Lens group for lidar, and lidar

Abstract

Provided in the present disclosure are a lens group for a LiDAR, and a LiDAR. The lens group comprises at least two positive lenses and a distortion lens. The at least two positive lenses are arranged along an optical path. The distortion lens is an aspheric lens, and the distortion lens enables the distortion of the lens group at a first field of view to reach a first distortion threshold.

Description

Lens group for lidar and lidar

[0001] The present disclosure claims priority to Chinese Patent Application No. 202411238398.2, filed on September 4, 2024, entitled “Lens group for lidar and lidar”, Chinese Patent Application No. 202422173760.4, filed on September 4, 2024, entitled “Lens group for lidar and lidar”, the contents of which are incorporated by reference in their entirety in the present disclosure. TECHNICAL FIELD

[0002] The present disclosure relates to the field of lidar, and in particular, to a lens group for lidar and a lidar. BACKGROUND

[0003] Lidar is a commonly used ranging sensor, which has the characteristics of long detection distance, high resolution, and small environmental interference. Lidar is widely used in the fields of unmanned driving, intelligent robots, unmanned aerial vehicles, etc. In recent years, with the rapid development of autonomous driving technology, lidar has become an indispensable core sensor for distance perception.

[0004] The size of the field of view and the size of the lidar are important parameters. Smaller size is conducive to the integration of lidar into unmanned vehicles, intelligent robots, unmanned aerial vehicles, etc. Larger field of view is conducive to the acquisition of more environmental information by lidar. Therefore, it is a problem to be solved in the art to reduce the size of the lidar while ensuring the size of the field of view.

[0005] SUMMARY

[0006] To solve the above problems, the present disclosure provides a lens group for lidar, comprising:

[0007] At least two positive lenses are arranged along the optical path, and the distortion lens is an aspherical lens. The distortion lens makes the distortion of the lens group in the first field of view angle reach the first distortion threshold.

[0008] Optionally, the positive lens in the at least two positive lenses is a spherical lens.

[0009] Optionally, the distortion lens is a positive lens.

[0010] Optionally, the first field of view angle is less than or equal to the first angle threshold.

[0011] Optionally, the focal length of the lens group is in the range of 20mm to 100mm.

[0012] Optionally, the F number of the lens group is in the range of 1 to 3.

[0013] Optionally, the lens group further comprises: a diaphragm.

[0014] Optionally, the diaphragm is located between the at least two positive lenses, or the diaphragm is located on one side of the at least two positive lenses.

[0015] Optionally, the diaphragm is located at a front focal position of the lens group.

[0016] Optionally, the at least two positive lenses are located on the same side of the distortion lens.

[0017] Optionally, the distortion lens is located at the most upstream or the most downstream of the optical path of the lens group.

[0018] Optionally, the lens group further comprises: at least one negative lens.

[0019] Optionally, the negative lens in the at least one negative lens is a spherical lens.

[0020] Correspondingly, the present disclosure also provides a laser radar, comprising: an optoelectronic device and a lens group. The lens group is any lens group described in the present disclosure.

[0021] Optionally, the field of view range of the first direction of the laser radar is greater than or equal to 20°.

[0022] Optionally, the field of view range of the first direction of the laser radar is less than or equal to 30°.

[0023] Optionally, in the field of view of the first direction of the laser radar, the distortion of the edge field of view angle is greater than or equal to 10%.

[0024] Optionally, the optoelectronic device comprises a light emitter; the light emitter is configured to generate probe light, and the probe light is guided by the lens group to exit to an external field of view.

[0025] Optionally, the optoelectronic device comprises a light receiver; the light receiver is configured to receive echo light formed by reflection of probe light by an object, and the echo light is guided by the lens group to the light receiver.

[0026] Optionally, the light receiver comprises: a two-dimensional array detector, and the two-dimensional array detector comprises: a plurality of detection areas.

[0027] Optionally, the light receiver comprises: a plurality of detectors.

[0028] Optionally, the plurality of detectors are arranged in an array.

[0029] Optionally, the detectors of adjacent columns are staggered along the column direction.

[0030] Optionally, the laser radar further comprises a light homogenizer, which is located in the light path of the probe light.

[0031] Optionally, the optoelectronic device comprises a light emitter and a light receiver, and the light emitter and the light receiver are arranged on the same circuit board.

[0032] Compared with the prior art, the technical scheme of the present disclosure has the following advantages:

[0033] In the technical scheme of the present disclosure, the lens group adopts at least two positive lenses and a distortion lens. The distortion lens is an aspherical lens, and the distortion lens makes the distortion of the lens group at the first field of view reach a first distortion threshold. By arranging the distortion lens in the lens group, distortion is introduced into the lens group. By utilizing the distortion generated by the lens group, the size of the optoelectronic device (such as a light emitter or a light receiver) required can be reduced, achieving the effect of reducing the size of the laser radar or increasing the field of view size of the laser radar. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical scheme in the embodiments of the present disclosure or the prior art, the drawings needed in the description of the embodiments or the prior art will be briefly introduced below. The drawings in the following description are only embodiments of the present disclosure, and those skilled in the art can also obtain other drawings according to the provided drawings without creating any creative labor. The drawings are used to provide further understanding of the present disclosure, and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the present disclosure, and do not constitute a limitation on the present disclosure. In the drawings:

[0035] Figure 1 shows a schematic diagram of the field of view range of a laser radar consistent with some embodiments of the present disclosure.

[0036] Figure 2 shows a schematic diagram of the optical path structure of a lens group for a laser radar consistent with some embodiments of the present disclosure.

[0037] Figure 3 shows a schematic diagram of the optical path structure of another lens group for a laser radar consistent with some embodiments of the present disclosure.

[0038] Figure 4 shows a schematic diagram of the distribution of detectors in a light receiver of a laser radar consistent with some embodiments of the present disclosure.

[0039] Figure 5 shows a schematic diagram of the optical path structure of a laser radar consistent with some embodiments of the present disclosure. DETAILED DESCRIPTION

[0040] In the following certain exemplary embodiments are simply described. As will be obvious to those skilled in the art, the described embodiments can be modified in various different ways and can be carried out in various different ways without departing from the spirit or scope of the present disclosure. Therefore, the drawings and descriptions are to be regarded as illustrative in nature rather than restrictive.

[0041] In the description of the present disclosure, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation. Therefore, it cannot be understood as a limitation on the present disclosure. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present disclosure, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0042] In the description of the present disclosure, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly. For example, it can be fixedly connected, or detachably connected, or integrally connected. For another example, it can be mechanically connected, or electrically connected, or can be connected in communication with each other. For another example, it can be directly connected, or indirectly connected through an intermediate medium, or can be the communication or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present disclosure can be understood according to the specific circumstances.

[0043] In the present disclosure, unless otherwise explicitly specified and limited, "on" or "under" of a first feature to a second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, "on", "above" and "over" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. "Below", "under" and "underneath" of the first feature to the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0044] The disclosure below provides many different embodiments or examples for implementing different structures of the disclosure. For simplicity of the disclosure, the components and settings of particular examples are described below. Of course, they are merely examples and are not intended to limit the disclosure. Furthermore, the disclosure can repeat reference numerals and / or letters in various examples and / or drawings, which can refer to a similar or identical functions accomplished by the similar or identical components and / or settings. This is for simplicity and clarity of the disclosure and does not in itself dictate a relationship between the various embodiments and / or settings discussed in the disclosure.

[0045] In the disclosure, the term "or" and "and / or" describe an association relationship between relevant objects, and means a non-exclusive inclusion. For example, "A and / or B" and "A or B" can include: only "A" exists, only "B" exists, and "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, "A" and "B" exist at the same time, "A" and "C" exist at the same time, "B" and "C" exist at the same time, and "A", "B" and "C" exist at the same time, where "A", "B" and "C" can be singular or plural. In addition, the symbol " / " in the disclosure represents an "or" relationship between the relevant objects before and after the symbol. In the disclosure, the term "at least one A or B" has the same meaning as "A or B" described above. The term "at least one A, B or C" has the same meaning as "A, B or C" described above.

[0046] As known from the background, existing laser radars are difficult to achieve both large field of view and small size.

[0047] In optical imaging, imaging distortion often needs to be overcome and improved as an unfavorable factor. Therefore, the design of the optical system of the laser radar generally requires to reduce the imaging distortion. In addition, the smaller the angle between the light beam and the optical axis in the optical lens, the smaller the degree of distortion, and the larger the angle between the light beam and the optical axis, the larger the degree of distortion. In the laser radar, the field of view (FOV) of the vertical direction of part of the laser radars is usually small, and the imaging distortion of the optical system in the field of view is usually small.

[0048] FIG. 1 shows a schematic diagram of a field of view range of a lidar consistent with some embodiments of the present disclosure. In some embodiments, the lidar can include a light emitting system and a light receiving system. The light emitting system can include a light emitter and an emitting lens, and the light emitter can be located on an image plane of the emitting lens. The light receiving system can include a light receiver and a receiving lens, and the light receiver can be located on an image plane of the receiving lens. In some embodiments, the field of view range of the lidar can be the field of view range of the light emitting system, such as the field of view range of the optical system including the light emitter and the emitting lens. In some embodiments, the field of view range of the lidar can be the field of view range of the light receiving system, such as the field of view range of the optical system including the light receiver and the receiving lens. As shown in FIG. 1, the image plane half-height h can be approximately represented as: h = f x tan(0 / 2), where f is the focal length of the optical system, 0 is the field of view range of the optical system, and 0 / 2 is half of the field of view range angle. When 0 is small, tan(0 / 2) can be approximately represented as 0 / 2. Therefore, the image plane half-height h can be further approximately represented as: h = f x 0 / 2.

[0049] Therefore, when the field of view range is small, the image plane size is linearly proportional to the field of view range, and the image plane size is linearly proportional to the focal length of the optical system. As the field of view range increases, the image plane size also increases. Correspondingly, the lidar needs to be configured with larger size light emitters and light receivers. This makes the size of the lidar also increase accordingly, especially the height of the lidar will significantly increase, and the cost of the lidar will also increase. This is not conducive to the commercial application of the lidar.

[0050] To solve the technical problem, the present disclosure provides a lens group for a lidar, including at least two positive lenses and a distortion lens. The at least two positive lenses are arranged along an optical path. The distortion lens is an aspherical lens, and the distortion lens makes the distortion of the lens group at a first field of view angle reach a first distortion threshold. The technical solution of the present disclosure utilizes the distortion generated by the lens group, so that the lidar can use smaller size light emitters and light receivers to achieve a preset field of view. In this way, the size of the lidar can be reduced, the overall cost of the lidar can be reduced, and the large field of view and small size of the lidar can be achieved.

[0051] In order to make the above-mentioned purposes, features and advantages of the present disclosure more obvious and easy to understand, the specific embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0052] FIG. 2 shows a schematic diagram of an optical path structure of a lens group for a lidar, according to some embodiments of the present disclosure. As shown in FIG. 2, the lens group 120 includes at least two positive lenses SL and an anamorphic lens ASL. The at least two positive lenses SL are arranged along the optical path, and the positive lenses in the at least two positive lenses SL can be spherical lenses or aspherical lenses. The anamorphic lens ASL is an aspherical lens, and the anamorphic lens ASL can cause the lens group to have an anamorphic value of a first field of view angle reaching a first anamorphic threshold.

[0053] In some embodiments, the anamorphic lens ASL in the lens group 120 is an aspherical lens. The anamorphic lens ASL causes the lens group to have an anamorphic value of a first field of view angle reaching a preset value. For example, the first field of view angle can be an edge field of view angle of the lidar, and the anamorphic lens ASL causes the anamorphic value of the edge field of view of the lidar to reach the preset value. By using the imaging anamorphic 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 range of external field of view can be formed while the size of the optoelectronic device 110 remains unchanged. In this way, the purpose of reducing the size of the lidar or increasing the FOV of the lidar can be achieved.

[0054] In some embodiments of the present disclosure, the lens group can include three lenses. The lens group includes two positive lenses and one anamorphic lens, and the two positive lenses are both spherical lenses. As shown in FIG. 2, the lens group 120 includes two positive lenses SL and one anamorphic lens ASL. The two positive lenses SL are a positive lens PSL1 and a positive lens PSL2, and both the positive lens PSL1 and the positive lens PSL2 are spherical lenses.

[0055] The anamorphic lens is suitable for introducing a known and controllable imaging anamorphic into the lens group to achieve the purpose of compressing the image height. The anamorphic lens ASL causes the image height of the light rays in the first field of view angle direction after passing through the lens group to be smaller than the image height under linear relationship by introducing anamorphic. As shown in FIG. 2, the image height under 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 size of the optoelectronic device (e.g., a light emitter or a light receiver) of the lidar. In this way, it is beneficial to reduce the size of the lidar and reduce the cost of the lidar.

[0056] It should be noted that the imaging surface can be the back focal focal plane of the lens group, that is, the focal plane of the side of the lens group away from the external field of view. In some embodiments, the imaging surface can be a plane at a preset distance from the back focal focal plane of the lens group.

[0057] In some embodiments of the present disclosure, the anamorphic lens is a positive lens. By setting the anamorphic lens as a positive lens, the imaging height on the imaging surface can be further compressed, thereby achieving the purpose of reducing the size of the lidar.

[0058] In some embodiments, the first angle of view is less than or equal to a first angle threshold. The distortion of the light rays with the angle of view less than or equal to the first angle threshold after being transmitted through the lens group including the distortion lens can reach a first distortion threshold.

[0059] For example, the lens group is a lens group for a lidar, and the lens group is used to transmit probe light or echo light of the lidar. The first angle threshold can be a maximum angle of view of the lidar, i.e., a maximum angle in a range of the field of view of the lidar. The first angle of view is equal to the first angle threshold, and the distortion of the first angle of view is greater than or equal to the first distortion threshold. Alternatively, the first angle of view is an angle less than the first angle threshold, and the distortion of the first angle of view is greater than or equal to the first distortion threshold. For another example, the first angle threshold can be another angle less than the maximum angle of view of the lidar. For example, the maximum angle of view of the lidar is 35°, the first angle threshold can be 20°, and the first angle of view can be 20° or 19° or 18°. In other embodiments of the present disclosure, the maximum angle of view of the lidar is 35°, and the first angle threshold can also be 25°, 30°, or other values, and the first angle of view can be 30°, 25°, 20°, 19°, or 18°.

[0060] In some embodiments of the present disclosure, at least two positive lenses are located on the same side of the distortion lens. For example, the distortion lens is located at the most upstream or the most downstream of the optical path of the lens group. For example, as shown in FIG. 2, the distortion lens ASL is located in the optical path between the imaging surface IS1 and the positive lens PSL2. For another example, the distortion lens can be arranged at the outermost side of the lens group close to the outer field of view.

[0061] In some embodiments of the present disclosure, the diaphragm can be located between two positive lenses.

[0062] In some embodiments of the present disclosure, the first distortion threshold is any value greater than or equal to 15%. The distortion lens makes the distortion of the first angle of view reach the first distortion threshold, including that the distortion of the first angle of view is greater than or equal to the first distortion threshold.

[0063] It should be noted that the distortion is the ratio between the difference between the first image height and the second image height and the first image height. The first image height refers to the image height when the angle of view and the image height do not conform to a linear relationship, and the second image height refers to the image height when the angle of view and the image height conform to a linear relationship. The difference between the first image height and the second image height can be the absolute value of the difference between the first image height and the second image height. That is, The distortion of the first field of view angle refers to the absolute value of the difference between the first image height of the imaging point on the image plane of the lens group after the light beam at the first field of view angle passes through the lens group and the second image height of the imaging point on the image plane of the ideal lens group (i.e., the lens group in which the field of view angle and the image height conform to a linear relationship) after the light beam at the first field of view angle passes through the lens group, and the first image height. Because the light path is reversible, when a light source is arranged at a certain position on the imaging plane to emit a light beam, the light beam can be guided out to the corresponding angle of the external field of view after passing through the lens group 120. As shown in FIG. 2, the emitted light beam at the first image height h1 on the imaging plane IS1 (such as the red solid line in FIG. 2) is transmitted to the preset field of view angle (for example, 20°) of the external field of view after passing through the lens group 120 including the distortion lens ASL. The light beam at the second image height h2 (such as the red dashed line in FIG. 2) is transmitted to the preset field of view angle (for example, 20°) of the external field of view after passing through the lens group not including the distortion lens ASL. In some embodiments, by arranging the distortion lens, the distortion of the first field of view angle can be greater than or equal to the first distortion threshold (for example, 15%). As can be seen from FIG. 2, when the field of view angle is the same, the first image height h1 is less than the second image height h2, that is, by introducing the distortion lens in the lens group, the image height on the imaging plane can be compressed.

[0064] By arranging the distortion lens, a nonlinear distortion relationship between the field of view angle and the focal length is achieved, the image height on the imaging plane can be effectively compressed, and a smaller image height can correspond to a larger range of the external field of view. In this way, it is beneficial to form a larger field of view range with smaller area light emitters and light receivers in the laser radar, and it is beneficial to provide a large field of view of the laser radar or reduce the size of the laser radar.

[0065] After the light beam is transmitted through the lens group, the overall parameters of the lens group also affect the imaging distortion on the imaging plane.

[0066] In some embodiments of the present disclosure, the focal length of the lens group is in the range of 20 mm to 100 mm. For example, the focal length of the lens group is 20 mm. For another example, the focal length of the lens group is 100 mm. For another example, the focal length of the lens group is 30 mm. The focal length of the lens group is appropriate in size, which can ensure the detection requirements of the laser radar while controlling the overall size of the laser radar.

[0067] In some embodiments of the present disclosure, the F number of the lens group is in the range of 1 to 3. The F number of the lens group (i.e., the aperture coefficient of the lens group) is the ratio of the focal length of the lens group to the light aperture. The light flux of the lens group is inversely proportional to the square of the F number, and the smaller the F number, the greater the light flux. The F number of the lens group is appropriate in size, which can effectively ensure the light flux of the emitted detection light or the received echo light. In this way, the detection performance of the laser radar can be effectively ensured.

[0068] In some embodiments of the present disclosure, the lens group further comprises a diaphragm. The diaphragm can be located between the at least two positive lenses, or located on one side of the at least two positive lenses. For example, the diaphragm is located at the front focal position of the lens group. The diaphragm can 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.). By setting the diaphragm at the front focal position, the diaphragm can isolate stray light while reducing the blocking of probe light and echo light, thereby achieving full utilization of the optical aperture. For example, as shown in FIG. 2, the diaphragm FS is located at the focal plane on the side of the lens group 120 close to the external field of view.

[0069] It should be noted that the front focal position can be near the front focal position, which means that the focal plane of the front focal position of the lens group is within a predetermined distance range in the direction of the optical axis. The focal plane of the front focal position refers to the focal plane on the side of the lens group close to the external field of view.

[0070] It should be further noted that the diaphragm is set at the front focal position of the lens group, which is only an example. In other embodiments of the present disclosure, the diaphragm can also be set at other positions in the lens group.

[0071] Referring to FIG. 3, FIG. 3 shows a schematic diagram of an optical path structure of another lens group for a lidar consistent with some embodiments of the present disclosure.

[0072] The same as the foregoing embodiments, the present disclosure will not be repeated here. Different from the foregoing embodiments, in some embodiments of the present disclosure, the lens group further comprises at least one negative lens. The negative lens in the at least one negative lens can be a spherical mirror or an aspherical mirror. The negative lens is used to adjust the field of view range or the focal length size of the lens group.

[0073] In some embodiments of the present disclosure, the lens group can comprise 4-lens lenses. The lens group comprises 2 positive lenses, a distortion lens and 1 spherical negative lens.

[0074] For example, as shown in FIG. 3, the lens group 220 comprises 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. For another example, the negative lens can also be set at other positions of the lens group. For example, 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.

[0075] As shown in FIG. 3, a light beam with a first field of view angle (e.g., 30°) (as shown in FIG. 3 by a red solid line) is transmitted by the lens set 220 including the distortion lens ASL2 and is imaged on the imaging surface IS2, and the imaging point has a first image height h3. A light beam with the first field of view angle (e.g., 30°) (as shown in FIG. 3 by a red dashed line) is transmitted by the lens set not including the distortion lens ASL2 and is imaged on the imaging surface IS2, and the imaging point has a second image height h4. In some embodiments, the lens set can be configured to have a distortion at the first field of view angle greater than or equal to a first distortion threshold (e.g., 15%). As shown in FIG. 3, when the field of view angles are the same, the first image height h3 is less than the second image height h4. That is, by introducing the distortion lens in the lens set, the image height on the imaging surface can be compressed. By configuring the distortion lens, a nonlinear distortion relationship between the field of view angle and the focal length is achieved, and the image height on the imaging surface can be effectively compressed. In this way, a smaller image height can correspond to a larger range of external field of view, which is conducive to forming a larger field of view range with a smaller area of light emitters and light receivers in the lidar, and is conducive to providing a large field of view of the lidar or reducing the size of the lidar.

[0076] With continued reference to FIGS. 2 and 3, the lidar includes an optoelectronic device and a lens set. The lens set can include any of the lens sets described in any of the embodiments of the present disclosure. The optoelectronic device can be adapted to generate probe light or collect return light.

[0077] In some embodiments, the optoelectronic device can be located at a back focal focal plane of the lens set or a predetermined distance from the back focal focal plane of the lens set. The back focal focal plane can be a focal plane of the lens set away from the external field of view. The lens set located in the optical path upstream or downstream of the optoelectronic device can be adapted to transmit light. The location of the lens set can be determined based on the function of the optoelectronic device. For example, the optoelectronic device can be adapted to generate probe light, and the lens set can be located in the optical path downstream of the optoelectronic device to transmit the probe light. For another example, the optoelectronic device can be adapted to collect return light, and the lens set can be located in the optical path upstream of the optoelectronic device to transmit the return light.

[0078] In some embodiments, the optoelectronic device can include a light emitter, and the optoelectronic device can be configured to generate probe light. For example, the light emitter 110 can include a laser. For example, the laser can include at least one of a vertical cavity surface emitting laser (VCSEL) or an edge emitting laser (EEL). As shown in FIG. 2, the optoelectronic device 110 can include a light emitter, and the lens set 120 can be located in the optical path downstream of the optoelectronic device.

[0079] In some embodiments, the optoelectronic device 110 includes a plurality of light emitters arranged along a first direction. The first direction can be a vertical field of view direction or a horizontal field of view direction.

[0080] In some embodiments, the laser radar has a field of view range in the first direction with an angle greater than or equal to 20°. For example, the first direction can be a vertical field of view direction, and the laser radar has a field of view range in the first direction with an angle of 20°, 25°, 30°, 40°, 45°, or other angles. The angle of the vertical field of view direction greater than or equal to 20° can enable the laser radar to meet basic detection requirements.

[0081] In some embodiments, the laser radar has a field of view range in the first direction with an angle less than or equal to 30°. For example, the first direction can be a vertical field of view direction, and the laser radar has a field of view range in the first direction with an angle of 20°, 25°, 30°, or other angles. The angle of the vertical field of view direction less than or equal to 30° can enable the laser radar to meet basic detection requirements while reducing the size of the laser radar.

[0082] Based on optical principles, it can be known that, when the field of view angle is less than or equal to 30°, in an optical lens without a distortion lens, 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 laser radar can effectively reduce the influence of the distortion of other lenses on the accuracy of the optical path, and is conducive to ensuring the detection performance of the laser radar.

[0083] In some embodiments, the laser radar has a field of view range in the first direction with a distortion of the edge field of view angle greater than or equal to 10%. The lens group of the laser radar includes a distortion lens, and the distortion introduced by the distortion lens is appropriate, which can compress the image height and avoid excessive influence on the detection performance of the laser radar. In this way, the size of the laser radar can be reduced, the overall cost of the laser radar can be reduced, and the large field of view and low cost of the laser radar can be achieved.

[0084] In some embodiments as shown in FIG. 2, the first direction is a vertical field of view direction. For example, the vertical field of view range of the laser radar is 45°, and the edge field of view angles are 22.5° and -22.5°. The distortion lens ASL causes the distortion of the edge field of view angle to be greater than or equal to 10%.

[0085] In some embodiments of the present disclosure, the laser radar further comprises a homogenizer. The homogenizer is located in the light path of the probe light. The homogenizer is suitable for homogenizing the probe light. In some embodiments, the homogenization direction of the homogenizer is determined based on the arrangement direction of the plurality of light emitters in the optoelectronic device 110. For example, the homogenization direction of the homogenizer is consistent with the arrangement direction of the plurality of light emitters in the optoelectronic device 110. For another example, the homogenization direction of the homogenizer is perpendicular to the arrangement direction of the plurality of light emitters in the optoelectronic device 110.

[0086] With continuous reference to FIG. 3, the same as the foregoing embodiments, the present disclosure will not be described again here. The difference from the foregoing embodiments is that FIG. 3 shows a schematic diagram of the light path structure of another lens group for a laser radar, which is consistent with some embodiments of the present disclosure.

[0087] In some embodiments, the optoelectronic device 210 comprises a light receiver configured to receive echo light formed by reflection of the probe light on the object. For example, the optoelectronic device 210 can collect light signals and convert the collected light signals into electrical signals for output. The optoelectronic device 210 can comprise a light detector, and the lens group 220 is located in the light path upstream of the optoelectronic device. The light detector can comprise one or more of a single photon avalanche diode (SPAD), a silicon photomultiplier (SiPM), an avalanche photo diode, and a photodiode (PD).

[0088] In some embodiments, the light receiver can comprise a two-dimensional array detector, which can comprise a plurality of detection regions. For example, the light receiver can comprise a plurality of detection units, and at least one detection unit can constitute the detection region. The plurality of detection units can be independently controlled, or the detection regions can be independently controlled. The plurality of detection units are arranged in a two-dimensional array. The detection units can comprise one or more of a single photon avalanche diode (SPAD), a silicon photomultiplier (SiPM), an avalanche photo diode, and a photodiode (PD).

[0089] It should be noted that the light receiver can comprise at least one two-dimensional array detector. In some embodiments, the light receiver can have only one two-dimensional array detector. In some embodiments, the light receiver can also have two or more two-dimensional array detectors.

[0090] It should be further noted that the transmitting end of the laser radar comprises a light transmitter, and the light transmitter comprises a plurality of lasers. In some embodiments, the plurality of detection regions in the two-dimensional array detector correspond one-to-one to the plurality of lasers in the light transmitter. In some embodiments, the plurality of detection regions in the two-dimensional array detector correspond to one laser in the light transmitter. In some embodiments, one detection region in the two-dimensional array detector corresponds to a plurality of lasers in the light transmitter. The correspondence between the detection region and the laser refers to that the detection region can receive the echo light formed by the reflected detection light generated by the corresponding laser.

[0091] In some embodiments, the light transmitter and the light receiver are arranged on the same circuit board. By arranging the light transmitter and the light receiver on the same circuit board, the assembly process of the laser radar can be effectively simplified, the assembly accuracy can be improved, and the production efficiency of the laser radar can be improved.

[0092] In some embodiments, the light transmitter and the light receiver are arranged on different circuit boards.

[0093] FIG. 4 shows a distribution diagram of detectors in a light receiver of a laser radar, according to some embodiments of the present disclosure. As shown in some embodiments of FIG. 4, the plurality of detectors in the light receiver are arranged in an array along a row direction and a column direction. One of the row direction and the column direction corresponds to the first direction.

[0094] In some embodiments, as shown in FIG. 4, the plurality of detectors are arranged in an array, and the detectors of adjacent columns are staggered along the column direction. Staggering the detectors of adjacent columns can complement the field of view ranges corresponding to the two adjacent columns of detectors, so as to improve the coverage of the external field of view of the laser radar and improve the angular resolution of the laser radar. For example, as shown in FIG. 4, the first column 311c and the second column 312c are adjacent along the row direction x, the plurality of detectors 311 in the first column 311c are arranged along the column direction y, and the plurality of detectors 312 in the second column 312c are also arranged along the column direction y. The plurality of detectors 311 in the first column 311c and the plurality of detectors 312 in the second column 312c are staggered along the y direction.

[0095] In some embodiments of the present disclosure, the laser radar further comprises a scanning module. For example, the scanning module can be a rotating platform, a rotating mirror, a swing mirror, a MEMS, or a rotating prism, etc. The swing mirror can be one-dimensional or two-dimensional, and the MEMS can be one-dimensional or two-dimensional. The scanning module has a scanning direction. The scanning direction is perpendicular to the first direction of the field of view range of the laser radar. For example, as shown in FIG. 4, the eight detectors are staggered along the column direction y, and the direction y is the first direction of the field of view range of the laser radar. The scanning direction of the scanning module in the laser radar 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 laser radar.

[0096] It should be noted that the foregoing embodiments respectively show the optical path structure of the transmitting end and the receiving end of the laser radar. In some embodiments, the optical path of the transmitting end and the optical path of the receiving end of the laser radar are separated, and at least one of the transmitting end and the receiving end comprises the lens group of the present disclosure.

[0097] In some embodiments, the transmitting end optical path and the receiving end optical path of the laser radar can also partially overlap. The laser radar further comprises a beam splitter, which divides the optical path of the laser radar into a coaxial portion and a transmitting branch portion and a receiving branch portion. For example, the beam splitter can be a hole mirror, a small mirror, a half-mirror, or a polarizing beam splitter, etc. At least one of the optical path of the transmitting branch portion, the optical path of the receiving branch portion and the optical path of the coaxial portion comprises the lens group of the embodiments of the present disclosure.

[0098] Figure 5 shows a schematic diagram of the optical path structure of a laser radar consistent with some embodiments of the present disclosure. As shown in Figure 5, the beam splitter 430 divides the optical path of the laser radar into a transmitting branch portion 441 between the optical transmitter 411 and the beam splitter 430, a receiving branch portion 442 between the optical receiver 412 and the beam splitter 430, and a coaxial portion 443 of the beam splitter 430 towards the side of the external field of view. The lens group of the present disclosure is disposed at at least one of the transmitting branch portion 441, the receiving branch portion 442 and the coaxial portion 443.

[0099] In summary, the lens group of the present disclosure comprises a distortion lens, which is an aspherical lens. In this way, the distortion of the first field of view of the lens group can reach the first distortion threshold. The distortion generated by the lens group can make the probe light generated by a smaller size optical transmitter exit to a larger range of external field of view, or make a smaller size optical receiver receive the echo formed in a larger range of external field of view. Therefore, the laser radar can realize the detection in the preset field of view range with smaller size optical transmitter and optical receiver. In this way, the size of the laser radar can be reduced, the overall cost of the laser radar can be reduced, and the large field of view and low cost of the laser radar can be achieved.

[0100] It should be understood that the division of the modules and units in the above system is only a logical functional division, and another division manner can be used in actual implementation. In actual implementation, all or part of the modules and units can be integrated into one physical entity, or can be distributed on different physical entities. In addition, the modules and units in the apparatus can be implemented in the form of processor calling software. For example, the apparatus includes a processor, the processor is connected with a memory, the memory stores instructions, and the processor calls the instructions stored in the memory to implement any one of the above methods or to implement the functions of each module and each unit of the apparatus. The processor can be a general processor, such as a central processing unit (CPU) or a microprocessor. The memory can be a memory in the system or a memory outside the system. Alternatively, the modules and units in the apparatus can be implemented in the form of hardware circuit, and the functions of part or all of the modules can be implemented by designing the hardware circuit. The hardware circuit can be understood as one or more processors. For example, in one implementation manner, the hardware circuit is an application specific integrated circuit (ASIC), and the functions of part or all of the modules are implemented by designing the logical relationship between elements in the circuit. For another example, in another implementation manner, the hardware circuit is 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 by a configuration file, so as to implement the functions of part or all of the modules. All the modules of the above system can be implemented in the form of processor calling program, or all the modules can be implemented in the form of hardware circuit, or part of the modules are implemented in the form of processor calling program, and the remaining part is implemented in the form of hardware circuit.

[0101] Although the present disclosure is disclosed as above, the present disclosure is not limited thereto. Any person skilled in the art can make various modifications and variations without departing from the spirit and scope of the present disclosure, and the protection scope of the present disclosure should be defined by the scope defined in the claims.

Claims

1. A lens group for a laser radar, characterized by comprising: Comprising: at least 2 positive lenses, disposed along an optical path; an anamorphic lens, the anamorphic lens being an aspherical lens, the anamorphic lens causing the lens group to have a distortion at a first field angle reaching a first distortion threshold.

2. The lens set according to claim 1, wherein The anamorphic lens is a positive lens.

3. The lens set according to claim 1 or 2, wherein The first field angle is less than or equal to a first angle threshold.

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

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

6. The lens set according to claim 1, wherein Further comprising: a diaphragm.

7. The lens set according to claim 1, wherein The at least two positive lenses are on the same side of the anamorphic lens.

8. The lens set according to claim 1, wherein Further comprising: at least 1 negative lens.

9. The lens set according to claim 1, wherein The at least 2 positive lenses are spherical lenses.

10. A lidar, comprising: Comprising: an optoelectronic device; a lens group as claimed in any one of claims 1 to 9.

11. The lidar of claim 10, wherein, The laser radar has a field of view in a first direction greater than or equal to 20°.

12. The lidar of claim 11, wherein, The laser radar has a field of view in a first direction less than or equal to 30°.

13. The lidar of claim 12, wherein, The laser radar has a distortion in a first direction greater than or equal to 10% at a peripheral field angle.

14. The lidar of claim 10, wherein, The optoelectronic device comprises a light emitter; the light emitter is configured to generate probe light, the probe light being directed by the lens group to exit to an external field of view.

15. The lidar of claim 10, wherein, The optoelectronic device comprises a light receiver; the light receiver is configured to receive echo light formed by reflection of probe light by an object, the echo light being directed by the lens group to the light receiver.

16. The lidar of claim 15, wherein, The light receiver comprises a two-dimensional array detector, the two-dimensional array detector comprising a plurality of detection zones.

17. The lidar of claim 15, wherein, The light receiver comprises a plurality of detectors.

18. The lidar of claim 17, wherein, The plurality of detectors are arranged in an array.

19. The lidar of claim 14, wherein, The laser radar further comprises a homogenizer, the homogenizer being disposed in an optical path of the probe light.

20. The lidar of claim 10, wherein, The optoelectronic device comprises a light emitter and a light receiver, the light emitter and the light receiver being disposed on the same circuit board.

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