Optical lens and optical imaging device

Abstract

An optical lens and an optical imaging device, relating to the technical field of laser radars. The optical lens comprises: a first lens array and a target lens combination which are coaxially arranged. The first lens array consists of M rows and N columns of first lenses, and is used for obtaining M*N divergent light beams respectively by means of M*N incident parallel light beams, M and / or N being an integer greater than 1. The target lens combination is used for obtaining M*N emergent parallel light beams by means of the M*N divergent light beams, and adjusting the angles of direction of the M*N emergent parallel light beams. The first lenses each have a negative focal power, the target lens combination has a positive focal power, and the spot diameter of the emergent parallel light beams is greater than the spot diameter of the incident parallel light beams. Because the first lenses in the present application each have a negative refractive power and the target lens combination has a positive focal power, the distance between the first lens array and the target lens combination can be less than the focal length of the target lens combination, aiding in miniaturization design of the optical lens.

Description

Optical lenses and optical imaging devices

[0001] This application claims priority to Chinese Patent Application No. 202410907061.X, filed on July 8, 2024, entitled "Optical Lens and Optical Imaging Apparatus", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of lidar technology, and in particular to an optical lens and an optical imaging device. Background Technology

[0003] LiDAR uses lasers to acquire point cloud data, requiring a highly collimated beam and a large aperture spot to meet its rangefinding and anti-interference performance requirements. Therefore, beam expanders are typically used to expand and shape the laser beam to obtain a highly collimated beam and a large aperture spot. Furthermore, to improve the detection performance of LiDAR, multi-channel LiDAR optical systems can be employed to significantly increase the refresh rate and resolution.

[0004] However, existing beam expansion systems cannot simultaneously possess functions such as multi-channel operation, beam expansion, and pointing angle adjustment, which often necessitates the addition of extra components, hindering the miniaturization design of beam expansion systems. Summary of the Invention

[0005] This application provides an optical lens and an optical imaging device, relating to the field of lidar technology, to enable a multi-channel beam expander system to have functions such as multi-channel, beam expansion and pointing angle adjustment, and to be miniaturized.

[0006] In a first aspect, this application provides an optical lens, comprising: a first lens array and a target lens assembly arranged coaxially along the direction of beam transmission. The first lens array consists of M rows and N columns of first lenses, and is used to pass through M*N incident parallel beams to obtain M*N diverging beams, where M and / or N are integers greater than 1. The target lens assembly is used to pass through the aforementioned M*N diverging beams to obtain M*N outgoing parallel beams, and to adjust the pointing angles of the M*N outgoing parallel beams. The first lenses have negative optical power, the target lens assembly has positive optical power, and the spot diameter of the outgoing parallel beams is larger than the spot diameter of the incident parallel beams.

[0007] This application provides an optical lens in which the first lens array consists of M*N first lenses, each with negative optical power. This allows the lens to simultaneously diffuse M*N incident parallel beams to the same degree, ensuring uniform beam expansion and guaranteeing that the M*N outgoing parallel beams form identical spot sizes on the target object. This avoids resolution differences caused by inconsistent spot sizes, resulting in a detection device using this optical lens with high detection resolution. Furthermore, the target lens assembly, possessing positive optical power, converges the diffused M*N parallel beams back into a highly collimated beam. Since the relative positions of the principal rays of each of the diffused M*N parallel beams and the principal optical axis of the target lens assembly are different, the beam after passing through the target lens assembly has a specific pointing angle, which helps to improve the coverage of the detection beam and thus increase detection efficiency. Furthermore, since the first lens in this application has a negative optical power and the target lens assembly has a positive optical angle, the distance between the first lens array and the target lens assembly can be made smaller than the focal length of the target lens assembly, thereby reducing the size of the optical lens and facilitating the miniaturization design of the optical lens.

[0008] Optionally, one of the lenses in the first lens array is used to diverge a beam of light.

[0009] Optionally, the focal point of the target lens assembly is located at the focal plane of the first lens array, so that each diverging beam obtained through the first lens array is converged by the target lens assembly into a parallel beam with high collimation.

[0010] Optionally, the wavelength of the incident parallel beam can be either visible or ultraviolet.

[0011] Optionally, the aforementioned optical lens is used to process light beams of any wavelength in the range of 5nm-1000000nm.

[0012] In one possible implementation, any two of the above M*N incident parallel beams are parallel to each other.

[0013] In the above embodiments, any two incident parallel beams are parallel to each other. On the one hand, this facilitates the design of simple light emitters. For example, it is only necessary to ensure that the beams emitted by multiple light emitters are parallel to each other, without needing to control the beams emitted by the light emitters to have a specific pointing angle. On the other hand, this application utilizes the position of the parallel beams entering the target lens assembly to adjust the pointing angle of the outgoing beam, without the need for additional optical elements to adjust the pointing angle of the outgoing beam. This also contributes to the simplification, miniaturization, and low cost design of the optical lens.

[0014] In another possible implementation, the first lens is any one of the following: a meniscus lens, a biconcave lens, or a plano-concave lens.

[0015] In the above embodiments, when the first lens is a meniscus lens, a biconcave lens, or a plano-concave lens, it can diverge the incident parallel beam to obtain a diverging beam. The meniscus lens, in particular, can collect as much light as possible within the field of view, allowing more light to enter the rear optical system. This enables the use of a small-diameter first lens to receive a sufficient amount of parallel beam. Furthermore, using a small-diameter first lens allows for greater freedom in the spacing between multiple parallel beams and facilitates miniaturization of the optical lens design.

[0016] In another possible implementation, the first lens is a meniscus lens, with a concave incident surface and a convex exit surface. Alternatively, the first lens is a meniscus lens with a convex incident surface and a concave exit surface. Alternatively, the first lens is a biconcave lens, with both its incident and exit surfaces being concave. Alternatively, the first lens is a plano-concave lens, with a planar incident surface and a concave exit surface.

[0017] In the above embodiments, the incident surface of the first lens is concave, which can diverge the incident light beam, and the exit surface of the first lens is convex, which can further converge the light beam to a certain extent, with the converging effect being less than the diverging effect, ultimately resulting in the light beam passing through the first lens being in a divergent state. Because the exit surface of the first lens is convex and the exit beam is in a divergent state, the light beam passing through the first lens has a high transmittance. Furthermore, having a concave incident surface and a convex exit surface also simplifies the design and facilitates manufacturing. When the incident surface of the first lens is convex and the exit surface is concave, the first lens can converge the light within the field of view as much as possible, allowing more light to enter the target lens assembly, and also helps to reduce the aperture of the target lens assembly. When the incident surface of the first lens is planar and the exit surface is concave, the first lens can also receive all the light within the field of view, allowing more light to enter the target lens assembly, and also helps to reduce the aperture of the target lens assembly. When the incident surface and the exit surface of the first lens are both concave, the light beam entering from the edge of the incident surface field of view will be filtered out by the first lens, thereby reducing the interference of stray light on the incident light beam.

[0018] In another possible implementation, the first lens described above is an aspherical lens.

[0019] The above embodiments provide one possible implementation of the first lens. Specifically, the first lens is an aspherical lens. Aspherical lenses are characterized by a continuous change in curvature from the center to the periphery, unlike spherical lenses which have a constant curvature from the center to the periphery. Aspherical lenses have better radius of curvature characteristics, greater degrees of freedom, and advantages in improving distortion aberrations and astigmatism. Using an aspherical lens for the first lens results in better light divergence and minimizes the interference of aberrations on the light beam.

[0020] In another possible implementation, the focal length of the first lens is -13.957mm.

[0021] In another possible implementation, the target lens assembly is a telecentric optical system.

[0022] In the above embodiments, the target lens assembly is a telecentric optical system, which makes the emitted beams parallel beams, that is, the spot diameter of the emitted beam does not increase with the increase of the beam propagation distance.

[0023] In another possible implementation, the target lens assembly includes a second, third, fourth, and fifth lens arranged coaxially. The second and fifth lenses have negative optical power, while the third and fourth lenses have positive optical power. The second lens is a biconcave lens, the third lens is a meniscus lens, the fourth lens is a biconvex lens, and the fifth lens is a meniscus lens.

[0024] In the above embodiments, the second lens of the target lens assembly is a negative optical power biconcave lens, which can filter out stray beams located at the edge of the field of view, reduce the error caused by the introduction of stray beams, and further diverge the beam, thereby increasing the beam expansion ratio. The third lens of the target lens assembly is a positive optical power meniscus lens, which can collect as much light as possible within the field of view and converge the collected light to a certain extent, thereby smoothly transitioning the collected light to the fourth lens, which is beneficial to reducing system aberrations and distortions. The fourth lens of the target lens assembly is a positive optical power biconvex lens, which can collect as much light as possible within the field of view, allowing more light to enter the fifth lens, and is beneficial to reducing the aperture of the fifth lens. The fifth lens of the target lens assembly is a negative optical power meniscus lens, used to adjust multiple diverging beams into a parallel beam. The above embodiments employ a four-lens optical architecture. By setting the shape of the four lenses and reasonably distributing the optical power, multiple emitted beams can be adjusted into parallel beams, and a certain pointing angle can be introduced to increase the coverage of the light spot, thereby improving the detection efficiency of the lidar. In addition, it can reduce the size of the optical lens, making it easier to miniaturize the optical lens design.

[0025] Optionally, the second lens can also be a meniscus lens or a plano-concave lens, the third lens can also be a concave-plano lens or a biconvex lens, the fourth lens can also be a plano-convex lens, and the fifth lens can also be a biconcave lens or a plano-concave lens.

[0026] Optionally, the target lens assembly may also include more or fewer lenses. For example, the target lens assembly may include a combination of two lenses, three lenses, or five lenses.

[0027] In another possible implementation, the incident surface of the second lens is concave, the exit surface of the second lens is concave, the incident surface of the third lens is concave, the exit surface of the third lens is convex, the incident surface of the fourth lens is convex, the incident surface of the fifth lens is convex, and the exit surface of the fifth lens is concave.

[0028] The above embodiments provide a possible implementation of the second, third, fourth, and fifth lenses. Specifically, the second lens has a concave incident surface and a concave exit surface. By setting the second lens as a biconcave, negative power lens, stray beams located at the edge of the field of view can be filtered out, reducing errors caused by the introduction of stray beams, and further diffusing the beam, thereby increasing the beam magnification. The third lens has a concave incident surface and a convex exit surface. By setting the third lens as a meniscus, positive power lens, it can collect as much light as possible within the field of view and converge the collected light to a certain extent, thus smoothly transitioning the collected light to the fourth lens, which helps to reduce system aberrations and distortion. The fourth lens has a convex incident surface. By setting the fourth lens as a biconvex, positive power lens, it can collect as much light as possible within the field of view, allowing more light to enter the fifth lens, and also helps to reduce the aperture of the fifth lens. The fifth lens has a convex incident surface and a concave exit surface. It is a meniscus-shaped lens with negative optical power, used to adjust multiple diverging beams into a parallel beam.

[0029] In another possible implementation, the second, third, fourth, and fifth lenses described above are all spherical lenses.

[0030] In the above embodiments, the second lens, the third lens, the fourth lens, and the fifth lens are all spherical lenses, which helps to reduce the manufacturing cost of the lens.

[0031] Optionally, one or more of the second, third, fourth, or fifth lenses described above can be aspherical lenses. For example, the second lens can be an aspherical lens, or both the second and fourth lenses can be aspherical lenses. By setting some or all of the lenses in the target lens assembly as aspherical lenses, the phase aberration introduced by the lenses can be reduced, thereby improving the focusing and collimation of the beam, and thus enhancing the detection performance of the lidar.

[0032] In another possible implementation, the focal length of the second lens is -24.591mm, the focal length of the third lens is 67.888mm, the focal length of the fourth lens is 87.232mm, and the focal length of the fifth lens is -390.932mm.

[0033] Optionally, the distances between two adjacent lenses in the second, third, fourth, and fifth lenses are 22.65 mm, 0.916 mm, and 0.617 mm, respectively.

[0034] Optionally, the distance between the first lens and the second lens is 21.591 mm.

[0035] Optionally, the focal length of the target lens assembly is 111.221 mm.

[0036] Optionally, the magnification A of the lens provided in this application depends on the focal length f1 of the target lens assembly and the focal length f2 of the first lens. For example, A = |f1 / f2|.

[0037] Optionally, the wavelength λ of the incident parallel beam is 1540 nm to 1560 nm.

[0038] In another possible implementation, the pointing angle of the emitted parallel beam depends on the first focal length of the target lens assembly and the distance between the target incident parallel beam and the principal optical axis of the target lens assembly. The emitted parallel beam is the beam obtained by passing the target incident parallel beam through the optical lens.

[0039] The above embodiment provides a specific implementation regarding the pointing angle of the emitted parallel beam, wherein the pointing angle of the emitted parallel beam depends on the first focal length of the target lens assembly and the distance between the target incident parallel beam and the principal optical axis of the target lens assembly, indicating that the pointing angle of the emitted parallel beam can be adjusted by adjusting the focal length of the target lens assembly and / or by adjusting the distance between the target incident parallel beam and the principal optical axis of the target lens assembly.

[0040] Optionally, the pointing angle θ of the outgoing parallel beam, the focal length f1 of the target lens assembly, and the distance L1 between the incident parallel beam and the principal optical axis of the target lens assembly satisfy the following relationship: θ = arctan(L1 / f1).

[0041] In another possible implementation, the first focal length f1 of the target lens assembly and the second focal length f2 of the first lens satisfy the following relationship: 5≤|f1 / f2|≤10.

[0042] In another possible implementation, the optical lens further includes a first optical element disposed between the first lens array and the target lens assembly. The first optical element includes one or more of the following: a polarizer, a quarter-wave plate, an optical window, or a filter.

[0043] In the above embodiments, the optical lens, in addition to including a first lens array and a target lens assembly, also includes a first optical element disposed between the first lens array and the target lens assembly. The first optical element includes one or more of a polarizer, a quarter-wave plate, an optical window, or a filter, enabling the optical lens to have functions other than beam expansion. For example, if the first optical element is a polarizer, the optical lens can also filter a beam of a specified polarization state. As another example, if the first optical element is a filter, the optical lens can also filter a beam of a specified wavelength.

[0044] In another possible implementation, the first optical element is tilted between the first lens array and the target lens assembly.

[0045] In the above embodiments, since each optical element is coaxially arranged, when the first optical element is introduced into the optical lens, the first optical element will reflect part of the light beam back along the original path, ultimately forming a ghost image. If the first optical element is tilted between the first lens array and the target lens assembly, the stray light introduced by the first optical element can be eliminated.

[0046] Optionally, the tilt angle of the first optical element is set to be between 0° and 10°, for example, the tilt angle of the first optical element is set to 8°. Exemplarily, the tilt angle of the first optical element can be understood as the angle between the principal optical axis of the first optical element and the principal optical axis of the target lens assembly.

[0047] Secondly, embodiments of this application provide an optical emitting device, including the optical lens described in any one of the first aspects, and a laser. The laser is used to emit a parallel beam of light.

[0048] Optionally, the laser is used to emit M*N incident parallel beams.

[0049] Optionally, the distance between the laser and the first lens array is 1.87 mm.

[0050] In one possible implementation, the optical emitting device further includes a base, a first fixing structure, and a second fixing structure. The first fixing structure is used to fix a first lens array in the optical lens, and the second fixing structure is used to fix a target lens assembly in the optical lens. The first fixing structure has a first through hole, and a first fastener is sequentially inserted through the first lens array, the first through hole, and the base. The second fixing structure has a second through hole, and a second fastener is sequentially inserted through the target lens assembly, the second through hole, and the base.

[0051] In the above embodiments, the first lens array is fixed by a first fixing structure, and the target lens assembly is fixed by a second fixing structure, allowing the first lens array and the target lens assembly to be assembled separately. It is understood that the first lens array is typically small in volume, while the lenses in the target lens assembly are typically large in volume; therefore, assembling the first lens array and the target lens assembly separately helps increase assembly efficiency. In the above embodiments, the first and second fixing structures are also fixed to a base to complete the assembly between the first lens array and the target lens assembly. Furthermore, by assembling the first lens array and the target lens assembly separately, it is also convenient to interchange first lenses and / or target lens assemblies with different focal lengths to obtain lenses with different beam magnifications. Separately assembling the first lens array and the target lens assembly also facilitates adjusting the spacing between the lenses in the first lens array and / or the focal length of the target lens assembly to adjust the pointing angle of the emitted parallel beam.

[0052] Optionally, the aforementioned optical emitting device further includes a first optical element, which is bonded to the first fixing structure. The first optical element includes one or more of the following: a polarizer, a quarter-wave plate, an optical window, or a filter.

[0053] Optionally, the aforementioned optical imaging device can be a lidar, camera, or other similar device.

[0054] Alternatively, the aforementioned optical lens can also be applied to other optical imaging devices that require the emission of light, without limitation here.

[0055] Thirdly, embodiments of this application provide a radar or radar system that includes the optical lens shown in the first aspect or any possible implementation of the first aspect, or includes the optical transmitting device shown in the second aspect.

[0056] Fourthly, embodiments of this application provide a terminal device, which includes an optical lens as shown in any of the first aspects and any possible implementations described above, or includes an optical transmitting device as shown in the second aspect described above, or includes a radar or radar system as shown in the third aspect described above.

[0057] Fifthly, embodiments of this application provide a vehicle terminal that includes an optical lens as shown in any of the first aspects and any possible implementations described above, or includes an optical imaging device as shown in the second aspect described above, or includes a radar or radar system as shown in the third aspect described above, or includes a terminal device as shown in the fourth aspect described above. Attached Figure Description

[0058] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0059] Figure 1 is a schematic diagram of the structure of a telecentric lens provided in an embodiment of this application;

[0060] Figure 2 is a schematic diagram of the structure of an optical lens provided in an embodiment of this application;

[0061] Figure 3 is a schematic diagram of the first lens array in Figure 2 above;

[0062] Figure 4 is a schematic diagram of a light path provided in an embodiment of this application;

[0063] Figure 5 is a schematic diagram of another light path provided in an embodiment of this application;

[0064] Figure 6 is a schematic diagram of a diffusion map provided in an embodiment of this application;

[0065] Figure 7 is a schematic diagram of a wavefront diagram provided in an embodiment of this application;

[0066] Figure 8 is a schematic diagram of an MTF chart provided in an embodiment of this application;

[0067] Figure 9 is a schematic diagram of another optical lens provided in an embodiment of this application;

[0068] Figure 10 is a schematic diagram of another optical lens provided in an embodiment of this application. Detailed Implementation

[0069] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described below with reference to the accompanying drawings.

[0070] The terms "first" and "second," etc., used in the specification, claims, and drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0071] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0072] It should be understood that in this application, "at least one (item)" means one or more, "more than one" means two or more, "at least two (items)" means two or three or more, and "and / or" is used to describe the relationship between related objects, indicating that there can be three relationships. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0073] The following is an explanation of some of the terms used in this application. It should be noted that these explanations are for the convenience of those skilled in the art and are not intended to limit the scope of protection claimed in this application.

[0074] (1) Object-centric telecentric lens.

[0075] A telecentric object lens typically refers to a lens whose entrance pupil is located at infinity in the object space, as shown in Figure 1. In a telecentric object lens, the principal ray in the object space is parallel to the optical axis, and the convergence center of the principal ray is located at infinity in the object space. This ensures that the emitted light beams are all parallel, resulting in a clear image at any position in the image space, and the magnification of the image is directly related to the distance between the two points.

[0076] In addition, telecentric lenses also include image-side telecentric lenses and double telecentric lenses. An image-side telecentric lens is one where the exit pupil is located at infinity in the object space, while a double telecentric lens is one where both the entrance pupil and exit pupil are located at infinity. For a detailed introduction to image-side and double telecentric lenses, please refer to existing technologies; further details will not be provided here.

[0077] (2) Eyepiece and objective lens.

[0078] Eyepieces and objectives are typically the basic combination in an optical microscope. Located at the eyepiece end and object end, respectively, they serve different purposes and functions. For example, the eyepiece determines the user's field of view, thus affecting the area the user can see in a single observation. Objectives, on the other hand, collect light reflected from the object, thereby affecting the microscope's magnification and resolution.

[0079] In this application, the eyepiece and objective lens can also be a basic combination of optical lenses. Exemplarily, the eyepiece is disposed adjacent to the light-emitting unit and is used to receive the light beam from the light-emitting unit, while the objective lens is used to process the light beam output by the eyepiece and provide the processed light beam to the target object. For example, the eyepiece is used to collect as much of the light beam emitted by the light-emitting unit as possible to provide to the objective lens, while the objective lens is used to perform beam expansion or phase correction and other processing on the light beam.

[0080] The explanations of the above terms can be applied in the following text.

[0081] The shapes of the spherical or aspherical surfaces shown in the accompanying drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not drawn strictly to scale.

[0082] As described in the background section, existing beam expansion systems cannot simultaneously perform functions such as multi-channel operation, beam expansion, and pointing angle adjustment. This often requires additional components, which is not conducive to the miniaturization design of beam expansion systems.

[0083] The optical lens and optical transmitting device provided in this application will be described below with reference to the accompanying drawings.

[0084] Please refer to Figure 2, which is a schematic diagram of the structure of an optical lens provided in an embodiment of this application.

[0085] As shown in Figure 2, the optical lens includes:

[0086] A first lens array A1, a second lens G2, a third lens G3, a fourth lens G4, and a fifth lens G5 are coaxially arranged. The first lens array A1 consists of four first lenses G1. Along the incident direction of light (from left to right in Figure 2), first lenses G1, second lenses G2, and fifth lenses G5 are negative power lenses, while third lenses G3 and fourth lenses G4 are positive power lenses. First lenses G1, third lenses G3, and fifth lenses G5 are all meniscus lenses, second lens G2 is a biconcave lens, and fourth lens G4 is a biconvex lens.

[0087] In one possible implementation, four incident parallel beams pass sequentially through a first lens array A1, a second lens G2, a third lens G3, a fourth lens G4, and a fifth lens G5, resulting in four outgoing parallel beams. Wherein:

[0088] The first lens array A1 is used to pass four incident parallel beams. For example, the four first lenses G1 in the first lens array A1 are each used to pass one incident parallel beam and diverge the incident parallel beam to obtain a diverging beam. Optionally, the incident surface S1 of the first lens G1 is concave, and the exit surface S2 of the first lens G1 is convex. The concave incident surface S1 of the first lens G1 can diverge the incident beam. The convex exit surface S2 of the first lens G1 can further converge the beam to a certain extent, and its converging effect is less than its diverging effect, ultimately making the beam passing through the first lens G1 divergent. Because the exit surface S2 of the first lens G1 is convex and the exit beam is divergent, the beam passing through the first lens G1 has a high transmittance. In addition, the concave incident surface S1 and convex exit surface S2 of the first lens G1 also facilitate design simplification and manufacturing. The first lens array A1 includes four identical first lenses G1, and can also make the first lens array A1 diffuse the four incident parallel beams to the same degree, ensuring that the four outgoing parallel beams corresponding to the four incident parallel beams form the same spot size on the target object, thereby avoiding different resolutions due to inconsistent spot sizes.

[0089] Optionally, the aforementioned four incident parallel beams are provided by an optical emitter M1. The optical emitter M1 may include one or more of the following light sources: a vertical cavity surface emitting laser (VCSEL), a photonic crystal surface emitting semiconductor laser (PCSEL), an edge emitting laser (EEL), a laser diode (LD), a distributed feedback laser diode (DFB-LD), a grating-coupled sampling reflection laser diode (GCSR-LD), or a micro opto-electro-mechanical system laser diode (MOEMS-LD), etc. Furthermore, the number of parallel beams that the optical emitter M1 can provide is not limited in this application. For example, the optical emitter M1 can provide four, five, or six parallel beams.

[0090] The second lens G2 has concave incident and exit surfaces S3 and S4, making it a negative power lens for further diverging the light beam and increasing the beam magnification. As a biconcave lens, the second lens G2 filters out stray beams at the edge of the field of view, reducing errors caused by introduced stray beams. It also reduces the aperture of the aperture stop, filtering out light rays not perpendicular to the second lens G2 and preventing them from entering the subsequent optical system. This ensures that the optical system composed of the second lens G2, third lens G3, fourth lens G4, and fifth lens G5 is a telecentric system, guaranteeing that all light beams exiting the optical lens are parallel.

[0091] The incident surface S5 of the third lens G3 is concave, and the exit surface S6 of the third lens G3 is convex, making the third lens G3 a meniscus lens with positive optical power. This allows it to collect as much light as possible within the field of view and converge the collected light to a certain extent, thus smoothly transitioning the collected light to the fourth lens G4, which helps to reduce system aberrations and distortions.

[0092] The incident surface S7 and the exit surface S8 of the fourth lens G4 are both convex, making the fourth lens G4 a lens with positive optical power. It can also collect as much light as possible in the field of view, allowing more light to enter the fifth lens G5, and it is also beneficial to reduce the aperture of the fifth lens G5.

[0093] The incident surface S9 of the fifth lens G5 is convex, which can collect as much light as possible within the field of view. The exit surface S10 of the fifth lens G5 is concave, which can focus the light collected by the fifth lens G5 and obtain a parallel beam with a certain pointing angle.

[0094] Based on the above description, it can be seen that the optical lens shown in Figure 2 can simultaneously expand four incident parallel beams, and the resulting outgoing beams are all highly collimated parallel beams. Essentially, the optical lens shown in Figure 2 includes four independent beam-expanding channels, achieving the effect of multiplexing multiple channels into a single optical lens. This improves beam-expanding efficiency, reduces lens size, and facilitates miniaturization and low-cost design of the beam-expanding lens. Furthermore, because the relative positions of the four incident parallel beams to the principal optical axis are different, the refraction angles of the second lens G2, third lens G3, fourth lens G4, and fifth lens G5 for different incident parallel beams are also different, ultimately resulting in the four outgoing parallel beams having different pointing angles.

[0095] Optionally, the second lens G2, the third lens G3, the fourth lens G4, and the fifth lens G5 can be considered as a target lens assembly. This target lens assembly is used to refocus the diverging beam emitted from the first lens array A1 into a parallel beam and impart a certain pointing angle. For an explanation of how the target lens assembly refocuses the diverging beam into a parallel beam and imparts a certain pointing angle, please refer to the corresponding descriptions above; they will not be repeated here.

[0096] Optionally, the first lens array A1 can be used as the eyepiece, and the target lens combination as the objective lens. The light beam enters through the eyepiece and exits through the objective lens, magnifying the corresponding light spot and achieving a beam expansion effect. The first lens array A1 can simultaneously receive multiple light beams, allowing the combination of the eyepiece and objective lens to simultaneously expand multiple beams, i.e., multi-channel beam expansion. Furthermore, because the objective lens has a telecentric object-side function, the beam expanded by the combination of the eyepiece and objective lens is a parallel beam with a certain pointing angle.

[0097] In another possible implementation, the magnification A of the optical lens depends on the focal length f1 of the target lens assembly and the focal length f2 of the first lens, for example, A = |f1 / f2|.

[0098] For example, if the focal length f1 of the target lens assembly is 111.221 mm and the focal length f2 of the first lens is -13.957 mm, then the magnification A = |111.221 / -13.957| ≈ 7.97.

[0099] Optionally, the focal length f1 of the target lens assembly and the focal length f2 of the first lens can satisfy the following relationship: 5≤|f1 / f2|≤10.

[0100] Optionally, the focal lengths of the second lens G2, the third lens G3, the fourth lens G4, and the fifth lens G5 are -24.591mm, 67.888mm, 87.232mm, and -390.932mm, respectively, and the distances between two adjacent lenses in the second lens G2, third lens G3, fourth lens G4, and fifth lens G5 are 22.65mm, 0.916mm, and 0.617mm, respectively. In this case, the focal length of the target lens assembly can be 111.221mm. For how to calculate the focal length of the lens assembly, please refer to existing technologies; details will not be elaborated here.

[0101] In another possible implementation, the pointing angle θ of the outgoing parallel beam, the focal length f1 of the target lens assembly, and the distance L1 between the target incident parallel beam and the principal optical axis of the target lens assembly satisfy the following relationship: θ = arctan(L1 / f1). Here, the outgoing parallel beam is the beam obtained by passing the target incident parallel beam through the optical lens.

[0102] For example, when the focal length f1 of the target lens assembly is 111.221 mm and the distance L1 between the incident parallel beam and the principal optical axis of the target lens assembly is 3.6 mm, the pointing angle θ of the emitted parallel beam is arctan(3.6 / 111.221) ≈ 1.85°. Therefore, the pointing angle θ of the emitted parallel beam can be adjusted by adjusting f1 and / or L1.

[0103] Optionally, the parameter information (radius of curvature, thickness / spacing, refractive index, and scattering coefficient) of each component of the optical lens shown in Figure 2 above can be as shown in Table 1 below:

[0104] Table 1

[0105] Optionally, the first lens is an aspherical lens. Aspherical lenses are characterized by a continuous change in curvature from the center to the periphery, unlike spherical lenses which have a constant curvature from the center to the periphery. Aspherical lenses have better radius of curvature characteristics, greater degrees of freedom, and advantages in improving distortion aberrations and astigmatism. Using an aspherical lens for the first lens results in better light divergence and minimizes the interference of aberrations on the light beam.

[0106] The surface shape (z) of the first lens G1 can satisfy the following formula:

[0107] Where z is the distance vector from the vertex of the aspherical surface along the optical axis at a position of height r, c is the paraxial curvature of the aspherical surface, c = 1 / R, R is the radius of curvature, k is the conic coefficient, and a4, a6, a8, a 10 a12 The coefficients for higher-order terms can be set as shown in Table 2 below:

[0108] Table 2

[0109] Optionally, the wavelength λ of the incident parallel beam is 1540 nm to 1560 nm.

[0110] In another possible implementation, the optical lens shown in FIG2 further includes a first optical element (not shown in FIG2) disposed between the first lens array and the target lens assembly. The first optical element includes one or more of the following: a polarizer, a quarter-wave plate, an optical window, or a filter. In this implementation, by disposing the first optical element between the first lens array and the target lens assembly, the optical lens can possess functions other than beam expansion. For example, if the first optical element is a polarizer, the optical lens also has the function of filtering a beam of a specified polarization state. As another example, if the first optical element is a filter, the optical lens also has the function of filtering a beam of a specified wavelength.

[0111] In another possible implementation, the first optical element is tilted between the first lens array and the target lens assembly. This method can eliminate stray light introduced by the first optical element.

[0112] In another possible implementation, referring to Figure 3, the first lens array A1 can consist of M rows and N columns of first lenses G1, where M and N are integers greater than or equal to 1, for example, M=3, N=4, or M=5, N=6, etc. In this implementation, the first lenses G1 are used to pass M*N incident parallel beams.

[0113] Based on the above description, the optical lens provided in this application can simultaneously expand four parallel beams, achieving the effect of multiple expansion channels sharing a single optical lens, i.e., multi-channel multiplexing. Furthermore, the lens assembly consisting of the second lens G2, the third lens G3, the fourth lens G4, and the fifth lens G5 has a telecentric object-side characteristic, resulting in the expanded beam having extremely high collimation and a certain exit angle. It is understood that the extremely high collimation of the exiting beam effectively reduces detection errors caused by beam imbalance, while the beam with a first exit angle increases the beam coverage. In addition, the first lens G1 has negative optical power, and the lens assembly consisting of the second lens G2, the third lens G3, the fourth lens G4, and the fifth lens G5 has a positive optical angle, which also shortens the overall system length of the optical lens, facilitating miniaturization. In summary, the optical lens provided in this application can simultaneously expand multiple parallel beams at high magnification and provide the expanded beam with extremely high collimation and a certain exit angle, thereby improving the detection efficiency of the detection device. Since the lenses in the first lens array A1 have negative optical power, the virtual focal point formed by the first lens array A1 can also significantly shorten the overall length of the optical lens, which is beneficial to the miniaturization design of the detection device.

[0114] Please refer to Figure 4, which is a schematic diagram of a light path provided in an embodiment of this application.

[0115] As shown in Figure 4, four incident parallel beams pass through the four first lenses G1 in the first lens array A1, and then sequentially pass through the second lens G2, the third lens G3, the fourth lens G4, and the fifth lens G5, resulting in four outgoing parallel beams. Next, referring to Figures 2 and 4, the light path is further described: the incident parallel beams sequentially pass through the incident surface S1 of the first lens G1, the exit surface S2 of the first lens G1, the incident surface S3 of the second lens G2, the exit surface S4 of the second lens G2, the incident surface S5 of the third lens G3, the exit surface S6 of the third lens G3, the incident surface S7 of the fourth lens G4, the exit surface S8 of the fourth lens G4, the incident surface S9 of the fifth lens G5, and the exit surface S10 of the fifth lens G5, ultimately resulting in outgoing parallel beams. As shown in Figure 4, the four incident parallel beams each produce four outgoing parallel beams, and the diameter of the outgoing parallel beams is larger than that of the incident parallel beams. This allows the optical lens provided in this application to simultaneously expand multiple parallel beams at a high magnification. Furthermore, the outgoing parallel beams shown in Figure 4 also form a certain angle with the principal optical axis, meaning they have a certain pointing angle. This results in a more uniform intensity distribution of the outgoing parallel beams and allows them to cover a larger area, thereby improving the detection resolution, detection range, and detection efficiency of the detection device. In a further step, since the lenses in the first lens array A1 have negative optical power, the virtual focal point formed by the first lens array A1 can significantly shorten the overall length of the optical lens, which is beneficial for the miniaturization design of the detection device.

[0116] To more clearly illustrate the pointing angle of the emitted parallel beams, please refer to Figure 5, which is a schematic diagram of another light path provided by an embodiment of this application. As can be seen from Figure 5, emitted parallel beams 1, 2, 3, and 4 all form a certain angle with the principal optical axis. Furthermore, since the distance between the incident parallel beam 1 and the principal optical axis is greater than the distance between the incident parallel beam 2 and the principal optical axis, the angle between the emitted parallel beam 1 and the principal optical axis is greater than the angle between the emitted parallel beam 2 and the principal optical axis. Similarly, since the distance between the incident parallel beam 4 and the principal optical axis is greater than the distance between the incident parallel beam 3 and the principal optical axis, the angle between the emitted parallel beam 4 and the principal optical axis is greater than the angle between the emitted parallel beam 3 and the principal optical axis.

[0117] It should be noted that Figure 5 is a simplified schematic diagram of a light path, used to illustrate the pointing angle of the emitted parallel beam. Furthermore, Figure 5 also illustrates the relationship between the pointing angle of the emitted parallel beam and the distance between the incident parallel beam and the principal optical axis. Therefore, the light path shown in Figure 5 should not be considered a limitation of this application.

[0118] Please refer to Figure 6, which is a schematic diagram of a blur pattern provided in an embodiment of this application. The blur pattern shown in Figure 6 is, for example, the blur pattern corresponding to a light beam passing through the optical lens shown in Figure 2. Combining Figures 2 and 5 above, Figure 6(a) is the blur pattern corresponding to the outgoing parallel beam 1, Figure 6(b) is the blur pattern corresponding to the outgoing parallel beam 2, Figure 6(c) is the blur pattern corresponding to the outgoing parallel beam 3, and Figure 6(d) is the blur pattern corresponding to the outgoing parallel beam 4. In Figure 6, the units for the horizontal and vertical axes in each diffusion plot are milliradians (mr). The field of view for each incident beam is (0, 0), meaning the field of view for each incident beam in both the meridional and sagittal directions is 0 mr. The corresponding field of view for the exit beams are (0, -0.032), (0, -0.011), (0, 0.011), and (0.032), respectively. For an explanation of the exit field of view, please refer to the description of the incident field of view above; it will not be repeated here. Furthermore, the wavelength of all the incident beams is 1550 nm. As can be seen in Figure 6, the root mean square radius (RMS) of each blur spot is less than 0.025 mr. For example, the RMS values ​​for the four outgoing parallel beams are 0.014, 0.010, 0.010, and 0.014, respectively, indicating that the parallel beams output from the optical lens shown in Figure 2 have extremely high collimation. Furthermore, the difference in the RMS radii of the four blur spots shown in Figure 6 is also less than 0.002 mr. For example, the RMS radii of outgoing parallel beam 1 and outgoing parallel beam 2 differ by 0.002 mr, the RMS radii of outgoing parallel beam 2 and outgoing parallel beam 3 differ by 0 mr, and the RMS radii of outgoing parallel beam 3 and outgoing parallel beam 4 differ by 0.002 mr. This shows that the spot sizes of the parallel beams output from the optical lens shown in Figure 2 are similar, exhibiting high consistency.

[0119] Please refer to Figure 7, which is a schematic diagram of a wavefront diagram provided in an embodiment of this application. The wavefront diagram shown in Figure 7 is, for example, the wavefront diagram corresponding to the beam passing through the optical lens shown in Figure 2. Combining Figures 2 and 5 above, Figure 7(a) is the wavefront diagram corresponding to the outgoing parallel beam 1, Figure 7(b) is the wavefront diagram corresponding to the outgoing parallel beam 2, Figure 7(c) is the wavefront diagram corresponding to the outgoing parallel beam 3, and Figure 7(d) is the wavefront diagram corresponding to the outgoing parallel beam 4. The horizontal axis of each wavefront diagram shown in Figure 7 is used to represent the normalized radius of the exit pupil in the sagittal direction, the vertical axis represents the normalized radius of the exit pupil in the meridional direction, and the color depth represents the wavefront value; for example, the darker the color, the larger the wavefront value.

[0120] As can be seen from the wavefront diagrams shown in Figure 7, the peak-to-valley (PV) value for each outgoing parallel beam is less than 0.05λ, which is close to the ideal state. For example, the PV values ​​of the four wavefront diagrams in Figure 7 are 0.445λ, 0.449λ, 0.449λ, and 0.0445λ, respectively. Furthermore, the RMS values ​​of the four wavefront diagrams in Figure 7 are 0.0084λ, 0.0107λ, 0.0107λ, and 0.0084λ, respectively. Therefore, the optical lenses shown in Figure 2 all have extremely high beam-expanding quality, which helps to improve the detection performance of the detection device. λ represents the wavelength of the beam; the wavelength of the beam in the wavefront diagrams shown in Figure 7 is 1550 nm.

[0121] Please refer to Figure 8, which is a schematic diagram of an MTF diagram provided in an embodiment of this application. The modulation transfer function (MTF) diagram shown in Figure 8 is, for example, the MTF diagram corresponding to the optical lens shown in Figure 2. The four MTF diagrams shown in Figure 8 are the MTF diagrams corresponding to the four channels in the optical lens shown in Figure 2, where (a) in Figure 8 is the MTF diagram corresponding to channel 1, (b) in Figure 8 is the MTF diagram corresponding to channel 2, (c) in Figure 8 is the MTF diagram corresponding to channel 3, and (d) in Figure 8 is the MTF diagram corresponding to channel 4. The four channels in the optical lens shown in Figure 2 can be understood as channels for passing four parallel light beams, i.e., each first lens G1 corresponds to one channel. Further, the four channels in the optical lens can be distinguished as channel 1, channel 2, channel 3, and channel 4 according to the position of the first lens G1 in the first lens array A1 (for example, from top to bottom as shown in Figure 2).

[0122] In Figure 8, the horizontal axis represents the ring per milliradian, and the vertical axis represents the modulation transfer function (MTF). Figure 8(a) and (d) show the curves corresponding to the diffraction limit and the actual MTF. In Figure 8(b) and (c), the curves corresponding to the diffraction limit and the actual MTF highly overlap, therefore they are not labeled in the figure. As can be seen from Figure 8, the MTF of each channel is close to the ideal state (diffraction limit). Therefore, the optical lens shown in Figure 2 has extremely high resolution. The diffraction limit refers to the optimal resolution or minimum detail size achievable in an optical system, which typically depends on factors such as the wavelength of the light wave and the aperture of the optical system (or other factors limiting light propagation).

[0123] Please refer to Figure 9, which is a schematic diagram of another optical lens structure provided in an embodiment of this application. As shown in Figure 9, a first lens array A1, a second lens G2, a third lens G3, a fourth lens G4, and a fifth lens G5 are arranged sequentially along the incident direction of the light beam (from left to right in Figure 9). The first lens array A1 is disposed on a first fixed structure 902, while the second lens G2, third lens G3, fourth lens G4, and fifth lens G5 are all disposed on a second fixed structure 903. The first fixed structure 902 and the second fixed structure 903 are disposed on a base 901. This application does not limit the manner in which the first lens array A1 is disposed on the first fixed structure 902, or the manner in which the second lens G2, third lens G3, fourth lens G4, and fifth lens G5 are disposed on the second fixed structure 903.

[0124] Optionally, the first lens array A1 can be used as the eyepiece, and the second lens G2, third lens G3, fourth lens G4, and fifth lens G5 can be used as the objective lenses. Of course, the first fixing structure 902 used to fix the first lens array A1 can also be part of the eyepiece; similarly, the second fixing structure 903 used to fix the second lens G2, third lens G3, fourth lens G4, and fifth lens G5 can also be part of the objective lens. Optionally, both the first lens array A1 and the first fixing structure 902 are provided with through holes (not shown in Figure 9), allowing the first lens array A1 to be mounted on the first fixing structure 902 by fasteners passing through the through holes.

[0125] Optionally, the first fixing structure 902 has a built-in snap-fit ​​structure (not shown in Figure 9) for fixing the first lens array A1.

[0126] Optionally, the second fixing structure 903, the second lens G2, the third lens G3, the fourth lens G4 and the fifth lens G5 are all provided with through holes (not shown in Figure 9), and the second lens G2, the third lens G3, the fourth lens G4 and the fifth lens G5 can be mounted on the second fixing structure 903 by means of fasteners passing through the through holes.

[0127] Optionally, the second lens G2, the third lens G3, the fourth lens G4, and the fifth lens G5 can be referred to as the target lens combination.

[0128] Optionally, the second fixing structure 903 incorporates a third fixing structure, which is disposed between every two lenses. For example, a third fixing structure 906a is disposed between the second lens G2 and the third lens G3, a third fixing structure 906b is disposed between the third lens G3 and the fourth lens G4, and a third fixing structure 906c is disposed between the fourth lens G4 and the fifth lens G5. In this application, the shape and size of the third fixing structure can depend on the size and spatial relationship of the two adjacent lenses. For example, if the distance between the second lens G2 and the third lens G3 is greater than the distance between the third lens G3 and the fourth lens G4, then the length of the third fixing structure 906a is greater than the length of the third fixing structure 906b.

[0129] In one possible design, the second fixing structure 903 incorporates a fourth fixing structure 905, and the fourth fixing structure 905 incorporates the aforementioned third fixing structure 906b. This application does not limit the specific implementation of how the fourth fixing structure 905 is positioned on the second fixing structure 903. For example, the fourth fixing structure 905 can be mounted on the second fixing structure 903 by means of embedding or snap-fitting.

[0130] In another possible design, a first fastener 907 passes sequentially through the first fixing structure 902 and the base 901 to fix the first fixing structure 902 to the base 901. Similarly, a second fastener 908 passes sequentially through the second fixing structure 903 and the base 901 to fix the second fixing structure 903 to the base 901. Exemplarily, the first fixing structure 902 has a first through hole, and the base 901 has a second through hole; the first fastener 907 passes sequentially through the first and second through holes. Exemplarily, the second fixing structure 903 has a third through hole, and the base 901 has a fourth through hole; the second fastener 908 passes sequentially through the third and fourth through holes.

[0131] Optionally, the optical lens also includes a first optical element 904, which is disposed between the first lens array A1 and the second lens G2. The first optical element is, for example, one or more of a polarizer, quarter-wave plate, optical window, or filter (the optical lens shown in Figure 9 can be equipped with one or two first optical elements 904). Of course, by tilting the first optical element within the optical lens, the aberration introduced by the first optical element can be reduced.

[0132] As shown in Figure 9, the first optical element 904 can be disposed on the base 901. Optionally, the first optical element 904 can also be bonded to the first fixing structure 902.

[0133] In another possible design, the optical lens may include more or fewer lenses; for example, the optical lens may include a first lens array, a second lens G2, and a third lens G3.

[0134] Optionally, the lens material in the optical lens may include, but is not limited to, at least one of the following: glass of model H-ZPK1A, glass of model H-FK61.

[0135] It should be noted that the optical lens shown in Figure 9 is exemplary and does not constitute a limitation of this application.

[0136] In the embodiment shown in Figure 9, the first lens array A1 is fixed by the first fixing structure 902, and the target lens assembly is fixed by the second fixing structure 903, allowing the first lens array A1 and the target lens assembly to be assembled separately. It is understood that the volume of the first lens array A1 is typically small, while the volume of the lenses in the target lens assembly is typically large. Therefore, assembling the first lens array A1 and the target lens assembly separately helps increase assembly efficiency. In the above embodiment, the first fixing structure 902 and the second fixing structure 903 are also fixed to the base 901 to complete the assembly between the first lens array A1 and the target lens assembly. Furthermore, by assembling the first lens array A1 and the target lens assembly separately, it is also convenient to interchange the first lens G1 and / or the target lens assembly with different focal lengths to obtain lenses with different beam magnifications. By assembling the first lens array A1 and the target lens assembly separately, it is also convenient to adjust the spacing of the first lenses G1 in the first lens array A1, and / or the focal length of the target lens assembly, to adjust the pointing angle of the emitted parallel beam.

[0137] Please refer to Figure 10, which is a schematic diagram of the structure of another optical lens provided in an embodiment of this application.

[0138] As shown in Figure 10, the optical lens 1000 includes a first lens array 1001 and a target lens assembly 1002 arranged coaxially along the direction of beam transmission.

[0139] The first lens array 1001 consists of M rows and N columns of first lenses 1003 (Figure 10 is a side view of the first lens array 1001, and the front view of the first lens array 1001 can be referred to Figure 3 above). M and / or N are integers greater than 1, for example, M=2, N=3, or M=4, N=2, etc.

[0140] The first lens 1003 has a negative beam angle, used to diverge the incident parallel beam to obtain a diverging beam. For example, the first lens 1003 is a meniscus lens. A detailed description of the first lens 1003 can be found in the description of the first lens G1 in Figure 2 above, and will not be repeated here.

[0141] The target lens assembly 1002 has a positive optical angle, used to converge the diverging light beam obtained through the first lens array 1001 into an outgoing parallel light beam, and to adjust the pointing angle of the outgoing parallel light beam. Exemplarily, the target lens assembly 1002 includes one or more lenses. When the target lens assembly 1002 includes one lens, that lens is a positive optical power lens. When the target lens assembly 1002 includes multiple lenses, the combined focal length of the multiple lenses is positive.

[0142] Optionally, the spot diameter of the outgoing parallel beam is larger than the spot diameter of the incident parallel beam. For example, the spot diameter of the outgoing parallel beam is 8 nm, and the spot diameter of the incident parallel beam is 2 nm.

[0143] It should be noted that the shapes of all the lenses shown in FIG10 (such as the first lens 1003 and the lenses in the target lens assembly 1002) do not constitute any limitation on this application and are only used for ease of understanding. For example, the first lens 1003 can be any one of a meniscus lens, a plano-concave lens, or a biconcave lens, rather than the biconvex lens shown in FIG10.

[0144] In the above embodiments, the first lens array 1001 comprises M*N first lenses 1003, each having the same negative optical power. This allows for the simultaneous diffusion of the M*N incident parallel beams to the same degree, ensuring that the optical lens 1000 provides the same beam-expanding effect on the M*N incident parallel beams. This guarantees that the M*N outgoing parallel beams form the same spot size on the target object, avoiding different resolutions due to inconsistent spot sizes. This results in a detection device using the optical lens of this application having high detection resolution. Combined with the positive optical power of the target lens assembly 1002, the diffused M*N parallel beams are converged again into a beam with extremely high collimation after passing through the target lens assembly 1002. Since the relative positions of the principal rays of each of the diffused M*N parallel beams and the principal optical axis of the target lens assembly 1002 are different, the beam after passing through the target lens assembly 1002 has a certain pointing angle, which helps to improve the coverage of the detection beam and thus increase detection efficiency. Furthermore, since the first lens 1003 in this application has a negative optical power and the target lens assembly has a positive optical angle, the distance between the first lens array 1001 and the target lens assembly 1002 can be less than the focal length of the target lens assembly 1002, thereby reducing the volume of the optical lens 1000 and facilitating the miniaturization design of the optical lens 1000.

[0145] Optionally, a first lens 1003 in the first lens array 1001 is used to diverge an incident parallel beam.

[0146] Optionally, the focal point of the target lens assembly 1002 is located at the focal plane of any one of the first lenses 1003 in the first lens array 1001, so that each diverging beam obtained through the first lens array 1001 is converged into a highly collimated parallel beam by the target lens assembly 1002. It is understood that since each first lens 1003 in the first lens array 1001 has the same focal length, the focal plane of each first lens 1003 is also the same.

[0147] Optionally, the wavelength of the incident parallel beam can be either visible or ultraviolet.

[0148] Optionally, the aforementioned optical lens is used to process light beams of any wavelength in the range of 5nm-1000000nm.

[0149] In one possible implementation, the optical lens 1000 is used to pass through M*N incident parallel beams respectively. That is, the optical lens 1000 can simultaneously expand the M*N incident parallel beams and assign different pointing angles to each. When the optical lens 1000 is applied to a lidar, it enables the detection beam emitted by the lidar to have a larger coverage area, thereby improving the scanning efficiency and resolution of the lidar, and thus enhancing the detection performance of the lidar.

[0150] Optionally, any two of the aforementioned M*N incident parallel beams are parallel to each other. The optical lens 1000 provided in this application, when the incident parallel beams are parallel, allows each outgoing beam to be parallel while also possessing a certain pointing angle by allowing the incident parallel beams to enter the target lens assembly 1002 at different positions. This enables the optical lens 1000 to adjust the pointing angle of the outgoing beam without adding additional optical elements, which is beneficial for the simplification, miniaturization, and low-cost design of the optical lens 1000. Furthermore, the parallelism between the incident parallel beams also facilitates the simplification and low-cost design of the light emitters. For example, it is sufficient to ensure that the emitting surfaces of multiple light emitters are on the same plane, without needing to adjust the angle of the beam emitted by each light emitter to adjust the pointing angle of the outgoing beam. Clearly, the implementation cost of setting the emitting surfaces of multiple light emitters to the same plane is significantly lower than the implementation cost of adjusting the beam emitted by each light emitter to a specific angle.

[0151] In another possible implementation, the first lens 1003 can be any of the following: a meniscus lens, a biconcave lens, or a plano-concave lens. When the first lens 1003 is a meniscus lens, a biconcave lens, or a plano-concave lens, it can diverge the incident parallel beam to obtain a diverging beam. Specifically, a meniscus lens can collect as much light as possible within the field of view, allowing more light to enter the rear optical system, thus enabling the use of a small-diameter first lens 1003 to receive a sufficient amount of parallel beam. Using a small-diameter first lens 1003 also allows for greater freedom in the spacing of multiple parallel beams and facilitates miniaturization of the optical lens design.

[0152] Next, we will describe in detail the configuration of the first lens 1003 and its corresponding beneficial effects. It should be noted that the incident surface or exit surface shown below refers to the incident surface and exit surface with respect to the direction of beam propagation.

[0153] 1) The first lens 1003 is a meniscus lens. Its incident surface is concave, which diverges the incident light beam. Its exit surface is convex, which further converges the beam to a certain extent, with the converging effect being less than the diverging effect, ultimately resulting in a divergent light beam after passing through the first lens. Because the exit surface of the first lens is convex and the exit beam is divergent, the light beam passing through the first lens has high transmittance. Furthermore, the concave incident surface and convex exit surface of the first lens also simplify the design and facilitate manufacturing. When the incident surface of the first lens is convex and the exit surface is concave, the first lens can converge the light within the field of view as much as possible.

[0154] 2) The first lens 1003 is a meniscus lens, with a convex incident surface and a concave exit surface. In this case, the incident surface of the first lens 1003 can converge the light in the field of view as much as possible, allowing more light to enter the target lens assembly 1002, and also helps to reduce the aperture of the target lens assembly 1002.

[0155] 3) The first lens 1003 is a biconcave lens, with both its incident and exit surfaces being concave. In this case, all light rays within the field of view can be received through the incident surface of the first lens 1003, allowing more light rays to enter the target lens assembly 1002, and also helping to reduce the aperture of the target lens assembly 1002.

[0156] 4) The first lens 1003 is a plano-concave lens, with a planar incident surface and a concave exit surface. In this case, because the incident surface of the first lens 1003 is concave, the light entering the first lens 1003 will be diverged, causing the light beam at the edge of the field of view of the first lens 1003 to be filtered out, thereby reducing the interference of stray light on the incident light beam.

[0157] In another possible design, the first lens 1003 is an aspherical lens. It is understood that aspherical lenses have a continuously changing curvature from the center to the periphery, unlike spherical lenses which have a constant curvature from the center to the periphery. Aspherical lenses have better radius of curvature characteristics, greater degrees of freedom, and advantages in improving distortion aberrations and astigmatism. Using an aspherical lens for the first lens 1003 will result in better light divergence and can minimize the interference of aberrations on the light beam.

[0158] In one possible design, the target lens assembly 1002 includes the second lens G2, the third lens G3, the fourth lens G4, and the fifth lens G5 as shown in Figure 2. For a description of the target lens assembly 1002, please refer to the corresponding content in Figure 2.

[0159] Optionally, the second lens G2 and the fifth lens root have negative optical power, while the third lens G3 and the fourth lens G4 have positive optical power. The second lens G2 is a biconcave lens, the third lens G3 is a meniscus lens, the fourth lens G4 is a biconvex lens, and the fifth lens G5 is a meniscus lens. The beneficial effects of this embodiment can be referred to the corresponding description in Figure 2 above, and will not be repeated here.

[0160] Optionally, the target lens assembly 1002 is an object-side telecentric system, meaning that each beam emitted from the target lens assembly 1002 is a parallel beam, and the spot diameter of the emitted beam does not increase with the increase of the beam propagation distance.

[0161] Optionally, the second lens G2 can also be a meniscus lens or a plano-concave lens, the third lens G3 can also be a concave-plano lens or a biconvex lens, the fourth lens G4 can also be a plano-convex lens, and the fifth lens G5 can also be a biconcave lens or a plano-concave lens.

[0162] Optionally, the incident surface of the second lens G2 is concave, the exit surface of the second lens G2 is concave, the incident surface of the third lens G3 is concave, the exit surface of the third lens G3 is convex, the incident surface of the fourth lens G4 is convex, the incident surface of the fifth lens G5 is convex, and the exit surface of the fifth lens G5 is concave.

[0163] Optionally, the second lens G2, the third lens G3, the fourth lens G4, and the fifth lens G5 are all spherical lenses. By setting the second lens G2, the third lens G3, the fourth lens G4, and the fifth lens G5 as spherical lenses, it is beneficial to reduce the manufacturing cost of the lens.

[0164] Optionally, one or more of the second lens G2, the third lens G3, the fourth lens G4, or the fifth lens G5 can be aspherical lenses. For example, the second lens G2 can be an aspherical lens, or both the second lens G2 and the fourth lens G4 can be aspherical lenses. By setting some or all of the lenses in the target lens assembly as aspherical lenses, the phase aberration introduced by the lenses can be reduced, thereby improving the focusing and collimation of the beam, and thus enhancing the detection performance of the lidar.

[0165] Optionally, the target lens assembly 1002 may also include more or fewer lenses. For example, the target lens assembly 1002 may include a combination of two lenses, three lenses, or five lenses.

[0166] For more detailed design parameters of the first lens G1, the second lens G2, the third lens G3, the fourth lens G4, and the fifth lens G5, please refer to the relevant content in Tables 1 and 2 above, which will not be repeated here.

[0167] In another possible implementation, the pointing angle of the emitted parallel beam depends on the first focal length f1 of the target lens assembly 1002 and the distance between the target incident parallel beam and the principal optical axis of the target lens assembly 1002, wherein the emitted parallel beam is the beam obtained by passing the target incident parallel beam through the optical lens. Exemplarily, the pointing angle θ of the emitted parallel beam, the focal length f1 of the target lens assembly, and the distance L1 between the target incident parallel beam and the principal optical axis of the target lens assembly satisfy the following relationship: θ = arctan(L1 / f1). For specific examples of calculating the pointing angle, please refer to the corresponding content in Figure 2 above, which will not be repeated here.

[0168] In another possible implementation, the magnification of the optical lens 1000 depends on the first focal length f1 of the target lens assembly 1002 and the second focal length f2 of the first lens. Exemplarily, f1, f2, and the magnification A satisfy the following relationship: A = |f1 / f2|. For a specific example of calculating the magnification, please refer to the corresponding content in Figure 2 above, which will not be repeated here.

[0169] In another possible embodiment, the optical lens 1000 further includes a first optical element disposed between the first lens array 1001 and the target lens assembly 1002. The first optical element includes one or more of the following: a polarizer, a quarter-wave plate, an optical window, or a filter. By disposing the first optical element between the first lens array 1001 and the target lens assembly 1002, the optical lens 1000 can possess functions other than beam expansion. For example, if the first optical element is a polarizer, the optical lens 1000 can also filter beams of a specified polarization state. As another example, if the first optical element is a filter, the optical lens 1000 can also filter beams of a specified wavelength.

[0170] Optionally, the first optical element is tilted between the first lens array 1001 and the target lens assembly 1002. Regarding the beneficial effects of this embodiment, please refer to the description of the corresponding content in Figure 2 above, which will not be repeated here.

[0171] In another possible implementation, this application also provides an optical emitting device, including the optical lenses mentioned in the various embodiments above. For example, the optical lens shown in FIG2 or the optical lens 1000 shown in FIG10.

[0172] Optionally, the optical emitting device may also include a light emitter for providing a parallel light beam. For example, the optical emitting device may also include the light emitter M1 shown in Figure 4 above.

[0173] Optionally, the aforementioned optical emitting device further includes a base, a first fixing structure, a second fixing structure, a first fastener, and a second fastener. The first fixing structure is used to fix the first lens array in the optical lens, and the second fixing structure is used to fix the target lens assembly in the optical lens. The first fastener is sequentially inserted through the first fixing structure and the base, and the second fastener is sequentially inserted through the second fixing structure and the base.

[0174] For a detailed description of this embodiment, please refer to the relevant description in Figure 9 above, which will not be repeated here. For example, the base is the base 901 shown in Figure 9, the first fixing structure is the first fixing structure 902 shown in Figure 9, the second fixing structure is the second fixing structure 903 shown in Figure 9, the first fastener is the first fastener 907 shown in Figure 9, and the second fastener is the second fastener 908 shown in Figure 9. It is understood that other components or lenses included in Figure 9 can be considered as optional solutions to this embodiment, and should not be considered as limitations of this embodiment. For example, the third fixing structures 906a, 906b, and 906c included in Figure 9 can be considered as optional solutions to this embodiment. Similarly, the first lens array A1, the second lens G2, the third lens G3, the fourth lens G4, and the fifth lens G5 included in Figure 9 can also be considered as optional solutions to this embodiment.

[0175] Alternatively, the optical transmitting device can be a lidar, a camera device (such as a security black light camera), or other similar device.

[0176] Optionally, the optical lenses described in the above embodiments can also be applied to other optical emitting devices that need to emit light, and this application does not limit this.

[0177] This application also provides a terminal device, which includes the optical lens or optical imaging device provided in this application. For example, the terminal device can be a means of transportation, such as a car, truck, aircraft, drone, slow-moving vehicle, spacecraft, or ship, or any other possible vehicle used in any scenario, such as surveying equipment, that can carry a detection device. One or more optical lenses or optical imaging devices provided in this application are deployed on the terminal device.

[0178] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An optical lens, characterized in that, include: A first lens array and a target lens assembly are sequentially and coaxially arranged along the direction of beam transmission; The first lens array consists of M rows and N columns of first lenses, where M and / or N are integers greater than 1; the first lens array is used to pass M*N incident parallel beams respectively; The first lens has negative optical power and is used to diverge the incident parallel beam to obtain a diverging beam; The target lens assembly has positive optical power and is used to converge the diverging beam into an outgoing parallel beam and adjust the pointing angle of the outgoing parallel beam. The spot diameter of the outgoing parallel beam is larger than the spot diameter of the incident parallel beam.

2. The optical lens according to claim 1, characterized in that, Any two incident parallel beams are parallel to each other.

3. The optical lens according to claim 1 or 2, characterized in that, The first lens is any one of the following: a meniscus lens, a biconcave lens, or a plano-concave lens.

4. The optical lens according to any one of claims 1-3, characterized in that, The first lens is a meniscus lens, with a concave incident surface and a convex exit surface; or... The first lens is a meniscus lens, with a convex incident surface and a concave exit surface; or... The first lens is a biconcave lens, with both its incident and exit surfaces being concave; or... The first lens is a plano-concave lens, with the incident surface of the first lens being a plane and the exit surface of the first lens being a concave surface.

5. The optical lens according to any one of claims 1-4, characterized in that, The target lens assembly is a telecentric optical system.

6. The optical lens according to any one of claims 1-5, characterized in that, The target lens assembly includes: The second, third, fourth, and fifth lenses are coaxially arranged; The second lens and the fifth lens have negative optical power, and the third lens and the fourth lens have positive optical power; The second lens is a biconcave lens, the third lens is a meniscus lens, the fourth lens is a biconvex lens, and the fifth lens is a meniscus lens.

7. The optical lens according to claim 6, characterized in that, The second lens has a concave incident surface and a concave exit surface. The third lens has a concave incident surface and a convex exit surface. The fourth lens has a convex incident surface and a convex exit surface. The fifth lens has a convex incident surface and a concave exit surface.

8. The optical lens according to claim 6 or 7, characterized in that, The second lens has a focal length of -24.591mm, the third lens has a focal length of 67.888mm, the fourth lens has a focal length of 87.232mm, and the fifth lens has a focal length of -390.932mm.

9. The optical lens according to any one of claims 1-8, characterized in that, The pointing angle of the outgoing parallel beam depends on the first focal length of the target lens assembly and the distance between the target incident parallel beam and the principal optical axis of the target lens assembly; the outgoing parallel beam is the beam obtained by passing the target incident parallel beam through the optical lens.

10. The optical lens according to any one of claims 1-9, characterized in that, The second focal length f2 of the first lens and the first focal length f1 of the target lens combination satisfy the following relationship: 5≤|f1 / f2|≤10.

11. The optical lens according to any one of claims 1-10, characterized in that, The optical lens further includes a first optical element disposed between the first lens array and the target lens assembly; the first optical element includes one or more of the following: a polarizer, a quarter-wave plate, an optical window, or a filter.

12. The optical lens according to claim 11, characterized in that, The first optical element is tilted between the first lens array and the target lens assembly.

13. The optical lens according to any one of claims 1-12, characterized in that, The first lens is an aspherical lens.

14. The optical lens according to any one of claims 1-13, characterized in that, The optical lens is used to process any wavelength in the range of 5nm-1000000nm.

15. The optical lens according to any one of claims 1-14, characterized in that, The focal length of the first lens is -13.957mm, and the focal length of the target lens assembly is 111.221mm.

16. An optical emitting device, characterized in that, It includes an optical lens as described in any one of claims 1 to 15, and a laser.

17. The optical emitting device according to claim 16, characterized in that, The optical emitting device further includes a base, a first fixing structure, a second fixing structure, a first fastener, and a second fastener. The first fixing structure is used to fix the first lens array in the optical lens, and the second fixing structure is used to fix the target lens assembly in the optical lens. The first fastener is sequentially inserted into the first fixing structure and the base, and the second fastener is sequentially inserted into the second fixing structure and the base.

18. The optical emitting device according to claim 16 or 17, characterized in that, The optical emitting device includes at least one of the following: a lidar or a camera device.

19. A vehicle end, characterized in that, The vehicle end includes an optical lens as described in any one of claims 1 to 15, or an optical emitting device as described in any one of claims 16 to 18.

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