired information. For example, the longitude and latitude can be used to determine the position of the vehicle, or the speed and direction can be used to determine the driving direction and destination of the vehicle in the future, or the distance of the surrounding objects can be used to determine the number and density of obstacles around the vehicle. Further, optionally, the function of the advanced driving assistant system (ADAS) can be combined to realize assisted driving or automatic driving of the vehicle.

[0086] 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 above-mentioned examples. For example, the detection device can also be installed in a road side 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 vehicles as an information collection source for path planning to assist the driver in realizing or automatically realizing safe driving. Other vehicles 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 can be, for example, a smart phone, a smart home device, a smart manufacturing device, a medical device, an industrial device, and a robot. They are not listed here one by one. It should be noted that the application scenarios described in this application are to more clearly illustrate the technical solution of this application and do not constitute a limitation on the technical solution provided in this application.

[0087] In addition, the above application scenarios can be applied to unmanned driving, assisted driving, intelligent driving, automatic 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.

[0088] As described in the background technology, in scanning LiDAR, 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. This problem is particularly evident in scanning LiDARs with coaxial transmission and reception. For example, see Figure 3a , showing a schematic diagram of the optical transmission path of a coaxial laser radar, where Figure 3a (A) shows the optical path transmission diagram of the returning light on the xoz plane. Figure 3a (B) shows the optical path transmission diagram of the returning light on the yoz plane, with the z direction being the main optical axis, the x direction being the fast axis, and the y direction being the slow axis. Figure 3a Middle (A) and Figure 3a In (B), the receiving optical system converges the light returned by the scanning component in both the x-direction and the y-direction, thereby converging the returned light to a point, and the receiver is located in the plane where the point is located. Figure 3aIn (A), the high-speed rotation of the scanning component will cause the returned light to have an offset angle θ in the x-direction, which in turn causes the position where the returned light is focused to be offset by Δx in the x-direction. With the convergence method, the returned light will eventually converge to a point in the x-direction, and the existence of the offset Δx will easily cause the point to deviate directly from the position of the receiver, causing the receiver to be unable to receive the returned light, greatly reducing the receiver's receiving efficiency.

[0089] In response to the above problems, the industry has proposed some solutions, such as:

[0090] Solution 1: Propose a detection device architecture with separate transmission and reception. Figure 3b Compared to Figure 3a , a polarization beamsplitter (PBS) and a quarter wave plate are added to the architecture, and a transmitter with a smaller aperture is placed on the left side of the PBS in the diagram, and a receiver with a larger aperture is placed on the upper side of the PBS in the diagram. In this way, after the light beam emitted by the transmitter (the solid line light beam in the diagram) is incident on the PBS from the left side of the diagram, it is transmitted to the scanning component through the PBS, the quarter glass slide and the transmitting optical system in sequence, and scanned to the detection area in the k1 state of the scanning component, and the returned light is scanned by the scanning component in the k2 state, and then passes through the transmitting optical system, the quarter glass slide and the PBS in sequence to be reflected to the upper area of ​​the diagram, and then received by the large-aperture receiver. It can be seen that by adopting this detection device architecture, by separating the transmitter and the receiver, the receiving aperture of the receiver can be increased separately, so that the receiving aperture can cover the influence of the offset angle introduced by the difference between the k2 state and the k1 state of the scanning component on the focusing position of the returned light, thereby improving the receiving efficiency of the receiver. 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 deviation angle, so that in these cases, the problem of low receiving efficiency still exists.

[0091] Solution 2 proposes a multi-receiver detection device architecture, see Figure 3c Compared to Figure 3a, the architecture sets multiple receivers on the receiving side, and the multiple receivers are arranged along the x direction affected by the offset angle, and can be specifically arranged in the area between the position without the offset angle and the position with the greatest offset angle influence. For example, assuming that the emitted light beam is incident on the scanning component along the horizontal direction shown in the figure, the position without the offset angle influence can be understood as the position where the return light is incident on the receiving side along the horizontal direction, such as the position where the return light of the detection distance corresponding to the target 3 is focused on the detector 3, and the position with the greatest offset angle influence can be understood as the position where the return light of the farthest detection distance is reflected by the scanning component and incident on the receiving side, such as the position where the return light of the detection distance corresponding to the target 1 is focused on the detector 1. In this architecture, multiple receivers can be arranged along the vertical direction between these two positions. With 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, so that the influence of the offset angle on the light beam received by the receiver can be reduced. However, setting up multiple receivers will not only increase the process difficulty, material cost, structural complexity and volume of the detection device on the receiving side, but also, due to the limitations of existing processes, 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, there will still be a problem of low receiving efficiency.

[0092] In summary, the two solutions provided by the industry are actually unable to effectively improve the receiving efficiency of the receiving side. Therefore, when assembling the receiver, it is usually necessary to first assemble it in the static state of the scanning component, and then adjust the position of the initially assembled receiver according to the generated offset angle in the rotating state of the scanning component, resulting in the problem of difficulty in assembling the receiver in the existing detection device. In addition, even if the position of the receiver is adjusted according to the different states of the scanning component, the adjusted receiver can only be balanced at different detection distances, and cannot solve the above-mentioned problem of low receiving efficiency.

[0093] 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 shrink the light returned by the scanning assembly in the first direction affected by the deviation 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 that the detection module cannot receive the returned light, thereby effectively improving the receiving efficiency of the detection module. Optionally, the lens assembly can also be used to shrink the light returned by the scanning assembly in the second direction not affected by the deviation angle. Since the size of the shrunken 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 deviation angle), part of the 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.

[0094] The lens assembly and receiving module proposed in this application are described in detail below with reference to specific drawings.

[0095] In the various embodiments of the present application, unless otherwise specified or provided for in any logical conflict, the terms and / or descriptions between the different embodiments are consistent and may be referenced to each other, and the technical features in the different embodiments may be combined to form new embodiments according to their inherent logical relationships.

[0096] In addition, in this application, "position" does not refer to an absolute position, and a certain engineering error may be allowed. "Distance" does not refer to an absolute distance, and a certain engineering error may be allowed. "Focal length" does not refer to an absolute distance, and a certain engineering error may be allowed.

[0097] See also Figure 4a , is a schematic diagram of the structure of a lens assembly provided in this application. Figure 4a As shown, the lens assembly 400 includes a first sub-lens assembly 410, and the first sub-lens assembly 410 includes at least two lenses (not shown in the figure), and the at least two lenses are located between the scanning assembly 500 and the detection module 600, and are used to reduce the light returned by the scanning assembly 500 in a first direction (i.e., 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), and the main optical axis L direction is the z direction in the figure.

[0098] In the above content, the first sub-lens assembly 410 focuses the 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. Figure 4a, 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 with the returned light without offset due to the existence of the offset angle θ, then, using Figure 4a In the lens assembly shown, 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 is contracted in the first direction x by the first sub-lens assembly 410, the beam width of the outgoing collimated light beam in the first direction x is reduced to B2. Figure 5 The existing receiving optical system shown in the figure 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 one point. Therefore, if the offset Δx is large, the focus position of the returned light with the offset is likely to deviate from the position where the detection module is located, resulting in the detection module not being able to receive the returned light. Figure 4a In the lens assembly shown, the beam width of the returned light in the first direction x is reduced, but it is not focused to a point, so even if the returned light is offset, it is highly likely that at least part of the returned light will illuminate the detection module. For example, see Figure 4b For the returned light with a shift of 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 a shift of Δx can be irradiated on the detection module 600, and Figure 5 In the existing receiving optical system shown, no matter where the detection module moves forward or backward, it cannot receive the returned light. It can be seen that compared with the existing receiving optical system, by performing beam contraction 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.

[0099] Optionally, the first direction x can be understood as a direction affected by the deviation angle, such as a fast axis direction. The fast axis direction refers to the vector direction in which the light propagates at a fast speed in the lens assembly, and is usually affected by the deviation angle, which is introduced by the high-speed rotation of the scanning assembly, such as the high-speed rotation of the rotating mirror in the one-dimensional scanning assembly or the two-dimensional scanning assembly. By performing beam reduction in the fast axis direction, the degree to which the return light is affected by the deviation angle when it is transmitted in the fast axis direction can be reduced.

[0100] Further, 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 Figure 4aThe exit pupil position a1 is shown. The exit pupil position a1 can be understood as the same position to which the light returned from different directions is emitted after being deflected in the first direction x by the first sub-lens assembly 410, and the centroid of the light spot emitted to this position by the light returned from different directions is the same. Optionally, at the exit pupil position, the plane perpendicular to the main optical axis L is called the exit pupil plane. In some scenarios, the detection module 600 can be placed in the area covering the centroid of the light spot at the exit pupil position a1, so that the receiving surface of the detection module 600 coincides with the exit pupil plane. In this way, no matter how large the offset Δx of the light returned by the scanning assembly 500 in the first direction x is, it can be incident on the detection module 600 in the same area of ​​the exit pupil position a1, thereby minimizing the degree to which the light beam received by the detection module 600 is affected by the offset angle, so that the detection module 600 can receive the return light corresponding to any detection distance, thereby improving the receiving efficiency of the detection module 600. In addition, since the return light with different offset angles will enter the detection module 600 in the same area, this method only needs to assemble the detection module 600 when the scanning component 500 is in a stationary state, and there is no need to adjust the position of the detection module 600 when the scanning component 500 is in a rotating state, thereby reducing the difficulty of assembling the detection module 600.

[0101] Optionally, see Figure 6 , shows a schematic diagram of the structure of another lens assembly provided by the present application. Among them, Figure 6 (A) shows the transmission light path diagram of the lens assembly 400 in the xoz direction. Figure 6 Middle (B1) and Figure 6 (B2) shows the transmission optical path diagram of the lens assembly 400 in the yoz direction. In this example, the lens assembly 400 may include a second sub-lens assembly 420 in addition to the aforementioned first sub-lens assembly 410. The second sub-lens assembly 420 is used to converge or reduce 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, refer to Figure 6 In (B1), the transmission optical path diagram corresponding to the scenario in which the second sub-lens assembly 420 converges the light returned by the scanning assembly 500 in the second direction y is shown. 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 Figure 6 In (B2), what is shown is 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.

[0102] Optionally, whether the second sub-lens assembly 420 converges or shrinks the returned light can be determined specifically according to 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 shrinkage, thereby saving the complexity of the lens assembly on the basis of 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 shrink 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 influence of other reasons, increasing the probability of the returned light irradiating the detection module 600 in the second direction y, and further improving the receiving efficiency of the detection module 600.

[0103] 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 beam offset due to some 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 usually does not deviate 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 deviate in the slow axis direction. In this case, the second sub-lens assembly 420 may be configured to shrink 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.

[0104] The foregoing describes the basic design of the lens assembly 400. Figure 6 Each of the components involved is described in detail to provide an exemplary specific implementation scheme.

[0105] 1. The first sub-lens assembly

[0106] Optionally, the first sub-lens assembly 410 has optical power in the first direction x, and has 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, and can deflect (contract) the light returned by the scanning assembly 500 in the first direction x, while in the second direction y, it is equivalent to a flat glass, and directly emits the light without deflection. In this way, the first sub-lens assembly 410 only affects the transmission direction of the light returned by the scanning assembly 500 in the first direction x, and does not affect its transmission direction in the second direction y.

[0107] Further, optionally, the first sub-lens assembly 410 includes at least two lenses, and at least two lenses are convex lenses, or a combination of a convex lens and a concave lens. The convex lens has a focusing effect on light, and the concave lens has a diverging effect on light. By combining focusing or focusing and diverging, the return light can be reduced in the first direction x through a simple optical path design, thereby reducing the difficulty of designing the lens assembly.

[0108] For example, the first sub-lens assembly 410 includes two lenses. Figure 7 , showing 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. 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. The first lens M1 is located between the scanning assembly 500 and the second lens M2. The illustration takes the scanning assembly 500 returning collimated light as an example. Figure 7 In (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 are 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 following introduction), 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, so that the collimated light can be reduced in the first direction x.

[0109] It can be understood that the first lens M1 and the second lens M2 can both be convex lenses, or a combination of a convex lens and a concave lens, for example, the first lens M1 is a convex lens and the second lens M2 is a concave lens. Figure 8a and Figure 8b , respectively showing the lens parameter diagrams of these two possible combinations, which are introduced in detail below.

[0110] In lens combination form 1, please refer to Figure 8a, the first lens M1 and the second lens M2 are both convex lenses, the distance between the first lens M1 and the second lens M2 is the sum of the focal length f1 of the first lens M1 and the focal length f2 of the second lens M2, and the focal length f1 of the first lens M1 is greater than the focal length f2 of the second lens M2. In this way, the light with a larger beam width (beam width is B1) returned by the scanning component 500 first passes through the large focal length f1 of the first lens M1 and is focused between the first lens M1 and the second lens M2 (as shown in the P plane in the figure, the P plane can be understood as the focal plane of the first lens M1 and the second lens M2), and then passes through the small focal length f2 of the second lens M2 and is converted into light with a smaller beam width (beam width becomes B2), and then is emitted through the second lens M2. Optionally, the light returned by the scanning component 500 is parallel light, and the first lens M1 focuses the parallel light to the focal plane and further transmits it to the second lens M2, and then is collimated into parallel light by the second lens M2 and then emitted. 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.

[0111] In lens combination form 2, please refer to Figure 8b , the first lens M1 is a convex lens, the second lens M2 is a concave lens, the distance between the first lens M1 and the second lens M2 is the difference between the focal length f1 of the first lens M1 and the focal length f2 of the second lens M2, and the focal length f1 of the first lens M1 is greater than the focal length f2 of the second lens M2. In this way, the light with a larger beam width (beam width is B1) returned by the scanning component 500 first passes through the large focal length f1 of the first lens M1 and then converges to the second lens M2. Since the focus F1 of the first lens M1 is located on the right side of the second lens M2, the light converged to the second lens M2 still has a certain beam width (beam width is B2), and the beam width B2 is smaller than the beam width B1 of the incident light. The light with the beam width B2 is then deflected by the second lens M2 and then emitted, for example, collimated into parallel light by the second lens M2 and then emitted. 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 the reduction of the incident light.

[0112] Further, optionally, in any of the above lens combinations, in order to enable the two lenses to achieve light converging in the first direction x, the focal length ratio of the two lenses needs to 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 need to satisfy the following formula (1.1):

[0113]

[0114] Wherein, 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, Figure 8a or Figure 8b B1 shown; h' is the image height, which can be understood as the height of the detection target image on the detection module 600 side, 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, Figure 8a or Figure 8b B2 shown.

[0115] Further, optionally, the first lens M1 and the second lens M2 may both be cylindrical lenses, for example, the first lens M1 and the second lens M2 are both convex cylindrical lenses, or the first lens M1 is a convex cylindrical lens, and the second lens M2 is a concave cylindrical lens. The cylindrical lens has a beam deflection capability in a single direction, and by configuring the first lens M1 and the second lens M2 to be cylindrical lenses, and configuring the two cylindrical lenses to have curvature on one or both sides in the first direction x, beam contraction in the first direction x can be achieved.

[0116] It should be noted that the above contents are all based on the example that the first sub-lens assembly 410 includes two lenses, and introduce the lens parameters that the two lenses need to 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 example that the first sub-lens assembly 410 includes three lenses:

[0117] In a possible lens combination, all three lenses are convex lenses, the focal length of the first lens is greater than the distance between the first lens and the second lens, the distance between the second lens and the third lens is equal to the sum of the focal lengths of the second lens and the third lens, 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 to the second lens. Since the focus 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 the light with this beam width passes through the second lens and the third lens (the second lens and the third lens are equivalent to the first lens M1 and the second lens M2 in the above-mentioned lens combination form one), it 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 achieve light beam reduction;

[0118] In another possible lens combination, the first two lenses are convex lenses, the last lens is a concave lens, the focal length of the first lens is greater than the distance between the first lens and the second lens, the focal length of the second lens is greater than the focal length of the third lens, and the distance between the second lens and the third lens is equal to the difference between the focal length of the second lens and 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 to the second lens. Since the focus 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 the light with this beam width passes through the second lens and the third lens (the second lens and the third lens are equivalent to the first lens M1 and the second lens M2 in the above-mentioned lens combination form two), it 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 beam reduction.

[0119] It is understandable that there are many possible lens combinations, which will not be listed one by one in this application.

[0120] 2. Second sub-lens assembly

[0121] Optionally, the second sub-lens assembly 420 has optical power in the second direction y, but has no optical power in the first direction x. In other words, the lens in the second sub-lens assembly 420 has curvature on one or both sides in the second direction y, and can deflect (converge or reduce) the light returned by the scanning assembly 500 in the second direction y, while in the first direction x, it is equivalent to a flat glass, and directly emits the light without deflection. In this way, the second sub-lens assembly 420 only affects the transmission direction of the light returned by the scanning assembly 500 in the second direction y, but does not affect its transmission direction in the first direction x.

[0122] Further, optionally, since the first sub-lens assembly 410 and the second sub-lens assembly 420 have optical power only in one of the two directions orthogonal to each other, any sub-lens assembly will not affect the beam deflection of the other sub-lens assembly, so 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 set arbitrarily. Figure 7 The lens assembly shown in FIG. 4 is taken as an example, in which the second sub-lens assembly 420 is placed between the scanning assembly 500 and the first sub-lens assembly 410. However, the first sub-lens assembly 410 can also be placed between the scanning assembly 500 and the second sub-lens assembly 420. Figure 9a Alternatively, the second sub-lens assembly 420 may also be placed between any two lenses of the first sub-lens assembly 410, as shown in Figure 9bAs shown, 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.

[0123] Understandably, Figure 9a Middle (A) and Figure 9b (A) shows the transmission path of the returned light on the yoz plane corresponding to different arrangements. Figure 9a Middle (B) and Figure 9b (B) shows the transmission optical paths of the returned light on the xoz plane corresponding to different arrangements. 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.

[0124] Further, optionally, Figure 7 Taking the arrangement relationship of the sub-lens components shown in FIG. 4 as an example, when the second sub-lens component 420 converges the light returned by the scanning component 500 in the second direction y, the detection module 600 can coincide with the focal plane of the second sub-lens component 420. The focal plane of the second sub-lens component 420 refers to the focal point of the second sub-lens component 420 (i.e. Figure 7 F3) and is perpendicular to the main optical axis L. Optionally, the receiving surface of the detection module 600 can be placed on the focal plane of the second sub-lens assembly 420 and cover the focus F3 and the surrounding area, so that the detection module 600 can receive the returned light that is focused to the focus F3 by the second sub-lens assembly 420 or focused to the vicinity thereof due to factors such as errors.

[0125] Further, optional, please continue to see Figure 7In order to ensure the 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 also 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 shrunk 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.

[0126] It can be understood that the second sub-lens assembly 420 includes at least one lens, at least one lens can be a convex lens, and the sum of the focal lengths of at least one lens can be the distance from at least one lens to the focal plane of the second sub-lens assembly 420. In this way, through the focusing ability of at least one lens, the light returned by the scanning assembly 500 can be focused to the detection module 600 placed at the focal plane.

[0127] For example, the second sub-lens assembly 420 includes one lens. Figure 7 The second sub-lens assembly 420 may include a third lens M3, and 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, it 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.

[0128] Understandably, Figure 7 The third lens M3 is located between the scanning assembly 500 and the first lens M1 as an example, but the third lens M3 can also be located between the second lens M2 and the detection module 600. Figure 9a As shown, or it can also be located between the first lens M1 and the second lens M2, as shown Figure 9b When the placement position of the third lens M3 is different, the correlation between the focal length f3 of the third lens M3 and the focal lengths of other lenses is also different, for example:

[0129] For an example, see Fig.10aand Fig.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, refer to Fig.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, refer to Fig.10b , 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 focus F1 of the first lens M1 and the exit pupil plane of the first sub-lens assembly 410, or 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, the focal length f2 of the second lens M2, and the distance between the focus F1 of the second lens M2 and the exit pupil plane of the first sub-lens assembly 410;

[0130] For another example, see Fig.10c , when the first lens M1, the second lens M2 and the third lens M3 are arranged in 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;

[0131] For another example, see Fig.10d 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.

[0132] Further, optionally, the third lens M3 may be a cylindrical lens, such as a convex cylindrical lens. The cylindrical lens has the ability to deflect light beams in a single direction. Therefore, by configuring the third lens M3 to be a convex cylindrical lens, and configuring the convex cylindrical lens to have a curvature on one or both sides in the second direction y, light beam convergence in the second direction y can be achieved.

[0133] It should be noted that the above content takes the second sub-lens assembly 420 including one lens as an example 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 one lens. Figure 7 For example, refer to the order of lens placement shown in the figure. Fig.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 to 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, that is, the focal plane. In this case, the distance from lens M31 to the focal plane of the second sub-lens assembly 420 is the focal length f of lens M31. 31 The focal length f of lens M32 32 The sum of the distances between the lens M32 and the first lens M1 is subtracted from the sum of the distances between the lens M32 and the first lens M1. There are many possible lens combinations, which will not be listed one by one in this application.

[0134] In addition, the above content only introduces the lens structure of the second sub-lens assembly 420 for realizing the function of converging light in the second direction y. When the second sub-lens assembly 420 is used to realize the function of focusing 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, and the present application will not repeat them one by one.

[0135] Furthermore, when the first sub-lens assembly 410 is used to realize the function of reducing the light in the first direction x, and the second sub-lens assembly 420 is used to realize the function of reducing the light in the second direction y, the exit pupil surface (such as Figure 4a The plane perpendicular to the principal optical axis L at the exit pupil position a1 shown in FIG. 1 is connected to the exit pupil plane of the second sub-lens assembly 420 (as shown in FIG. Figure 6The 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 converged to the position where the exit pupil surface is located after passing through the two sub-lens assemblies, so that the detection module 600 arranged on the exit pupil surface can receive the return light in the same area, effectively improving the receiving efficiency of the detection module 600 in any direction of the first direction x and the second direction y.

[0136] Based on the structure of the lens assembly described above, the present application can also provide a receiving module.

[0137] See also Fig.12 , showing 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 1130. 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 1130. In this way, since the light incident to the receiving optical system 1120 will be emitted from the same area at the exit pupil position after being reduced, 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 of influence of the offset angle on the light beam received by the detection module 1130, 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 be incident on 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.

[0138] Below Fig.12 Each of the components involved is described in detail to provide an exemplary specific implementation scheme.

[0139] 1. Scanning Components

[0140] Exemplarily, the scanning component 1110 may be, for example, a polyhedron (e.g., an octahedron, a hexahedron, or a tetrahedron) rotating mirror, a micro electro-mechanical system (MEMS) galvanometer, or a swinging mirror. It should be noted that the present application does not limit the type of the scanning component 1110, and any structure that can reflect the returned light to the receiving optical system 1120 may be used.

[0141] 2. Receiving Optical System

[0142] Optionally, the receiving optical system 1120 may include a lens assembly as described above, such as Figures 4a to 11 The lens assembly 400 described in any embodiment of the present invention. Exemplarily, other optical elements may also be included, such as multiple lenses, and the lens may be a spherical lens (such as a concave lens, or a convex lens, etc.), or may also be an aspherical lens. The combination of multiple spherical lenses and / or aspherical lenses helps to improve the receiving quality of 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.

[0143] 3. Detection Module

[0144] Optionally, the detection module 1130 may include a detector, which is used to receive the optical signal from the receiving optical system 1120 and convert the optical signal into an electrical signal to achieve target detection using the electrical signal.

[0145] Further, optionally, Fig.13a The schematic diagram of the structure of a detection module provided by the present application is shown. When the detection device works in a single-channel mode, it means that the detection device will only emit one beam of light in the same period, 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 the 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 more comprehensive return light.

[0146] Further, optionally, Fig.13bThe schematic diagram of the structure of another detection module provided by the present application is shown. When the detection device works in a multi-channel mode, it means that the detection device will emit multiple beams of light in different directions in the same period of 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 the focal point F 01 In this case, the receiving module 1130 may include a plurality of detectors, which are arranged in sequence along the second direction y on the focal plane of the receiving optical system 1120. For example, for 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.

[0147] In a possible implementation, the detector may include a detection array, and in some scenarios, may also include an optical transmission medium. The optical transmission medium is a medium capable of transmitting light, and generally includes 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 the light transmitted from the receiving optical system 1120 to the detection array, so that the detection array converts the light into an electrical signal.

[0148] It should be noted that the size of the detection array is usually relatively large, while the size of the optical transmission medium is usually relatively small. Therefore, when the detection device adopts single-channel detection, the range of the returned light focused to the focal plane is relatively 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 relatively large. The detection module 1130 may include only one detector, which is a detection array with a relatively large aperture, or the detection module 1130 may include multiple detectors arranged along the second direction y, each of which is 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.

[0149] As mentioned above, whether the detector includes a detection array or a detection array and an optical transmission medium can be determined according to the radar's ranging principle. For example, when the time-of-flight ranging principle is adopted, the speed and time of light propagation in the air are used to measure the distance. In this case, the detector may only include a detection array, which is used to sense the time when the return light arrives, and then the flight time of the light in the air can be calculated in combination with the time when the detection light is emitted. The flight time combined with the speed of light is sufficient to complete the ranging. For another example, when the FMCW ranging principle is adopted, the frequency change (i.e., Doppler effect) and time difference of the return light compared to the detection light are used to measure the distance. In this case, the detector may include an optical transmission medium and a detection array. The optical transmission medium is used to sense the frequency of the return light, and the detection array is used to sense the time when the return light arrives. The frequency of the return light and the time when the return light arrives can be combined with the frequency of the detection light and the time when the detection light is emitted to complete the ranging.

[0150] In addition, when the detector only includes a detection array, the "receiving surface of the detection module" mentioned in the above content 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 the optical transmission medium, the "receiving surface of the detection module" mentioned in the above content refers to the receiving surface of the optical transmission medium, such as the surface where the light aperture of the optical transmission medium is located.

[0151] The foregoing content introduces the specific structure of the receiving module, which can be used to reduce the degree to which the returned light is affected by the offset angle when it is transmitted in the first direction. In order to more clearly introduce the role of the receiving module in reducing the impact of the offset angle, a specific receiving module design example is given below.

[0152] Please join together Fig.14 As shown in Table 1, Fig.14 The figure shows the structure of the receiving module and the transmission optical path in the design, where: Fig.14 (A) shows the transmission optical path of the receiving module on the xoz plane. Fig.14 (B) shows the transmission optical path of the receiving module on the yoz plane. In this example, the receiving optical system 1120 in the receiving module is Figure 7 Taking the lens combination shown as an example, the lens combination is used to focus 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 (ie, M1, M2 and M3) in the lens combination.

[0153] Table 1

[0154]

[0155]

[0156] Combined with Table 1 and Fig.14 , using the lens parameters shown in Table 1, assuming that due to the high-speed rotation of the scanning component 1110, the detection device has a deviation angle range of 0° to 0.036 in the x direction when detecting different distances. Then, by setting a detection module 1130 at the exit pupil surface, the light spot information transmitted to the exit pupil surface at different deviation angles, such as the shape and size of the light spot, can be simulated. Assuming the simulation results are as follows Fig.15 As shown, then: See Fig.15 , the blackened light spot can be understood as the light spot presented by the returned light when the offset angle is 0° and the large light spot outside the blackened light spot can be understood as the light spot presented by the returned light when the offset angle is 0.036° and the exit pupil surface. 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 100um×10um, and when the offset angle becomes 0.036°, the light spot size at the exit pupil position becomes 100um×12um. 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 surface are the same regardless of the offset angle of 0° or 0.036°. Therefore, by predicting the exit pupil position and placing the receiving surface of the detection module 1130 at the exit pupil position, the returned light at any offset angle can be well received by the detection module 1130. This can effectively reduce the degree to which the returned 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 the y direction is converging, light with different offset angles in the x direction should theoretically be focused at the same position in the y direction. In other words, the spot widths of the light spot corresponding to 0° and the light spot corresponding to 0.036° in the y direction should be the same. 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 above example, there is a 2um deviation between the light spot corresponding to 0° and the light spot corresponding to 0.036° in the y direction. 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] See also Fig.16, showing 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. Fig.16 As shown, 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 Fig.12 , Fig.13a or Fig.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 converge the received light in a first direction (the x direction shown in the figure) and then transmit it to the detection module 1513. The detection module 1513 is used to convert the received optical signal into an electrical signal for target detection. It is understandable that the receiving optical system 1512 can also converge or converge the received light in a second direction (the y direction not shown in the figure), or perform other possible beam deflection, which is not specifically limited.

[0160] In a possible implementation, the detection device may further include an emission module 1520, the emission module 1520 is used to emit light to the scanning component 1511, and the scanning component 1511 is also used to scan the light from the emission module 1520 to the detection area. Optionally, the light emitted by the emission module 1520 may be continuous light or pulsed light, for example, continuous light emitted by the emission module 1520 in a frequency modulated continuous wave (FMCM) mode.

[0161] In a further possible implementation, the detection device may also include an emission optical system 1530, which is located between the emission module 1520 and the scanning component 1511, and is used to shape the light emitted by the emission module 1520. Exemplarily, the emission optical system 1530 may include micro-nano optical elements, such as a microlens array (MLA) or a diffractive optical element (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, which is located at the optical path overlap position of the transmitting module 1520, the scanning component 1511 and the detection module 1513, and is used to transmit the light emitted by the transmitting module 1520 to the scanning component 1511, and transmit the light returned by the scanning component 1511 to the detection module 1513. By arranging the transceiver separation component in the optical system, the separation of the emitted light and the returned light can be achieved, so that the transmitting module and the detection module can be separately arranged to support the addition of a receiving optical system 1512 for beam reduction on the detection module side.

[0163] Optionally, see Fig.16 , the transmitting and receiving separation component 1540 may include a PBS and a quarter wave plate, the PBS is located at the position where the optical paths of the transmitting module 1520, the scanning component 1511 and the detection module 1513 overlap, and the quarter wave plate is located between the PBS and the scanning component 1511, specifically, between the PBS and the transmitting optical system 1530. When the detection device is working, the linearly polarized P light emitted by the transmitting module 1520 is first transmitted to the PBS, and after being converted by the PBS into circularly polarized P light, it is transmitted to the quarter wave plate, and then transmitted to the scanning component 1511 through the quarter wave plate, and then scanned to the detection space through the scanning component 1511. When there is a target in the detection space, the target reflects the circularly polarized P light back to the scanning component 1511, and then reflects it back to the quarter wave plate through the scanning component 1511, and then it is converted into circularly polarized S light after being converted by the quarter wave plate, and then converted into linearly polarized S light through the PBS, and then reflected to the receiving optical system 1512, so as to achieve the separation of the transmitted light and the received light.

[0164] In a possible implementation, the detection device may further include a control module (not shown in the figure), which may be used to process the electrical signal from the detection module 1513 to obtain the associated information of the target. Furthermore, the driving path may be planned based on the determined associated information of the target, such as avoiding obstacles on the path to be driven, realizing automatic driving of the vehicle, etc.

[0165] Exemplarily, the control module may include one or more processors, and the processor may be a circuit with signal (or data) processing capability. In one implementation, the processor may be a circuit with instruction reading and running capability, such as a central processing unit (CPU), a microprocessor, a graphics processing unit (GPU) (which may 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 may be 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 may 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 Fig.16 The given detection device architecture 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 manner, and this application does not make any specific limitations on this.

[0167] Based on the structure and functional principle of the detection device described above, the present 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, a playground vehicle, a construction vehicle, a tram, a golf cart, a train, an unmanned vehicle, a smart car and a digital car, etc.), a robot, a mapping device, a smart home device (such as a TV, a sweeping robot, a smart 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, etc.), an intelligent manufacturing device (such as an industrial equipment, a lawn mower, etc.), an intelligent transportation device (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 PDA, a desktop, a headset, a sound system, a wearable device, a vehicle-mounted device, a virtual reality device, an augmented reality device, etc.), etc.

[0168] In the present 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 there may be three relationships. 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" or similar expressions refers to any combination of these items, including any combination of single 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 the present application, the character " / " generally indicates that the associated objects before and after are in an "or" relationship. In the formula of the present application, the character " / " indicates that the associated objects before and after are in a "divided" relationship. In addition, in the present application, the word "exemplarily" is used to indicate examples, illustrations or explanations. Any embodiment or design described as an "example" in this application should not be interpreted as being more preferred or more 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 is to be understood that the various digital numbers involved in the present application are only for the convenience of description and are not intended to limit the scope of the embodiments of the present application. The size of the sequence number of the above-mentioned processes does not mean the order of execution, and the order of execution of each process should be determined by its function and inherent logic. The terms "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, including a series of steps or units. Methods, systems, products or equipment are not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment.

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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