CN222125436U - Receiving lens and laser radar - Google Patents

Abstract

A receiving lens and a laser radar relate to the technical field of optics. The receiving lens comprises a diaphragm, a filter and a lens group which are sequentially arranged along the direction of an optical axis, wherein the diaphragm is used for receiving a signal light beam and an ambient light beam and limiting the light passing caliber of the light beam, the filter is used for filtering the ambient light beam and enabling the signal light beam to penetrate, the lens group is used for collecting and converging the signal light beam and then emitting the signal light beam, and the distance from the diaphragm to the lens group is between 10mm and 40 mm. The receiving lens can also reduce the volume of the laser radar on the premise of meeting the requirement of a larger view field, and meets the requirement of miniaturization of the laser radar.

Description

Receiving lens and laser radar

Technical Field

The utility model relates to the technical field of optics, in particular to a receiving lens and a laser radar.

Background

The laser radar works in an optical frequency band, emits detection signals to a target object by utilizing electromagnetic waves in the optical frequency band, and then carries out information processing on the reflected same-wave signals and the emission signals, so that information such as the position (distance from the target object, azimuth and height of the target object) and motion state (speed and gesture of the target object) of the target object is obtained, and detection, tracking and identification of the target object are realized. The laser radar has the advantages of strong anti-interference capability, simpler structure, convenient use and the like, is increasingly widely applied and continuously expanded in the fields of military field, civil production and the like, and becomes an indispensable technical means in social development service.

When the laser radar is applied to the field of vehicle-mounted laser radars, due to the limitation of the current optical path structural design of the laser radars, the field of view of the laser radars and the volume of the laser radars are positively correlated, so that for a large receiving field of view, the volume of the laser radars is larger. However, in the field of vehicle-mounted lidar, the height of the lidar is often limited greatly, so that the requirement of miniaturization of the lidar on the premise of meeting the requirement of a large field of view of the lidar is a technical problem to be solved.

Disclosure of utility model

The utility model aims to provide a receiving lens and a laser radar, which can reduce the volume of the laser radar on the premise of meeting the requirement of larger view field and meet the requirement of miniaturization of the laser radar.

Embodiments of the present utility model are implemented as follows:

The utility model provides a receiving lens, which comprises a diaphragm, a light filter and a lens group, wherein the diaphragm, the light filter and the lens group are sequentially arranged along the direction of an optical axis, the diaphragm is used for receiving a signal light beam and an environment light beam and limiting the light passing caliber of the light beam, the light filter is used for filtering the environment light beam and enabling the signal light beam to pass through, the lens group is used for collecting and converging the signal light beam and then emitting the signal light beam, and the distance from the diaphragm to the lens group is between 10mm and 40 mm. The receiving lens can also reduce the volume of the laser radar on the premise of meeting the requirement of a larger view field, and meets the requirement of miniaturization of the laser radar.

Optionally, the residual astigmatism of the receiving lens satisfies the following formula:

Wherein, ' is the refractive index of the image space, ' is the aperture angle of the image space, ' SIII is the primary astigmatism distribution coefficient, and k is the number of refractive surfaces in the receiving lens.

Optionally, the lens group comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens which are sequentially arranged, wherein the first lens is positioned between the second lens and the optical filter, and the first lens, the second lens, the third lens, the fourth lens and the fifth lens are all spherical lenses.

Optionally, the first lens, the third lens, the fourth lens and the fifth lens have positive optical power, respectively, and the second lens has negative optical power.

Optionally, the first, third, fourth and fifth lenses have optical powers of 0 to 0.04, respectively, and the second lens has optical power of-0.04 to 0.

Optionally, the first lens satisfies 0.5< (r2+r1)/(r2-R1) <1.0, the second lens satisfies 0.9< (r2+r1)/(r2-R1) <1.1, the third lens satisfies-0.3 < (r2+r1)/(r2-R1) < -0.6, the fourth lens satisfies 2.0< (r2+r1)/(r2-R1) <2.5, the fifth lens satisfies 5.0< (r2+r1)/(r2-R1) <6.0, wherein R2 is the radius of curvature of the light entrance surface of the lens, and R1 is the radius of curvature of the light exit surface of the lens.

Optionally, the light incident surface of the first lens is a convex surface, the light emergent surface of the first lens is a convex surface, the light incident surface of the second lens is a concave surface, the light emergent surface of the second lens is a convex surface, the light incident surface of the third lens is a convex surface, the light emergent surface of the third lens is a convex surface, the light incident surface of the fourth lens is a convex surface, the light emergent surface of the fourth lens is a concave surface, the light incident surface of the fifth lens is a convex surface, and the light emergent surface of the fifth lens is a concave surface.

Optionally, the first lens, the second lens and the third lens are the same in material, and any two of the fourth lens, the fifth lens and the first lens are different in material.

Optionally, the aperture factor of the receiving lens is greater than 0.7, and/or the field angle of the receiving lens is greater than or equal to 25 °.

In another aspect of the present utility model, there is provided a lidar including the receiving lens described above.

The beneficial effects of the utility model include:

The receiving lens comprises a diaphragm, a light filter and a lens group which are sequentially arranged along the direction of an optical axis, wherein the diaphragm is used for receiving a signal light beam and an ambient light beam and limiting the light passing caliber of the light beam, the light filter is used for filtering the ambient light beam and enabling the signal light beam to pass through, the lens group is used for collecting and converging the signal light beam and then emitting the signal light beam, and the distance between the diaphragm and the lens group is between 10mm and 40 mm. According to the application, the diaphragm is arranged on one surface of the optical filter, which is away from the lens group (namely, the diaphragm is arranged in front of the lens group), and the distance between the diaphragm and the lens group is between 10mm and 40mm, so that the diameter of each lens of the receiving lens can be smaller on the premise of the same field angle compared with the arrangement of the diaphragm in the lens group, and therefore, when the receiving lens provided by the application is applied to the field of vehicle-mounted laser radar, on one hand, the volume of the laser radar can be smaller by adopting the receiving lens provided by the application under the same field of view, and on the other hand, the larger field of view can be obtained by adopting the receiving lens provided by the application under the same volume of the laser radar.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present utility model and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a receiving lens according to an embodiment of the present utility model;

FIG. 2 is one of the dot patterns obtained by the receiving lens according to the embodiment of the present utility model;

FIG. 3 is a second point diagram of a receiving lens according to an embodiment of the present utility model;

FIG. 4 is a third point chart obtained by the receiving lens according to the embodiment of the present utility model;

FIG. 5 is a fourth example of a point diagram obtained by the receiving lens according to the present utility model;

FIG. 6 is a fifth example of a point list obtained by the receiving lens according to the present utility model;

Fig. 7 is a light ray fan diagram obtained by the receiving lens according to the embodiment of the present utility model.

The icons are 10-diaphragm, 20-filter, 30-lens group, 31-first lens, 32-second lens, 33-third lens, 34-fourth lens and 35-fifth lens.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments of the present utility model. The components of the embodiments of the present utility model generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the utility model, as presented in the figures, is not intended to limit the scope of the utility model, as claimed, but is merely representative of selected embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that like reference numerals and letters refer to like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

In the description of the present utility model, it should be noted that, directions or positional relationships indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., are directions or positional relationships based on those shown in the drawings, or are directions or positional relationships conventionally put in use of the inventive product, are merely for convenience of describing the present utility model and simplifying the description, and are not indicative or implying that the apparatus or element to be referred to must have a specific direction, be constructed and operated in a specific direction, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," "third," and the like are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal," "vertical," and the like do not denote a requirement that the component be absolutely horizontal or overhang, but rather may be slightly inclined. As "horizontal" merely means that its direction is more horizontal than "vertical", and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the present utility model, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, integrally connected, mechanically connected, electrically connected, directly connected, indirectly connected through an intermediary, or in communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

Referring to fig. 1, the present embodiment provides a receiving lens, which includes a diaphragm 10, a filter 20 and a lens group 30 sequentially disposed along an optical axis, wherein the diaphragm 10 is configured to receive a signal light beam and an ambient light beam and limit a light aperture of the beam, the filter 20 is configured to filter the ambient light beam and allow the signal light beam to pass through, and the lens group 30 collects and converges the signal light beam and then emits the signal light beam, and a distance from the diaphragm 10 to the lens group 30 is between 10mm and 40 mm. The receiving lens can also reduce the volume of the laser radar on the premise of meeting the requirement of a larger view field, and meets the requirement of miniaturization of the laser radar.

The diaphragm 10 is used for receiving a signal light beam and an ambient light beam and limiting the aperture of the light beam. It should be noted that, the diaphragm 10 can reduce the generation of astigmatism of the receiving lens, and is beneficial to converging the light entering the receiving lens, reducing the end caliber of the receiving lens, and being beneficial to the miniaturization design of the receiving lens.

The diaphragm 10 is disposed on a side of the filter 20 away from the lens assembly 30, that is, in the present embodiment, the diaphragm 10 is disposed in front of the receiving lens. Therefore, the application can also reduce the diameter of the corresponding lens of the receiving lens under the condition of meeting the requirement of a larger field angle, thereby being beneficial to reducing the cost of the receiving lens and reducing the whole volume of the receiving lens.

In this embodiment, the distance from the diaphragm 10 to the lens group 30 is between 10mm and 40mm, and the distance from the diaphragm 10 to the lens group 30 may be 10mm, 20mm, 30mm or 40mm, for example, and the specific present application is not limited, and those skilled in the art may reasonably select according to the size required for receiving the lens. It is worth to describe that the distance from the diaphragm 10 to the lens group 30 is set between 10mm and 40mm, so that on one hand, the radial size of the receiving lens can be reduced on the premise of meeting a larger field angle, the problem that the laser radar adopting the receiving lens is limited in height when being applied to the field of vehicle-mounted laser radars is solved, and on the other hand, the range value can also effectively control the transverse size of the receiving lens, so that the whole size of the receiving lens is miniaturized.

The above-mentioned optical filter 20 is disposed between the lens assembly 30 and the diaphragm 10, in this embodiment, the optical filter 20 is used for filtering the ambient light beam and making the signal light beam pass through, so that the wavelength of the incident light beam can be screened, the receiving lens can filter the impurity wave, only the light beam of the imaging band of the designated range passes through, so that the imaging quality of the receiving lens can be improved, and the optical performance of the laser radar can be effectively improved.

In this embodiment, the filter 20 can pass light beams with wavelength of 905nm±15nm, and can filter light beams with other wavelength bands.

The lens group 30 is disposed on the light-emitting side of the optical filter 20, and is configured to collect and concentrate the light beam to shape and emit the light beam, so that the light beam obtains a light spot on the imaging surface.

In summary, the receiving lens provided by the application comprises a diaphragm 10, a filter 20 and a lens group 30 which are sequentially arranged along the optical axis direction, wherein the diaphragm 10 is used for receiving a signal light beam and an ambient light beam and limiting the light aperture of the beam, the filter 20 is used for filtering the ambient light beam and enabling the signal light beam to permeate, and the lens group 30 is used for collecting and converging the signal light beam and then emitting, and the distance from the diaphragm 10 to the lens group 30 is between 10mm and 40 mm. According to the application, the diaphragm 10 is arranged on one surface of the optical filter 20, which is away from the lens group 30 (namely, the diaphragm 10 is arranged in front of the lens group 30), and the distance between the diaphragm 10 and the lens group 30 is between 10mm and 40mm, so that the diameter of each lens of the receiving lens can be smaller on the premise of the same view angle compared with the arrangement of the diaphragm 10 in the lens group 30, and therefore, when the receiving lens provided by the application is applied to the field of vehicle-mounted laser radar, on one hand, the volume of the laser radar can be smaller by adopting the receiving lens provided by the application under the same view field, and on the other hand, the receiving lens provided by the application can obtain a larger view field by adopting the receiving lens provided by the application under the same volume of the laser radar.

The dynamic range of a single pixel of a receiving end chip of the current laser radar is limited, a plurality of pixels are required to be combined into an array for use in order to enlarge the dynamic range, and if a square array is used, the number of line pairs (pl/mm) in the vertical direction is unchanged, the array can only be expanded in the horizontal direction, namely, N multiplied by N is expanded into N multiplied by M (wherein N is less than M), and at the moment, corresponding receiving light spots need to be shaped into a rectangle. The diffuse speckles of the receiving end of the conventional axisymmetric lens are round or approximate to round, which is insufficient to meet the requirement of the receiving end chip on enlarging the long square receiving area in the dynamic range.

In addition, conventional lenses use line pairs (pl/mm) to measure or describe the resolution of the lens, often requiring the identification of higher line pairs, i.e., the MTF curve is flat, in order to improve imaging quality. Typically, 30pl/mm is used to test the resolution capability, sharpness and imaging clarity of the lens, and 10pl/mm is used to test the contrast capability and imaging permeability of the lens. When the MTF index is corresponding, the contrast of a high-frequency and low-frequency reaction lens is high, the contrast of a low-frequency reaction lens is 10pl/mm, and the resolution of a high-frequency reaction lens is 30 pl/mm. However, for the chip-type receiving device of the laser radar, the requirement on the resolution of the lens is not very high, but only the contrast requirement of the lens is high, namely the clear imaging light spot boundary of the lens and the uniform distribution of the energy in the light spot are required.

Therefore, in order for the lidar to meet the requirement of a rectangular receiving area when expanding the dynamic range, and for the lidar to have high contrast, in the present embodiment, optionally, the residual astigmatism of the receiving lens satisfies the following formula:

Where x _ts is the residual astigmatism of the receiving lens, n 'is the refractive index of the image space, u' is the aperture angle of the image space, S _III is the primary astigmatism distribution coefficient, and k is the number of refractive surfaces in the receiving lens.

The S _III is the primary astigmatic distribution coefficient, i.e. the third Saeder sum, in whichH is the incident height of the first paraxial ray on the refractive surface, h _z is the incident height of the second paraxial ray on the refractive surface, Q _z is abbe invariant of the second paraxial ray, n is the refractive index of the object, and l is the distance of the object from the optical system.

WhileJ is the terahertz invariant, j= nyu =n 'y' u ', y is the height of the object, u is the angle between the chief ray and the optical axis (i.e., the aperture angle of the object), n' is the refractive index of the image side, y 'is the height of the image, u' is the aperture angle of the image side, Q is the abbe invariant,R is the radius of curvature of the refractive surface and l' is the distance of the object from the optical system.

It should be noted that, the first paraxial ray is a ray passing through an edge point of the entrance pupil and emitted from an on-axis object point, and the second paraxial ray is a ray passing through a center of the entrance pupil and emitted from an off-axis field point.

Referring to fig. 2 to 6, the light spot patterns of the receiving lens in different fields of view can be made to be basically rectangular by the arrangement of the application, and fig. 2, 3, 4, 5 and 6 are respectively point column patterns obtained by the receiving lens in different fields of view, so that it can be seen that the point column patterns obtained by the receiving lens in the application are approximately rectangular.

Referring to the light ray fan diagram provided in fig. 7, it can be seen from fig. 7 that the aberration correction of the receiving lens provided by the application is high in imaging quality.

In this embodiment, the specific structure of the lens assembly 30 is not limited by the present application, for example, in a first possible implementation manner, the lens assembly 30 may include a first lens 31, a second lens 32, a third lens 33, a fourth lens 34, and a fifth lens 35 sequentially disposed, where the first lens 31 is located between the second lens 32 and the optical filter 20, and the first lens 31, the second lens 32, the third lens 33, the fourth lens 34, and the fifth lens 35 are all spherical lenses.

The specific optical parameters (such as radius of curvature, refractive index, etc.) of each lens are not particularly limited, and may be determined by those skilled in the art according to practical situations.

Alternatively, the first lens 31, the third lens 33, the fourth lens 34, and the fifth lens 35 each have positive optical power, and the second lens 32 has negative optical power.

Illustratively, the optical powers of the above-described first, third, fourth, and fifth lenses 31, 33, 34, and 35 are between 0 and 0.04, respectively. For example, the optical powers of the first lens 31, the third lens 33, the fourth lens 34, and the fifth lens 35 may be 0, 0.01, 0.02, 0.03, 0.04, or the like.

The optical power of the second lens 32 is between-0.04 and 0. For example, the optical power of the second lens 32 may be-0.04, -0.03, -0.02, -0.01, or 0, etc.

In addition, in order to further improve the optical performance of the receiving lens, in the present embodiment, alternatively, the first lens 31 satisfies 0.5< (r2+r1)/(r2—r1) <1.0, the second lens 32 satisfies 0.9< (r2+r1)/(r2—r1) <1.1, the third lens 33 satisfies-0.3 < (r2+r1)/(r2—r1) < -0.6, the fourth lens 34 satisfies 2.0< (r2+r1)/(r2—r1) <2.5, the fifth lens 35 satisfies 5.0< (r2+r1)/(r2—r1) <6.0, where R2 is the light entrance surface radius of curvature of the lens, and R1 is the light exit surface radius of curvature of the lens.

In the present embodiment, the first lens 31, the second lens 32, the third lens 33, the fourth lens 34, and the fifth lens 35 are spherical lenses. Alternatively, the light incident surface of the first lens 31 may be convex, and the light emergent surface of the first lens 31 may be convex (i.e., the first lens 31 is a biconvex lens), the light incident surface of the second lens 32 may be concave, and the light emergent surface of the second lens 32 may be convex (i.e., the second lens 32 is a meniscus lens), the light incident surface of the third lens 33 may be convex, the light emergent surface of the third lens 33 may be convex (i.e., the third lens 33 is a biconvex lens), the light incident surface of the fourth lens 34 may be convex, the light emergent surface of the fourth lens 34 may be concave (i.e., the fourth lens 34 is a convex), the light incident surface of the fifth lens 35 may be convex, and the light emergent surface of the fifth lens 35 may be concave (i.e., the fifth lens 35 may be a convex-concave lens). It should be noted that the specific types of lenses described above are only examples, and are not limiting of the present application.

Alternatively, the first lens 31, the second lens 32 and the third lens 33 are made of the same material, and any two of the fourth lens 34, the fifth lens 35 and the first lens 31 are made of different materials.

Illustratively, the first, second and third lenses 31, 32, 33 may be made of H-ZF4A, the fourth lens 34 may be made of H-ZLAF A, and the fifth lens 35 may be made of H-ZLAF A.

In a second possible embodiment, the lens group 30 may further include at least two aspherical lenses. It should be noted that, in general, one aspherical lens may replace two spherical lenses, and thus, by providing an aspherical lens in the lens group 30, the volume of the lens group 30 may be further reduced, so that the overall volume of the receiving lens is further reduced, which is beneficial to miniaturization of the device.

Optionally, the aperture factor of the receiving lens is greater than 0.7, and/or the field angle of the receiving lens is greater than or equal to 25 °. The aperture coefficient of the receiving lens is larger than 0.7, so that the light receiving capacity of the receiving lens is stronger, and the receiving effect of the receiving lens is better. The visual angle of the receiving lens is larger than or equal to 25 degrees, so that the use requirement of the vehicle-mounted laser radar can be met.

According to the application, the diaphragm 10 is arranged in front of the lens group 30, so that a certain anti-corona effect is formed on the edge view field, and the radial dimension of the receiving lens can be reduced while the view field angle of 25 degrees or more is met, so that the laser radar adopting the receiving lens can ensure the ranging capability and can be applied to a space with a limited height, the cost can be reduced due to the reduction of the volume of the receiving lens, and the popularization and the use of the receiving lens are facilitated. Meanwhile, by adopting the receiving lens provided by the application, the obtained point column diagram has clearer boundary and more uniform internal distribution, each pixel in the array pixel can receive nearly even the same energy in a fixed pixel array N multiplied by M (N is more than or equal to 1, N is less than M) when corresponding to a chip receiving device, and because the boundary of a light spot is clear, the energy falling outside a non-working pixel is extremely less, so that the crosstalk between arrays can be reduced.

In addition, the receiving lens of the application utilizes the residual aberration of each lens in the lens to control and shape the dispersion spot of the image surface to obtain the wanted shape and size, and as the non-circular axisymmetric elements such as the wedge-shaped flat plate, the cylindrical mirror and the like are not added, compared with the prior art, the receiving lens can also reduce the assembling and adjusting difficulty, reduce the cost and reduce the volume of the receiving lens. Meanwhile, the facula image obtained by adopting the receiving lens provided by the application is approximately rectangular, covers the receiving pixel array with corresponding resolution, has clear boundary and uniform internal distribution, and greatly expands the dynamic range of the N.times.M array pixels in the fixed pixel array like N.times.M (N is more than or equal to 1, N is less than or equal to M) array pixels when corresponding to the chip receiving device.

In another aspect of the present utility model, there is provided a lidar including the receiving lens described above. Since the specific structure and effects of the receiving lens are described and illustrated in detail above, the present utility model is not repeated here.

The above description is only of alternative embodiments of the present utility model and is not intended to limit the present utility model, and various modifications and variations will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

In addition, the specific features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various possible combinations are not described further.

Claims (10)

1. The receiving lens is characterized by comprising a diaphragm, a filter and a lens group which are sequentially arranged along the optical axis direction, wherein the diaphragm is used for receiving a signal light beam and an environment light beam and limiting the light passing caliber of the light beam, the filter is used for filtering the environment light beam and enabling the signal light beam to pass through, the lens group is used for collecting and converging the signal light beam and then emitting the signal light beam, and the distance from the diaphragm to the lens group is between 10mm and 40 mm.

2. The receiving lens of claim 1, wherein the residual astigmatism of the receiving lens satisfies the following formula:

Wherein x _ts is the residual astigmatism of the receiving lens, n 'is the refractive index of the image space, u' is the aperture angle of the image space, S _III is the primary astigmatism distribution coefficient, and k is the number of refractive surfaces in the receiving lens.

3. The receiving lens according to claim 2, wherein the lens group comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens which are sequentially arranged, wherein the first lens is positioned between the second lens and the optical filter, and the first lens, the second lens, the third lens, the fourth lens and the fifth lens are spherical lenses.

4. The receiving lens according to claim 3, wherein the first lens, the third lens, the fourth lens, and the fifth lens each have positive optical power, and the second lens has negative optical power.

5. The receiving lens according to claim 4, wherein optical powers of the first lens, the third lens, the fourth lens and the fifth lens are respectively between 0 and 0.04, and optical powers of the second lens are between-0.04 and 0.

6. The receiving lens according to claim 4 or 5, wherein the first lens satisfies 0.5< (r2+r1)/(r2-r1) <1.0, the second lens satisfies 0.9< (r2+r1)/(r2-R1) <1.1, the third lens satisfies-0.3 < (r2+r1)/(r2-R1) < -0.6, the fourth lens satisfies 2.0< (r2+r1)/(r2-R1) <2.5, the fifth lens satisfies 5.0< (r2+r1)/(r2-R1) <6.0, wherein R2 is a light-in surface curvature radius of the lens, and R1 is a light-out surface curvature radius of the lens.

7. The receiving lens of claim 3, wherein the light incident surface of the first lens is a convex surface, the light emergent surface of the first lens is a convex surface, the light incident surface of the second lens is a concave surface, the light emergent surface of the second lens is a convex surface, the light incident surface of the third lens is a convex surface, the light emergent surface of the third lens is a convex surface, the light incident surface of the fourth lens is a convex surface, the light emergent surface of the fourth lens is a concave surface, the light incident surface of the fifth lens is a convex surface, and the light emergent surface of the fifth lens is a concave surface.

8. The receiving lens of claim 3, wherein the first lens, the second lens and the third lens are made of the same material, and any two of the fourth lens, the fifth lens and the first lens are made of different materials.

9. The receiving lens according to claim 1, wherein an aperture coefficient of the receiving lens is greater than 0.7, and/or a field angle of the receiving lens is greater than or equal to 25 °.

10. A lidar comprising the receiving lens of any of claims 1 to 9.