Lens group for laser radar and laser radar

Abstract

The utility model provides a lens group for a laser radar and the laser radar, and the lens group comprises at least two positive lenses which are arranged along a light path, and are spherical lenses; and the distortion lens is an aspherical lens, so that the image height distortion of a preset field angle reaches a preset threshold value. According to the technical scheme, the size of the laser radar can be reduced, or the field of view of the laser radar can be increased.

Description

Technical Field

[0001] The present disclosure relates to the field of lidar, and particularly to a lens group for lidar and a lidar. Background Art

[0002] Lidar is a commonly used ranging sensor, which has the characteristics of long detection distance, high resolution, and small environmental interference, and is widely used in fields such as unmanned driving, intelligent robots, and drones. In recent years, the development of autonomous driving technology has been rapid, and lidar, as the core sensor for distance perception, has become indispensable.

[0003] The field of view size and size of lidar are important parameters. A smaller size is beneficial for integrating lidar into devices such as driverless cars, intelligent robots, and drones. A larger field of view is beneficial for lidar to obtain more environmental information. Therefore, reducing the size of lidar while ensuring the field of view size is a problem to be solved in this field. Summary of the Utility Model

[0004] To solve the above problems, the present disclosure provides a lens group for lidar, including:

[0005] At least two positive lenses, at least two of the positive lenses are arranged along the optical path, and the positive lenses are spherical mirrors; a distortion lens, the distortion lens is an aspherical lens so that the image height distortion of a preset field of view angle reaches a preset threshold.

[0006] Optionally, the distortion lens is a positive lens.

[0007] Optionally, the preset field of view angle is less than or equal to a first angle threshold.

[0008] Optionally, the focal length of the lens group is in the range of 20 mm to 100 mm.

[0009] Optionally, the F-number of the lens group is in the range of 1 to 3.

[0010] Optionally, the lens group further includes: a diaphragm, and the diaphragm is located at the front focal position of the lens group.

[0011] Optionally, the distortion lens is located at the uppermost or lowermost reaches of the optical path of the lens group.

[0012] Optionally, the lens group further includes: at least one negative lens, and the negative lens is a spherical mirror.

[0013] Correspondingly, the present disclosure further provides a lidar, including: a photoelectric device and a lens group. The lens group is any of the foregoing lens groups of the present disclosure.

[0014] Optionally, the angle of the field of view range in the first direction of the lidar is greater than or equal to 20°.

[0015] Optionally, the angle of the field of view range in the first direction of the lidar is less than or equal to 30°.

[0016] Optionally, in the field of view in the first direction of the lidar, the image height distortion of the edge field of view angle is greater than or equal to 10%.

[0017] Optionally, the optoelectronic device includes a light emitter configured to generate detection light, and the detection light is guided by the lens group to exit to the external field of view.

[0018] Optionally, the optoelectronic device includes a light receiver configured to receive the reflected light formed by the detection light reflected by an object, and the reflected light is guided by the lens group to the light receiver.

[0019] Optionally, the light receiver includes: a two-dimensional array detector, and the two-dimensional array detector includes: a plurality of detection areas.

[0020] Optionally, the light receiver includes: a plurality of detectors.

[0021] Optionally, the plurality of detectors are arranged in an array; the detectors in adjacent columns are staggered in the column direction.

[0022] Optionally, the lidar further includes: a light homogenizer, and the light homogenizer is located in the optical path of the detection light.

[0023] Optionally, the optoelectronic device includes a light emitter and a light receiver, and the light emitter and the light receiver are arranged on the same circuit board.

[0024] Compared with the prior art, the technical solution of the present disclosure has the following advantages:

[0025] In the technical solution of the present disclosure, the lens group adopts at least 2 positive lenses and a distortion lens, and the distortion lens is an aspherical lens so that the image height distortion of a preset field of view angle reaches a preset threshold. By setting a distortion lens in the lens group, the image height distortion of a preset field of view angle reaches a preset threshold, thereby using the image height distortion generated by the lens group to reduce the size of the required optoelectronic device (for example, a light emitter or a light receiver), so as to reduce the size of the lidar or increase the field of view size of the lidar. Description of the Drawings

[0026] To more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. The drawings in the following description are only those of the embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings. The drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. They are used together with the embodiments of the present disclosure to explain the present disclosure, but do not constitute a limitation to the present disclosure. In the drawings:

[0027] Figure 1 shows a schematic diagram of the field of view range of a lidar;

[0028] Figure 2 shows a schematic diagram of the optical path structure of some embodiments of the lens group for the lidar of the present disclosure;

[0029] Figure 3 shows a schematic diagram of the optical path structure of some other embodiments of the lens group for the lidar of the present disclosure;

[0030] Figure 4 shows a schematic diagram of the distribution of detectors in the optical receiver in some embodiments of the lidar of the present disclosure;

[0031] Figure 5 shows a schematic diagram of the optical path structure of some embodiments of the lidar of the present disclosure. Detailed Embodiments

[0032] In the following, only some exemplary embodiments are briefly described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present disclosure. Therefore, the drawings and the description are considered to be exemplary in nature rather than restrictive.

[0033] In the description of the present disclosure, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present disclosure. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present disclosure, "a plurality" means two or more, unless otherwise specifically defined.

[0034] In the description of the present disclosure, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, an electrical connection, or a communication connection that can interact with each other; it may be directly connected, or indirectly connected through an intermediate medium, and may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0035] In the present disclosure, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over", and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath", and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0036] The following disclosure provides many different embodiments or examples for implementing different structures of the present disclosure. To simplify the disclosure of the present disclosure, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present disclosure. In addition, the present disclosure may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplification and clarity and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present disclosure provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0037] In the present disclosure, the term "or" and "and / or" describe the association relationship between related objects and represent a non-exclusive inclusion. For example, "A and / or B" and "A or B" can include: only "A" exists, only "B" exists, and both "A" and "B" exist at the same time, where "A" and "B" can be singular or plural. For another example, "A, B and / or C" and "A, B or C" can include: only "A" exists, only "B" exists, only "C" exists, both "A" and "B" exist at the same time, both "A" and "C" exist at the same time, both "B" and "C" exist at the same time, and both "A", "B" and "C" exist at the same time, where "A", "B" and "C" can be singular or plural. In addition, the symbol " / " in this disclosure indicates that there is an "or" relationship between the related objects before and after the symbol. In this disclosure, the term "at least one of A or B" has the same meaning as "A or B" above. The term "at least one of A, B or C" has the same meaning as "A, B or C" above.

[0038] As can be seen from the background art, it is difficult for existing lidars to achieve both a large field of view and a small size.

[0039] In optical imaging, imaging distortion is often an adverse factor that needs to be overcome and improved. Therefore, the design of the optical system of a lidar generally takes reducing imaging distortion as a technical requirement. In addition, the smaller the angle between the light beam and the optical axis in an optical lens, the smaller the distortion degree, and the larger the angle between the light beam and the optical axis, the larger the distortion degree. In a lidar, the field of view (FOV) in the vertical direction of some lidars is usually small, and the imaging distortion of the optical system within this field of view is often small.

[0040] As Figure 1 shown, the half height h of the image plane can be approximately expressed as: h = f × tan(θ / 2), where f is the focal length of the optical system, θ is the field of view of the optical system, and θ / 2 is half of the field of view angle. When θ is small, tan(θ / 2) can be approximately expressed as θ / 2, so the half height h of the image plane can be further approximately expressed as: h = f × θ / 2.

[0041] It can be seen that when the field of view is small, the image plane size is linearly proportional to the field of view FOV and the focal length of the optical system. As the field of view increases, the image plane size also increases. The corresponding laser radar needs to be equipped with larger light transmitters and light receivers. The size of the laser radar will also increase accordingly, especially the height of the laser radar will increase significantly, and the cost of the laser radar will also increase, which is very unfavorable for the commercial application of the laser radar.

[0042] In order to solve the technical problem, the present disclosure provides a lens group for laser radar, comprising:

[0043] At least two positive lenses, at least two of which are arranged along the optical path, and the positive lenses are spherical lenses; and a distortion lens, which is an aspherical lens so that the image height distortion of a preset field of view angle reaches a preset threshold.

[0044] The technical solution disclosed in the present invention utilizes the image height distortion produced by the lens group so that the laser radar can achieve a preset field of view with a smaller optical transmitter and optical receiver, thereby reducing the size of the laser radar, reducing the overall cost of the laser radar, and achieving a balance between a large field of view and a small size.

[0045] In order to make the above-mentioned objects, features and advantages of the present disclosure more obvious and easy to understand, the specific embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0046] Figure 2 Schematic diagrams of optical path structures of some embodiments of lens groups for laser radars disclosed in the present invention are shown. Figure 2 As shown, the lens group 120 includes: at least 2 positive lenses SL, at least 2 of the positive lenses SL are arranged along the optical path, and the positive lenses SL are spherical lenses; an distortion lens ASL, and the distortion lens ASL is an aspherical lens so that the image height distortion of a preset field of view angle reaches a preset threshold.

[0047] The anamorphic lens ASL in the lens group 120 is an aspherical lens. The design of the anamorphic lens ASL makes the image height distortion of the preset field of view angle reach a preset value, especially makes the image height distortion of the edge field of view reach a preset value. By using the known and controllable imaging distortion of the anamorphic lens, the size of the optoelectronic device 110 can be reduced while the external field of view range remains unchanged, or a larger external field of view can be formed while the size of the optoelectronic device 110 remains unchanged, thereby achieving the purpose of reducing the size of the laser radar or increasing the FOV of the laser radar.

[0048] In some embodiments of the present disclosure, the lens group may include three lenses. The lens group includes two positive lenses and one anamorphic lens, and both of the two positive lenses are spherical lenses. Figure 2As shown, the lens group 120 includes: 2 positive lenses SL and 1 anamorphic lens ASL. The 2 positive lenses SL are respectively a positive lens PSL1 and a positive lens PSL2, and the positive lens PSL1 and the positive lens PSL2 are respectively spherical mirrors.

[0049] The anamorphic lens is suitable for introducing known and controllable imaging distortion into the lens group to achieve the purpose of compressing the image height. The anamorphic lens ASL makes the image height of the light rays in the preset field angle direction after passing through the lens group smaller than the image height under the linear relationship by introducing distortion. As Figure 2 shown, the image height under the linear relationship is h2, and the image height after introducing the anamorphic lens ASL is h1. The anamorphic lens compresses the image height, which can reduce the optoelectronic components (such as light emitters or light receivers) of the lidar, facilitating the reduction of the size of the lidar and the cost of the lidar.

[0050] It should be noted that the imaging plane is the rear focal plane of the lens group, which is the focal plane on the side of the lens group far from the external field of view.

[0051] In some embodiments of the present disclosure, the anamorphic lens is a positive lens. The anamorphic lens is set as a positive lens to further compress the imaging height on the imaging plane, so as to achieve the purpose of reducing the size of the lidar.

[0052] In some embodiments, the preset field angle is less than or equal to the first angle threshold. The image height distortion of the light rays with a field angle less than or equal to the first angle threshold reaches the preset threshold after passing through the lens group with the anamorphic lens.

[0053] For example, when the lens group is a lens group for a lidar and is used to transmit the detection light and the echo light of the lidar, the first angle threshold can be the maximum field angle of the lidar, that is, the maximum angle in the lidar field of view range. Again, for example, the first angle threshold can be other angles less than the maximum field angle of the lidar. By way of example, the first angle threshold can be 20°. In other embodiments of the present disclosure, the first angle threshold can also be other values such as 25°, 30°, etc.

[0054] In some embodiments of the present disclosure, the anamorphic lens is located at the uppermost or lowermost reaches of the optical path of the lens group. For example, as Figure 2 shown, the anamorphic lens ASL is located in the optical path between the imaging plane IS and the positive lens PSL2. Again, for example, the anamorphic lens can be arranged on the outermost side of the lens group close to the external field of view.

[0055] In some embodiments of the present disclosure, the preset threshold is any value greater than or equal to 15%. The anamorphic lens making the image height distortion of a preset field of view reach the preset threshold includes that the image height distortion of the preset field of view is greater than or equal to the preset threshold.

[0056] It should be noted that the image height distortion is the ratio of the difference between the first image height and the second image height to the first image height. Wherein, the first image height refers to the image height where the field of view angle and the image height do not conform to a linear relationship, and the second image height refers to the image height where the field of view angle and the image height conform to a linear relationship.

[0057] Based on the principle of reversibility of the optical path, when a light source emits a light beam at a certain position on the imaging surface, after being guided by the lens group 120, the light beam can be emitted to the corresponding angle of the external field of view. As Figure 2 shown, the light beam emitted at the first image height h1 on the imaging surface IS1 (such as Figure 2 the red solid line in) is transmitted through the lens group 120 including the anamorphic lens ASL and then emitted to the preset field of view angle (for example, 20°) of the external field of view. The light beam at the second image height h2 (such as Figure 2 the red dashed line in) is transmitted through the lens group not including the anamorphic lens ASL and then emitted to the preset field of view angle (for example, 20°) of the external field of view. At the preset field of view angle, setting the anamorphic lens can make the image height distortion greater than or equal to the preset threshold (for example, 15%). It can be seen from Figure 2 that when the field of view angle is the same, the first image height h1 is smaller than the second image height h2, that is, by introducing the anamorphic lens into the lens group, the image height on the imaging surface can be compressed.

[0058] By setting the anamorphic lens, a non-linear distortion relationship between the field of view angle and the focal length is achieved, which can effectively compress the image height on the imaging surface, enable a smaller image height to correspond to a larger range of the external field of view, is beneficial to forming a larger field of view with a smaller area of light emitters and light receivers in the lidar, and is beneficial to providing a large field of view of the lidar or reducing the size of the lidar.

[0059] The light beam is imaged on the imaging surface after being transmitted through the lens group, and the overall parameters of the lens group will also affect the imaging distortion on the imaging surface.

[0060] In some embodiments of the present disclosure, the focal length of the lens group is in the range of 20 mm to 100 mm. The focal length of the lens group is appropriate, which can control the overall size of the lidar while ensuring the detection requirements of the lidar.

[0061] In some embodiments of the present disclosure, the F-number of the lens group is in the range of 1 to 3. Among them, the F-number of the lens group, such as the aperture coefficient of the lens group, is the ratio of the focal length of the lens group to the light passing aperture. The luminous flux of the lens group is inversely proportional to the square of the F-number. The smaller the F-number, the larger the luminous flux. The size of the F-number of the lens group is appropriate, which can effectively ensure the luminous flux of the emitted detection light or the received echo light, and can effectively ensure the detection performance of the lidar.

[0062] In some embodiments of the present disclosure, the lens group further includes: a diaphragm, and the diaphragm is located at the front focal position of the lens group. The diaphragm is used to restrict the range of light transmitted by the lens group to isolate stray light (for example, ambient light or stray light outside the FOV, etc.). Setting the diaphragm at the front focal position can reduce the blockage of the diaphragm to the detection light and the echo light while isolating the stray light, and realize the full utilization of the optical aperture. For example, as Figure 2 shown, the diaphragm FS is located at the focal plane on the side of the lens group 120 close to the external field of view.

[0063] It should be noted that the front focal position, that is, near the front focus, refers to the range within a preset distance along the optical axis before and after the front focal plane of the lens group. Among them, the front focal plane refers to the focal plane on the side of the lens group close to the external field of view.

[0064] It should also be noted that the method of setting the diaphragm at the front focal position of the lens group is only an example. In other embodiments of the present disclosure, the diaphragm can also be set at other positions in the lens group.

[0065] Refer to Figure 3 , which shows a schematic diagram of the optical path structure of some other embodiments of the lens group for lidar of the present disclosure.

[0066] The same as the foregoing embodiments, the present disclosure will not be repeated here. The difference from the foregoing embodiments is that in some embodiments of the present disclosure, the lens group further includes: at least 1 negative lens, and the negative lens is a spherical mirror. The negative lens is used to adjust the field of view range or the focal length of the lens group.

[0067] In some embodiments of the present disclosure, the lens group may include a 4-lens lens, including 2 positive lenses. In addition to the distortion lens, the lens group further includes 1 spherical negative lens.

[0068] For example, as Figure 3As shown, the lens group 220 includes a spherical positive lens PSL3 and a positive lens PSL4, an aspherical distortion lens ASL2, and a spherical negative lens NSL. The negative lens NSL is located in the optical path between the positive lens PSL3 and the positive lens PSL3. Also, for example, the negative lens can be arranged at other positions of the lens group. Such as, between the positive lens PSL4 and the distortion lens ASL2, on the side of the positive lens PSL3 close to the external field of view, etc.

[0069] Such as Figure 3 As shown, a beam of a preset field of view angle (for example, 30°) (such as Figure 3 the red solid line in) is imaged on the imaging surface IS2 after being transmitted through the lens group 220 including the distortion lens ASL2, and the imaging point has a first image height h3. A beam of a preset field of view angle (for example, 30°) (such as Figure 3 the red dashed line in) is imaged on the imaging surface IS2 after being transmitted through the lens group not including the distortion lens ASL2, and the imaging point has a second image height h4. At the preset field of view angle, setting the distortion lens can make the image height distortion greater than or equal to a preset threshold (for example, 15%). Through Figure 3 it can be known that when the field of view angle is the same, the first image height h3 is smaller than the second image height h4, that is, by introducing the distortion lens into the lens group, the image height on the imaging surface can be compressed. By setting the distortion lens, a non-linear distortion relationship between the field of view angle and the focal length is achieved, the image height on the imaging surface can be effectively compressed, and a smaller image height can correspond to a larger range of the external field of view, which is beneficial to forming a larger field of view with a smaller area of optical transmitters and optical receivers in the lidar, and is beneficial to providing a large field of view of the lidar or reducing the size of the lidar.

[0070] Continue to refer to Figure 2 and Figure 3 , the lidar includes: an optoelectronic device; a lens group, and the lens group includes the lens group of the present disclosure. The optoelectronic device is suitable for generating detection light or collecting echo light.

[0071] In some embodiments, the optoelectronic device is located on the rear focal plane of the lens group. The rear focal plane is the focal plane of the lens group far from the external field of view. The lens group in the optical path upstream or downstream of the optoelectronic device is suitable for transmitting light. The position of the lens group is determined based on the function of the optoelectronic device. The optoelectronic device is suitable for generating detection light, and the lens group is located in the optical path downstream of the optoelectronic device to transmit the detection light. The optoelectronic device is suitable for collecting echo light, and the lens group is located in the optical path upstream of the optoelectronic device to transmit the echo light.

[0072] In some embodiments, the optoelectronic device may include a light emitter, and the optoelectronic device may be configured to generate detection light. For example, the light emitter 110 may include a laser. Exemplarily, the laser may include at least one of a vertical cavity surface emitting laser (VCSEL) or an edge emitting laser (EEL). As Figure 2 shown, the optoelectronic device 110 may include a light emitter, and the lens group 120 is located in the optical path downstream of the optoelectronic device.

[0073] In some embodiments, the optoelectronic device 110 includes: a plurality of light emitters, and the plurality of light emitters are arranged along a first direction. Wherein, the first direction may be a vertical field of view direction or a horizontal field of view direction.

[0074] In some embodiments of the present disclosure, the angle of the field of view range in the first direction of the lidar is greater than or equal to 20°. For example, the first direction may be a vertical field of view direction, and the angle of the field of view range in the first direction of the lidar may be 20°, 25°, 30°, 40°, 45° or other angles. The angle in the vertical field of view direction being greater than or equal to 20° can enable the lidar to meet basic detection requirements.

[0075] In some embodiments, the angle of the field of view range in the first direction of the lidar is less than or equal to 30°. For example, the first direction may be a vertical field of view direction, and the angle of the field of view range in the first direction of the lidar may be 20°, 25°, 30° or other angles. The angle in the vertical field of view direction being less than or equal to 30° can enable the lidar to meet basic detection requirements while reducing the size of the lidar.

[0076] Based on the optical principle, it can be known that when the field of view angle is less than or equal to 30°, the image height and the field of view angle can be approximately linearly proportional; limiting the upper limit of the angle of the field of view range in the first direction of the lidar can effectively reduce the influence of other lens distortions on the optical path accuracy, which is beneficial to ensuring the detection performance of the lidar.

[0077] In some embodiments, in the field of view in the first direction of the lidar, the image height distortion of the edge field of view angle is greater than or equal to 10%. The lens group in the lidar has a distortion lens, and the image height distortion introduced by the distortion lens is of appropriate size, which can compress the image height and avoid having too much influence on the detection performance of the lidar, reduce the size of the lidar, lower the overall cost of the lidar, and achieve the balance of a large field of view and low cost.

[0078] As Figure 2In some of the illustrated embodiments, the first direction is the direction perpendicular to the field of view. The vertical field of view of the lidar is, for example, 45°, and the edge field of view angles are, for example, 22.5° and -22.5°. The distortion lens ASL causes the image height distortion of the edge field of view angle to reach more than 10%.

[0079] In some embodiments of the present disclosure, the lidar further includes: a homogenizer, which is located in the optical path of the detection light. The homogenizer is adapted to homogenize the detection light. In some embodiments, the homogenizing direction of the homogenizer is determined based on the arrangement direction of a plurality of light emitters in the optoelectronic device 110. For example, the homogenizing direction of the homogenizer is the same as the arrangement direction of a plurality of light emitters in the optoelectronic device 110. Alternatively, the homogenizing direction of the homogenizer is perpendicular to the arrangement direction of a plurality of light emitters in the optoelectronic device 110.

[0080] Continuing to refer to Figure 3 , for the same parts as the foregoing embodiments, the present disclosure will not be described herein again. The differences from the foregoing embodiments are that Figure 3 shows a schematic diagram of the optical path structure of the receiving end in some embodiments of the lidar of the present disclosure.

[0081] In some embodiments, the optoelectronic device 210 includes a light receiver configured to receive the reflected light formed by the detection light reflected by an object. For example, the optoelectronic device 210 can collect an optical signal and convert the collected optical signal into a typical output. The optoelectronic device 210 may include a photodetector, and the lens group 220 is located in the optical path upstream of the optoelectronic device. The photodetector may include one or several of a single photon avalanche diode (SPAD), a silicon photomultiplier (SiPM), an avalanche photodiode, and a photodiode (PD).

[0082] In some embodiments, the optical receiver may include a two-dimensional array detector, and the two-dimensional array detector may include: a plurality of detection regions. For example, the optical receiver may include a plurality of detection units, at least one of the detection units may form the detection region, the plurality of detection units may be independently controlled or the detection region may be independently controlled, and the plurality of detection units are arranged in a two-dimensional array. The detection unit may include one or more of a single photon avalanche diode (SPAD), a silicon photomultiplier (SiPM), an avalanche photo diode, and a photodiode (PD).

[0083] It should be noted that the optical receiver includes at least one two-dimensional array detector. In some embodiments, the optical receiver may have only one two-dimensional array detector. In some embodiments, the optical receiver may also have two or more two-dimensional array detectors.

[0084] It should also be noted that the transmitting end of the lidar has an optical transmitter, and the optical transmitter includes a plurality of lasers. In some embodiments, the plurality of detection regions of the two-dimensional array detector in the two-dimensional array detector correspond one-to-one to the plurality of lasers in the optical transmitter. In some embodiments, the plurality of detection regions of the two-dimensional array detector in the two-dimensional array detector correspond to one laser in the optical transmitter. In some embodiments, one detection region of the two-dimensional array detector in the two-dimensional array detector corresponds to the plurality of lasers in the optical transmitter. Among them, the corresponding relationship between the detection region and the laser means that the detection region can receive the echo light formed by the reflection of the detection light generated by the corresponding laser.

[0085] In some embodiments, the optical transmitter and the optical receiver are disposed on the same circuit board. By disposing the optical transmitter and the optical receiver on the same board, the assembly process of the lidar can be effectively simplified, the alignment accuracy can be improved, and it is beneficial to improve the production efficiency of the lidar.

[0086] Figure 4 The distribution schematic diagram of the detectors in the optical receiver in some embodiments of the lidar of the present disclosure is shown. As Figure 4 In some embodiments shown, the plurality of detectors in the optical receiver are arranged in an array in the row direction and the column direction. Among them, one of the row direction and the column direction corresponds to the first direction.

[0087] In some embodiments, as Figure 4As shown, multiple detectors are arranged in an array, and the detectors in adjacent columns are staggered in the column direction. By arranging the detectors in adjacent columns in this staggered manner, the field of view ranges corresponding to adjacent columns of detectors complement each other, so as to improve the coverage of the external field of view of the lidar and improve the angular resolution of the lidar. For example, Figure 4 For the 8 detectors shown, the first column 311c and the second column 312c are adjacent in the row direction x. Multiple detectors 311 in the first column 311c are arranged in the column direction y, and multiple detectors 312 in the second column 312c are also arranged in the column direction y. The multiple detectors 311 in the first column 311c and the multiple detectors 312 in the second column 312c are staggered in the y direction.

[0088] It should be noted that in some embodiments of the present disclosure, the lidar further includes: a scanning module, and the scanning module has a scanning direction. The scanning direction is perpendicular to the first direction of the field of view range of the aforementioned lidar. For example, Figure 4 For the 8 detectors shown, they are staggered in the column direction y, and the direction y is the first direction of the field of view range of the lidar. The scanning direction of the scanning module in the lidar can be perpendicular to the column direction y. In some embodiments, the scanning direction can be parallel to the first direction of the field of view range of the aforementioned lidar.

[0089] It should be noted that the foregoing embodiments respectively show the optical path structure diagrams of the transmitting end and the receiving end of the lidar. In some embodiments, the optical path of the transmitting end and the optical path of the receiving end of the lidar are separated, and at least one of the transmitting end and the receiving end includes the lens group of the present disclosure.

[0090] In some embodiments, the optical path of the transmitting end and the optical path of the receiving end of the lidar may partially overlap. The lidar includes a beam splitter, and the beam splitter divides the optical path of the lidar into a coaxial part, a transmitting branch part, and a receiving branch part. The lens group of the present disclosure is included in at least one of the optical paths of the transmitting branch part, the receiving branch part, and the coaxial part.

[0091] Figure 5 The schematic diagram of the optical path structure of some embodiments of the lidar of the present disclosure is shown. As Figure 5 shown, the beam splitter 430 divides the optical path of the lidar into: a transmitting branch part 441 between the optical transmitter 411 and the beam splitter 430, a receiving branch part 442 between the optical receiver 412 and the beam splitter 430, and a coaxial part 443 on the side of the beam splitter 430 facing the external field of view. The lens group of the present disclosure is provided at least at one of the transmitting branch part 441, the receiving branch part 442, and the coaxial part 443.

[0092] In summary, the distortion lens adopted in the present disclosure is an aspherical lens, which enables the image height distortion of a preset field of view angle of the lens group to reach a preset threshold. By using the image height distortion generated by the lens group, the detection light generated by a smaller-sized light emitter can be emitted to a larger external field of view, or a smaller-sized light receiver can receive the echo formed in a larger external field of view. Therefore, the lidar can use smaller-sized light emitters and light receivers to achieve detection within a preset field of view, reduce the size of the lidar, lower the overall cost of the lidar, and achieve both a large field of view and low cost.

[0093] It should be understood that the division of each module and unit in the above system is only a division of logical functions. In actual implementation, there may be other division methods. In actual implementation, they can be fully or partially integrated into a physical entity, or physically separated. In addition, the modules and units in the device can be implemented in the form of a processor calling software; for example, the device includes a processor, the processor is connected to a memory, and instructions are stored in the memory. The processor calls the instructions stored in the memory to implement any of the above methods or the functions of each module and unit of the device. The processor is, for example, a general-purpose processor, such as a central processing unit (CPU) or a microprocessor, and the memory is a memory inside or outside the system. Alternatively, the modules and units in the device can be implemented in the form of hardware circuits, and the functions of some or all of the modules can be implemented through the design of the hardware circuit, and the hardware circuit can be understood as one or more processors; for example, in one implementation, the hardware circuit is an application specific integrated circuit (ASIC), and through the design of the logical relationship of the components in the circuit, the functions of some or all of the above modules are implemented; again, in another implementation, the hardware circuit can be implemented by a programmable logic device (PLD), which can include a large number of logic gate circuits, and the logical relationship between the logic gate circuits is configured through a configuration file to implement the functions of some or all of the above modules. All modules of the above system can be all implemented in the form of a processor calling a program, or all implemented in the form of hardware circuits, or some implemented in the form of a processor calling a program and the remaining part implemented in the form of hardware circuits.

[0094] Although the present disclosure is disclosed as above, the present disclosure is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the scope defined by the claims.

Claims

1. A lens group for a lidar, characterized in that, Comprising: At least two positive lenses, at least two of the positive lenses being arranged along the optical path, the positive lenses being spherical mirrors; A distortion lens, the distortion lens being an aspherical lens such that the image height distortion of a preset field of view angle reaches a preset threshold.

2. The lens group according to claim 1, wherein The distortion lens is a positive lens.

3. The lens group according to claim 1 or 2, characterized in that, The preset field of view angle is less than or equal to a first angle threshold.

4. The lens group according to claim 1, wherein The focal length of the lens group is in the range of 20 mm to 100 mm.

5. The lens group according to claim 1, wherein The F-number of the lens group is in the range of 1 to 3.

6. The lens group according to claim 1, wherein Further comprising: A diaphragm, the diaphragm being located at the front focal position of the lens group.

7. The lens group according to claim 1, wherein The distortion lens is located at the most upstream or the most downstream of the optical path of the lens group.

8. The lens group according to claim 1, wherein, Further comprising: At least one negative lens, the negative lens being a spherical mirror.

9. A lidar, characterized in that, Comprising: An optoelectronic device; A lens group, the lens group being as described in any one of claims 1 to 8.

10. The lidar according to claim 9, characterized in that, The angle of the field of view range of the lidar in the first direction is greater than or equal to 20°.

11. The lidar according to claim 10, wherein, The angle of the field of view range of the lidar in the first direction is less than or equal to 30°.

12. The lidar according to claim 11, wherein, In the field of view of the lidar in the first direction, the image height distortion of the edge field of view angle is greater than or equal to 10%.

13. The lidar according to claim 9, characterized in that, The optoelectronic device includes a light emitter configured to generate detection light, and the detection light is guided by the lens group to be emitted to an external field of view.

14. The lidar according to claim 9, wherein, The optoelectronic device includes a light receiver configured to receive the echo light formed by the reflection of the detection light by an object, and the echo light is guided by the lens group to the light receiver.

15. The lidar according to claim 14, characterized in that, The light receiver includes: a two-dimensional array detector, and the two-dimensional array detector includes: a plurality of detection areas.

16. The lidar according to claim 14, characterized in that, The light receiver includes: a plurality of detectors.

17. The lidar according to claim 16, wherein A plurality of the detectors are arranged in an array; The detectors in adjacent columns are staggered in the column direction.

18. The lidar according to claim 13, wherein, The lidar further includes: a light homogenizer, and the light homogenizer is located in the optical path of the detection light.

19. The lidar according to claim 9, characterized in that, The optoelectronic device includes a light emitter and a light receiver, and the light emitter and the light receiver are arranged on the same circuit board.

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