Laser radar

Abstract

The invention provides a laser radar. The laser radar comprises a laser emitting plate, a laser receiving plate, an emitting lens group, a receiving lens group, a semi-transparent and semi-reflecting mirror and an angle expanding mirror group, wherein the first transmitting lens in the transmitting lens group and the second receiving lens in the receiving lens group are the same lens, and the second transmitting lens in the transmitting lens group and the first receiving lens in the receiving lens group are the same lens. According to the laser radar, a large pitching field angle is realized through the transmitting lens group, the receiving lens group, the semi-transparent and semi-reflecting mirror and the angle expanding mirror group; meanwhile, the optical elements on the light receiving path and the light emitting path of the laser radar are the same, so that the influence of optical distortion on the received laser beams is greatly reduced, and the distance measurement precision and the distance measurement capability of the laser radar are improved.

Description

Technical Field

[0001] The present application relates to the field of laser radar technology, and in particular to a laser radar. Background Art

[0002] With the development and application of LiDAR technology, market demand for LiDARs with large elevation and field-of-view angles is increasing. However, the larger the elevation angle, the greater the optical distortion inherent in the LiDAR optical system. Especially for LiDARs with elevation angles above 100°, the optical distortion can exceed 30%. This optical distortion bends the LiDAR's transmitted and received laser beams, reducing the amplitude of the received laser beam and degrading the LiDAR's ranging accuracy and range capability.

[0003] Therefore, how to enable the laser radar to have a large pitch field of view and reduce the impact of optical distortion on the received laser beam has become a technical problem that needs to be solved urgently. Summary of the Invention

[0004] The main purpose of this application is to provide a laser radar that has a large pitch field of view and can reduce the impact of optical distortion on the received laser beam, thereby improving the ranging accuracy and distance measurement capability of the laser radar.

[0005] The present invention provides a laser radar, comprising:

[0006] A laser emitting board, comprising at least one light emitting unit configured to emit laser light;

[0007] a laser receiving plate, the laser receiving plate comprising at least one photosensitive unit;

[0008] An emitting lens group, comprising a first emitting lens and a second emitting lens;

[0009] A receiving lens group, comprising a first receiving lens and a second receiving lens; wherein the first transmitting lens and the second receiving lens are the same lens, and the second transmitting lens and the first receiving lens are the same lens;

[0010] Semi-transparent, semi-reflective mirror and angle expander group;

[0011] Among them, the laser is collimated by the first emitting lens and the second emitting lens in sequence, and then emitted to the semi-transparent and semi-reflective mirror. The laser that passes through the semi-transparent and semi-reflective mirror is expanded in angle by the angle expansion lens group and then emitted to the object to be measured; the laser reflected back by the object to be measured is converged on the semi-transparent and semi-reflective mirror through the angle expansion lens group, reflected to the first receiving lens by the semi-transparent and semi-reflective mirror, and after passing through the converging action of the first receiving lens and the second receiving lens, is incident on at least one of the photosensitive units.

[0012] In one embodiment, at least one of the light-emitting units forms a light-emitting area on the laser emitting plate, and at least one of the photosensitive units forms a photosensitive area on the laser receiving plate; wherein the light-emitting area and the photosensitive area have the same size in the vertical direction and the tops of the light-emitting area and the photosensitive area are aligned, and the vertical direction is a direction parallel to the rotation axis of the laser radar.

[0013] In one embodiment, the size of the photosensitive area in the horizontal direction is greater than or equal to the size of the light-emitting area in the horizontal direction, and the horizontal direction is a direction perpendicular to the rotation axis of the laser radar.

[0014] In one embodiment, the laser radar further includes: a reflector, wherein the laser light passing through the semi-transparent and semi-reflective mirror is reflected by the reflector onto the angle expansion mirror group, wherein the reflector is tilted at an angle α relative to the vertical direction, and the angle expansion mirror group is tilted at an angle 2α relative to the vertical direction, wherein the vertical direction is a direction parallel to the rotation axis of the laser radar.

[0015] In one embodiment, the reflector is arranged at the aperture of the emitting lens group, and the aperture is optimally arranged at the edge of the rotating platform of the laser radar.

[0016] In one embodiment, α=15°.

[0017] In one embodiment, when the angle expansion mirror group is tilted at an angle of 2α relative to the vertical direction, the pitch field angle of the laser radar is -30° to 90°.

[0018] In one embodiment, the angle expander lens assembly includes at least one angle expander lens, and the refractive index relationship between the angle expander lens, the first emitting lens, and the second emitting lens satisfies the following relationship:

[0019] n1=n2,n2>n3

[0020] Among them, n1, n2 and n3 are the refractive indices of the first emitting lens, the second emitting lens and the angle expander respectively.

[0021] In one embodiment, the curvature radius of the incident surface of the first emitting lens is smaller than the curvature radius of the exit surface of the first emitting lens, and both are negative values; the curvature radius of the incident surface of the second emitting lens is positive, and the curvature radius of the exit surface of the second emitting lens is negative; the angle expansion mirror group includes at least one angle expansion mirror, and the curvature radius of a surface of the angle expansion mirror facing the object to be measured is smaller than the curvature radius of a surface facing away from the object to be measured, and both are positive values.

[0022] In one embodiment, the transflective mirror comprises a transflective lens or a transflective prism.

[0023] An embodiment of the present application provides a laser radar, which achieves a large pitch and elevation field of view through a transmitting lens group, a receiving lens group, a semi-transparent and semi-reflective mirror, and an angle expansion mirror group; at the same time, the laser radar sets the first transmitting lens in the transmitting lens group and the second receiving lens in the receiving lens group to be the same lens, and sets the second transmitting lens in the transmitting lens group and the first receiving lens in the receiving lens group to be the same lens, so that the optical elements on the receiving and light emitting paths of the laser radar are the same, and the influence of the optical distortion on the transmitting light path on the bending of the laser beam is weakened by the optical distortion on the receiving light path, thereby reducing the influence of the optical distortion on the amplitude and other aspects of the received laser beam, and improving the ranging accuracy and distance measurement capability of the laser radar. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0025] Figure 1 Schematic diagram of the optical structure of a laser radar in one embodiment of the present application;

[0026] Figure 2 for Figure 1 The schematic diagram of the structure of the laser transmitting board and the laser receiving board in the laser radar shown;

[0027] Figure 3 This is a schematic structural diagram of a laser radar in another embodiment of the present application;

[0028] Figure 4 for Figure 3 Schematic diagram of the cross-sectional structure of the laser radar shown;

[0029] Figure 5 for Figure 3 Schematic diagram of the optical structure of the laser radar shown;

[0030] Figure 6 for Figure 3 Schematic diagram of the field of view of the lidar shown.

[0031] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0033] The following describes some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0034] Please refer to Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the optical structure of a laser radar provided in one embodiment of the present application. Figure 2 for Figure 1 The laser radar includes a laser emitting board 10, a laser receiving board 20, a transmitting lens group 30, a receiving lens group 40, a semi-transparent mirror 50, and an angle-expanding lens group 60.

[0035] The laser emitting board 10 includes at least one light emitting unit 11 , and the light emitting unit 11 is used to emit laser light.

[0036] The laser receiving plate 20 includes at least one photosensitive unit 21 , and the photosensitive unit 21 is used to receive the returned laser.

[0037] The emitting lens group 30 includes a first emitting lens 31 and a second emitting lens 32. The laser light emitted by the light emitting unit 11 is collimated by the first emitting lens 31 and the second emitting lens 32 in sequence.

[0038] In one embodiment, the curvature radius of the incident surface of the first emitting lens 31 (i.e., the side facing the laser emitting plate 10) is smaller than the curvature radius of the exit surface of the first emitting lens (i.e., the side facing the second emitting lens 32), and both are negative values; the curvature radius of the incident surface of the second emitting lens 32 (i.e., the side facing the first emitting lens 31) is positive, and the curvature radius of the exit surface of the second emitting lens 32 (i.e., the side facing the semi-transparent and semi-reflective mirror 50) is negative.

[0039] The collimated laser beam is incident on a semi-transparent mirror 50. The semi-transparent mirror 50 transmits 50% of the laser beam and reflects 50%. The semi-transparent mirror 50 can be a semi-transparent lens or a semi-transparent prism, as long as it performs the above functions, and is not specifically limited here.

[0040] The laser beam transmitted through the half mirror 50 is incident on the angle expansion mirror set 60 .

[0041] The angle expansion lens group 60 is used to expand the angle of the laser. Figure 1 In the laser radar shown, the angle expansion mirror group 60 is a single angle expansion mirror. Of course, in other embodiments, the angle expansion mirror group 60 can also be composed of multiple angle expansion mirrors. As long as the angle expansion mirror group 60 can achieve the angle expansion effect, no specific limitation is made here.

[0042] In one embodiment, the curvature radius of the side of the angle expander lens in the angle expander lens assembly 60 facing the object to be measured is smaller than the curvature radius of the side facing away from the object to be measured, and both are positive values.

[0043] The laser light reflected by the object to be measured passes through the angle expansion lens assembly 60 and converges on the semi-transparent mirror 50 . After being reflected by the semi-transparent mirror 50 , the laser light is incident on the receiving lens assembly 40 .

[0044] The receiving lens group 40 includes a first receiving lens 41 and a second receiving lens 42. The first receiving lens 41 and the second receiving lens 42 are used to converge the laser light, thereby converging the laser light onto the photosensitive unit 21 in the laser receiving plate 20.

[0045] In this embodiment, the first transmitting lens 31 and the second receiving lens 42 are the same lens, and the second transmitting lens 32 and the first receiving lens 41 are the same lens. It should be noted that the same lens means that all parameters of the two lenses are the same.

[0046] Since the optical element through which the laser emitted by the laser emitting board 10 passes to the object to be measured is the same as the optical element through which the laser returned by the object to be measured passes to the laser receiving board 20, that is, the optical elements on the light receiving and light emitting paths of the laser radar are the same, the optical distortion on the transmitting light path matches the optical distortion on the receiving light path, and the effects of the optical distortion on the transmitting light path on the bending of the laser beam will be offset by the optical distortion on the receiving light path, thereby reducing the effects of the optical distortion on the amplitude and other aspects of the received laser beam, and improving the ranging accuracy and distance measurement capability of the laser radar.

[0047] In order to further reduce the influence of the inherent optical distortion of the optical system on the amplitude of the received laser beam and improve the ranging accuracy of the laser radar, the size of the light-emitting area and the light-sensitive area of the laser radar can be matched. Figure 2 As shown, at least one of the light emitting units 11 forms a light emitting area 12 on the laser emitting plate 10. The light emitting area 12 is Figure 2 At least one of the photosensitive units 21 forms a photosensitive area 22 on the laser receiving plate 20. The photosensitive area 22 is Figure 2The area enclosed by the dotted frame on the right side is shown; wherein, the light-emitting area 12 and the photosensitive area 22 have the same size in the vertical direction and the tops of the light-emitting area 12 and the photosensitive area 22 are aligned, and the vertical direction is parallel to the rotation axis of the laser radar.

[0048] For example, Figure 2 As shown, there are multiple rows of light-emitting units 11 on the laser emitting plate 10, and multiple rows of photosensitive units 21 on the laser receiving plate 20. The light-emitting area 12 and the photosensitive area 22 have the same size in the vertical direction. The number of rows of light-emitting units 11 on the laser emitting plate 10 is set to be the same as the number of rows of photosensitive units 21 on the laser receiving plate 20, and the height of the first row of light-emitting units 11 is the same as the height of the first row of photosensitive units 21, that is, the top of the first row of light-emitting units 11 is aligned with the top of the first row of photosensitive units 21. In this way, the light-emitting unit 11 in the laser emitting board 10 and the photosensitive unit 21 in the laser receiving board 20 can be more matched in arrangement, thereby making the optical distortion of the emitting optical system and the optical distortion of the receiving optical system more matched; coupled with the same optical elements on the receiving and emitting paths, the receiving and emitting optical systems of the laser radar are the same optical systems, and the optical distortion of the receiving and emitting optical systems is matched. The optical distortion of the receiving optical system can offset the influence of the optical distortion of the emitting optical system on the laser beam, thereby making the laser beam received by the laser receiving board 20 have the same arrangement as the laser beam emitted by the laser emitting board 10, and the amplitude of the laser beam received by the laser receiving board 20 is further improved, thereby improving the ranging accuracy of the laser radar.

[0049] In one embodiment, the light-emitting area 12 and the photosensitive area 22 may be configured to have the same horizontal dimensions, where the horizontal direction is perpendicular to the rotation axis of the laser radar. This can further reduce the impact of optical distortion on the amplitude and other aspects of the received laser beam. Of course, in other embodiments, the light-emitting area 12 and the photosensitive area 22 may have different horizontal dimensions, for example, the photosensitive area 22 may have a larger horizontal dimension than the light-emitting area 12.

[0050] exist Figure 1In the laser radar shown, the laser radar can achieve a pitch field of view of 120°, and the pitch field of view angle can range from -60° to 60°. While having a large pitch field of view angle, by setting the first transmitting lens 31 and the second receiving lens 42 as the same lens, and setting the second transmitting lens 32 and the first receiving lens 41 as the same lens, the optical element through which the laser emitted by the laser emitting plate 10 passes to the object to be measured is the same as the optical element through which the laser reflected back by the object to be measured passes to the laser receiving plate 20, that is, the optical elements on the receiving and emitting paths are the same, thereby reducing the influence of optical distortion on the amplitude and other aspects of the received laser beam, and improving the ranging accuracy and distance measurement capability of the laser radar.

[0051] See Figures 3 to 5 , Figure 3 This is a schematic diagram of the structure of a laser radar in another embodiment of the present application. Figure 4 for Figure 3 The cross-sectional structure diagram of the laser radar shown in FIG. Figure 5 for Figure 3 The laser radar 100 comprises a laser emitting plate 10 , a laser receiving plate 20 , a transmitting lens group 30 , a receiving lens group 40 , a semi-transparent and semi-reflective mirror 50 , an angle-expanding mirror group 60 and a reflecting mirror 70 .

[0052] The laser emitting board 10 includes at least one light emitting unit, which is used to emit laser.

[0053] The laser receiving plate 20 includes at least one photosensitive unit, which is used to receive the returned laser.

[0054] The emitting lens group 30 includes a first emitting lens 31 and a second emitting lens 32. The emitting lens group 30 is used to collimate the laser.

[0055] The semi-transparent mirror 50 allows 50% of the laser light to pass through and 50% of the laser light to be reflected. The laser light passing through the semi-transparent mirror 50 is incident on the reflective mirror 70 .

[0056] The reflector 70 is tilted at an angle α relative to the vertical direction (eg Figure 4 As shown), wherein the vertical direction is a direction parallel to the rotation axis of the laser radar 100.

[0057] In one embodiment, in order to make the internal layout of the laser radar 100 more compact and reduce the size of the laser radar 100, the reflector 70 can be set at the aperture of the transmitting lens group 30, wherein the aperture is optimally set at the edge of the rotating platform of the laser radar 100, specifically as follows: Figure 3 and Figure 4 shown.

[0058] It should be noted that in the above embodiment, the aperture of the emitting lens group 30 is a simulated aperture, and setting the reflector 70 at the aperture can save space. Of course, in other embodiments, the aperture of the emitting lens group 30 can also be a real aperture, and the reflector 70 is placed near the aperture.

[0059] The reflector 70 reflects the laser light transmitted through the semi-transparent mirror 50 to the angle expansion lens assembly 60 .

[0060] The angle expansion lens assembly 60 is tilted at an angle of 2α relative to the vertical direction to expand the angle of the laser.

[0061] In one embodiment, the angle expander lens assembly 60 includes at least one angle expander lens, and the refractive index relationship between the angle expander lens, the first emitting lens 31 and the second emitting lens 32 satisfies the following relationship:

[0062] n1=n2,n2>n3

[0063] Wherein, n1, n2 and n3 are the refractive indices of the first emitting lens 31, the second emitting lens 32 and the angle expander respectively.

[0064] The laser light reflected by the object to be measured passes through the angle expansion lens assembly 60 and converges on the reflector 70 . The laser light is then reflected by the reflector 70 and the semi-transparent mirror 50 and incident on the receiving lens assembly 40 .

[0065] The receiving lens group 40 includes a first receiving lens 41 and a second receiving lens 42. The first transmitting lens 31 and the second receiving lens 42 are the same lens, and the second transmitting lens 32 and the first receiving lens 41 are the same lens.

[0066] Since the optical element through which the laser emitted by the laser emitting plate 10 passes to the object to be measured is the same as the optical element through which the laser reflected by the object to be measured passes to the laser receiving plate 20, the influence of optical distortion on the amplitude and other aspects of the received laser beam is weakened, thereby improving the ranging accuracy and distance measurement capability of the laser radar.

[0067] In order to further reduce the impact of optical distortion on the amplitude and other aspects of the received laser beam and improve the ranging accuracy of the laser radar, the size of the laser radar's light-emitting area and photosensitive area can be matched to further improve the matching degree of optical distortion of the transmitting and receiving optical systems. For example, at least one light-emitting unit forms a light-emitting area on the laser emitting plate 10, and at least one photosensitive unit forms a photosensitive area on the laser receiving plate 20. The light-emitting area and the photosensitive area have the same size in the vertical direction, and the tops of the light-emitting area and the photosensitive area are aligned. For another example, the light-emitting area and the photosensitive area can be further set to the same size in the horizontal direction, thereby further reducing the impact of optical distortion on the laser beam.

[0068] In one embodiment, when the angle α of the reflector 70 relative to the vertical direction is set to 15°, the angle expansion mirror group 60 is tilted 30° relative to the vertical direction, and the pitch field angle of the laser radar 100 can be -30° to 90°.

[0069] A specific implementation is given below to achieve the above-mentioned elevation viewing angle of -30° to 90°. In this specific implementation, the angle α is set to 15°. Figures 3 to 5 The specific parameter settings of the first emitting lens 31, the second emitting lens 32 and the angle expander are shown in Table 1 below:

[0070] Table 1:

[0071]

[0072] Among them, in Table 1, G1S1 represents the incident surface of the first emitting lens 31, and G1S2 represents the exit surface of the first emitting lens 31; G2S1 represents the incident surface of the second emitting lens 32, and G2S2 represents the exit surface of the second emitting lens 32; G3S1 represents the side of the expansion mirror facing the reflector 70, and G3S2 represents the side of the expansion mirror facing the object to be measured; the incident surface of the first receiving lens 41 (that is, the side facing the semi-transparent and semi-reflective mirror 50) and the exit surface of the second emitting lens 32 are the same curved surface, the exit surface of the first receiving lens 41 (that is, the side facing the second receiving lens 42) and the incident surface of the second emitting lens 32 are the same curved surface, the incident surface of the second receiving lens 42 (that is, the side facing the first receiving lens 41) and the exit surface of the first emitting lens 31 are the same curved surface, and the exit surface of the second receiving lens 42 (that is, the side facing the laser receiving plate 20) and the incident surface of the first emitting lens 31 are the same curved surface.

[0073] In addition, the material of the first emitting lens 31 and the second emitting lens 32 is flint glass, specifically H-ZLAF92, whose refractive index is 2.003 and the Abbe number is 28.3; the material of the angle expander is optical glass, specifically D-K9, whose refractive index is 1.516 and the Abbe number is 64.05; the thicknesses of the first emitting lens 31, the second emitting lens 32 and the angle expander are 3.039 mm, 2.719 mm and 2.520 mm respectively; the air gap between the first emitting lens 31 and the second emitting lens 32 is 1.889 cm, the air distance between the second emitting lens 32 and the reflector 70 is 5 cm, and the air distance between the reflector 70 and the angle expander is 5 cm.

[0074] The laser radar 100 after the above parameters are set has a pitch field angle of -30° to 90°. When the rotary motor in the laser radar 100 rotates, it can form the following Figure 6 Field of view shown.

[0075] It should be noted that the parameters in the above specific embodiments, such as the thickness of each lens, the air gap between lenses and other parameters, can be designed according to actual needs and are not limited to the above specific values. The specific values of the above parameters are only examples.

[0076] In addition, the structures, parameters, working principles and other information corresponding to certain elements and regions in this embodiment can refer to the previous embodiments, and for the sake of brevity of the description, they will not be repeated in this embodiment.

[0077] In summary, the laser radar 100 in the embodiment of the present application not only has a large pitch field angle, but also weakens the influence of optical distortion on the amplitude of the received laser light beam, thereby improving the ranging accuracy and distance measurement capability of the laser radar; at the same time, since the laser radar 100 can achieve a large pitch field angle without tilting the fuselage, the size of the laser radar 100 is smaller, which better meets the needs of miniaturization.

[0078] The disclosure above provides many different embodiments or examples for realizing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described above. Of course, they are merely examples and are not intended to limit the present application. Any non-substantial changes and replacements made by those skilled in the art based on the present application all fall within the scope of protection claimed in the present application.

[0079] In addition, this application may repeat reference numbers and / or reference letters in different examples. This repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, this application provides examples of various specific processes and materials, but those of ordinary skill in the art will recognize the application of other processes and / or the use of other materials.

Claims

1. A laser radar, characterized in that: The laser radar includes: A laser emitting board, comprising at least one light emitting unit configured to emit laser light; a laser receiving plate, the laser receiving plate comprising at least one photosensitive unit; An emitting lens group, comprising a first emitting lens and a second emitting lens; A receiving lens group, comprising a first receiving lens and a second receiving lens; wherein the first transmitting lens and the second receiving lens are the same lens, and the second transmitting lens and the first receiving lens are the same lens; Semi-transparent, semi-reflective mirror and angle expander group; Among them, the laser is collimated by the first emitting lens and the second emitting lens in sequence, and then emitted to the semi-transparent and semi-reflective mirror. The laser that passes through the semi-transparent and semi-reflective mirror is expanded in angle by the angle expansion lens group and then emitted to the object to be measured; the laser reflected back by the object to be measured is converged on the semi-transparent and semi-reflective mirror through the angle expansion lens group, reflected to the first receiving lens by the semi-transparent and semi-reflective mirror, and after passing through the converging action of the first receiving lens and the second receiving lens, is incident on at least one of the photosensitive units.

2. The laser radar according to claim 1, characterized in that At least one of the light-emitting units forms a light-emitting area on the laser emitting plate, and at least one of the photosensitive units forms a photosensitive area on the laser receiving plate; wherein, the light-emitting area and the photosensitive area have the same size in the vertical direction and the tops of the light-emitting area and the photosensitive area are aligned, and the vertical direction is a direction parallel to the rotation axis of the laser radar.

3. The laser radar according to claim 2, characterized in that The size of the photosensitive area in the horizontal direction is greater than or equal to the size of the light-emitting area in the horizontal direction, and the horizontal direction is a direction perpendicular to the rotation axis of the laser radar.

4. The laser radar according to claim 1, wherein The laser radar further includes: A reflector, wherein the laser light passing through the semi-transparent and semi-reflective mirror is reflected by the reflector onto the angle expansion mirror group, wherein the reflector is tilted at an angle α relative to the vertical direction, and the angle expansion mirror group is tilted at an angle 2α relative to the vertical direction, wherein the vertical direction is a direction parallel to the rotation axis of the laser radar.

5. The laser radar according to claim 4, characterized in that The reflector is arranged at the aperture of the emitting lens group, and the aperture is optimally arranged at the edge of the rotating platform of the laser radar.

6. The laser radar according to claim 4, characterized in that α＝15°。 7. The laser radar according to claim 6, characterized in that When the angle expansion mirror group is tilted at an angle of 2α relative to the vertical direction, the pitch field angle of the laser radar is -30° to 90°.

8. The laser radar according to claim 7, characterized in that The angle expansion lens group includes at least one angle expansion lens, and the refractive index relationship between the angle expansion lens, the first emitting lens and the second emitting lens satisfies the following relationship: n1=n2,n2>n3 Among them, n1, n2 and n3 are the refractive indices of the first emitting lens, the second emitting lens and the angle expander respectively.

9. The laser radar according to claim 1, characterized in that The curvature radius of the incident surface of the first emitting lens is smaller than the curvature radius of the exit surface of the first emitting lens, and both are negative values; the curvature radius of the incident surface of the second emitting lens is positive, and the curvature radius of the exit surface of the second emitting lens is negative; the angle expansion mirror group includes at least one angle expansion mirror, and the curvature radius of a surface of the angle expansion mirror facing the object to be measured is smaller than the curvature radius of a surface facing away from the object to be measured, and both are positive values.

10. The laser radar according to claim 1, characterized in that The semi-transparent and semi-reflective mirror includes a semi-transparent and semi-reflective lens or a semi-transparent and semi-reflective prism.

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