Optical system and manufacturing method thereof

Abstract

The invention discloses an optical system, the optical system comprises a transmitting module and a receiving module, the transmitting module comprises a light source and a micro-lens array element which are sequentially arranged from a first side to a second side along an optical axis, the micro-lens array element performs angle-expanding homogenization on a light beam emitted by the light source in a first direction and / or a second direction to form a uniform light beam, the first direction and the second direction are perpendicular to each other and are perpendicular to the optical axis; the receiving module comprises a detection array element, and the detection array element receives reflected light of the uniform light beams.

Description

Technical Field

[0001] The present application relates to the field of optical technology, and in particular to an optical system and a method for manufacturing the same. Background Art

[0002] With the rapid development of intelligent autonomous driving, optical systems are expected to improve the ranging shortcomings of cameras and millimeter-wave radars and have become the core sensors of autonomous driving.

[0003] Traditional optical systems usually achieve matching between the receiving end and the transmitting end in a point-to-point or single-line-to-point manner. That is, the transmitting end of a traditional optical system emits discrete points and lines, which causes dark areas between rows or between columns in the transmitting area, resulting in dark areas in the detection area of ​​the receiving end and missing some detection information, seriously affecting the detection efficiency of the optical system. Summary of the invention

[0004] The embodiments of the present application provide an optical system and a method for manufacturing the same that can at least partially resolve at least one of the above-mentioned disadvantages or other disadvantages in the prior art.

[0005] The first aspect of the present application provides an optical system, which includes a transmitting module and a receiving module, the transmitting module includes a light source and a microlens array element arranged in sequence from a first side to a second side along an optical axis, the microlens array element expands and homogenizes the light beam emitted by the light source in a first direction and / or a second direction to form a uniform light beam, wherein the first direction and the second direction are perpendicular to each other and both perpendicular to the optical axis; the receiving module includes a detection array element, which receives reflected light of the uniform light beam.

[0006] According to an exemplary embodiment of the present application, the ratio of the area of ​​the receiving surface of the detection array element to the light emitting area of ​​the light source is n×m, wherein n≥1 and m≥1.

[0007] According to an exemplary embodiment of the present application, the light source includes a plurality of sub-light sources arranged in an array, and the light in the reflected light corresponding to any row of sub-light sources covers n rows of detection units in the detection array element, and the light in the reflected light corresponding to any column of sub-light sources covers m columns of detection units in the detection array element.

[0008] According to an exemplary embodiment of the present application, the diffusion angles of the uniform light beam in the first direction and the second direction are the same.

[0009] According to an exemplary embodiment of the present application, the diffusion angles of the uniform light beam in the first direction and the second direction are different.

[0010] According to an exemplary embodiment of the present application, the transmitting module includes a microlens array element, and the microlens array element homogenizes the light beam expansion angle in a first direction and a second direction.

[0011] According to an exemplary embodiment of the present application, the transmitting module includes two microlens array elements, namely a first microlens array element and a second microlens array element. The first microlens array element homogenizes the light beam expansion angle in the first direction, and the second microlens array element homogenizes the light beam expansion angle in the second direction.

[0012] According to an exemplary embodiment of the present application, the microlens array element includes a plurality of microlenses arranged in an array, and the optical system satisfies: |R1| / |R2|≤10, wherein R1 is the radius of curvature of the surface of the microlens perpendicular to the second direction, and R2 is the radius of curvature of the surface of the microlens perpendicular to the first direction.

[0013] According to an exemplary embodiment of the present application, the microlens array element includes a plurality of microlenses arranged in an array, and the optical system satisfies: 0<|F1 / F2|≤5, wherein F1 is the effective focal length of the microlens in the first direction, and F2 is the effective focal length of the microlens in the second direction.

[0014] According to an exemplary embodiment of the present application, the microlens array element includes a plurality of microlenses arranged in an array, and the optical system satisfies: 2≤|R1 / D1|≤100, wherein R1 is the radius of curvature of the surface of the microlens perpendicular to the second direction, and D1 is the effective aperture of the microlens in the first direction.

[0015] According to an exemplary embodiment of the present application, the microlens array element includes a plurality of microlenses arranged in an array, and the optical system satisfies: 2≤|R2 / D2|≤70, wherein R2 is the radius of curvature of the surface of the microlens perpendicular to the first direction, and D2 is the effective aperture of the microlens in the second direction.

[0016] According to an exemplary embodiment of the present application, the microlens array element includes a plurality of microlenses arranged in an array, and the optical system satisfies: max / d min ≤2, where d max is the maximum thickness of the microlens, d min is the minimum thickness of the microlens.

[0017] According to an exemplary embodiment of the present application, the microlens array element includes a plurality of microlenses arranged in an array, and the optical system satisfies: |R1 max | / |R1 min |≤1.5, where R1 maxThe maximum value of the radius of curvature of the surface perpendicular to the second direction in the microlens, R1 min is the minimum value of the radius of curvature of the surface perpendicular to the second direction in the microlens.

[0018] According to an exemplary embodiment of the present application, the microlens array element includes a plurality of microlenses arranged in an array, and the optical system satisfies: |R2 max | / |R2 min | ≤ 1.5, where R2 max is the maximum value of the radius of curvature of the surface perpendicular to the first direction in the microlens, and R2 min is the minimum value of the radius of curvature of the surface perpendicular to the first direction in the microlens.

[0019] According to an exemplary embodiment of the present application, the emission module further includes an emission optical element disposed between the light source and the microlens array element, and the optical system satisfies: HFOV / (|R1| / D1) ≤ 30°, where HFOV is the horizontal field of view angle of the emission optical element, D1 is the effective aperture of the microlens in the microlens array element in the first direction, and R1 is the radius of curvature of the surface perpendicular to the second direction in the microlens.

[0020] According to an exemplary embodiment of the present application, the receiving module further includes a receiving optical element that focuses the reflected light, and the focused reflected light is received by the detection array element, and the optical system satisfies: 0.5 ≤ |Fθ TX / Fθ RX | ≤ 1.5, where Fθ TX is the distortion of the emission optical element, and Fθ RX is the distortion of the receiving optical element.

[0021] According to an exemplary embodiment of the present application, the optical system satisfies: 0 < L2 / L1 ≤ 3, where L1 is the distance from the light source to the second side surface of the microlens array element, and L2 is the distance from the receiving surface of the receiving optical element to the detection array element.

[0022] According to an exemplary embodiment of the present application, the microlens array element is attached to the surface of the emission optical element away from the light source.

[0023] According to an exemplary embodiment of the present application, the emission module includes an emission optical element disposed between the light source and the microlens array element, and the light source is configured as a plurality of light-emitting channels in the second direction or the first direction, and the optical system satisfies: 1 ≤ α2 / α1 ≤ F T×2×tan(HFOV / 2) / (C / i) / Le, where α1 is the collimation of the sub-light source before passing through the microlens array element, α2 is the collimation of the sub-light source after passing through the microlens array element, and F T is the focal length of the emitting optical element, HFOV is the horizontal field of view of the emitting optical element, C is the number of sub-light sources contained in the light-emitting channel, i is the number of rows of sub-light sources contained in the light-emitting channel in the second direction or the number of columns of the sub-light sources contained in the light-emitting channel in the first direction; Le is the maximum diameter of the sub-light source, where 1≤F T ×2×tan(HFOV / 2) / (C / i) / Le≤35.

[0024] The second aspect of the present application provides a method for manufacturing an optical system, which includes: setting a transmitting module, the transmitting module includes a light source and a microlens array element arranged in sequence from a first side to a second side along an optical axis; and setting a receiving module, the receiving module includes a detection array element, wherein the manufacturing method further includes: using the microlens array element to expand and homogenize the light beam emitted by the light source in a first direction and / or a second direction to form a uniform light beam, wherein the first direction and the second direction are perpendicular to each other and both perpendicular to the optical axis; and using the detection array element to receive reflected light of the uniform light beam.

[0025] According to an exemplary embodiment of the present application, the method further includes: adjusting the structure of the microlens array element so that the ratio of the area of ​​the receiving surface of the detection array element to the light emitting area of ​​the light source is n×m, where n≥1, m≥1.

[0026] According to an exemplary embodiment of the present application, the method further includes: adjusting the structure of the transmitting module and making the transmitting module include a microlens array element, the microlens array element homogenizing the light beam expansion angle in the first direction and the second direction.

[0027] According to an exemplary embodiment of the present application, the method also includes: adjusting the structure of the transmitting module and making the transmitting module include two microlens array elements, namely a first microlens array element and a second microlens array element, the first microlens array element homogenizes the light beam expansion angle in the first direction, and the second microlens array element homogenizes the light beam expansion angle in the second direction.

[0028] According to an exemplary embodiment of the present application, the method also includes: adjusting the structure of the microlens of the microlens array element and making the optical system satisfy: |R1| / |R2|≤10, wherein R1 is the radius of curvature of the surface of the microlens perpendicular to the second direction, and R2 is the radius of curvature of the surface of the microlens perpendicular to the first direction.

[0029] According to an exemplary embodiment of the present application, the method also includes: adjusting the structure of the microlens of the microlens array element and making the optical system satisfy: 0<|F1 / F2|≤5, wherein F1 is the effective focal length of the microlens in the first direction, and F2 is the effective focal length of the microlens in the second direction.

[0030] According to an exemplary embodiment of the present application, the method also includes: adjusting the structure of the microlens of the microlens array element and making the optical system satisfy: 2≤|R1 / D1|≤100, wherein R1 is the radius of curvature of the surface of the microlens perpendicular to the second direction, and D1 is the effective aperture of the microlens in the first direction.

[0031] According to an exemplary embodiment of the present application, the method also includes: adjusting the structure of the microlens of the microlens array element and making the optical system satisfy: 2≤|R2 / D2|≤70, wherein R2 is the radius of curvature of the surface of the microlens perpendicular to the first direction, and D2 is the effective aperture of the microlens in the second direction.

[0032] According to an exemplary embodiment of the present application, the method further includes: adjusting the structure of the microlenses of the microlens array element so that the optical system satisfies: d max / d min ≤2, where d max is the maximum thickness of the microlens, d min is the minimum thickness in the microlens.

[0033] According to an exemplary embodiment of the present application, the method further includes: adjusting the structure of the microlens of the microlens array element so that the optical system satisfies: |R1 max | / |R1 min |≤1.5, where R1 max is the maximum radius of curvature of the surface of the microlens perpendicular to the second direction, R1 min is the minimum value of the radius of curvature of the surface of the microlens that is perpendicular to the second direction.

[0034] According to an exemplary embodiment of the present application, the method further includes: adjusting the structure of the microlens of the microlens array element so that the optical system satisfies: | R2 max | / |R2 min |≤1.5, where R2 max is the maximum radius of curvature of the surface of the microlens perpendicular to the first direction, R2 min is the minimum value of the radius of curvature of the surface of the microlens that is perpendicular to the first direction.

[0035] According to an exemplary embodiment of the present application, the method further includes: arranging an emission optical element between the light source and the microlens array element, adjusting the structures of the emission optical element and the microlenses of the microlens array element, and making the optical system satisfy: HFOV / (|R1| / D1) ≤ 30°, where HFOV is the horizontal field of view angle of the emission optical element, R1 is the radius of curvature of the surface of the microlens perpendicular to the second direction, and D1 is the effective aperture of the microlens in the first direction.

[0036] According to an exemplary embodiment of the present application, the method further includes: arranging a receiving optical element in the receiving module, adjusting the structures of the emission optical element and the receiving optical element, and making the optical system satisfy: 0.5 ≤ |Fθ TX / Fθ RX | ≤ 1.5, where Fθ TX is the distortion of the emission optical element, and Fθ RX is the distortion of the receiving optical element.

[0037] According to an exemplary embodiment of the present application, the method further includes: adjusting the positions of the light source and the receiving optical element, and making the optical system satisfy: 0 < L2 / L1 ≤ 3, where L1 is the distance from the light source to the second side surface of the microlens array element, and L2 is the distance from the receiving surface of the receiving optical element to the detection array element.

[0038] According to an exemplary embodiment of the present application, the method further includes: arranging an emission optical element between the light source and the microlens array element, where the light source includes a plurality of sub-light sources arranged in an array, the light source is configured as a plurality of light-emitting channels in the second direction or the first direction, and making the optical system satisfy: 1 ≤ α2 / α1 ≤ F T ×2×tan(HFOV / 2) / (C / i) / Le, α1 is the collimation of the sub-light source before passing through the microlens array element, α2 is the collimation of the sub-light source after passing through the microlens array element, F T is the focal length of the emission optical element, HFOV is the horizontal field of view angle of the emission optical element, C is the number of sub-light sources included in the light-emitting channel, i is the number of rows of sub-light sources included in the light-emitting channel in the second direction or the number of columns of sub-light sources included in the light-emitting channel in the first direction; Le is the maximum diameter of the sub-light source, where 1 ≤ F T ×2×tan(HFOV / 2) / (C / i) / Le ≤ 35.

[0039] According to one or more of the above-mentioned embodiments of the present application, a microlens array element is used to expand and homogenize the light beam emitted by the light source in the first direction and / or the second direction, and the light beam emitted by the light source is transformed into a uniform light beam. The uniform light beam can form a flooded light spot, thereby ensuring that there is no dark area on the receiving surface of the detection array element, achieving efficient matching of the receiving module and the transmitting module, and improving the detection efficiency of the optical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Other features, purposes and advantages of the embodiments of the present application will become more apparent by reading the detailed description of the non-limiting embodiments made with reference to the following drawings, in which:

[0041] Figure 1 A schematic diagram of the structure of an optical system according to an exemplary embodiment of the present application;

[0042] Figure 2 A schematic diagram of the structure of a transmitting module according to an exemplary embodiment of the present application;

[0043] Figure 3 A schematic diagram of the structure of a transmitting module according to an exemplary embodiment of the present application;

[0044] Figure 4 A schematic diagram of the structure of a transmitting module according to an exemplary embodiment of the present application;

[0045] Figure 5 A schematic diagram of the structure of a transmitting module according to an exemplary embodiment of the present application;

[0046] Figure 6 A schematic structural diagram of a first microlens array element according to an exemplary embodiment of the present application;

[0047] Figure 7 A schematic structural diagram of a second microlens array element according to an exemplary embodiment of the present application;

[0048] Figure 8 is a schematic structural diagram of a microlens array element according to an exemplary embodiment of the present application;

[0049] Fig. 9 is a schematic structural diagram of a microlens array element according to an exemplary embodiment of the present application;

[0050] Fig. 10A and Fig. 10B All of them are schematic diagrams of illumination areas of light sources and detection array elements according to exemplary embodiments of the present application;

[0051] Fig.11 A schematic diagram of the structure of a light source according to an exemplary embodiment of the present application;

[0052] Fig.12A schematic diagram of the structure of a light source according to an exemplary embodiment of the present application; and

[0053] Fig.13 It is a schematic structural diagram of a light source according to an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0054] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application, and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0055] It should be noted that in this specification, the expressions first, second, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the feature. Therefore, without departing from the teachings of the present application, the first direction discussed below may be referred to as the second direction, and the first side may be referred to as the second side. The surface of each component (such as a light source, a microlens array element, or an emitting optical element) closest to the first side is referred to as the first side of the component, and the surface closest to the second side is referred to as the second side of the component.

[0056] In the drawings, the thickness, size and shape of each component may be slightly exaggerated for convenience of explanation. The drawings are only examples and are not drawn strictly to scale.

[0057] It should also be understood that the terms "comprising", "including", "having" and / or "configured with", when used in this specification, indicate the presence of stated features, elements and / or components, but do not exclude the presence of one or more other features, elements, components and / or combinations thereof. In addition, the term "exemplarily" is intended to refer to an example or illustration.

[0058] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this application have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as those defined in commonly used dictionaries) should be understood to have the same meaning as their meaning in the context of the relevant technology, and should not be interpreted in an idealized or overly formal sense, unless explicitly defined in this application.

[0059] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0060] The traditional optical system usually achieves the matching of the receiving end and the transmitting end in a point-to-point or single-line-to-point manner. In order to match the detection element of the receiving end, the light source of the transmitting end is usually set to a light source with a large light-emitting area. A light source with a large light-emitting area requires a larger transmitting optical element to match, which will result in a larger volume and higher cost of the optical system. In addition, a light source with a large light-emitting area requires a more complex driving circuit to drive it, which will make the driving circuit design more complicated.

[0061] The transmitting end of a traditional optical system emits discrete dots and lines, which causes dark areas between rows or columns in the transmitting area, resulting in dark areas in the detection area of ​​the receiving end and missing some detection information, seriously affecting the detection efficiency of the optical system.

[0062] In order to at least partially solve one or more of the above-mentioned problems and other potential problems, the first aspect of the present application proposes an optical system. Specifically, an optical system is proposed that utilizes a microlens array element to homogenize the angle of expansion of the light beam emitted by a light source to ensure that there is no dark area on the receiving surface of the detection array element, and to achieve efficient matching of the receiving module and the transmitting module.

[0063] Figure 1 A schematic structural diagram of an optical system 100 according to an exemplary embodiment of the present application is schematically shown. Figure 2 , Figure 3 , Figure 4 and Figure 5 The schematic diagrams of the structures of the transmitting module 110 according to the exemplary embodiments of the present application are schematically shown respectively. The optical system 100 may be, for example, a laser radar system, which is applicable to application scenarios such as autonomous driving, for example, it is applicable to application scenarios such as L2 and above autonomous driving, and L2 level autonomous driving refers to partial autonomous driving, in which the basic operations are completed by the vehicle, and the driver is responsible for monitoring the surroundings and taking over the vehicle at any time. It should be understood that the optical system 100 may also be applied to other types of application scenarios.

[0064] like Figures 1 to 5As shown, the optical system 100 may include a transmitting module 110 and a receiving module 120. The transmitting module 110 may include a light source 111 and a microlens array element 113 arranged in sequence from the first side to the second side along the optical axis, and the microlens array element 113 homogenizes the light beam emitted by the light source 111 in the first direction and / or the second direction to form a uniform light beam, wherein the first direction and the second direction are perpendicular to each other and are both perpendicular to the optical axis. The receiving module 120 may include a detection array element 122, and the detection array element 122 receives the reflected light of the uniform light beam. The optical axis herein extends in the direction where the X-axis is located, the first direction refers to the direction where the Y-axis is located, and the second direction refers to the direction where the Z-axis is located. The expansion angle herein refers to the diffusion of the light beam.

[0065] The working process of the optical system 100 is described below by taking the detection process of the object to be detected 200 as an example.

[0066] The light source 111 of the transmitting module 110 emits a light beam, which is expanded and homogenized by the microlens array element 113 to form a uniform light beam. The uniform light beam is incident on the detection object 200 to be detected and reflected by the detection object 200 to form a reflected light of the uniform light beam. The reflected light of the uniform light beam is received by the detection array element 122 of the receiving module 120, and the detection array element 122 compares the received reflected light with the light beam emitted by the light source 111. After appropriate processing, relevant information such as the distance, position, height, speed, and posture of the detection object 200 to be detected can be obtained, thereby realizing detection, tracking, and identification of the detection object 200 to be detected.

[0067] The optical system 100 provided in the present application utilizes a microlens array element 113 to expand and homogenize the light beam emitted by the light source 111 in a first direction and / or a second direction, and makes the light beam emitted by the light source 111 become a uniform light beam. The uniform light beam can form a flooded light spot, thereby ensuring that there is no dark area on the receiving surface of the detection array element 122, achieving efficient matching of the receiving module 120 and the transmitting module 110, and improving the detection efficiency of the optical system 100.

[0068] In an exemplary embodiment, if Figures 1 to 5 As shown, the transmitting module 110 may further include an emitting optical element 112 disposed between the light source 111 and the microlens array element 113. The emitting optical element 112 may collimate the light beam emitted by the light source 111. The emitting optical element 112 may be used to make the light beam emitted by the light source 111 become a collimated light beam with a preset divergence angle, so as to cooperate with the microlens array element 113 to achieve efficient matching between the receiving module 120 and the transmitting module 110. The use of the above-mentioned microlens array element 113 may reduce the size of the light source 111, thereby reducing the size of the emitting optical element 112 and reducing the cost of the optical system 100.

[0069] In an exemplary embodiment, if Figure 1 As shown, the receiving module 120 may further include a receiving optical element 121 . The receiving optical element 121 focuses the reflected light of the uniform light beam, and the focused reflected light is received by the detection array element 122 .

[0070] In an exemplary embodiment, the ratio of the area of ​​the receiving surface of the detection array element 122 to the light emitting area of ​​the light source 111 may be n×m, where n≥1 and m≥1. Fig. 10A and Fig. 10B Schematic diagrams of the illumination area of ​​the light source and the detection array element according to an exemplary embodiment of the present application are schematically shown. The light source 111 may include a plurality of sub-light sources arranged in an array, and the light corresponding to any row of sub-light sources in the reflected light covers n rows of detection units ( Fig. 10A ), the light corresponding to any column of sub-light sources in the reflected light covers the m columns of detection units in the detection array element 122 ( Fig. 10B ). In other words, the light beams emitted by each row of sub-light sources can illuminate n rows of detection units after being homogenized by the expansion angle of the microlens array element 113, and the light beams emitted by each column of sub-light sources can illuminate m columns of detection units after being homogenized by the expansion angle of the microlens array element 113. It should be understood that the direction of the rows described in the present application extends in the direction indicated by the first direction, and the direction of the columns extends in the direction indicated by the second direction.

[0071] As an example, the light source 111 may include a vertical cavity surface emitting laser (VCSEL). The light source 111 may have M×N sub-light sources, where M represents the number of rows of sub-light sources in the light source 111 and N represents the number of columns of sub-light sources in the light source 111.

[0072] As an example, the detection array element 122 may include, for example, a single photon avalanche diode (SPAD) array element. The detection array element 122 may have, for example, nM×mN detection units, where nM represents the number of rows of detection units in the detection array element 122, and mN represents the number of columns of detection units in the detection array element 122. In the present embodiment, the detection unit is a single photon avalanche diode.

[0073] The above-mentioned microlens array element 113 can be used to compensate for the dark area in the detection array element 122 caused by the pixel defects of the light source 111, ensuring that there are no dark areas between rows and columns in the detection array element 122, thereby achieving that there is no dark area on the entire receiving surface of the detection array element 122. At the same time, the use of the above-mentioned microlens array element 113 can also reduce the size of the light source 111, simplify the driving circuit corresponding to the light source 111, and thus reduce the cost of the optical system 100.

[0074] It should be understood that, without departing from the teaching of the present application, the light source 111 may also be other types of light sources, and the detection array element 122 may also be other types of detection elements, and the present application does not impose any limitation on this.

[0075] In an exemplary embodiment, the diffusion angles of the uniform light beam in the first direction and the second direction are the same. In other words, the number of rows n of detection units that can be illuminated by the light beams emitted by each row of sub-light sources after being homogenized by the dilation angle of the microlens array element 113 is the same as the number of columns m of detection units that can be illuminated by the light beams emitted by each column of sub-light sources after being homogenized by the dilation angle of the microlens array element 113. In one example, n=m=2.

[0076] In an exemplary embodiment, the diffusion angles of the uniform light beam in the first direction and the second direction are different. In other words, the number of rows n of detection units that can be illuminated by the light beams emitted by each row of sub-light sources after being homogenized by the dilation angle of the microlens array element 113 is different from the number of columns m of detection units that can be illuminated by the light beams emitted by each column of sub-light sources after being homogenized by the dilation angle of the microlens array element 113. In one example, n=1.5, m=2; or, n=2, m=1.5.

[0077] In an exemplary embodiment, if Figure 2 and Figure 3 As shown, the transmitting module 110 may include two microlens array elements 113. The two microlens array elements 113 are respectively a first microlens array element 114 and a second microlens array element 115. The first microlens array element 114 may homogenize the angle of expansion of the light beam emitted by the light source 111 in a first direction, and the second microlens array element 115 may homogenize the angle of expansion of the light beam emitted by the light source 111 in a second direction. In one example, the first microlens array element 114 and the second microlens array element 115 may be bonded together.

[0078] As an example, the first microlens array element 114 may be attached to a surface of the emitting optical element 112 that is away from the light source 111. By attaching the first microlens array element 114 to the emitting optical element 112, the total length of the optical system 100 can be effectively controlled, which is conducive to miniaturization of the optical system 100.

[0079] In an exemplary embodiment, if Figure 4 and Figure 5As shown, the transmitting module 110 may include a microlens array element 113. The microlens array element 113 may simultaneously homogenize the expansion angle of the light beam emitted by the light source 111 in the first direction and the second direction. As an example, the microlens array element 113 may be attached to the surface of the side of the emitting optical element 112 away from the light source 111, or the microlens array element 113 may be attached to the optical window of the optical system, or the microlens array element 113 may be integrally formed with the optical window of the optical system. By attaching the microlens array element 113 to the emitting optical element 112 or the optical window, the total length of the optical system 100 can be effectively controlled, which is conducive to miniaturization of the optical system 100.

[0080] In an exemplary embodiment, the microlens array element 113 may include a plurality of microlenses arranged in an array. The optical system 100 may satisfy: 0<|R1| / |R2|≤10, wherein R1 is the radius of curvature of the surface of the microlens perpendicular to the second direction, and R2 is the radius of curvature of the surface of the microlens perpendicular to the first direction. By constraining the ratio of the radius of curvature of the surface of the microlens perpendicular to the second direction to the radius of curvature of the surface of the microlens perpendicular to the first direction within a certain range, the ability of the microlens array element 113 to adjust the light beam can be better controlled, the imaging capability and field of view of the optical system 100 can be improved, and it is also beneficial to achieve efficient matching of the receiving module 120 and the transmitting module 110.

[0081] In an exemplary embodiment, the optical system 100 may satisfy: 0<|F1 / F2|≤5, where F1 is the effective focal length of the microlens in the first direction, and F2 is the effective focal length of the microlens in the second direction. By constraining the ratio of the effective focal length of the microlens in the first direction to the effective focal length of the microlens in the second direction within a certain range, the ability of the microlens array element 113 to adjust the light beam can be better controlled, and the diffusion effect and uniform light effect of the microlens array element 113 on the light beam can be improved.

[0082] In an exemplary embodiment, the optical system 100 may satisfy: 2≤|R1 / D1|≤100, where R1 is the radius of curvature of the surface of the microlens perpendicular to the second direction, and D1 is the effective aperture of the microlens in the first direction. As an example, 5≤|R1 / D1|≤50. By constraining the ratio of the radius of curvature of the surface of the microlens perpendicular to the second direction to the effective aperture of the microlens in the first direction within a certain range, it is beneficial to improve the diffusion effect and uniform light effect of the microlens array element 113 on the light beam.

[0083] In an exemplary embodiment, the optical system 100 may satisfy: 2≤|R2 / D2|≤70, where R2 is the radius of curvature of the surface of the microlens perpendicular to the first direction, and D2 is the effective aperture of the microlens in the second direction. As an example, 5≤|R2 / D2|≤30. By constraining the ratio of the radius of curvature of the surface of the microlens perpendicular to the first direction to the effective aperture of the microlens in the second direction within a certain range, it is beneficial to improve the diffusion effect and uniform light effect of the microlens array element 113 on the light beam.

[0084] In an exemplary embodiment, the optical system 100 may satisfy: d max / d min ≤2, where d max is the maximum thickness of the microlens, d min is the minimum thickness of the microlens. As an example, 1≤d max / d min By randomly designing the thickness of the microlenses in the microlens array element 113 and making the ratio of the maximum thickness to the minimum thickness of the microlenses less than or equal to 2, the diffraction effect can be greatly suppressed.

[0085] In an exemplary embodiment, the optical system 100 may satisfy: |R1 max | / |R1 min |≤1.5, where R1 max is the maximum radius of curvature of the surface of the microlens perpendicular to the second direction, R1 min is the minimum value of the radius of curvature of the surface of the microlens perpendicular to the second direction. As an example, 0.5≤|R1 max | / |R1 min |≤1.5. The diffraction effect can be greatly suppressed by randomly designing the curvature radius of the surface of the microlens perpendicular to the second direction and making the ratio of the maximum curvature radius to the minimum curvature radius less than or equal to 1.5.

[0086] In an exemplary embodiment, the optical system 100 may satisfy: |R2 max | / |R2 min |≤1.5, where R2 max is the maximum radius of curvature of the surface of the microlens perpendicular to the first direction, R2 min is the minimum value of the radius of curvature of the surface of the microlens perpendicular to the first direction. As an example, 0.5≤|R2 max | / |R2 min|≤1.5. The diffraction effect can be greatly suppressed by randomly designing the curvature radius of the surface of the microlens perpendicular to the first direction and making the ratio of the maximum curvature radius to the minimum curvature radius less than or equal to 1.5.

[0087] In an exemplary embodiment, the center points of the microlenses in the microlens array element 113 are randomly arranged in the first direction, for example, the center points of the microlenses are randomly distributed on the center line of the microlens array element 113 or on both sides of the center line, and the distance from the center point of each microlens to the center line of the microlens array element 113 does not exceed one sixth of the effective aperture of the microlens in the first direction. Similarly, the center points of the microlenses in the microlens array element 113 are randomly arranged in the second direction, for example, the center points of each microlens are randomly distributed on the center line of the microlens array element 113 or on both sides of the center line, and the distance from the center point of each microlens to the center line of the microlens array element 113 does not exceed one sixth of the effective aperture of the microlens in the second direction. By randomly designing the center points of the microlenses, diffraction can be effectively eliminated.

[0088] In an exemplary embodiment, the optical system 100 satisfies: HFOV / (|R1| / D1)≤30°, where HFOV is the horizontal field of view of the emitting optical element 112, D1 is the effective aperture of the microlens in the first direction, and R1 is the radius of curvature of the surface of the microlens perpendicular to the second direction. As an example, HFOV / (|R1| / D1)≤12°. By controlling the above conditional expression, it is possible to ensure that the microlens array element 113 has a better diffusion effect and uniform light effect on the light beam emitted by the light source 111 in the first direction.

[0089] In an exemplary embodiment, the optical system 100 may satisfy: 0.5≤|Fθ TX / Fθ RX |≤1.5, where Fθ TX is the distortion of the emitting optical element 112, Fθ RX is the distortion of the receiving optical element 121. As an example, |Fθ TX / Fθ RX -1|≤0.1, that is, 0.9≤|Fθ TX / Fθ RX |≤1.1. Distortion Fθ of the emitting optical element 112 TX Can satisfy: Fθ TX =((Y-Y0) / Y0)×100%, where Y represents the actual image height of the transmitting optical element 112, and Y0 represents the ideal image height of the transmitting optical element 112. Distortion Fθ of the receiving optical element 121 RX Can satisfy: Fθ RX= ((Y’ - Y0’) / Y0’) × 100%, where Y’ represents the actual image height of the receiving optical element 121, and Y0’ represents the ideal image height of the receiving optical element 121. By constraining the ratio of the distortion of the transmitting optical element 112 to the distortion of the receiving optical element 121 within a certain range, co-distortion of the receiving optical element 121 and the transmitting optical element 112 can be achieved, thereby ensuring the matching of the receiving module 120 and the transmitting module 110 and improving the detection efficiency of the optical system 100.

[0090] In an exemplary embodiment, the optical system 100 may satisfy: 0 < L2 / L1 ≤ 3, where L1 is the distance from the light source 111 to the second side surface of the microlens array element 113, and L2 is the distance from the receiving surface of the receiving optical element 121 to the detection array element 122. As an example, 0.5 < L2 / L1 ≤ 2. By controlling the above conditional expression, the total optical length of the transmitting module 110 and the receiving module 120 can be constrained, the matching efficiency of the receiving module 120 and the transmitting module 110 can be improved, and the problem of mismatch between the receiving module 120 and the transmitting module 110 caused by a large difference in the total optical length between the receiving module 120 and the transmitting module 110 can be avoided. For example, problems such as a large field of view and light blocking of the transmitting module 110 caused by an excessive total optical length of the receiving module 120 can be avoided. At the same time, it is also beneficial to realize the miniaturization of the optical system 100 and reduce the cost of the optical system 100.

[0091] In an exemplary embodiment, the light source 111 is configured as a plurality of light-emitting channels in the second direction or the first direction. When the light source 111 is configured as a plurality of light-emitting channels in the second direction, each light-emitting channel includes i rows of sub-light sources in the second direction. When the light source 111 is configured as a plurality of light-emitting channels in the first direction, each light-emitting channel includes i columns of sub-light sources in the first direction.

[0092] And the optical system 100 may satisfy: 1 ≤ α2 / α1 ≤ F T × 2 × tan(HFOV / 2) / (C / i) / Le, where α1 is the collimation of the sub-light source before passing through the microlens array element 113, α2 is the collimation of the sub-light source after passing through the microlens array element 113, F T is the focal length of the transmitting optical element 112, HFOV is the horizontal field of view angle of the transmitting optical element 112, C is the number of sub-light sources included in the light-emitting channel, i is the number of rows of sub-light sources included in the light-emitting channel in the second direction or the number of columns of sub-light sources included in the light-emitting channel in the first direction; Le is the maximum diameter of the sub-light source, where 1 ≤ F T×2×tan(HFOV / 2) / (C / i) / Le≤35. By controlling the above conditional expression, each sub-light source in each light-emitting channel can be effectively utilized, ensuring that the microlens array element 113 has a better diffusion effect and uniform light effect on the light beam emitted by the light source 111. As an example, F T ×tan(HFOV / 2) / (C / i) / Le≤α2 / α1≤F T ×2×tan(HFOV / 2) / (C / i) / Le.

[0093] A specific embodiment of the optical system 100 applicable to the above-mentioned embodiments is further described below.

[0094] Example 1

[0095] Figure 2 The structural diagram of the transmitting module 110 of Embodiment 1 is schematically shown. Figure 6 The structural diagram of the first microlens array element 114 of Example 1 is schematically shown. Figure 7 The schematic diagram of the structure of the second microlens array element 115 of Example 1 is shown schematically. Figure 1 , Figure 2 , Figure 6 and Figure 7 As shown, the optical system 100 may include a transmitting module 110 and a receiving module 120 .

[0096] The transmitting module 110 may include a light source 111, an emitting optical element 112, and two microlens array elements 113 arranged in sequence from the first side to the second side along the optical axis, wherein the two microlens array elements 113 are respectively independently arranged first microlens array element 114 and second microlens array element 115, wherein the second microlens array element 115 is closer to the light source 111 than the first microlens array element 114. The light beam emitted by the light source 111 is first expanded and collimated by the emitting optical element 112, and then expanded and homogenized by the second microlens array element 115 and the first microlens array element 114 to form a uniform light beam. The first microlens array element 114 can expand and homogenize the light beam emitted by the light source 111 in a first direction, and the second microlens array element 115 can expand and homogenize the light beam emitted by the light source 111 in a second direction, wherein the first direction and the second direction are perpendicular to each other and are perpendicular to the optical axis. The first microlens array element 114 and the second microlens array element 115 can each include a plurality of microlenses arranged in an array.

[0097] The receiving module 120 may include a receiving optical element 121 and a detection array element 122. The reflected light of the uniform light beam is focused by the receiving optical element 121 and then received by the detection array element 122.

[0098] As an example, Fig.11 Schematically shows the structure of the light source 111, Fig.11 The black shadow holes in are light-emitting holes, that is, one black shadow hole corresponds to one sub-light source. Fig.11 As shown, the light source 111 is configured as a plurality of light-emitting channels in the second direction, specifically 32 light-emitting channels, each light-emitting channel is composed of two rows of sub-light sources in the second direction, and the sub-light sources are distributed in a triangular shape. Each sub-light source is a circular hole, and the maximum diameter of each sub-light source is 30 μm. The number C of sub-light sources contained in each light-emitting channel is 120.

[0099] As an example, the ratio of the area of ​​the receiving surface of the detection array element 122 to the light emitting area of ​​the light source 111 may be 3, for example.

[0100] As an example, L1 is the distance from the light source 111 to the second side surface of the first microlens array element 114, and L2 is the distance from the receiving surface of the receiving optical element 121 to the detection array element 122. L1=L2, that is, the total optical lengths of the transmitting module 110 and the receiving module 120 are equal and are both 30 mm.

[0101] As an example, the radius of curvature of the surface of the microlens perpendicular to the second direction in the first microlens array element 114 is R1, and the radius of curvature of the surface of the microlens perpendicular to the first direction in the second microlens array element 115 is R2. And |R1| / |R2|=0.824, where |R1|=3.75mm, |R2|=4.55mm.

[0102] As an example, the aspect ratio of the detection array elements 122 is 4:3.

[0103] As an example, the distortion Fθ of the transmitting optical element 112 is TX and the distortion Fθ of the receiving optical element 121 RX The same, that is, |Fθ TX / Fθ RX |=1.

[0104] As an example, the optical system 100 may satisfy: HFOV / (|R1| / D1)≤30°, wherein HFOV is the horizontal field of view of the emitting optical element 112, R1 is the radius of curvature of the surface of the microlens in the first microlens array element 114 that is perpendicular to the second direction, and D1 is the effective aperture of the microlens in the first microlens array element 114 in the first direction, wherein 0.005mm≤D1≤1mm, and 0.1mm≤R1≤20mm.

[0105] As an example, the effective focal length of the microlenses in the first microlens array element 114 in the first direction is F1, and the effective focal length of the microlenses in the second microlens array element 115 in the second direction is F2. Moreover, |F1 / F2|=0.824, where F1=7.23 mm, F2=-8.77 mm.

[0106] As an example, the collimation degree of the sub-light source before passing through the microlens array element 113 is α1, the collimation degree of the sub-light source after passing through the microlens array element 113 is α2, and α2 / α1=2. The focal length F of the emitting optical element 112 T is 2 mm, the horizontal field of view HFOV of the emitting optical element 112 is 128°, and F T ×2×tan(HFOV / 2) / (C / i) / Le=4.556.

[0107] As an example, the overall divergence angle of the optical system 100 is 128°×96°. The matching efficiency of the receiving module 120 and the transmitting module 110 is as high as 98%.

[0108] Example 2

[0109] Figure 3 The schematic diagram of the structure of the transmitting module 110 of Embodiment 2 is shown schematically. Figure 1 and Figure 3 As shown, the optical system 100 may include a transmitting module 110 and a receiving module 120 .

[0110] The transmitting module 110 may include a light source 111, an emitting optical element 112, and two microlens array elements 113 arranged in sequence from the first side to the second side along the optical axis, wherein the two microlens array elements 113 are respectively a first microlens array element 114 and a second microlens array element 115, wherein the first microlens array element 114 is closer to the light source 111 than the second microlens array element 115, and the first microlens array element 114 and the second microlens array element 115 are bonded together. The light beam emitted by the light source 111 is firstly expanded and collimated by the emitting optical element 112, and then expanded and homogenized by the first microlens array element 114 and the second microlens array element 115 to form a uniform light beam. The first microlens array element 114 can expand and homogenize the light beam emitted by the light source 111 in a first direction, and the second microlens array element 115 can expand and homogenize the light beam emitted by the light source 111 in a second direction, wherein the first direction and the second direction are perpendicular to each other and are both perpendicular to the optical axis. The first microlens array element 114 and the second microlens array element 115 may each include a plurality of microlenses arranged in an array.

[0111] The receiving module 120 may include a receiving optical element 121 and a detection array element 122. The reflected light of the uniform light beam is focused by the receiving optical element 121 and then received by the detection array element 122.

[0112] As an example, the light source 111 is configured as a plurality of light-emitting channels in the second direction, specifically 32 light-emitting channels, each light-emitting channel is composed of three rows of sub-light sources in the second direction, and the sub-light sources are distributed in a triangle or a rectangle. Each sub-light source is a circular hole, and the maximum diameter of each sub-light source is 26 μm. The number C of sub-light sources contained in each light-emitting channel is 156.

[0113] As an example, the ratio of the area of ​​the receiving surface of the detection array element 122 to the light emitting area of ​​the light source 111 may be 3, for example.

[0114] As an example, L1 is the distance from the light source 111 to the second side surface of the second microlens array element 115, and L2 is the distance from the receiving surface of the receiving optical element 121 to the detection array element 122. L1=L2, that is, the total optical length of the transmitting module 110 and the receiving module 120 are equal and are both 35 mm.

[0115] As an example, the curvature radius of the surface of the microlens perpendicular to the second direction in the first microlens array element 114 is R1, and the curvature radius of the surface of the microlens perpendicular to the first direction in the second microlens array element 115 is R2. And |R1| / |R2|=1, where |R1|=3.35mm, |R2|=3.35mm.

[0116] As an example, the aspect ratio of the detection array elements 122 is 5:4.

[0117] As an example, the distortion Fθ of the transmitting optical element 112 is TX and the distortion Fθ of the receiving optical element 121 RX The same, that is, |Fθ TX / Fθ RX |=1.

[0118] As an example, the optical system 100 may satisfy: HFOV / (|R1| / D1)≤30°, wherein HFOV is the horizontal field of view of the emitting optical element 112, R1 is the radius of curvature of the surface of the microlens in the first microlens array element 114 that is perpendicular to the second direction, and D1 is the effective aperture of the microlens in the first microlens array element 114 in the first direction, wherein 0.005mm≤D1≤1mm, and 0.1mm≤R1≤20mm.

[0119] As an example, the effective focal length of the microlenses in the first microlens array element 114 in the first direction is F1, and the effective focal length of the microlenses in the second microlens array element 115 in the second direction is F2. Moreover, |F1 / F2|=1, where F1=6.46 mm, F2=-6.46 mm.

[0120] As an example, the collimation degree of the sub-light source before passing through the microlens array element 113 is α1, the collimation degree of the sub-light source after passing through the microlens array element 113 is α2, and α2 / α1=4. The focal length F of the emitting optical element 112 T is 2 mm, the horizontal field of view HFOV of the emitting optical element 112 is 128°, and F T ×2×tan(HFOV / 2) / (C / i) / Le=6.066.

[0121] As an example, the overall divergence angle of the optical system 100 is 128°×96°. The matching efficiency of the receiving module 120 and the transmitting module 110 is as high as 98%.

[0122] Example 3

[0123] Figure 4 The structural diagram of the transmitting module 110 of Example 3 is schematically shown. Figure 8 The schematic diagram of the structure of the microlens array element 113 of Example 3 is shown schematically. Figure 1 , Figure 4 and Figure 8 As shown, the optical system 100 may include a transmitting module 110 and a receiving module 120 .

[0124] The transmitting module 110 may include a light source 111, an emitting optical element 112 and a microlens array element 113 arranged in sequence from the first side to the second side along the optical axis. The light beam emitted by the light source 111 is first expanded and collimated by the emitting optical element 112 and then expanded and homogenized by the microlens array element 113 to form a uniform light beam. The microlens array element 113 can simultaneously expand and homogenize the light beam emitted by the light source 111 in the first direction and the second direction, wherein the first direction and the second direction are perpendicular to each other and are perpendicular to the optical axis. The microlens array element 113 may include a plurality of microlenses arranged in an array. The microlens array element 113 may be attached to a surface of the side of the emitting optical element 112 away from the light source 111, or may be attached to the optical window, or may be integrally formed on the optical window.

[0125] The receiving module 120 may include a receiving optical element 121 and a detection array element 122. The reflected light of the uniform light beam is focused by the receiving optical element 121 and then received by the detection array element 122.

[0126] As an example, Fig.12 Schematically shows the structure of the light source 111, Fig.12 The black shadow holes in are light-emitting holes, that is, one black shadow hole corresponds to one sub-light source. Fig.12 As shown, the light source 111 is configured as a plurality of light-emitting channels in the second direction, specifically 32 light-emitting channels, each light-emitting channel is composed of two rows of sub-light sources in the second direction, and the sub-light sources are distributed in a rectangular shape. Each sub-light source is a circular hole, and the maximum diameter of each sub-light source is 33 μm. The number C of sub-light sources contained in each light-emitting channel is 136.

[0127] As an example, the ratio of the area of ​​the receiving surface of the detection array element 122 to the light emitting area of ​​the light source 111 may be 4, for example.

[0128] As an example, the distance L1 from the light source 111 to the second side surface of the microlens array element 113 is not equal to the distance L2 from the receiving surface of the receiving optical element 121 to the detection array element 122, that is, the total optical lengths of the transmitting module 110 and the receiving module 120 are not equal, for example, L1=18mm, L2=30mm.

[0129] As an example, for each microlens in the microlens array element 113, the radius of curvature of the surface of the microlens perpendicular to the second direction is R1, and the radius of curvature of the surface of the microlens perpendicular to the first direction is R2. And |R1| / |R2|=0.587, where |R1|=1.75mm, |R2|=2.98mm.

[0130] As an example, the aspect ratio of the detection array elements 122 is 4:3.

[0131] As an example, the distortion Fθ of the transmitting optical element 112 is TX and the distortion Fθ of the receiving optical element 121 RX Satisfies: |Fθ TX / Fθ RX |=1.1.

[0132] As an example, the optical system 100 can satisfy: HFOV / (|R1| / D1)≤30°, where HFOV is the horizontal field of view of the emitting optical element 112, R1 is the radius of curvature of the surface of the microlens perpendicular to the second direction, and D1 is the effective aperture of the microlens in the first direction, where 0.005mm≤D1≤1mm.

[0133] As an example, the effective focal length of the microlens in the first direction is F1, and the effective focal length of the microlens in the second direction is F2. Moreover, |F1 / F2|=0.586, where F1=3.37 mm, F2=5.75 mm.

[0134] As an example, the collimation degree of the sub-light source before passing through the microlens array element 113 is α1, the collimation degree of the sub-light source after passing through the microlens array element 113 is α2, and α2 / α1=3. The focal length F of the emitting optical element 112 T is 2.8 mm, the horizontal field of view HFOV of the emitting optical element 112 is 128°, and F T ×2×tan(HFOV / 2) / (C / i) / Le=5.117.

[0135] As an example, the overall divergence angle of the optical system 100 is 128°×96°. The matching efficiency of the receiving module 120 and the transmitting module 110 is as high as 94%.

[0136] Example 4

[0137] Figure 5 The structural diagram of the transmitting module 110 of Embodiment 4 is schematically shown. Fig. 9 The schematic diagram of the structure of the microlens array element 113 of Example 4 is shown schematically. Figure 1 , Figure 5 and Fig. 9 As shown, the optical system 100 may include a transmitting module 110 and a receiving module 120 .

[0138] The transmitting module 110 may include a light source 111, an emitting optical element 112 and a microlens array element 113 arranged in sequence from the first side to the second side along the optical axis. The light beam emitted by the light source 111 is first expanded and collimated by the emitting optical element 112 and then expanded and homogenized by the microlens array element 113 to form a uniform light beam. The microlens array element 113 can simultaneously expand and homogenize the light beam emitted by the light source 111 in the first direction and the second direction, wherein the first direction and the second direction are perpendicular to each other and are perpendicular to the optical axis. The microlens array element 113 may include a plurality of microlenses arranged in an array. The microlens array element 113 may be attached to a surface of the side of the emitting optical element 112 away from the light source 111, or may be attached to the optical window, or may be integrally formed on the optical window.

[0139] The receiving module 120 may include a receiving optical element 121 and a detection array element 122. The reflected light of the uniform light beam is focused by the receiving optical element 121 and then received by the detection array element 122.

[0140] As an example, Fig.13 Schematically shows the structure of the light source 111, Fig.13 The black shadow holes in are light-emitting holes, that is, one black shadow hole corresponds to one sub-light source. Fig.13As shown, the light source 111 is configured as a plurality of light-emitting channels in the first direction, specifically 128 light-emitting channels, each of which is composed of a column of sub-light sources in the first direction. Each sub-light source is a circular hole, and the maximum diameter of each sub-light source is 32 μm. The number C of sub-light sources contained in each light-emitting channel is 68.

[0141] As an example, the ratio of the area of ​​the receiving surface of the detection array element 122 to the light emitting area of ​​the light source 111 may be, for example, 1.4.

[0142] As an example, the distance L1 from the light source 111 to the second side surface of the microlens array element 113 is not equal to the distance L2 from the receiving surface of the receiving optical element 121 to the detection array element 122, that is, the total optical lengths of the transmitting module 110 and the receiving module 120 are not equal, for example, L1=16mm, L2=30mm.

[0143] As an example, for each microlens in the microlens array element 113, the radius of curvature of the surface of the microlens perpendicular to the second direction is R1, and the radius of curvature of the surface of the microlens perpendicular to the first direction is R2. And |R1| / |R2|=3.862, where |R1|=12.55mm, |R2|=3.25mm.

[0144] As an example, the aspect ratio of the detection array elements 122 is 3:2.

[0145] As an example, the distortion Fθ of the transmitting optical element 112 is TX and the distortion Fθ of the receiving optical element 121 RX The same, and |Fθ TX / Fθ RX |=1.

[0146] As an example, the optical system 100 may satisfy: HFOV / (|R1| / D1)≤30°, where HFOV is the horizontal field of view of the emitting optical element 112, R1 is the radius of curvature of the surface of the microlens perpendicular to the second direction, and D1 is the effective aperture of the microlens in the first direction, where 0.005mm≤D1≤1mm, and 0.1mm≤R1≤20mm.

[0147] As an example, the effective focal length of the microlens in the first direction is F1, and the effective focal length of the microlens in the second direction is F2. Moreover, |F1 / F2|=3.867, where F1=-24.21 mm, F2=-6.26 mm.

[0148] As an example, the collimation degree of the sub-light source before passing through the microlens array element 113 is α1, the collimation degree of the sub-light source after passing through the microlens array element 113 is α2, and α2 / α1=2. The focal length F of the emitting optical element 112 T is 2.8 mm, the horizontal field of view HFOV of the emitting optical element 112 is 96°, and F T ×2×tan(HFOV / 2) / (C / i) / Le=2.858.

[0149] As an example, the overall divergence angle of the optical system 100 is 126°×96°. The matching efficiency of the receiving module 120 and the transmitting module 110 is as high as 97%.

[0150] The second aspect of the present application provides a method for manufacturing an optical system. The optical system obtained according to the manufacturing method may be, for example, the optical system 100 provided in the first aspect. The manufacturing method may include the following steps:

[0151] S10, setting up a transmission module, the transmission module comprising a light source and a microlens array element arranged in sequence from a first side to a second side along an optical axis.

[0152] As an example, the transmitting module may further include an emitting optical element disposed between the light source and the microlens array element. The emitting optical element may collimate the light beam emitted by the light source. The emitting optical element may be used to convert the light beam emitted by the light source into a collimated light beam with a preset divergence angle so as to cooperate with the microlens array element to achieve efficient matching of the receiving module and the transmitting module. The use of the above-mentioned microlens array element may reduce the size of the light source, thereby reducing the size of the emitting optical element and reducing the cost of the optical system.

[0153] S20. Setting a receiving module, where the receiving module includes a detection array element.

[0154] As an example, the receiving module may further include a receiving optical element. The receiving optical element focuses the reflected light of the uniform light beam, and the focused reflected light is received by the detection array element.

[0155] The manufacturing method also includes: using a microlens array element to homogenize the light beam emitted by the light source in a first direction and / or a second direction to form a uniform light beam, wherein the first direction and the second direction are perpendicular to each other and both perpendicular to the optical axis; and using a detection array element to receive reflected light of the uniform light beam.

[0156] In an exemplary embodiment, the manufacturing method further includes: adjusting the structure of the microlens array element so that the ratio of the area of ​​the receiving surface of the detection array element to the light emitting area of ​​the light source can be n×m, where n≥1 and m≥1. The light source may include a plurality of sub-light sources arranged in an array, the light corresponding to any row of sub-light sources in the reflected light covers n rows of detection units in the detection array element, and the light corresponding to any column of sub-light sources in the reflected light covers m columns of detection units in the detection array element. In other words, the light beams emitted by each row of sub-light sources can illuminate n rows of detection units after being homogenized by the expansion angle of the microlens array element, and the light beams emitted by each column of sub-light sources can illuminate m columns of detection units after being homogenized by the expansion angle of the microlens array element. It should be understood that the direction of the rows described in the present application extends in the direction indicated by the first direction, and the direction of the columns extends in the direction indicated by the second direction.

[0157] As an example, the diffusion angles of the uniform light beam in the first direction and the second direction are the same. In other words, the number of rows n of detection units that can be illuminated by the light beams emitted by each row of sub-light sources after being homogenized by the dilation angle of the microlens array element 113 is the same as the number of columns m of detection units that can be illuminated by the light beams emitted by each column of sub-light sources after being homogenized by the dilation angle of the microlens array element 113. In one example, n=m=2.

[0158] As an example, the diffusion angles of the uniform light beam in the first direction and the second direction are different. In other words, the number of rows n of detection units that can be illuminated by the light beams emitted by each row of sub-light sources after being homogenized by the dilation angle of the microlens array element 113 is different from the number of columns m of detection units that can be illuminated by the light beams emitted by each column of sub-light sources after being homogenized by the dilation angle of the microlens array element 113. In one example, n=1.5, m=2; or, n=2, m=1.5.

[0159] The above-mentioned microlens array element can be used to compensate for the dark area caused by the pixel defects of the light source in the detection array element, ensuring that there is no dark area between rows and columns in the detection array element, thereby achieving that the entire receiving surface of the detection array element has no dark area. At the same time, the use of the above-mentioned microlens array element can also reduce the size of the light source, simplify the driving circuit corresponding to the light source, and thus reduce the cost of the optical system.

[0160] In an exemplary embodiment, the manufacturing method further includes: adjusting the structure of the transmitting module and making the transmitting module include a microlens array element, which homogenizes the beam expansion angle in the first direction and the second direction. As an example, the microlens array element can be attached to the surface of the side of the transmitting optical element away from the light source, or the microlens array element is attached to the optical window of the optical system, or the microlens array element is integrally formed with the optical window of the optical system. By attaching the microlens array element to the transmitting optical element or the optical window, the total length of the optical system can be effectively controlled, which is conducive to miniaturization of the optical system.

[0161] In an exemplary embodiment, the manufacturing method further includes: adjusting the structure of the transmitting module so that the transmitting module includes two microlens array elements, namely a first microlens array element and a second microlens array element, wherein the first microlens array element homogenizes the beam expansion angle in a first direction, and the second microlens array element homogenizes the beam expansion angle in a second direction. In one example, the first microlens array element and the second microlens array element can be bonded together.

[0162] In an exemplary embodiment, the manufacturing method further includes: adjusting the structure of the microlens of the microlens array element so that the optical system satisfies: 0<|R1| / |R2|≤10, wherein R1 is the radius of curvature of the surface of the microlens perpendicular to the second direction, and R2 is the radius of curvature of the surface of the microlens perpendicular to the first direction. By constraining the ratio of the radius of curvature of the surface of the microlens perpendicular to the second direction to the radius of curvature of the surface of the microlens perpendicular to the first direction within a certain range, the ability of the microlens array element to adjust the light beam can be better controlled, the imaging ability and field of view of the optical system can be improved, and it is also conducive to achieving efficient matching of the receiving module and the transmitting module.

[0163] In an exemplary embodiment, the manufacturing method further includes: adjusting the structure of the microlens of the microlens array element so that the optical system can satisfy: 0<|F1 / F2|≤5, where F1 is the effective focal length of the microlens in the first direction, and F2 is the effective focal length of the microlens in the second direction. By constraining the ratio of the effective focal length of the microlens in the first direction to the effective focal length of the microlens in the second direction within a certain range, the ability of the microlens array element to adjust the light beam can be better controlled, and the diffusion effect and uniform light effect of the microlens array element on the light beam can be improved.

[0164] In an exemplary embodiment, the manufacturing method further includes: adjusting the structure of the microlens of the microlens array element so that the optical system can satisfy: 2≤|R1 / D1|≤100, where R1 is the radius of curvature of the surface of the microlens perpendicular to the second direction, and D1 is the effective aperture of the microlens in the first direction. As an example, 5≤|R1 / D1|≤50. By constraining the ratio of the radius of curvature of the surface of the microlens perpendicular to the second direction to the effective aperture of the microlens in the first direction within a certain range, it is beneficial to improve the diffusion effect and uniform light effect of the microlens array element on the light beam.

[0165] In an exemplary embodiment, the manufacturing method further includes: adjusting the structure of the microlens of the microlens array element so that the optical system can satisfy: 2≤|R2 / D2|≤70, where R2 is the radius of curvature of the surface of the microlens perpendicular to the first direction, and D2 is the effective aperture of the microlens in the second direction. As an example, 5≤|R2 / D2|≤30. By constraining the ratio of the radius of curvature of the surface of the microlens perpendicular to the first direction to the effective aperture of the microlens in the second direction within a certain range, it is beneficial to improve the diffusion effect and uniform light effect of the microlens array element on the light beam.

[0166] In an exemplary embodiment, the manufacturing method further includes: adjusting the structure of the microlenses of the microlens array element so that the optical system can satisfy: d max / d min ≤2, where d max is the maximum thickness of the microlens, d min is the minimum thickness of the microlens. As an example, 1≤d max / d min ≤1.5. The diffraction effect can be greatly suppressed by randomly designing the thickness of the microlenses in the microlens array element and making the ratio of the maximum thickness to the minimum thickness of the microlenses less than or equal to 2.

[0167] In an exemplary embodiment, the manufacturing method further includes: adjusting the structure of the microlens of the microlens array element so that the optical system can satisfy: |R1 max | / |R1 min |≤1.5, where R1 max is the maximum radius of curvature of the surface of the microlens perpendicular to the second direction, R1 min is the minimum value of the radius of curvature of the surface of the microlens perpendicular to the second direction. As an example, 0.5≤|R1 max | / |R1 min|≤1.5. The diffraction effect can be greatly suppressed by randomly designing the curvature radius of the surface of the microlens perpendicular to the second direction and making the ratio of the maximum curvature radius to the minimum curvature radius less than or equal to 1.5.

[0168] In an exemplary embodiment, the manufacturing method further includes: adjusting the structure of the microlens of the microlens array element so that the optical system can satisfy: | R2 max | / |R2 min |≤1.5, where R2 max is the maximum radius of curvature of the surface of the microlens perpendicular to the first direction, R2 min is the minimum value of the radius of curvature of the surface of the microlens perpendicular to the first direction. As an example, 0.5≤|R2 max | / |R2 min |≤1.5. The diffraction effect can be greatly suppressed by randomly designing the curvature radius of the surface of the microlens perpendicular to the first direction and making the ratio of the maximum curvature radius to the minimum curvature radius less than or equal to 1.5.

[0169] In an exemplary embodiment, the manufacturing method further includes: adjusting the structure of the microlenses of the microlens array element and making the center points of each microlens in the microlens array element randomly arranged in the first direction, for example, the center points of each microlens are randomly distributed on the center line of the microlens array element or on both sides of the center line, and the distance from the center point of each microlens to the center line of the microlens array element does not exceed one sixth of the effective aperture of the microlens in the first direction. Similarly, adjusting the structure of the microlenses of the microlens of the microlens array element and making the center points of each microlens in the microlens array element randomly arranged in the second direction, for example, the center points of each microlens are randomly distributed on the center line of the microlens array element or on both sides of the center line, and the distance from the center point of each microlens to the center line of the microlens array element does not exceed one sixth of the effective aperture of the microlens in the second direction. By randomly designing the center points of the microlenses, diffraction can be effectively eliminated.

[0170] In an exemplary embodiment, the manufacturing method includes: adjusting the structure of the microlens of the emitting optical element and the microlens array element so that the optical system satisfies: HFOV / (|R1| / D1)≤30°, wherein HFOV is the horizontal field of view of the emitting optical element, D1 is the effective aperture of the microlens in the first direction, and R1 is the radius of curvature of the surface of the microlens perpendicular to the second direction. As an example, HFOV / (|R1| / D1)≤12°. By controlling the above conditional formula, it is possible to ensure that the diffusion effect and uniform light effect of the microlens array element on the light beam emitted by the light source in the first direction are better.

[0171] In an exemplary embodiment, the manufacturing method includes: adjusting the structures of the transmitting optical element and the receiving optical element such that the optical system can satisfy: 0.5 ≤ |Fθ TX / Fθ RX | ≤ 1.5, where Fθ TX is the distortion of the transmitting optical element, and Fθ RX is the distortion of the receiving optical element. As an example, |Fθ TX / Fθ RX -1| ≤ 0.1, that is, 0.9 ≤ |Fθ TX / Fθ RX | ≤ 1.1. The distortion Fθ TX of the transmitting optical element can satisfy: Fθ TX = ((Y - Y0) / Y0) × 100%, where Y represents the actual image height of the transmitting optical element, and Y0 represents the ideal image height of the transmitting optical element. The distortion Fθ RX of the receiving optical element can satisfy: Fθ RX = ((Y' - Y0') / Y0') × 100%, where Y' represents the actual image height of the receiving optical element, and Y0' represents the ideal image height of the receiving optical element. By constraining the ratio of the distortion of the transmitting optical element to the distortion of the receiving optical element within a certain range, co-distortion of the receiving optical element and the transmitting optical element can be achieved, thereby ensuring the matching of the receiving module and the transmitting module and improving the detection efficiency of the optical system.

[0172] In an exemplary embodiment, the manufacturing method includes: adjusting the positions of the light source and the receiving optical element such that the optical system can satisfy: 0 < L2 / L1 ≤ 3, where L1 is the distance from the light source to the second side surface of the microlens array element, and L2 is the distance from the receiving surface of the receiving optical element to the detection array element. As an example, 0.5 < L2 / L1 ≤ 2. By controlling the above conditional expression, the optical total length of the transmitting module and the receiving module can be constrained, the matching efficiency of the receiving module and the transmitting module can be improved, and the problem of mismatch between the receiving module and the transmitting module caused by a large difference in the optical total length between the receiving module and the transmitting module can be avoided. For example, problems such as a large field of view and light blocking of the transmitting module caused by an excessive optical total length of the receiving module can be avoided. At the same time, it is also beneficial to realize the miniaturization of the optical system and reduce the cost of the optical system.

[0173] In an exemplary embodiment, the manufacturing method includes: disposing a transmitting optical element between the light source and the microlens array element, where the light source includes a plurality of sub-light sources arranged in an array, the light source is configured as a plurality of light-emitting channels in the second direction or the first direction, and the optical system is made to satisfy: 1 ≤ α2 / α1 ≤ F T×2×tan(HFOV / 2) / (C / i) / Le, where α1 is the collimation of the sub-light source before passing through the microlens array element, α2 is the collimation of the sub-light source after passing through the microlens array element, and F T is the focal length of the emitting optical element, HFOV is the horizontal field of view of the emitting optical element, C is the number of sub-light sources contained in the light-emitting channel, i is the number of rows of sub-light sources contained in the light-emitting channel in the second direction or the number of columns of sub-light sources contained in the light-emitting channel in the first direction; Le is the maximum diameter of the sub-light source, where 1≤F T ×2×tan(HFOV / 2) / (C / i) / Le≤35. By controlling the above conditional expression, each sub-light source in each light-emitting channel can be effectively utilized, ensuring that the diffusion effect and uniform light effect of the light beam emitted by the microlens array element are better. As an example, F T ×tan(HFOV / 2) / (C / i) / Le≤α2 / α1≤F T ×2×tan(HFOV / 2) / (C / i) / Le.

[0174] The above is only an exemplary embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present application. These improvements and substitutions should also be regarded as the scope of protection of the present application.

Claims

1. An optical system, characterized in that: include: An emission module, comprising a light source and a microlens array element arranged in sequence from a first side to a second side along an optical axis, wherein the microlens array element homogenizes the angle of a light beam emitted by the light source in a first direction and / or a second direction to form a uniform light beam, wherein the first direction and the second direction are perpendicular to each other and are perpendicular to the optical axis; as well as The receiving module comprises a detection array element, and the detection array element receives the reflected light of the uniform light beam.

2. The optical system according to claim 1, characterized in that The ratio of the area of ​​the receiving surface of the detection array element to the light emitting area of ​​the light source is n×m, wherein n≥1 and m≥1.

3. The optical system according to claim 2, characterized in that The light source includes a plurality of sub-light sources arranged in an array, and the light in the reflected light corresponding to any row of the sub-light sources covers n rows of detection units in the detection array element, and the light in the reflected light corresponding to any column of the sub-light sources covers m columns of detection units in the detection array element.

4. The optical system according to any one of claims 1 to 3, characterized in that: The microlens array element includes a plurality of microlenses arranged in an array, and the optical system satisfies: |R1| / |R2|≤10, Wherein, R1 is the curvature radius of the surface of the microlens perpendicular to the second direction, and R2 is the curvature radius of the surface of the microlens perpendicular to the first direction.

5. The optical system according to any one of claims 1 to 3, characterized in that: The microlens array element includes a plurality of microlenses arranged in an array, and the optical system satisfies: 0<|F1 / F2|≤5, Wherein, F1 is the effective focal length of the microlens in the first direction, and F2 is the effective focal length of the microlens in the second direction.

6. The optical system according to any one of claims 1 to 3, characterized in that: The microlens array element includes a plurality of microlenses arranged in an array, and the optical system satisfies: 2≤|R1 / D1|≤100, Wherein, R1 is the radius of curvature of the surface of the microlens perpendicular to the second direction, and D1 is the effective aperture of the microlens in the first direction.

7. The optical system according to any one of claims 1 to 3, characterized in that: The transmitting module further comprises a transmitting optical element disposed between the light source and the microlens array element, and the optical system satisfies: HFOV / (|R1| / D1)≤30°, Wherein, HFOV is the horizontal field of view of the emitting optical element, D1 is the effective aperture of the microlens in the microlens array element in the first direction, and R1 is the radius of curvature of the surface of the microlens perpendicular to the second direction.

8. The optical system according to claim 7, characterized in that The receiving module further includes a receiving optical element, which focuses the reflected light, and the focused reflected light is received by the detection array element, and the optical system satisfies: 0.5≤|Fθ TX / Fθ RX |≤1.5, Among them, Fθ TX is the distortion of the emitting optical element, Fθ RX is the distortion of the receiving optical element.

9. The optical system according to claim 8, characterized in that The optical system satisfies: 0 <L2 / L1≤3, Wherein, L1 is the distance from the light source to the second side surface of the microlens array element, and L2 is the distance from the receiving surface of the receiving optical element to the detection array element.

10. A method for manufacturing an optical system, characterized in that: include: Provide a transmitting module, the transmitting module comprising a light source and a microlens array element arranged in sequence from a first side to a second side along an optical axis; as well as A receiving module is provided, wherein the receiving module comprises a detection array element, Wherein, the manufacturing method further comprises: Using the microlens array element to homogenize the light beam emitted by the light source in a first direction and / or a second direction to form a uniform light beam, wherein the first direction and the second direction are perpendicular to each other and are perpendicular to the optical axis; and The detection array elements are used to receive reflected light of the uniform light beam.

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