Uniform-light angle-expanding optical device, system and transmitting device
By arranging microlens units arranged according to the uniform light expansion angle direction of the light source to be processed on the substrate, a microlens array is formed, which solves the problem in the prior art that uniform light optical devices cannot simultaneously achieve small loss of light energy and uniform light output, and achieves It provides a highly uniform luminous area and an improved irradiation range.
Patent Information
- Application Number
- CN202310913857.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-07-24
- Publication Date
- 2025-01-24
AI Technical Summary
The existing uniform optical devices cannot achieve small loss of light output energy and uniform light output at the same time, resulting in the inability to increase the illumination range of the emitting device.
Design a uniform light expansion optical device, and set a microscopic unit corresponding to the discharge direction according to the light expansion direction of the light source on the base to form a microscopic array of a specific uniform light expansion direction, so as to realize the treatment light source in the treatment light source in The uniform light expansion function on a specific emitting area.
A highly uniform emitting area is realized. It is applied to the scanning detection device to achieve the non -dark area of the detection area and high uniform illumination, which improves the radiation range of the launch device.
Smart Images
Figure CN119355852A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of optical technology, and in particular to a light uniformity and angle expansion optical device, system and transmitting device. Background Art
[0002] The fields of machine vision, mobile electronic devices, projection, lidar, etc. have increasingly higher requirements for the illumination range, and the illumination range is mainly determined by the light output energy and light uniformity of the uniform light optical device.
[0003] Commonly used light homogenizing optical devices include diffusers and diffraction homogenizing elements. Among them, diffusers are commonly used in floodlighting systems. After the light source passes through the diffuser for homogenization, the refraction of the diffuser will cause the optical signal to weaken, the light output energy will be reduced, and then the echo light signal will be weak. If used in the detection system, it will not be able to recover enough information, and the energy utilization rate is low; while the light emitted by the diffraction homogenizing element is a dot matrix. Although through special design, most of the energy emitted by the point light source can be received by the photosensitive area, the diffraction homogenizing element will also bring stray light while homogenizing the light, causing the effective signal to be annihilated. At the same time, due to the diffraction characteristics, the energy uniformity after the diffraction homogenizing element is low, reducing the overall matching efficiency of the system.
[0004] In summary, after the light source is homogenized by the existing light homogenizing optical device, it is impossible to simultaneously achieve low light output energy loss and uniform light output, and thus it is impossible to increase the irradiation range of the transmitting equipment. Summary of the invention
[0005] The present application provides a light homogenizing and angle expanding optical device, system and transmitting device, which are used to solve the problem that after the light source is homogenized by the existing light homogenizing optical device, it is impossible to simultaneously achieve low light energy loss and uniform light output, and thus the irradiation range of the transmitting device cannot be improved.
[0006] In a first aspect, the present application provides a light homogenization and angle expansion optical device, comprising:
[0007] substrate; and
[0008] At least one microlens array, the microlens array comprises a plurality of microlens units arranged along the substrate, and the arrangement of the microlens units is arranged in accordance with the direction of uniform light expansion of the light source to be processed.
[0009] In a possible design, if the uniform light expansion direction of the light source to be processed is horizontal:
[0010] The microlens array includes a single row of microlens units arranged horizontally in the same direction; the horizontal curvature radius R1 and the horizontal aperture D1 of the single row of microlens units satisfy the following relationship:
[0011] 2≤|R1 / D1|≤100;
[0012] or,
[0013] 5≤|R1 / D1|≤50.
[0014] In a possible design, if the uniform light expansion direction of the light source to be processed is in the vertical direction:
[0015] The microlens array includes a single row of microlens units arranged vertically in the same direction, and the vertical curvature radius R2 and the vertical aperture D2 of the single row of microlens units satisfy the following relationship:
[0016] 2≤|R2 / D2|≤70;
[0017] or,
[0018] 5≤|R2 / D2|≤30.
[0019] In a possible design, if the uniform light expansion direction of the light source to be processed includes both the horizontal direction and the vertical direction:
[0020] The microlens array is provided with at least one single-row microlens unit arranged in the same direction horizontally and one single-row microlens unit arranged in the same direction vertically, and the array composed of the single-row microlens unit arranged in the same direction horizontally and the array composed of the single-row microlens unit arranged in the same direction vertically are arranged orthogonally to each other;
[0021] The horizontal radius of curvature R1 and the horizontal aperture D1 of the single row of microlens units arranged in the same direction horizontally satisfy the following relationship:
[0022] 2≤|R1 / D1|≤100;
[0023] or,
[0024] 5≤|R1 / D1|≤50;
[0025] The vertical radius of curvature R2 and the vertical aperture D2 of the single row of microlens units arranged vertically in the same direction satisfy the following relationship:
[0026] 2≤|R2 / D2|≤70;
[0027] or,
[0028] 5≤|R2 / D2|≤30.
[0029] In a possible design, the array consisting of the single-row microlens units arranged horizontally in the same direction and the array consisting of the single-row microlens units arranged vertically in the same direction are arranged side by side, and the side-by-side arrangement includes an aligned row arrangement or a non-aligned row arrangement.
[0030] In a possible design, if the uniform light expansion direction of the light source to be processed includes both the horizontal direction and the vertical direction:
[0031] The microlens array also includes a plurality of block-shaped microlens units;
[0032] The horizontal curvature radius R1 and the horizontal aperture D1 of the block-shaped microlens unit satisfy the following relationship:
[0033] 2≤|R1 / D1|≤100;
[0034] or,
[0035] 5≤|R1 / D1|≤50;
[0036] The vertical curvature radius R2 and the vertical aperture D2 of the block-shaped microlens unit satisfy the following relationship:
[0037] 2≤|R2 / D2|≤70;
[0038] or,
[0039] 5≤|R2 / D2|≤30.
[0040] In a possible design, the thickness of the microlens unit is a random thickness value, and the variation d0 of the random thickness value satisfies the following relationship with the preset microlens unit thickness d:
[0041] |d0|≤1 / 3*d;
[0042] or,
[0043] |d0|≤1 / 5*d.
[0044] In a possible design, the horizontal radius of curvature of the microlens unit is a random value of the horizontal radius of curvature, and the maximum random value R1max and the minimum random value R1min of the horizontal radius of curvature among the random values of the horizontal radius of curvature satisfy the following relationship:
[0045] |R1max / R1min|≤1.5.
[0046] In a possible design, the vertical curvature radius of the microlens unit is a vertical curvature radius random value, and the maximum vertical curvature radius random value R2max and the minimum vertical curvature radius random value R2min among the vertical curvature radius random values satisfy the following relationship:
[0047] |R2max / R2min|≤1.5.
[0048] In a possible design, the center points of the horizontal apertures of the plurality of microlens arrays are not in the same plane, and the height difference D3 between the center point of the horizontal aperture and the center point of the preset microlens unit aperture and the preset microlens unit aperture D4 in the horizontal direction satisfy the following relationship:
[0049] |D3|≤1 / 3*D4.
[0050] In a possible design, the center points of the vertical apertures of the plurality of microlens arrays are not in the same plane, and the height difference D5 between the center point of the vertical aperture and the center point of the preset microlens unit aperture and the preset microlens unit aperture D6 in the vertical direction satisfy the following relationship:
[0051] |D5|≤1 / 3*D6.
[0052] In a second aspect, the present application provides a light homogenization and angle expansion optical system, comprising: a light source; and
[0053] At least one light homogenizing and angle expanding optical device as claimed in any one of claims 1 to 11, wherein the light source is processed by the light homogenizing and angle expanding optical device to obtain a homogenized and angle expanded light beam.
[0054] In a possible design, a transmitting end lens is further arranged between the light source and the light uniforming and angle expanding optical device, the light source and the transmitting end lens are arranged non-fittingly, and the transmitting end lens and the light uniforming and angle expanding optical device are arranged fittingly or non-fittingly.
[0055] In a possible design, the horizontal field of view HFOV of the transmitting end lens and the horizontal curvature radius R1 and horizontal aperture D1 of the microlens unit satisfy the following dark area compensation relationship:
[0056] HFOV / (R1 / D1)≤30;
[0057] or,
[0058] HFOV / (R1 / D1)≤12.
[0059] In a possible design, the collimation degree α1 before homogenization and the collimation degree α2 after homogenization of the light source satisfy the following irradiation area relationship with the horizontal field of view HFOV of the transmitting end lens, the focal length F of the transmitting end lens, the number C of light-emitting holes in a single row of channels in the horizontal direction, and the diameter Le of a single light-emitting hole of the light source:
[0060] 1≤α2 / α1≤F*2tan(HFOV / 2) / C / Le;
[0061] in,
[0062] α1>0,1≤F*2tan(HFOV / 2) / C / Le≤35;
[0063] or,
[0064] F*tan(HFOV / 2) / C / Le≤α2 / α1≤F*2tan(HFOV / 2) / C / Le.
[0065] In a possible design, when the emitting end lens and the light uniforming and angle expanding optical device are fitted together, the curvature of the rearmost surface of the emitting end lens is consistent with the curvature of the fitting surface of the light uniforming and angle expanding optical device.
[0066] In a third aspect, the present application provides a transmitting device, including a light uniformity and angle expansion optical system.
[0067] The present application provides a uniform light expansion optical device, system and transmitting device, including a substrate, which is a planar structure; and at least one microlens array, which includes a plurality of microlens units arranged along the substrate, and the arrangement of the microlens units is arranged in accordance with the uniform light expansion direction of the light source to be processed. Compared with the defect that the uniform light optical device in the prior art cannot simultaneously achieve the functions of low light output energy loss and uniform light output, and thus cannot improve the irradiation range of the transmitting device, the present application arranges microlens units arranged in accordance with the uniform light expansion direction of the transmitting device on the substrate to obtain a microlens array with a specific uniform light expansion direction, thereby achieving the uniform light expansion function of the light source to be processed in a specific light-emitting area, so as to obtain a light-emitting area with high uniformity, and when applied to a scanning detection device, it can achieve high uniformity illumination of the detection area without dark areas. BRIEF DESCRIPTION OF THE DRAWINGS
[0068] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0069] Figure 1 A schematic diagram of an application scenario of the light uniforming and angle expanding optical device provided in an embodiment of the present application;
[0070] Figure 2 Schematic diagram of the structure of the light uniformity and angle expansion optical device provided in the embodiment of the present application Figure 1 ;
[0071] Figure 3 Schematic diagram of the structure of the light uniformity and angle expansion optical device provided in the embodiment of the present application Figure 2 ;
[0072] Figure 4 A schematic diagram of a partial structure of a block microlens unit provided in an embodiment of the present application;
[0073] Figure 5 A schematic diagram of the horizontal position of the center point of the arrangement of multiple microlens units provided in an embodiment of the present application;
[0074] Figure 6 Schematic diagram of the structure of the uniform light expansion optical system provided in the embodiment of the present application Figure 1 ;
[0075] Figure 7 Schematic diagram of the structure of the uniform light expansion optical system provided in the embodiment of the present application Figure 2 ;
[0076] Figure 8 Schematic diagram of the structure of the uniform light expansion optical system provided in the embodiment of the present application Figure 3 ;
[0077] Fig. 9 Schematic diagram of the structure of the uniform light expansion optical system provided in the embodiment of the present application Figure 4 ;
[0078] Fig.10 Schematic diagram of the structure of the uniform light expansion optical system provided in the embodiment of the present application Figure 5 ;
[0079] Fig.11 Schematic diagram of the structure of the uniform light expansion optical system provided in the embodiment of the present application Figure 6 ;
[0080] Fig.12 Schematic diagram of the structure of the uniform light expansion optical system provided in the embodiment of the present application Figure 7 . DETAILED DESCRIPTION
[0081] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation methods described in the following exemplary embodiments do not represent all implementation methods consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims, rather than all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.
[0082] Existing scanning equipment such as radar mainly uses light-homogenizing optical devices to increase the irradiation range. In existing light-homogenizing optical devices, the diffuser uses the principle of light refraction to diverge the light beam emitted by the light source to expand the light output angle of the light beam, but due to the light absorption characteristics of the diffuser itself, part of the energy in the light beam is absorbed by the diffuser, which leads to a decrease in the light output energy, resulting in information loss due to insufficient energy during the detection process; in existing light-homogenizing optical devices, the diffraction light-homogenizing element diffuses the light beam emitted by the light source through the diffraction of light. This method effectively retains the energy of the light beam, but due to the characteristics of diffraction itself, stray light will appear in the light beam, making the effective signal in the light beam easily interfered by stray light, which leads to information loss during the detection process.
[0083] Based on the above technical problems, the inventive concept of the present application is to introduce a microlens array as a new light homogenizing optical device, and determine whether the microlens units in the microlens array are arranged in a single row horizontally, a single row vertically, or a double row orthogonally according to whether the light homogenizing angle is in the horizontal direction, the vertical direction, or both, so as to achieve angle homogenization, and to eliminate diffraction and compensate for dark areas by setting specific parameters to improve the angle homogenization effect, aiming to solve the above technical problems of the prior art.
[0084] The specific application scenarios of this application are as follows:
[0085] Figure 1 A schematic diagram of an application scenario of the light uniformity and angle expansion optical device provided in an embodiment of the present application. Figure 1 As shown, a laser radar 101 including a light homogenizing and angle expanding optical device detects a target object 102. The light source in the laser radar 101 emits a light beam, which is homogenized and expanded by the light homogenizing and angle expanding optical device and then irradiates the surface of the target object 102. The light beam is reflected by the target object 102 and then received by a light beam receiving device of the laser radar 101 to obtain a reflection signal of the target object 102, and then the relevant information of the target object 102 is determined based on the reflection signal.
[0086] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.
[0087] Figure 2 Schematic diagram of the structure of the light uniformity and angle expansion optical device provided in the embodiment of the present application Figure 1 .like Figure 2 As shown, the light uniformity and angle expansion optical device comprises:
[0088] a substrate 201; and
[0089] At least one microlens array 202, the microlens array 202 includes a plurality of microlens units 203 arranged along the substrate 201, and the arrangement of the microlens units 203 is arranged corresponding to the direction of uniform light expansion of the light source to be processed.
[0090] Specifically, a microlens array is formed by etching or molding on a substrate, and each microlens unit 203 in the microlens array can be the same as or different from the other microlens units 203; the shape of each microlens unit 203 can be regular or irregular; the microlens array 202 composed of the microlens units 203 can be single-sided or double-sided.
[0091] Preferably, when the uniform light expansion direction of the light source to be processed is horizontal, the microlens array includes a single row of microlens units arranged horizontally in the same direction; the horizontal curvature radius R1 and the horizontal aperture D1 of the single row of microlens units satisfy the following relationship:
[0092] 2≤|R1 / D1|≤100;
[0093] or,
[0094] 5≤|R1 / D1|≤50.
[0095] Specifically, this relationship enables the microlens unit to be designed to be homogenized in the horizontal direction, which is beneficial to achieving the homogenization of the angle expansion in the horizontal direction.
[0096] Preferably, when the uniform light expansion direction of the light source to be processed is a vertical direction, the microlens array includes a single row of microlens units arranged vertically in the same direction, and the vertical curvature radius R2 and the vertical aperture D2 of the single row of microlens units satisfy the following relationship:
[0097] 2≤|R2 / D2|≤70;
[0098] or,
[0099] 5≤|R2 / D2|≤30.
[0100] Specifically, this relationship enables the microlens unit to be designed to be homogenized in the vertical direction, which is beneficial to achieving the homogenization of the angle expansion in the vertical direction.
[0101] Preferably, when the uniform light expansion direction of the light source to be processed includes both the horizontal direction and the vertical direction, the microlens array is provided with at least one single-row microlens unit arranged in the same direction horizontally and one single-row microlens unit arranged in the same direction vertically, and the array composed of the single-row microlens unit arranged in the same direction horizontally and the array composed of the single-row microlens unit arranged in the same direction vertically are arranged orthogonally to each other;
[0102] The horizontal radius of curvature R1 and the horizontal aperture D1 of the single row of microlens units arranged in the same direction horizontally satisfy the following relationship:
[0103] 2≤|R1 / D1|≤100;
[0104] or,
[0105] 5≤|R1 / D1|≤50;
[0106] The vertical curvature radius R2 and the vertical aperture D2 of the single row of microlens units arranged vertically in the same direction satisfy the following relationship:
[0107] 2≤|R2 / D2|≤70;
[0108] or,
[0109] 5≤|R2 / D2|≤30.
[0110] Specifically, since it has both horizontal and vertical homogenization designs, it is possible to achieve angle homogenization in both directions at the same time. It should be noted that the homogenization degree in the horizontal and vertical directions can be the same or different, and the diffusion in the two directions is not symmetrical, and needs to be set accordingly according to actual diffusion requirements.
[0111] In another preferred real-time mode, the arrays composed of the microlens units in the above two directions can be arranged in a row in a manner that is close to each other or in a row that is not close to each other.
[0112] Figure 3 Schematic diagram of the structure of the light uniformity and angle expansion optical device provided in the embodiment of the present application Figure 2 . Figure 4 This is a schematic diagram of the partial structure of the block microlens unit provided in the embodiment of the present application. Figure 3 and Figure 4 As shown, another possible implementation is that the microlens array 301 further includes a plurality of block-shaped microlens units 401;
[0113] The horizontal curvature radius R1 and the horizontal aperture D1 of the block microlens unit satisfy the following relationship:
[0114] 2≤|R1 / D1|≤100;
[0115] or,
[0116] 5≤|R1 / D1|≤50;
[0117] The vertical curvature radius R2 and the vertical aperture D2 of the block-shaped microlens unit satisfy the following relationship:
[0118] 2≤|R2 / D2|≤70;
[0119] or,
[0120] 5≤|R2 / D2|≤30.
[0121] Specifically, the single-row microlens unit array in the horizontal and vertical directions is replaced by a block microlens unit array having curvature radius and aperture characteristics in both the horizontal and vertical directions to achieve the angle expansion and homogenization function; wherein the block includes a regular square shape, a regular hemispherical block or any irregular block structure.
[0122] Furthermore, the thickness of the microlens unit is a random thickness value, and the variation d0 of the random thickness value satisfies the following relationship with the preset microlens unit thickness d:
[0123] |d0|≤1 / 3*d;
[0124] or,
[0125] |d0|≤1 / 5*d.
[0126] Specifically, the random thickness value makes the thickness between multiple adjacent microlens units not uniform, but fluctuates within a certain range, thereby avoiding the diffraction effect caused by uniform thickness and greatly suppressing the diffraction effect.
[0127] Furthermore, the horizontal radius of curvature of the microlens unit is a random value of the horizontal radius of curvature, and the maximum random value R1max and the minimum random value R1min of the horizontal radius of curvature in the random value of the horizontal radius of curvature satisfy the following relationship:
[0128] |R1max / R1min|≤1.5.
[0129] Furthermore, the vertical curvature radius of the microlens unit is a vertical curvature radius random value, and the maximum vertical curvature radius random value R2max and the minimum vertical curvature radius random value R2min in the vertical curvature radius random value satisfy the following relationship:
[0130] |R2max / R2min|≤1.5.
[0131] Specifically, the curvature radii in the horizontal and vertical directions are set to random values that fluctuate within a certain range, thereby avoiding the diffraction effect caused by the uniform curvature radius and greatly suppressing the diffraction effect.
[0132] Figure 5 This is a schematic diagram of the horizontal position of the center point of the arrangement of multiple microlens units provided in the embodiment of the present application. Figure 5As shown, further, the center points of the horizontal apertures of the plurality of microlens arrays are not in the same plane, and the height difference D3 between the center point of the horizontal aperture and the center point of the preset microlens unit aperture and the preset microlens unit aperture D4 in the horizontal direction satisfy the following relationship:
[0133] |D3|≤1 / 3*D4.
[0134] Furthermore, the center points of the vertical apertures of the plurality of microlens arrays are not in the same plane, and the height difference D5 between the center point of the vertical aperture and the center point of the preset microlens unit aperture and the preset microlens unit aperture D6 in the vertical direction satisfy the following relationship:
[0135] |D5|≤1 / 3*D6.
[0136] Specifically, the horizontal center points and vertical center points of the microlens array are randomly arranged, which ensures the uniform light and angle expansion effect while helping to eliminate diffraction.
[0137] The light uniformity and angle expansion optical device provided in this embodiment is achieved by arranging microlens units arranged corresponding to the light uniformity and angle expansion direction of the light source to be processed on a substrate to obtain a microlens array with a specific light uniformity and angle expansion direction, thereby realizing the light uniformity and angle expansion function of the light source to be processed in a specific light-emitting area, so as to obtain a light-emitting area with high uniformity. When applied to a scanning detection device, it is possible to achieve illumination of the detection area without dark areas.
[0138] The present application also provides a light homogenizing and angle expanding optical system, comprising: a light source; and a light homogenizing and angle expanding optical device, wherein a light beam emitted by the light source is processed by the light homogenizing and angle expanding optical device to obtain a light beam with a homogenized and angle expanded shape.
[0139] Specifically, the light-homogenizing and angle-expanding optical device is applied to the light-homogenizing and angle-expanding optical system to perform light-homogenizing and angle-expanding processing on the light beam emitted by the light source, thereby expanding the irradiation area of the light source to the detected area while retaining the emission energy of the light source.
[0140] Furthermore, a transmitting end lens is arranged between the light source and the light uniforming and angle expanding optical device, the light source and the transmitting end lens are arranged non-fittingly, and the transmitting end lens and the light uniforming and angle expanding optical device are arranged fittingly or non-fittingly.
[0141] Preferably, when the emitting end lens and the light uniforming and angle expanding optical device are fitted together, the curvature of the rearmost surface of the emitting end lens is consistent with the curvature of the fitting surface of the light uniforming and angle expanding optical device.
[0142] Specifically, when the emitting end lens and the light-uniform angle-expanding optical device are fitted together, the total length of the system can be effectively shortened, which is conducive to the miniaturized design of the system. Moreover, when fitting together, the curvature of the second side surface of the last lens of the emitting end lens needs to be kept consistent with the fitted light-uniform angle-expanding optical device to improve the matching degree between the emitting end lens and the light-uniform angle-expanding optical device. The curvature can be any of convex, concave, and flat surfaces.
[0143] Preferably, since an optical window for protecting the transmitting end lens is usually provided on the outside of the transmitting end lens, the light uniforming and angle expanding optical device can also be fitted with the optical window of the transmitting end lens, or the light uniforming and angle expanding optical device and the optical window can be integrated into a single piece to shorten the length of the system.
[0144] Furthermore, the horizontal field of view HFOV of the transmitting end lens and the horizontal curvature radius R1 and the horizontal aperture D1 of the microlens unit satisfy the following dark area compensation relationship:
[0145] HFOV / (R1 / D1)≤30;
[0146] or,
[0147] HFOV / (R1 / D1)≤12.
[0148] Specifically, this setting parameter can make the light beam obtain a better homogenization and expansion effect in the horizontal direction, which is beneficial to compensate for the dark area.
[0149] Furthermore, the collimation degree α1 before homogenization and the collimation degree α2 after homogenization of the light source satisfy the following irradiation area relationship with the horizontal field of view HFOV of the transmitting end lens, the focal length F of the transmitting end lens, the number C of light-emitting holes in a single row of channels in the horizontal direction, and the diameter Le of a single light-emitting hole of the light source:
[0150] 1≤α2 / α1≤F*2tan(HFOV / 2) / C / Le;
[0151] in,
[0152] α1>0,1≤F*2tan(HFOV / 2) / C / Le≤35;
[0153] or,
[0154] F*tan(HFOV / 2) / C / Le≤α2 / α1≤F*2tan(HFOV / 2) / C / Le.
[0155] Specifically, this setting parameter can make full and effective use of each light source in the horizontal direction, avoid energy loss, and thus improve the uniform light expansion effect.
[0156] Figure 6Schematic diagram of the structure of the uniform light expansion optical system provided in the embodiment of the present application Figure 1 .like Figure 6 As shown, the light uniforming and angle expanding optical system comprises a light source 601, a transmitting end lens 602, and a light uniforming and angle expanding optical device 603 comprising a plurality of horizontally arranged single-row micro lens units 604. The dotted arrow in the figure indicates that the light uniforming and angle expanding optical device 603 displayed from the side is flipped to be displayed from the front.
[0157] The curvature radii of the multiple single-row microlens units 604 arranged horizontally in the same direction may be the same or different, and the apertures of the multiple single-row microlens units 604 arranged horizontally in the same direction may be the same or different.
[0158] Specifically, the light homogenizing and angle expanding optical device is used to homogenize the light beam in the horizontal direction, 2≤|microlens unit curvature radius R1 / microlens unit aperture D1|≤100, preferably 5≤|microlens unit curvature radius R1 / microlens unit aperture D1|≤50.
[0159] The thickness of the plurality of single-row microlens units arranged horizontally in the same direction is random, and the random range is ≤1 / 3*preset microlens thickness d, and preferably the random range is ≤1 / 5*preset microlens thickness d.
[0160] The horizontal curvature radius of multiple single-row microlens units arranged in the same direction horizontally is randomly designed, and the random range is 0.5≤|R1max / R1min|≤1.5.
[0161] The horizontal center points of multiple single-row microlens units arranged in the same direction are randomly arranged, and the horizontal center points are randomly arranged, and the random range is ≤1 / 3*preset microlens unit aperture D4.
[0162] The horizontal field of view HFOV of the transmitting end lens and the horizontal curvature radius R1 and the horizontal aperture D1 of the microlens unit satisfy HFOV / (R1 / D1)≤16.
[0163] Among them, 0.005mm≤D1≤1mm; 0.1mm≤R1≤20mm; HFOV is 96°.
[0164] The collimation degree after homogenization of the homogenization and angle expansion optical system is α2 / collimation degree before homogenization is α1=3.2. The focal length of the transmitting end lens is F=2.2mm; the number of light-emitting holes in a single row of channels in the horizontal direction is C=48; the diameter of a single light-emitting hole of the light source is Le=22 microns; F*2tan(HFOV / 2) / C / Le=4.628.
[0165] The light uniforming and angle expansion optical system provided in this embodiment collimates and shapes the light beam emitted by the light source through the emission end lens, and then uniformly expands the light beam of the light source in the horizontal direction through the light uniforming and angle expansion optical device, thereby expanding the illumination area, compensating for the dark area caused by pixel defects, increasing the detection range, and improving the imaging quality.
[0166] Figure 7 Schematic diagram of the structure of the uniform light expansion optical system provided in the embodiment of the present application Figure 2 .like Figure 7 As shown, the light uniforming and angle expanding optical system comprises a light source 701, a transmitting end lens 702, and a light uniforming and angle expanding optical device 703 comprising a plurality of vertically arranged single-row micro lens units 704. The dotted arrow in the figure indicates that the light uniforming and angle expanding optical device 703 displayed from the side is flipped to be displayed from the front.
[0167] The curvature radii of the multiple single-row microlens units 704 arranged vertically in the same direction may be the same or different, and the apertures of the multiple single-row microlens units 704 arranged vertically in the same direction may be the same or different.
[0168] Specifically, the light homogenizing and angle expanding optical device is used to homogenize the light beam in the vertical direction, 2≤|microlens unit curvature radius R2 / microlens unit aperture D2|≤70, preferably 5≤|microlens unit curvature radius R2 / microlens unit aperture D2|≤30.
[0169] The thickness of the plurality of single-row microlens units arranged horizontally in the same direction is random, and the random range is ≤1 / 3*preset microlens thickness d, and preferably the random range is ≤1 / 5*preset microlens thickness d.
[0170] The vertical curvature radius of multiple single-row microlens units arranged in the same direction horizontally is randomly designed, and the random range is 0.5≤|R2max / R2min|≤1.5.
[0171] The vertical center points of multiple single-row microlens units arranged in the same direction horizontally are randomly arranged, and the vertical center points are randomly arranged, and the random range is ≤1 / 3*preset microlens unit aperture D6.
[0172] The vertical field of view VFOV of the transmitting end lens and the vertical curvature radius R2 and vertical aperture D2 of the microlens unit satisfy VFOV / (R1 / D1)≤30.
[0173] Among them, 0.005mm≤D2≤1mm; 0.1mm≤R2≤20mm; VFOV is 96°.
[0174] The collimation degree after homogenization of the homogenization and angle expansion optical system is α2 / collimation degree before homogenization is α1=4. The focal length of the transmitting end lens is F=2.2mm; the number of light-emitting holes in a single row of channels in the vertical direction is C=48; the diameter of a single light-emitting hole of the light source is Le=22 microns; F*2tan(VFOV / 2) / C / Le=4.628.
[0175] The light-homogenizing and angle-expanding optical system provided in this embodiment collimates and shapes the light beam emitted by the light source through the lens at the transmitting end, and then homogenizes and expands the light beam of the light source in the vertical direction through the light-homogenizing and angle-expanding optical device, thereby expanding the illumination area, compensating for the dark area caused by pixel defects, increasing the detection range, and improving the imaging quality.
[0176] Figure 8 Schematic diagram of the structure of the uniform light expansion optical system provided in the embodiment of the present application Figure 3 .like Figure 8 As shown, the light uniforming and angle-expanding optical system includes a light source 801, a transmitting end lens 802, and a light uniforming and angle-expanding optical device 803 including a plurality of single-row microlens units 804 arranged in the same direction horizontally and a single-row microlens unit 805 arranged in the same direction vertically. The dotted arrow in the figure indicates that the light uniforming and angle-expanding optical device 803 displayed from the side is flipped to be displayed from the front.
[0177] Among them, the curvature radius of the multiple single-row microlens units 804 arranged horizontally in the same direction and the single-row microlens units 805 arranged vertically in the same direction can be the same or different; the aperture of the multiple single-row microlens units 804 arranged horizontally in the same direction and the single-row microlens units 805 arranged vertically in the same direction can be the same or different; the multiple single-row microlens units 804 arranged horizontally in the same direction and the single-row microlens units 805 arranged vertically in the same direction are arranged without being close to each other, and the two are perpendicular to each other and together form a double-row orthogonal microlens array.
[0178] Specifically, the light homogenizing and angle expanding optical device is used to homogenize light beams in the horizontal and vertical directions simultaneously.
[0179] In the horizontal direction: 2≤|microlens unit curvature radius R1 / microlens unit aperture D1|≤100, preferably 5≤|microlens unit curvature radius R1 / microlens unit aperture D1|≤50.
[0180] In the vertical direction: 2≤|microlens unit curvature radius R2 / microlens unit aperture D2|≤70. Preferably, 5≤|microlens unit curvature radius R2 / microlens unit aperture D2|≤30.
[0181] The thickness of the plurality of single-row microlens units arranged horizontally in the same direction is random, and the random range is ≤1 / 3*preset microlens thickness d, and preferably the random range is ≤1 / 5*preset microlens thickness d.
[0182] The horizontal curvature radius of multiple single-row microlens units arranged in the same direction are randomly designed, and the random range is 0.5≤R1max / R1min≤1.5.
[0183] The vertical curvature radius of multiple single-row microlens units arranged in the same direction horizontally is randomly designed, and the random range is 0.5≤R2max / R2min≤1.5.
[0184] The horizontal center points of multiple single-row microlens units arranged in the same direction are randomly arranged, and the horizontal center points are randomly arranged, and the random range is ≤1 / 3*preset microlens unit aperture D4.
[0185] The vertical center points of multiple single-row microlens units arranged in the same direction horizontally are randomly arranged, and the vertical center points are randomly arranged, and the random range is ≤1 / 3*preset microlens unit aperture D6.
[0186] The horizontal field of view HFOV of the transmitting end lens and the horizontal curvature radius R1 and the horizontal aperture D1 of the microlens unit satisfy HFOV / (R1 / D1)≤16.
[0187] Among them, 0.005mm≤D1≤1mm; 0.1mm≤R1≤20mm; the horizontal field of view HFOV of the transmitting end lens is 126°, and the vertical field of view VFOV of the transmitting end lens is 96°.
[0188] The collimation degree after homogenization of the homogenization and angle expansion optical system is α2 / collimation degree before homogenization is α1=3.2. The focal length of the transmitting end lens is F=2mm; the number of light-emitting holes in a single row of channels in the horizontal direction is C=60; the diameter of a single light-emitting hole of the light source is Le=30 microns; F*2tan(HFOV / 2) / C / Le=4.361.
[0189] The light-homogenizing and angle-expanding optical system provided in this embodiment collimates and shapes the light beam emitted by the light source through the emission end lens, and then homogenizes and expands the light beam of the light source in the horizontal and vertical directions through the light-homogenizing and angle-expanding optical device of the double-row orthogonal microlens array, thereby expanding the illumination area, compensating for the dark area caused by pixel defects, increasing the detection range, and improving the imaging quality.
[0190] Fig. 9 Schematic diagram of the structure of the uniform light expansion optical system provided in the embodiment of the present application Figure 4 .like Fig. 9 As shown, the light uniforming and angle-expanding optical system includes a light source 901, a transmitting end lens 902, and a light uniforming and angle-expanding optical device 903 including a plurality of single-row microlens units 904 arranged in the same direction horizontally and a single-row microlens unit 905 arranged in the same direction vertically. The dotted arrow in the figure indicates that the light uniforming and angle-expanding optical device 903 displayed from the side is flipped to be displayed from the front.
[0191] The specific implementation method of the light homogenization and angle expansion optical system in this embodiment can refer to the above Figure 8 The system embodiment is different only in that in this embodiment, a plurality of single-row microlens units 904 arranged in the same direction horizontally and a single-row microlens unit 905 arranged in the same direction vertically are bonded together to form a uniform light expansion optical device 903. In the parameters, HFOV is 110°, VFOV is 96°, and the collimation degree after uniform light α2 / collimation degree before uniform light α1 of the uniform light expansion optical system is 3. The focal length of the transmitting end lens F is 2mm; the number of light-emitting holes in the single-row channel in the horizontal direction C is 60; the diameter of a single light-emitting hole of the light source Le is 26 microns; F*2tan(HFOV / 2) / C / Le is 3.662.
[0192] The remaining implementation principles and technical effects are similar and will not be described in detail in this embodiment.
[0193] Fig.10 Schematic diagram of the structure of the uniform light expansion optical system provided in the embodiment of the present application Figure 5 .like Fig.10 As shown, the light uniforming and angle expanding optical system includes a light source 1001 , a transmitting end lens 1002 , and a light uniforming and angle expanding optical device 1003 including a plurality of block-shaped micro lens units 1004 .
[0194] Among them, one surface of the block microlens unit 1004 is a microlens array, and the other surface has no curvature. The curvature radii of multiple block microlens units 1004 can be the same or different, the apertures of multiple block microlens units 1004 can be the same or different, and the sizes of individual block microlens units 1004 are the same.
[0195] Specifically, the light homogenizing and angle expanding optical device is used to homogenize light beams in the horizontal and vertical directions simultaneously.
[0196] In the horizontal direction: 2≤|microlens unit curvature radius R1 / microlens unit aperture D1|≤100, preferably 5≤|microlens unit curvature radius R1 / microlens unit aperture D1|≤50.
[0197] In the vertical direction: 2≤|microlens unit curvature radius R2 / microlens unit aperture D2|≤70. Preferably, 5≤|microlens unit curvature radius R2 / microlens unit aperture D2|≤30.
[0198] The thickness of the plurality of block-shaped microlens units is random, and the random range is ≤1 / 3*preset microlens unit thickness d, and preferably the random range is ≤1 / 5*preset microlens unit thickness d.
[0199] The horizontal curvature radii of multiple block microlens units are randomly designed, and the random range is 0.5≤R1max / R1min≤1.5.
[0200] The vertical curvature radii of multiple block-shaped microlens units are randomly designed, and the random range is 0.5≤R2max / R2min≤1.5.
[0201] The horizontal center points of multiple block-shaped microlens units are randomly arranged, and the horizontal center points are randomly arranged, and the random range is ≤1 / 3*preset microlens unit aperture D4.
[0202] The vertical center points of multiple block-shaped microlens units are randomly arranged, and the vertical center points are randomly arranged, and the random range is ≤1 / 3*preset microlens unit aperture D6.
[0203] The horizontal field of view HFOV of the transmitting end lens and the horizontal curvature radius R1 and the horizontal aperture D1 of the microlens unit satisfy HFOV / (R1 / D1)≤16.
[0204] Among them, 0.005mm≤D1≤1mm; 0.1mm≤R1≤20mm;
[0205] The HFOV is 120° and the VFOV is 96°.
[0206] The collimation degree after homogenization of the homogenization angle expansion optical system is α2 / collimation degree before homogenization is α1=4. The focal length of the transmitting end lens is F=2.8mm; the number of light-emitting holes in a single row of channels in the horizontal direction is C=68; the diameter of a single light-emitting hole of the light source is Le=33 microns; F*2tan(HFOV / 2) / C / Le=4.322.
[0207] A single block microlens unit may be a multi-layer structure, and the block microlens unit structure may be a symmetrical structure or an asymmetrical structure. The short axis length of a single block microlens unit is random, and the random range is ≤ 1 / 2*preset microlens unit thickness d.
[0208] The uniform light expansion optical system provided in this embodiment collimates and shapes the light beam emitted by the light source through the transmitting end lens, and then uniformly expands the light beam of the light source in the horizontal and vertical directions through the uniform light expansion optical device with block microlens units, thereby expanding the irradiation area, compensating for the dark area caused by pixel defects, increasing the detection range, and improving the imaging quality. Among them, the uniform light expansion optical device is not set in close contact with the transmitting end lens, but is placed behind the transmitting end lens, and can also be attached to the outer cover protective glass of the transmitting end lens, or it can be etched on the side of the protective glass close to the light source, which is conducive to the miniaturization design of the overall device.
[0209] Fig.11 Schematic diagram of the structure of the uniform light expansion optical system provided in the embodiment of the present application Figure 6 .like Fig.11As shown, the light uniforming and angle expanding optical system includes a light source 1101, a transmitting end lens 1102, and a light uniforming and angle expanding optical device 1103 including a plurality of block-shaped micro lens units.
[0210] The specific implementation method of the light homogenization and angle expansion optical system in this embodiment can refer to the above Fig.10 The system embodiment is different only in that the uniform light expansion optical device 1103 composed of block microlens units in this embodiment is fitted with the transmitting end lens 1102 to control the total length of the system and ensure the miniaturization design of the system, and the curvature of the uniform light expansion optical device 1103 is consistent with the curvature of the fitted transmitting end lens 1102 to better match the transmitting end lens 1102, for example, it can be a curved surface with consistent lens curvature; in addition, the HFOV in the parameters is 122°, the VFOV is 96°, and the collimation degree after uniform light α2 / collimation degree before uniform light α1 of the uniform light expansion optical system is 2.6. The focal length of the transmitting end lens F is 2.8mm; the number of light-emitting holes in a single row of channels in the horizontal direction is C=68; the diameter of a single light-emitting hole of the light source is Le=32 microns; F*2tan(HFOV / 2) / C / Le=4.643.
[0211] The remaining implementation principles and technical effects are similar and will not be described in detail in this embodiment.
[0212] Fig.12 Schematic diagram of the structure of the uniform light expansion optical system provided in the embodiment of the present application Figure 7 .like Fig.12 As shown, the light uniforming and angle expanding optical system includes a light source 1201 and a light uniforming and angle expanding optical device 1202 including a plurality of block-shaped microlens units.
[0213] The specific implementation method of the light homogenization and angle expansion optical system in this embodiment can refer to the above Fig.10 The system implementation example is different only in that there is no transmitting end lens in this implementation example, so the HFOV, VFOV and collimation parameters related to the transmitting end lens are not involved; since the light uniformity and angle expansion optical device 1202 can control the angle and uniformity of the light emitted by the light source 1201, it can directly play the role of uniformity and angle expansion for the light source 1201 without the assistance of the transmitting end lens.
[0214] In addition, in this embodiment, the curvature radius of each block microlens unit in the horizontal and vertical directions is approximately equal to ensure that the degree of angle expansion and homogenization is equivalent. In this embodiment, the light beam emitted by the light source 1201 is homogenized by the light homogenization and angle expansion optical device 1202, thereby achieving dark area compensation caused by pixel defects in the light source emission area.
[0215] This embodiment also provides a transmitting device, including a light uniforming and angle expanding optical system.
[0216] The specific implementation of the light homogenizing and angle expanding optical system of this embodiment can refer to the above system embodiment, and its implementation principle and technical effect are similar, so this embodiment will not be repeated here.
[0217] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.
[0218] Those skilled in the art can understand that in the description of the embodiments of the present application, the term "and / or" merely represents an association relationship that describes the associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist at the same time, and B exists alone. In addition, the term "at least one" represents any combination of at least two of any one or more of a plurality of. For example, at least one of A, B, and C may represent any one or more elements selected from a set that communicates A, B, and C. In addition, the term "plurality" means two or more, unless otherwise precisely and specifically specified.
[0219] In the description of the embodiment of the present application, the terms "first", "second", "third", "fourth", etc. (if present) are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.
[0220] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A light homogenizing and angle expanding optical device, characterized in that: include: substrate; as well as At least one microlens array, the microlens array comprises a plurality of microlens units arranged along the substrate, and the arrangement of the microlens units is arranged corresponding to the direction of uniform light expansion of the light source to be processed.
2. The light homogenizing and angle expanding optical device according to claim 1, characterized in that: If the uniform light expansion direction of the light source to be processed is horizontal: The microlens array includes a single row of microlens units arranged horizontally in the same direction; the horizontal curvature radius R1 and the horizontal aperture D1 of the single row of microlens units satisfy the following relationship: 2≤|R1 / D1|≤100.
3. The light homogenizing and angle expanding optical device according to claim 1, characterized in that: If the uniform light expansion direction of the light source to be processed is in the vertical direction: The microlens array includes a single row of microlens units arranged vertically in the same direction, and the vertical curvature radius R2 and the vertical aperture D2 of the single row of microlens units satisfy the following relationship: 2≤|R2 / D2|≤70.
4. The light homogenizing and angle expanding optical device according to claim 1, characterized in that: If the uniform light expansion direction of the light source to be processed includes both the horizontal direction and the vertical direction: The microlens array is provided with at least one single-row microlens unit arranged in the same direction horizontally and one single-row microlens unit arranged in the same direction vertically, and the array composed of the single-row microlens unit arranged in the same direction horizontally and the array composed of the single-row microlens unit arranged in the same direction vertically are arranged orthogonally to each other; The horizontal radius of curvature R1 and the horizontal aperture D1 of the single row of microlens units arranged in the same direction horizontally satisfy the following relationship: 2≤|R1 / D1|≤100; The vertical radius of curvature R2 and the vertical aperture D2 of the single row of microlens units arranged vertically in the same direction satisfy the following relationship: 2≤|R2 / D2|≤70.
5. The light uniforming and angle expanding optical device according to claim 4, characterized in that: The array composed of the single-row microlens units arranged horizontally in the same direction and the array composed of the single-row microlens units arranged vertically in the same direction are arranged side by side, and the side-by-side arrangement includes an aligned row arrangement or a non-aligned row arrangement.
6. The light homogenizing and angle expanding optical device according to claim 1, characterized in that: If the uniform light expansion direction of the light source to be processed includes both the horizontal direction and the vertical direction: The microlens array also includes a plurality of block-shaped microlens units; The horizontal curvature radius R1 and the horizontal aperture D1 of the block-shaped microlens unit satisfy the following relationship: 2≤|R1 / D1|≤100; The vertical curvature radius R2 and the vertical aperture D2 of the block-shaped microlens unit satisfy the following relationship: 2≤|R2 / D2|≤70.
7. The light homogenizing and angle expanding optical device according to any one of claims 1 to 6, characterized in that: The thickness of the microlens unit is a random thickness value, and the variation d0 of the random thickness value satisfies the following relationship with the preset microlens unit thickness d: |d0|≤1 / 3*d.
8. The light homogenizing and angle expanding optical device according to any one of claims 1 to 6, characterized in that: The horizontal radius of curvature of the microlens unit is a random value of the horizontal radius of curvature, and the maximum random value R1max and the minimum random value R1min of the horizontal radius of curvature among the random values of the horizontal radius of curvature satisfy the following relationship: |R1max / R1min|≤1.
5.
9. The light homogenizing and angle expanding optical device according to any one of claims 1 to 6, characterized in that: The vertical curvature radius of the microlens unit is a vertical curvature radius random value, and the maximum vertical curvature radius random value R2max and the minimum vertical curvature radius random value R2min among the vertical curvature radius random values satisfy the following relationship: |R2max / R2min|≤1.
5.
10. The light homogenizing and angle expanding optical device according to any one of claims 1 to 6, characterized in that: The center points of the horizontal apertures of the plurality of microlens arrays are not in the same plane, and the height difference D3 between the center point of the horizontal aperture and the center point of the preset microlens unit aperture and the preset microlens unit aperture D4 in the horizontal direction satisfy the following relationship: |D3|≤1 / 3*D4.
11. The light homogenizing and angle expanding optical device according to any one of claims 1 to 6, characterized in that: The center points of the vertical apertures of the plurality of microlens arrays are not in the same plane, and the height difference D5 between the center point of the vertical aperture and the center point of the preset microlens unit aperture and the preset microlens unit aperture D6 in the vertical direction satisfy the following relationship: |D5|≤1 / 3*D6.
12. A light homogenization and angle expansion optical system, characterized in that: include: light source; as well as At least one light homogenizing and angle expanding optical device as claimed in any one of claims 1 to 11, wherein the light source is processed by the light homogenizing and angle expanding optical device to obtain a homogenized and angle expanded light beam.
13. The light homogenizing and angle expanding optical system according to claim 12, characterized in that: An emitting end lens is also arranged between the light source and the light uniforming and angle expanding optical device. The light source and the emitting end lens are arranged non-bonded, and the emitting end lens and the light uniforming and angle expanding optical device are arranged bonded or non-bonded.
14. The light homogenizing and angle expanding optical system according to claim 13, characterized in that: The horizontal field of view HFOV of the transmitting end lens and the horizontal curvature radius R1 and horizontal aperture D1 of the microlens unit satisfy the following dark area compensation relationship: HFOV / (R1 / D1)≤30.
15. The light homogenizing and angle expanding optical system according to claim 13, characterized in that: The collimation degree α1 before homogenization and the collimation degree α2 after homogenization of the light source satisfy the following irradiation area relationship with the horizontal field of view HFOV of the transmitting end lens, the focal length F of the transmitting end lens, the number C of light-emitting holes in a single row of channels in the horizontal direction, and the diameter Le of a single light-emitting hole of the light source: 1≤α2 / α1≤F*2tan(HFOV / 2) / C / Le; in, α1>0, 1≤F*2tan(HFOV / 2) / C / Le≤35.
16. The light uniforming and angle expanding optical system according to claim 13, characterized in that: When the emitting end lens and the light uniforming and angle expanding optical device are fitted together, the curvature of the rearmost surface of the emitting end lens is consistent with the curvature of the fitting surface of the light uniforming and angle expanding optical device.
17. A launching device, characterized in that: It comprises the light homogenizing and angle expanding optical system as described in any one of claims 12 to 16.