Lens unit, lighting device and color sorter

Abstract

The present disclosure provides a lens unit, an illumination device, and a color sorter. The lens unit includes a transparent substrate, the transparent substrate having a first side and a second side; the transparent substrate is directly and integrally formed with a first microlens array on the first side, the first microlens array is a two-dimensional array, and the first microlens array is configured to receive and homogenize light from a light source; the transparent substrate is directly and integrally formed with a second microlens array and a third microlens array on the second side, the second microlens array and the third microlens array are both two-dimensional arrays and are spaced apart, and the second microlens array and the third microlens array are configured to converge the homogenized light passing through the first microlens array in a plurality of straight light rays arranged in a width direction toward the second microlens array and the third microlens array in a direction opposite to each other. The illumination device includes a lens unit. The color sorter includes an identification device, and the identification device includes an illumination device. Thus, the intensity and uniformity of the illumination at the light receiving surface can be improved.

Description

Technical Field

[0001] The present disclosure relates to the field of optics, and in particular to a lens unit, a lighting device and a color sorter. Background Art

[0002] Color sorters usually include an identification device. The identification device determines whether the material meets the requirements based on the color and / or material of the material entering the identification device. The identification device is usually provided with an illumination device and a collection component. The illumination device is used to illuminate the material entering the identification area. The collection component is used to collect image information of the material in the identification area so that the color sorter can identify and sort the material based on the image information collected by the collection component. Since the intensity and uniformity of the illumination irradiated on the material have a significant impact on the accuracy and precision of the image information of the material collected by the collection component, the industry is committed to improving this aspect. Summary of the invention

[0003] In view of the deficiencies in the prior art, an object of the present disclosure is to provide a lens unit, an illumination device and a color sorter, which can improve the intensity and uniformity of illumination at a light receiving surface.

[0004] In some embodiments, the present disclosure provides a lens unit, which includes a transparent substrate, the transparent substrate having a first side and a second side opposite to each other along the thickness direction; a first microlens array is directly and integrally formed on the first side of the transparent substrate, the first microlens array is a two-dimensional array along the length direction and the width direction of the transparent substrate, and the first microlens array is configured to receive light from a light source and to homogenize the received light; a second microlens array and a third microlens array are directly and integrally formed on the second side of the transparent substrate, the second microlens array is a two-dimensional array along the length direction and the width direction of the transparent substrate, the third microlens array is a two-dimensional array along the length direction and the width direction of the transparent substrate, the second microlens array and the third microlens array are spaced apart along the width direction of the transparent substrate, and the second microlens array and the third microlens array are configured to converge the homogenized light passing through the first microlens array in the direction opposite to each other as a plurality of straight light rays arranged along the width direction.

[0005] In some embodiments, the first microlens array is composed of a plurality of first microlenses, each of which has an outer surface that is a portion of a spherical surface, whose orthographic projection along the thickness direction is a circle and convex in a direction away from the first side.

[0006] In some embodiments, the circles formed by the orthographic projections of the plurality of first microlenses along the thickness direction have the same radius, and the circles formed by the orthographic projections of the plurality of first microlenses along the thickness direction are arranged in multiple rows along the length direction; the circles in each row are arranged in the width direction, the centers of the circles in each row are located on the same straight line, two adjacent circles in each row are tangent to each other, and the tangent point of the two adjacent circles is located on the straight line; the centers of the circles in two adjacent rows are staggered in the width direction with the radius of the circle as a spacing, each circle in one of the two adjacent rows is tangent to an adjacent circle in the other row of the two adjacent rows, and the tangent point of the two tangent circles is in a straight line with the centers of the two tangent circles; the circumscribed regular hexagons of all the circles are arranged in multiple rows along the length direction, the regular hexagons in two adjacent rows are staggered in the width direction, and the adjacent corresponding sides of the regular hexagons in two adjacent rows overlap, thereby forming a two-dimensional array of regular hexagons.

[0007] In some embodiments, the second microlens array is composed of a plurality of second microlenses, and the plurality of second microlenses are arranged in a plurality of columns along the width direction; the transparent substrate has a flat base surface on the second side; each second microlens has a first inclined plane, and the first inclined plane extends obliquely from the base surface of the transparent substrate toward the third microlens array, and the first inclined plane is configured to converge the light after being homogenized by the first microlens array along the width direction toward the direction in which the second microlens array and the third microlens array are opposite to each other.

[0008] In some embodiments, the first inclined plane is inclined only along the width direction relative to the base surface.

[0009] In some embodiments, the first oblique planes of the second microlenses in each column are coplanar; the first oblique planes of the second microlenses in each column are configured so that light rays emerging from the first oblique planes of the second microlenses in the column are coplanar.

[0010] In some embodiments, the inclination angle of the first inclined plane and the highest height along the thickness direction of the second microlenses in the plurality of columns gradually decrease as the columns approach the third microlens array along the width direction.

[0011] In some embodiments, the base surface has a first side edge and a second side edge located on both sides in the width direction; the outermost side of the second microlens array away from the third microlens array along the width direction is close to the first side edge; the first oblique plane of each second microlens has a first edge, a second edge, a third edge and a fourth edge connected in sequence, the first edge is located on the base surface of the transparent substrate, the first edge is close to the first side edge, the third edge is parallel to the first edge, and the third edge is shorter than the first edge; each second microlens also has a second oblique plane, the second oblique plane is away from the base surface of the transparent substrate along the thickness direction of the transparent substrate and is inclined toward the second edge of the first oblique plane along the length direction of the transparent substrate, the second oblique plane intersects with the first oblique plane, and the second oblique plane and the first oblique plane share the fourth edge; the second oblique plane is configured to converge the light after homogenization through the first microlens array toward the direction in which the second microlens array and the third microlens array are opposite to each other; in each second microlens, the light coming out of the second oblique plane is not parallel to the light coming out of the first oblique plane.

[0012] In some embodiments, the second oblique planes of the second microlenses in each column are parallel; and the second oblique planes of the second microlenses in each column are configured so that light rays emerging from the second oblique planes of the second microlenses in the column are coplanar.

[0013] In some embodiments, the intersection line of each second microlens and the base surface of the transparent substrate forms a rectangle, the rectangles of all the second microlenses in each column are the same, the rectangles of the second microlenses in multiple columns are the same, and all the rectangles of the second microlenses in multiple columns form rows aligned along the length direction and columns aligned along the width direction.

[0014] In some embodiments, the third microlens array is composed of a plurality of third microlenses, and the plurality of third microlenses are arranged in a plurality of columns along the width direction; the transparent substrate has a flat base surface on the second side; each third microlens has a fifth oblique plane, and the fifth oblique plane extends obliquely from the base surface of the transparent substrate toward the second microlens array; the fifth oblique plane is configured to converge the light after being homogenized by the first microlens array along the width direction toward the direction in which the second microlens array and the third microlens array are relative to each other.

[0015] In some embodiments, the fifth inclined plane is inclined only along the width direction relative to the base surface.

[0016] In some embodiments, the fifth oblique planes of the third microlenses in each column are coplanar; the fifth oblique planes of the third microlenses in each column are configured so that light rays emerging from the fifth oblique planes of the third microlenses in the column are coplanar.

[0017] In some embodiments, the inclination angle of the fifth oblique plane and the highest height along the thickness direction of the third microlenses in the plurality of columns gradually decrease as the columns approach the second microlens array along the width direction.

[0018] In some embodiments, the base surface has a first side edge and a second side edge located on both sides in the width direction; the outermost side of the third microlens array away from the second microlens array along the width direction is close to the second side edge; the fifth oblique plane of each third microlens has a fifth side, a sixth side, a seventh side and an eighth side connected in sequence, the fifth side is located on the base surface of the transparent substrate, the fifth side is close to the second side edge, the seventh side is parallel to the fifth side, and the seventh side is shorter than the fifth side; each third microlens also has a sixth oblique plane, the sixth oblique plane is away from the base surface of the transparent substrate along the thickness direction of the transparent substrate and is inclined toward the sixth side of the fifth oblique plane along the length direction of the transparent substrate, the sixth oblique plane intersects with the fifth oblique plane, and the sixth oblique plane and the fifth oblique plane share the eighth side; the sixth oblique plane is configured to converge the light after homogenization through the first microlens array toward the direction in which the second microlens array and the third microlens array are opposite to each other; in each third microlens, the light coming out of the sixth oblique plane and the light coming out of the fifth oblique plane are not parallel.

[0019] In some embodiments, the sixth oblique planes of the third microlenses in each column are parallel; the sixth oblique planes of the third microlenses in each column are configured so that light rays emerging from the sixth oblique planes of the third microlenses in the column are coplanar.

[0020] In some embodiments, the intersection line of each third microlens and the base surface of the transparent substrate forms a rectangle, the rectangles of all the third microlenses in each column are the same, the rectangles of the third microlenses in multiple columns are the same, and all the rectangles of the third microlenses in multiple columns form rows aligned along the length direction and columns aligned along the width direction.

[0021] In some embodiments, the second microlens array is a mirror image of the third microlens array.

[0022] In some embodiments, the present disclosure also provides a lighting device, which includes a light source, and the lighting device also includes the aforementioned lens unit, the light source is a plurality of Lambertian light sources arranged at least along the length direction of the transparent substrate of the lens unit; the light source faces the first microlens array of the lens unit and is centered relative to the first microlens array of the lens unit; along the projection in the thickness direction of the transparent substrate of the lens unit, the light source is located in the interval between the projection of the second microlens array and the projection of the third microlens array.

[0023] In some embodiments, the present disclosure further provides a color sorter, which includes an identification device, the identification device is used to identify materials, the identification device includes the aforementioned lighting device, and the lighting device is used to illuminate the materials.

[0024] The beneficial effects of the present disclosure are as follows: through the convergence effect of the light of the second microlens array and the third microlens array combined with the uniformization effect of the light of the first microlens array, the intensity and uniformity of the illumination at the light receiving surface can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic diagram of an embodiment of a color sorter according to the present disclosure.

[0026] Figure 2 This is a stereoscopic diagram for schematically illustrating light rays coming out of a first oblique plane and a fifth oblique plane of a lens unit of an illumination device for a color sorter according to an embodiment of the present disclosure, wherein for the sake of clarity, only a light path diagram of a Lambertian light source is shown, a portion of the lens unit is cut away, and a portion where light rays converge is shown as a material.

[0027] Figure 3 is with Figure 2 A similar stereoscopic diagram is used to schematically illustrate the light rays coming out of the second oblique plane and the sixth oblique plane of the lens unit of the lighting device, wherein for the sake of comparison, the light rays coming out of a first oblique plane and the light rays coming out of a fifth oblique plane are shown in dotted lines.

[0028] Figure 4 is a cutaway perspective view of an embodiment of a lens unit according to the present disclosure.

[0029] Figure 5 yes Figure 4 Cross-sectional view of .

[0030] Figure 6 yes Figure 4 A perspective view of a lens unit observed from a first side, showing a first microlens array.

[0031] Figure 7 yes Figure 6 Top view of the .

[0032] Figure 8 is with Figure 7 The same view showing a regular hexagon circumscribing a circle.

[0033] Fig. 9 is with Figure 7 Similar partial view with the first microlens array arranged in another layout.

[0034] Fig.10 yes Figure 4 A perspective view of the lens unit as viewed from a second side, showing a second microlens array and a third microlens array.

[0035] Fig.11 yes Fig.10 Top view of the .

[0036] Fig.12 is a top view of one of the second microlenses, the second microlens being selected from Figure 4 The second microlens array is adjacent to a column of a third microlens array.

[0037] Fig.13 yes Fig.12 Right view of the second microlens.

[0038] Fig.14 yes Fig.12 Front view of the second microlens.

[0039] Fig.15A yes Fig.12 3D diagram of the forming process of the second microlens, wherein the rectangular hexahedron on the left is used to illustrate the spatial positional relationship of each surface of the second microlens.

[0040] Fig. 15B yes Fig.15A A variation of .

[0041] Fig.16 is a top view of one of the third microlenses, the third microlens being selected from Figure 4 The third microlens array is in a column adjacent to the second microlens array.

[0042] Fig.17 yes Fig.16 Left view of the third microlens.

[0043] Fig.18 yes Fig.16 Front view of the third microlens.

[0044] Fig.19A yes Fig.16 3D diagram of the forming process of the third microlens, wherein the rectangular hexahedron on the left is used to illustrate the spatial positional relationship of each surface of the third microlens.

[0045] Fig.19B yes Fig.19A A variation of .

[0046] Fig. 20 This is an embodiment of a light source of the lighting device according to the present disclosure.

[0047] Fig.21 is another embodiment of the light source of the lighting device according to the present disclosure.

[0048] The reference numerals are described as follows:

[0049] P Material

[0050] 100 Color Sorter

[0051] M1 Feeding Device

[0052] M11 Channel

[0053] M12 Feed Hopper

[0054] M13 vibrating hopper

[0055] M14 Vibrator

[0056] M2 Identification Device

[0057] M21 lighting fixture

[0058] 1 Lens unit

[0059] 11 Transparent substrate

[0060] L Length direction

[0061] W Width direction

[0062] T thickness direction

[0063] S1 First side

[0064] S2 Second side

[0065] 110 base surface

[0066] 110a First side edge

[0067] 110b Second side edge

[0068] 110c Third side edge

[0069] 110d Fourth side edge

[0070] 111 First microlens array

[0071] 111a First microlens

[0072] 111s outer surface

[0073] 112 second microlens array

[0074] 112a Second microlens

[0075] F1 First inclined plane

[0076] E1 First side

[0077] E2 Second side

[0078] E3 Third side

[0079] E4 Fourth side

[0080] F2 Second inclined plane

[0081] F3 Third vertical plane

[0082] F4 Fourth vertical plane

[0083] 113 Third microlens array

[0084] 113a The third microlens

[0085] F5 Fifth inclined plane

[0086] E5 Fifth Side

[0087] E6 Sixth side

[0088] E7 Seventh Side

[0089] E8 The Eighth Side

[0090] F6 Sixth inclined plane

[0091] F7 Seventh vertical plane

[0092] F8 Eighth vertical plane

[0093] 2 Light Source

[0094] M22 Background Components

[0095] M23 Acquisition Components

[0096] M3 Sorting Device

[0097] M4 Feeding Device DETAILED DESCRIPTION

[0098] The accompanying drawings show embodiments of the present disclosure, and it will be understood that the disclosed embodiments are merely examples and the present disclosure can be implemented in various forms. Therefore, the specific details disclosed herein should not be interpreted as limiting, but merely as the basis for the claims and as a representative basis for teaching ordinary technicians in the field to implement the present disclosure in various ways.

[0099] In the description of the present disclosure, unless otherwise specified, the terms "first", "second", "third", "fourth", "fifth", "sixth", "seventh", "eighth", etc. are only used for the purpose of description and component identification and are not to be understood as relative importance and mutual relationship.

[0100] In the present disclosure, expressions indicating directions such as up, down, left, right, front, and back, etc., used to illustrate the structure and action of the components of the color sorter are not absolute but relative. When the parts of the components of the color sorter are in the postures shown in the figures, these expressions are appropriate. However, when the postures of the components of the color sorter change, these expressions should be interpreted differently according to the changes in the postures.

[0101] Reference Figure 1 In one embodiment, the color sorter 100 includes a feeding device M1 and an identification device M2.

[0102] The feeding device M1 is used to receive the material P.

[0103] like Figure 1 As shown, in one embodiment, the feeding device M1 includes a channel M11, a feeding hopper M12, a vibrating hopper M13 and a vibrator M14.

[0104] The channel M11 is arranged obliquely relative to the horizontal direction. The upper and lower ends of the channel M11 are open, and the lower end of the channel M11 faces the identification device M2. The channel M11 is used to transport the material P received from the vibrating hopper M13 to the identification device M2. Figure 1 In the embodiment, the upper end of the channel M11 is located at the upper right, and the lower end of the channel M11 is located at the lower left. Figure 1 In the viewing direction, the channel M11 is inclined at an angle where the upper end is located at the upper left and the lower end is located at the lower right. The channel M11 is arranged inclined, so that the material P can not only slide to the lower end in the channel M11 by its own gravity, but also the wall of the channel M11 in contact with the material P can play a limiting and guiding role, reduce the bounce of the material P in the channel M11, and adjust the speed at which the material P enters the identification device M2. Figure 1 In the embodiment, the inclination angle of the channel M11 is about 60 degrees, so that when the material P enters the recognition area of ​​the recognition device M2, the speed can ensure that the recognition device M2 captures the entire shape image, thereby improving the recognition effect. The inclination angle of the channel M11 can be adjusted according to the speed requirements of the material P thrown out at the lower end of the channel M11. Figure 1 In the embodiment, the lower end of the channel M11 is located in the identification device M2, however, in a variant embodiment, the lower end of the channel M11 is outside the identification device M2, that is, the lower end of the channel M11 is located above the corresponding part of the identification device M2. In one embodiment, the channel M11 is a U-shaped structure, that is, the channel M11 is open on one side facing the vibrating hopper M13. In another embodiment, the channel M11 is open only at the part corresponding to the outlet of the vibrating hopper M13 in addition to the openings at the upper and lower ends, so that the vibrating hopper M13 is connected to the corresponding part of the channel M11.

[0105] The feed hopper M12 is opened at the top and bottom, and is used to receive the material P and send the material P downward. In other words, the feed hopper M12 receives the material P from the top and sends the material P from the bottom. Figure 1 As shown, in order to facilitate the downward delivery of the material P, the feed hopper M12 adopts a structure with a large upper part and a small lower part, and the lower part is gradually reduced.

[0106] The vibrating hopper M13 is located below the feed hopper M12 and is used to receive the material P sent out by the feed hopper M12 and output it to the channel M11. Figure 1 In the embodiment, the vibrating hopper M13 is arranged horizontally as a whole.

[0107] The vibrator M14 is located below the vibrating hopper M13 and applies vibration to the vibrating hopper M13 so that the material in the vibrating hopper M13 is unidirectionally output to the channel M11. The speed and amount of the unidirectional conveying of the material P are adjusted according to the vibration force and frequency of the vibrator M14. The structure of the vibrator M14 can adopt any suitable structure, such as the structure adopted in the Chinese patent application publication number CN109225942A published on January 18, 2019.

[0108] The identification device M2 is located below the feeding device M1. The identification device M2 is used to identify the material P conveyed through the channel M11. Specifically, the identification device M2 determines whether the material P meets the requirements according to the color and / or material of the material P entering the identification device M2.

[0109] In one embodiment, referring to Figure 1 The recognition device M2 includes a lighting device M21, a background component M22 and a collection component M23.

[0110] The lighting device M21 is used to illuminate the material P entering the identification area. The background component M22 is used to provide an image background, so that the image information collected by the acquisition component M23 is more accurate and the identification of the material P is more precise. The acquisition component M23 is used to collect image information of the material P in the identification area, so that the color sorter 100 can identify and sort the material P according to the image information collected by the acquisition component M23. The background component M22 and the acquisition component M23 can be any suitable known structure, for example, the structure of the Chinese patent application authorization announcement number CN210131821U authorized and announced on March 10, 2020.

[0111] In one embodiment, referring to Figure 2 and Figure 3 , the lighting device M21 includes a lens unit 1 and a light source 2.

[0112] In one embodiment, referring to 2 to Figure 5 , the lens unit 1 includes a transparent substrate 11 .

[0113] The material of the transparent substrate 1 is not particularly limited, and may be plastic or glass. In one embodiment, the plastic is optical grade acrylic material.

[0114] The transparent substrate 11 has a first side S1 and a second side S2 opposite to each other in a thickness direction T. The transparent substrate 11 has a flat base surface 110 on the second side S2. The base surface 110 has a first side edge 110a and a second side edge 110b located on both sides in a width direction W. Fig.10 In the embodiment, the first side edge 110a is located on the left side, and the second side edge 110b is located on the right side. Further, the base surface 110 has a third side edge 110c and a fourth side edge 110d located on both sides of the length direction L. Fig.10 In the embodiment, the third side edge 110c is located at the front side, and the fourth side edge 110d is located at the rear side.

[0115] The transparent substrate 11 has a first microlens array 111 formed integrally on the first side S1. The first microlens array 111 is a two-dimensional array along the length direction L and the width direction W of the transparent substrate 11. The first microlens array 111 is configured to receive light from the light source 2 and homogenize the received light.

[0116] The first microlens array 111 is composed of a plurality of first microlenses 111a. Figures 6 to 8 Combined with Figures 4 to 5 Each first microlens 111a has an outer surface 111s, which is a part of a spherical surface, and the orthographic projection of the outer surface 111s along the thickness direction T is a circle and convex in the direction away from the first side S1. The curvature of the spherical surface is determined by the distance from the outer surface 111s to the light source 2. In a variant embodiment, the outer surface 111s of each first microlens 111a can adopt other suitable shapes as long as the light can be uniformed.

[0117] In one embodiment, referring to Figure 7 and Figure 8 The circles formed by the orthographic projections of the plurality of first microlenses 111a along the thickness direction T have the same radius, and the circles formed by the orthographic projections of the plurality of first microlenses 111a along the thickness direction T are arranged in multiple rows along the length direction L; the circles in each row are arranged in the width direction W, and the centers of the circles in each row are located on the same straight line, and two adjacent circles in each row are tangent to each other, and the tangent point of the two adjacent circles is located on the straight line; the centers of the circles in two adjacent rows are staggered in the width direction W with the radius of the circle as a spacing, and each circle in one of the two adjacent rows is tangent to an adjacent circle in the other row of the two adjacent rows, and the tangent point of the two tangent circles is in a straight line with the centers of the two tangent circles; the circumscribed regular hexagons of all the circles are arranged in multiple rows along the length direction L, and the regular hexagons in two adjacent rows are staggered in the width direction W, and the corresponding adjacent sides of the regular hexagons in two adjacent rows overlap, thereby forming a regular hexagonal two-dimensional array.

[0118] In another embodiment, if Fig. 9As shown, all the circumscribed squares of the circles are arranged to form a layout in which the columns along the length direction L and the rows along the width direction W are aligned. Fig. 9 In the layout of , there is a gap between adjacent first micro lenses 111a. Figure 8 In the layout of FIG. 1 , there is also a gap between adjacent first microlenses 111 a, but Figure 8 The gap in Fig. 9 Since there is no first microlens 111a in the gap, the gap part does not have the first microlens 111a to homogenize the incoming light. After the unhomogenized light is converged by the second microlens array 112 and the third microlens array 113, it will focus on the focusing area (in Figure 2 and Figure 3 The smaller the gap is, the smaller the impact on the uniformity of the illumination of the light-collecting area of ​​the second microlens array 112 and the third microlens array 113 is. Fig. 9 Compared with the layout of the first microlens 111a, Figure 8 The layout of the first microlens 111a has much less influence in this regard, so in theory it can be considered that after the first microlens array 111 has homogenized the light from the light source 2, the light at any position within the area of ​​the transparent substrate 11 covered by the first microlens array 111 is uniform.

[0119] Reference Fig.10 and Fig.11 Combined with Figures 2 to 5 The transparent substrate 11 is directly formed with a second microlens array 112 and a third microlens array 113 on the second side S2. In other words, the second microlens array 112 and the third microlens array 113 are directly formed integrally with the first microlens array 111 by the transparent substrate 11. The forming method may be, for example, a substrate die forming, but is not limited thereto, and may also be injection molding or transparent substrate 11 engraving.

[0120] As shown, the outermost side of the second microlens array 112 away from the third microlens array 113 along the width direction W is close to the first side edge 110a, and the outermost side of the third microlens array 113 away from the second microlens array 112 along the width direction W is close to the second side edge 110b.

[0121] The second microlens array 112 is a two-dimensional array along the length direction L and the width direction W of the transparent substrate 11. The third microlens array 113 is a two-dimensional array along the length direction L and the width direction W of the transparent substrate 11. The second microlens array 112 and the third microlens array 113 are spaced apart along the width direction W of the transparent substrate 11. The second microlens array 112 and the third microlens array 113 are configured to converge the uniformized light passing through the first microlens array 111 through the second microlens array 112 and the third microlens array 113 as a plurality of straight light rays arranged along the width direction W toward the second microlens array 112 and the third microlens array 113 in the direction opposite to each other, such as Figure 2 and Figure 3 The light collected by the second microlens array 112 and the third microlens array 113 is reflected on the light receiving surface (at Figure 2 and Figure 3 In the embodiment, the receiving surface is the side of the material P facing the light, and a rectangular area is formed instead of a spot where the light of the traditional lens converges in a conical distribution. The convergence effect of the light of the second microlens array 112 and the third microlens array 113 combined with the uniformity effect of the light of the first microlens array 111 can improve the light receiving surface (on the Figure 2 and Figure 3 The receiving surface is the side of the material P facing the light) to measure the intensity and uniformity of the illumination. It is noted that the thickness of the transparent substrate 11 other than the first microlens array 111, the second microlens array 112 and the third microlens array 113 is determined based on the structural strength and the energy loss of the light.

[0122] The second microlens array 112 is composed of a plurality of second microlenses 112a, which are arranged in a plurality of rows along the width direction W. The number of the plurality of rows is determined by the number of the focused light on the light receiving surface (on the Figure 2 and Figure 3 The more columns there are, the better the intensity and uniformity of the illumination at the light receiving surface. In one embodiment, referring to Figures 12 to 15A , Fig. 15B Combined with Figures 2 to 5 Each second microlens 112a has a first inclined plane F1, which extends obliquely from the base surface 110 of the transparent substrate 11 toward the third microlens array 113, and the first inclined plane F1 is configured to converge the uniformized light passing through the first microlens array 111 along the width direction W toward the direction in which the second microlens array 112 and the third microlens array 113 are relative to each other.

[0123] In one embodiment, if Figures 2 to 5 and Fig.10As shown, the first inclined plane F1 is inclined relative to the base surface 110 only along the width direction W. In this way, the first inclined plane F1 is not only simple in design and formation, but also easy to control the convergence direction of the light emitted from the first inclined plane F1.

[0124] In one embodiment, referring to Fig.10 Combined with Figures 2 to 5 , the first oblique planes F1 of the second microlenses 112a in each column are coplanar; the first oblique planes F1 of the second microlenses 112a in each column are configured so that the light rays coming out of the first oblique planes F1 of the second microlenses 112a in the column are coplanar. Thus, the light rays coming out of the first oblique planes F1 of the second microlenses 112a in each column form a straight line along the length direction L of the transparent substrate 11 (note that the straight line has a certain width in the width direction W of the transparent substrate), thereby making the light receiving surface (on the side of the light receiving surface) of the converged light Figure 2 and Figure 3 In the example, the receiving surface is the side of the material P facing the light, and the illumination uniformity of the area covered by the straight line is good.

[0125] In one embodiment, referring to Fig.10 Combined with Figures 2 to 5 , the inclination angle of the first oblique plane F1 of the second microlenses 112a in the plurality of columns and the highest height along the thickness direction T gradually decrease as the columns approach the third microlens array 113 along the width direction W. Thus, the first oblique plane F1 of the second microlenses 112a in the plurality of columns forms light rays that converge layer by layer from the outside to the inside along the width direction W at the inner and outer positions of the columns along the width direction W (i.e., the position close to the first side edge 110a is the outside, and the position close to the third microlens array 113 is the inside). In addition, the second microlens array 112 and the third microlens array 113 are spaced apart along the width direction W of the transparent substrate 11, and the second microlens 112a disappears in the area where the second microlens array 112 and the third microlens array 113 are spaced apart. In other words, the inclination angle of the first inclined plane F1 and the maximum height along the thickness direction T of the second microlenses 112a in the multiple columns gradually decrease as the columns approach the third microlens array 113 along the width direction W, until the inclination angle of the first inclined plane F1 and the maximum height along the thickness direction T are both zero, and the first inclined plane F1 is coplanar with the base surface 110 of the transparent substrate 11.

[0126] In one embodiment, referring to Figures 12 to 15A , Fig. 15B Combined with Figures 2 to 5, the first oblique plane F1 of each second microlens 112a has a first side E1, a second side E2, a third side E3 and a fourth side E4 connected in sequence, the first side E1 is located on the base surface 110 of the transparent substrate 11, the first side E1 is close to the first side edge 110a, the third side E3 is parallel to the first side E1, and the third side E3 is shorter than the first side E1. In one embodiment, as shown in the figure, the third side E3 is half of the first side E1. Of course, it is not limited to this, and the relative relationship between the third side E3 and the first side E1 in size can be determined by combining the light converging effect of the first oblique plane F1 and the light converging effect of the second oblique plane F2 described later. Note that in Fig.15A In FIG. 1 , the second side E2 is closer to the third side edge 110 c of the base surface 110 than the fourth side E4, and the first side E1, the second side E2, the third side E3 and the fourth side E4 are sequentially connected in a clockwise direction; and Fig. 15B In the figure, the second side E2 is closer to the fourth side edge 110d of the base surface 110 than the fourth side E4, and the first side E1, the second side E2, the third side E3 and the fourth side E4 are connected in sequence in a counterclockwise direction; in other words, the second side E2 is closer to a side edge of the length direction L of the base surface 110 (i.e., the third side edge 110c or the fourth side edge 110d) than the fourth side E4.

[0127] In one embodiment, referring to Figures 12 to 15A , Fig. 15B Combined with Figures 2 to 5 Each second microlens 112a also has a second inclined plane F2, which is inclined from the base surface 110 of the transparent substrate 11 along the thickness direction T of the transparent substrate 11 away from the base surface 110 of the transparent substrate 11 and along the length direction L of the transparent substrate 11 toward the second side E2 of the first inclined plane F1, the second inclined plane F2 intersects with the first inclined plane F1, and the second inclined plane F2 and the first inclined plane F1 share a fourth side E4. The second inclined plane F2 is configured to converge the light after being homogenized by the first microlens array 111 toward the direction in which the second microlens array 112 and the third microlens array 113 are opposite to each other, such as Figure 3 In each second microlens 112a, the light coming out of the second oblique plane F2 is not parallel to the light coming out of the first oblique plane F1. Figure 3 As shown. Fig.15A and Fig. 15BAs shown, the second inclined plane F2 is not only inclined along the width direction W relative to the base surface 110 like the first inclined plane F1, but also inclined along the length direction L relative to the base surface 110, whereby the second inclined plane F2 not only converges the light emitted therefrom toward the directions in which the second microlens array 112 and the third microlens array 113 are relative to each other, but also deviates the light emitted from the second inclined plane F2 along the length direction L toward one side of the light emitted from the corresponding first inclined plane F1, thereby increasing the intensity of the light emitted from the first inclined plane F1 at or near the position of the focusing area, and increasing the utilization rate of the light emitted in the length direction L provided by the light source 2.

[0128] In one embodiment, referring to Fig.10 Combined with Figure 3 , the second oblique planes F2 of the second microlenses 112a in each column are parallel; the second oblique planes F2 of the second microlenses 112a in each column are arranged so that the light rays coming out of the second oblique planes F2 of the second microlenses 112a in the column are coplanar. Similarly, the second oblique planes F2 of the second microlenses 112a in the plurality of columns form light rays that converge layer by layer from the outside to the inside along the width direction W at the inner and outer positions of the columns along the width direction W (i.e., the position close to the first side edge 110a is the outside, and the position close to the third microlens array 113 is the inside), thereby improving the uniformity of illumination at the light-focusing area.

[0129] Reference Figures 12 to 15A , Fig. 15B Combined with Figure 4 , each second microlens 112a also has a third vertical plane F3 and a fourth vertical plane F4. The third vertical plane F3 is located in a plane formed by the width direction W and the thickness direction T. The fourth vertical plane F4 is located in a plane formed by the length direction L and the thickness direction T. The third vertical plane F3 and the second inclined plane F2 are separated by the first inclined plane F1 and the fourth vertical plane F4. In this way, the optical path control of each second microlens 112a becomes simple (i.e., it is sufficient to control the first inclined plane F1 and the second inclined plane F2), the forming design is simple in the structure of the mold, and the shape is easy to control.

[0130] In one embodiment, the intersection line of each second microlens 112a and the base surface 110 of the transparent substrate 11 forms a rectangle, the rectangles of all the second microlenses 112a in each column are the same, the rectangles of the second microlenses 112a in multiple columns are the same, and all the rectangles of the second microlenses 112a in multiple columns form rows aligned along the length direction L and columns aligned along the width direction W. By adopting a rectangle, the light path control of each second microlens 112a becomes simple, the forming design is simple in the structure of the mold, and the shape is easy to control. Similarly, the number of rows of the multiple rows is determined based on the requirements of the intensity and uniformity of the illumination of the converged light on the light receiving surface. The more rows, the better the intensity and uniformity of the illumination of the converged light on the light receiving surface. In one embodiment, the rectangle is a square, such as Fig.11 As shown, in this way, the optical path control of each second microlens 112a becomes simpler, the forming design is simpler in the structure of the mold, and the shape is easier to control. In addition, when the rectangle is a square and the third side E3 is half of the first side E1, the light from the first oblique plane F1 of each second microlens 112a and the light from the second oblique plane F2 are on the same straight line along the length direction L on the light receiving plane perpendicular to the thickness direction T of the transparent substrate 11. It should be noted that there is not necessarily a one-to-one correspondence between the rectangle (or even the square) of the second microlens 112a and the regular hexagon of the first microlens 112a, as long as the coverage area of ​​the regular hexagonal two-dimensional array of the aforementioned first microlens array 111 on the transparent substrate 11 can cover the coverage area of ​​the rectangular array (or even the square array) of the second microlens array 112 on the transparent substrate 11.

[0131] Reference Fig.10 Combined with Figures 2 to 5 The third microlens array 113 is composed of a plurality of third microlenses 113a, and the plurality of third microlenses 113a are arranged in a plurality of columns along the width direction W. As in the case of the second microlens array 112, the number of the plurality of columns is determined according to the requirements of the intensity and uniformity of the illumination of the convergent light at the light receiving surface, and the greater the number of columns, the better the intensity and uniformity of the illumination of the convergent light at the light receiving surface.

[0132] Each of the third microlenses 113a has a fifth oblique plane F5, which extends obliquely from the base surface 110 of the transparent substrate 11 toward the second microlens array 112. Figure 2 The fifth oblique plane F5 is configured to converge the light after being homogenized by the first microlens array 111 along the width direction W toward the direction in which the second microlens array 112 and the third microlens array 113 are opposite to each other.

[0133] Like the first inclined plane F1, in one embodiment, the fifth inclined plane F5 is inclined relative to the base surface 110 only along the width direction W. Thus, the fifth inclined plane F5 is not only simple in design and formation, but also easy to control the convergence direction of the light from the fifth inclined plane F5.

[0134] Reference Fig.10 Combined with Figures 2 to 5 , the fifth oblique planes F5 of the third microlenses 113a in each column are coplanar, and the fifth oblique planes F5 of the third microlenses 113a in each column are configured so that the light rays coming out of the fifth oblique planes F5 of the third microlenses 113a in the column are coplanar. Thus, as in the case of the second microlens array 112, the light rays coming out of the fifth oblique planes F5 of the third microlenses 113a in each column form a straight line along the length direction L of the transparent substrate 11 (note that the straight line has a certain width in the width direction W of the transparent substrate), thereby making the light receiving surface (at the direction W of the width direction W of the transparent substrate) of the converged light Figure 2 and Figure 3 In the example, the receiving surface is the side of the material P facing the light, and the illumination uniformity of the area covered by the straight line is good.

[0135] Reference Fig.10 Combined with Figures 2 to 5 , the inclination angle of the fifth oblique plane F5 of the third microlenses 113a in the plurality of columns and the highest height along the thickness direction T gradually decrease as the columns approach the second microlens array 112 along the width direction W. Thus, as in the case of the second microlens array 112, the fifth oblique plane F5 of the third microlenses 113a in the plurality of columns forms light rays that converge layer by layer from the outside to the inside along the width direction W at the inner and outer positions of the columns along the width direction W (i.e., the position close to the second side edge 110b is the outside, and the position close to the second microlens array 112 is the inside). In addition, the second microlens array 112 and the third microlens array 113 are spaced apart along the width direction W of the transparent substrate 11, and the third microlens 113a disappears in the area where the second microlens array 112 and the third microlens array 113 are spaced apart. In other words, the inclination angle of the fifth oblique plane F5 and the maximum height along the thickness direction T of the third microlenses 113a in the multiple columns gradually decrease as the columns approach the second microlens array 112 along the width direction W, until the inclination angle of the fifth oblique plane F5 and the maximum height along the thickness direction T are both zero, and the fifth oblique plane F5 is coplanar with the base surface 110 of the transparent substrate 11.

[0136] In one embodiment, referring to Figures 16 to 19A , Fig.19B Combined with Figures 2 to 5, the fifth oblique plane F5 of each third microlens 113a has a fifth side E5, a sixth side E6, a seventh side E7 and an eighth side E8 connected in sequence, the fifth side E5 is located on the base surface 110 of the transparent substrate 11, the fifth side E5 is close to the second side edge 110b, the seventh side E7 is parallel to the fifth side E5, and the seventh side E7 is shorter than the fifth side E5. In one embodiment, as shown in the figure, the seventh side E7 is half of the fifth side E5. Of course, it is not limited to this. The relative relationship between the seventh side E7 and the fifth side E5 in size can be determined by combining the light converging effect of the fifth oblique plane F5 and the light converging effect of the sixth oblique plane F6 described later. Note that in Fig.19A In FIG. 1 , the sixth side E6 is closer to the third side edge 110 c of the base surface 110 than the eighth side E8, and the fifth side E5, the sixth side E6, the seventh side E7 and the eighth side E8 are sequentially connected in a counterclockwise direction; and Fig.19B , the sixth side E6 is closer to the fourth side edge 110d of the base surface 110 than the eighth side E8, and the fifth side E5, the sixth side E6, the seventh side E7 and the eighth side E8 are connected in sequence in a clockwise direction; in other words, the sixth side E6 is closer to a side edge (i.e., the third side edge 110c or the fourth side edge 110d) in the length direction L of the base surface 110 than the eighth side E8.

[0137] In one embodiment, referring to Figures 16 to 19A , Fig.19B Combined with Figures 2 to 5 Each third microlens 113a also has a sixth oblique plane F6, which is inclined from the base surface 110 of the transparent substrate 11 along the thickness direction T of the transparent substrate 11 away from the base surface 110 of the transparent substrate 11 and along the length direction L of the transparent substrate 11 toward the sixth side E6 of the fifth oblique plane F5, the sixth oblique plane F6 intersects with the fifth oblique plane F5, and the sixth oblique plane F6 and the fifth oblique plane F5 share an eighth side E8. The sixth oblique plane F6 is configured to converge the light after being uniformed by the first microlens array 111 toward the direction in which the second microlens array 112 and the third microlens array 113 are opposite to each other, such as Figure 3 In each third microlens 113a, the light coming out of the sixth oblique plane F6 and the light coming out of the fifth oblique plane F5 are not parallel, as shown in FIG. Figure 3 As shown. Fig.19A and Fig.19BAs shown, the sixth inclined plane F6 is not only inclined along the width direction W relative to the base surface 110 like the second inclined plane F2, but also inclined along the length direction L relative to the base surface 110, whereby the sixth inclined plane F6 not only converges the light emitted therefrom toward the directions in which the second microlens array 112 and the third microlens array 113 are relative to each other, but also deviates the light emitted from the sixth inclined plane F6 along the length direction L toward one side of the light emitted from the corresponding fifth inclined plane F5, thereby increasing the intensity of the light emitted from the sixth inclined plane F6 at or near the position of the focusing area, and increasing the utilization rate of the light emitted in the length direction L provided by the light source 2.

[0138] In one embodiment, referring to Fig.10 Combined with Figure 3 , the sixth oblique planes F6 of the third microlenses 113a in each column are parallel. The sixth oblique planes F6 of the third microlenses 113a in each column are configured so that the light rays coming out of the sixth oblique planes F6 of the third microlenses 113a in the column are coplanar. Similarly, the sixth oblique planes F6 of the third microlenses 113a in the plurality of columns form light rays that converge from the outside to the inside along the width direction W at the inner and outer positions of the columns along the width direction W (i.e., the position close to the second side edge 110b is the outside, and the position close to the second microlens array 112 is the inside), thereby improving the uniformity of illumination at the light-focusing area.

[0139] In one embodiment, referring to Figures 16 to 19A , Fig.19B Combined with Figure 4 , each third microlens 113a also has a seventh vertical plane F7 and an eighth vertical plane F8. The seventh vertical plane F7 is located in a plane formed by the width direction W and the thickness direction T. The eighth vertical plane F8 is located in a plane formed by the length direction L and the thickness direction T. The seventh vertical plane F7 and the sixth oblique plane F6 are separated by the fifth oblique plane F5 and the eighth vertical plane F8. In this way, the optical path control of each third microlens 113a becomes simple (i.e., the fifth oblique plane F2 and the sixth oblique plane F6 can be controlled), the forming design is simple in the structure of the mold, and the shape is easy to control.

[0140] In one embodiment, the intersection line of each third microlens 113a and the base surface 110 of the transparent substrate 11 forms a rectangle, the rectangles of all the third microlenses 113a in each column are the same, the rectangles of the third microlenses 113a in multiple columns are the same, and all the rectangles of the third microlenses 113a in multiple columns form rows aligned along the length direction L and columns aligned along the width direction W. By adopting a rectangle, the light path control of each third microlens 113a becomes simple, the forming design is simple in the structure of the mold, and the shape is easy to control. Similarly, the number of rows of the multiple rows is determined based on the requirements of the intensity and uniformity of the illumination of the converged light at the light receiving surface. The more rows, the better the intensity and uniformity of the illumination of the converged light at the light receiving surface. In one embodiment, the rectangle is a square, such as Fig.11 As shown, in this way, the optical path control of each third microlens 113a becomes simpler, the forming design is simpler in the structure of the mold, and the shape is easier to control. In addition, when the rectangle is a square and the seventh side E7 is half of the fifth side E5, the light from the fifth oblique plane F5 of each third microlens 113a and the light from the sixth oblique plane F6 are on the same straight line along the length direction L on the light receiving plane perpendicular to the thickness direction T of the transparent substrate 11. Similarly, it is noted that there is not necessarily a one-to-one correspondence between the rectangle (or even the square) of the third microlens 113a and the regular hexagon of the first microlens 112a, as long as the coverage area of ​​the regular hexagonal two-dimensional array of the aforementioned first microlens array 111 on the transparent substrate 11 can cover the coverage area of ​​the rectangular array (or even the square array) of the third microlens array 113 on the transparent substrate 11.

[0141] In one embodiment, as 10 and Fig.11 As shown, the second microlens array 112 is mirrored with the third microlens array 113. In other words, the second microlens array 112 is mirrored with the third microlens array 113 in the same shape and size, thereby simplifying the optical path control of the second microlens array 112 and the third microlens array 113, simplifying the mold structure, and making the shape easy to control.

[0142] Reference Figure 2 , Figure 3 , Fig. 20 and Fig.21 The light source 2 is a plurality of Lambertian light sources arranged at least along the length direction L of the transparent substrate 11 of the lens unit 1. The light source 2 is arranged at least along the length direction L of the transparent substrate 11 of the lens unit 1 to form an extended light source, and the size (i.e., span) of the extended light source in the length direction L of the transparent substrate 11 is determined according to the range within which the edge light of the light source 2 in the length direction W of the transparent substrate 11 can be projected into the first microlens array 111.

[0143] The light source 2 faces the first microlens array 111 of the lens unit 1 and is centered relative to the first microlens array 111 of the lens unit 1. The light source 2 is located in the interval between the projection of the second microlens array 112 and the projection of the third microlens array 113 along the projection of the thickness direction T of the transparent substrate 11 of the lens unit 1. In this way, the light source 2 in the form of a Lambertian light source can provide symmetrical incident light to the first microlens array 111 with the light source 2 as the center in the width direction W of the transparent substrate 11, as shown in FIG. Figure 2 and Figure 3 As shown. Due to the existence of the interval, the light after homogenization by the first microlens array 111 is directly incident on the light receiving surface, and the size of the interval is determined according to the distance between the second microlens array 112 and the third microlens array 113 and the light receiving surface along the thickness direction of the transparent substrate 11 and the uniformity of the illumination at the light receiving surface.

[0144] In one embodiment, if Fig. 20 As shown, the plurality of light sources 2 in the form of Lambertian light sources are arranged in a one-dimensional array along the length direction L. In another embodiment, as Fig.21 As shown, the multiple light sources 2 in the form of Lambertian light sources are a two-dimensional array arranged along the length direction L and the width direction W. Whether the multiple light sources 2 in the form of Lambertian light sources are in a one-dimensional array or the two-dimensional array, they are determined based on the range within which the edge light of the light source 2 in the width direction W of the transparent substrate 11 can be projected into the first microlens array 111, in other words, based on the divergence angle of the Lambertian light source and the distance from the Lambertian light source to the first microlens array 111 along the thickness direction T of the transparent substrate 11.

[0145] In photometry, the luminous intensity emitted by a Lambertian light source in a certain direction is equal to the luminous intensity in the direction perpendicular to the luminous surface of the light source multiplied by the cosine of the direction angle, so the Lambertian light source is also called a cosine emitter.

[0146] In one embodiment, each light source 2 in the form of a Lambertian light source is an LED, but is not limited thereto, as long as it can work with the lens unit 1. In one embodiment, the divergence angle of the LED is 120°, and the LED with a divergence angle of 120° is an isotropic light source, so that the light source can have consistent brightness in all directions, and of course other divergence angles can also be used.

[0147] like Figure 1 As shown, in one embodiment, the color sorter 100 further includes a sorting device M3, a material receiving device M4 and a frame (not shown).

[0148] The sorting device M3 is communicatively connected to the identification device M2. The sorting device M3 is located below the identification device M2. The sorting device M3 ejects the non-compliant material P to change the trajectory of the material P and removes it, or ejects the compliant material P to change the trajectory of the compliant material P and collect it, based on whether the material P meets the requirements as determined by the identification device M2. The ejection can be implemented based on any suitable air path system and control system.

[0149] The material receiving device M4 is provided with a first receiving chamber (not shown) and a second receiving chamber (not shown) which are separated from each other. The first receiving chamber and the second receiving chamber are used to receive materials P that meet the requirements or materials P that do not meet the requirements, respectively.

[0150] The feeding device M1, the identifying device M2, the sorting device M3 and the receiving device M4 are all installed on a frame (not shown).

[0151] Note that, based on the functions of the lighting device M2 and the lens unit 1 , the lighting device M2 and the lens unit 1 can each be applied to other fields besides the color sorter 100 .

[0152] The above detailed description describes multiple exemplary embodiments, but this document is not intended to be limited to the explicitly disclosed combinations. Therefore, unless otherwise stated, the various features disclosed herein may be combined together to form multiple additional combinations that are not shown for the sake of simplicity.

Claims

1. A lens unit (1), comprising a transparent substrate (11), the transparent substrate (11) having a first side (S1) and a second side (S2) opposite to each other along a thickness direction (T); It is characterized in that A first microlens array (111) is directly and integrally formed on a first side (S1) of the transparent substrate (11), the first microlens array (111) being a two-dimensional array along a length direction (L) and a width direction (W) of the transparent substrate (11), the first microlens array (111) being configured to receive light from a light source (2) and to homogenize the received light; A second microlens array (112) and a third microlens array (113) are directly and integrally formed on a second side (S2) of the transparent substrate (11); the second microlens array (112) is a two-dimensional array along the length direction (L) and the width direction (W) of the transparent substrate (11); the third microlens array (113) is a two-dimensional array along the length direction (L) and the width direction (W) of the transparent substrate (11); the second microlens array (112) and the third microlens array (113) are spaced apart along the width direction (W) of the transparent substrate (11); the second microlens array (112) and the third microlens array (113) are configured to converge a plurality of straight light rays arranged along the width direction (W) after the light rays homogenized by the first microlens array (111) pass through the second microlens array (111) toward the direction in which the second microlens array (112) and the third microlens array (113) are opposite to each other; The second microlens array (112) is composed of a plurality of second microlenses (112a), and the plurality of second microlenses (112a) are arranged in a plurality of rows along a width direction (W); The transparent substrate (11) has a flat base surface (110) on the second side (S2), and the base surface (110) has a first side edge (110a) and a second side edge (110b) located on both sides of the width direction (W); Each second microlens (112a) has a first inclined plane (F1), and the first inclined plane (F1) extends obliquely from the base surface (110) of the transparent substrate (11) toward the third microlens array (113); The first oblique plane (F1) of each second microlens (112a) has a first edge (E1), a second edge (E2), a third edge (E3) and a fourth edge (E4) connected in sequence, the first edge (E1) is located on the base surface (110) of the transparent substrate (11), the first edge (E1) is close to the first side edge (110a), the third edge (E3) is parallel to the first edge (E1), and the third edge (E3) is shorter than the first edge (E1); Each second microlens (112a) further comprises a second inclined plane (F2), the second inclined plane (F2) being inclined from the base surface (110) of the transparent substrate (11) along the thickness direction (T) of the transparent substrate (11) away from the base surface (110) of the transparent substrate (11) and along the length direction (L) of the transparent substrate (11) toward the second edge (E2) of the first inclined plane (F1), the second inclined plane (F2) intersecting with the first inclined plane (F1), and the second inclined plane (F2) and the first inclined plane (F1) sharing a fourth edge (E4); The third microlens array (113) is composed of a plurality of third microlenses (113a), and the plurality of third microlenses (113a) are arranged in a plurality of rows along a width direction (W); Each third microlens (113a) has a fifth oblique plane (F5), and the fifth oblique plane (F5) extends obliquely from the base surface (110) of the transparent substrate (11) toward the second microlens array (112); The fifth oblique plane (F5) of each third microlens (113a) has a fifth side (E5), a sixth side (E6), a seventh side (E7) and an eighth side (E8) connected in sequence, the fifth side (E5) is located on the base surface (110) of the transparent substrate (11), the fifth side (E5) is close to the second side edge (110b), the seventh side (E7) is parallel to the fifth side (E5), and the seventh side (E7) is shorter than the fifth side (E5); Each third microlens (113a) further comprises a sixth oblique plane (F6), the sixth oblique plane (F6) being inclined from the base surface (110) of the transparent substrate (11) along the thickness direction (T) of the transparent substrate (11) away from the base surface (110) of the transparent substrate (11) and along the length direction (L) of the transparent substrate (11) toward the sixth edge (E6) of the fifth oblique plane (F5), the sixth oblique plane (F6) intersecting with the fifth oblique plane (F5), and the sixth oblique plane (F6) and the fifth oblique plane (F5) sharing an eighth edge (E8).

2. The lens unit (1) according to claim 1, characterized in that: The first microlens array (111) is composed of a plurality of first microlenses (111a). Each first microlens (111a) has an outer surface (111s), which is a part of a spherical surface, and the orthographic projection of the outer surface (111s) along the thickness direction (T) is a circle and convex in a direction away from the first side (S1).

3. The lens unit (1) according to claim 2, characterized in that: The circles formed by the orthographic projections of the plurality of first microlenses (111a) along the thickness direction (T) have the same radius, and the circles formed by the orthographic projections of the plurality of first microlenses (111a) along the thickness direction (T) are arranged in multiple rows along the length direction (L); The circles in each row are arranged along the width direction (W), the centers of the circles in each row are located on the same straight line, and two adjacent circles in each row are tangent to each other and the tangent point between the two adjacent circles is located on the straight line; The centers of the circles of two adjacent rows are staggered in the width direction (W) with the radius of the circle as the interval, each circle in one of the two adjacent rows is tangent to an adjacent circle in the other of the two adjacent rows, and the tangent point of the two tangent circles is in a straight line with the centers of the two tangent circles; All the circumscribed regular hexagons of the circle are arranged in multiple rows along the length direction (L), and the regular hexagons in two adjacent rows are staggered in the width direction (W). The corresponding sides of the regular hexagons in two adjacent rows overlap, thereby forming a two-dimensional array of regular hexagons.

4. The lens unit (1) according to claim 1, characterized in that: The first inclined plane (F1) is configured to converge the light after being homogenized by the first microlens array (111) along the width direction (W) toward the direction in which the second microlens array (112) and the third microlens array (113) are opposite to each other.

5. The lens unit (1) according to claim 4, characterized in that: The first inclined plane (F1) is inclined only in the width direction (W) relative to the base surface (110).

6. The lens unit (1) according to claim 4, characterized in that: The first oblique planes (F1) of the second microlenses (112a) in each column are coplanar; The first oblique planes (F1) of the second microlenses (112a) in each column are arranged so that the light rays emerging from the first oblique planes (F1) of the second microlenses (112a) in the column are coplanar.

7. The lens unit (1) according to claim 4, characterized in that: The inclination angle of the first inclined plane (F1) of the second microlenses (112a) in the plurality of columns and the highest height along the thickness direction T gradually decrease as the columns approach the third microlens array (113) along the width direction (W).

8. The lens unit (1) according to claim 4, characterized in that: The second inclined plane (F2) is configured to converge the light after being homogenized by the first microlens array (111) toward the direction in which the second microlens array (112) and the third microlens array (113) are opposite to each other; In each second microlens (112a), the light rays coming out of the second inclined plane (F2) and the light rays coming out of the first inclined plane (F1) are not parallel.

9. The lens unit (1) according to claim 8, characterized in that: The second inclined planes (F2) of the second microlenses (112a) in each column are parallel; The second oblique planes (F2) of the second microlenses (112a) in each column are arranged so that the light rays emerging from the second oblique planes (F2) of the second microlenses (112a) in the column are coplanar.

10. The lens unit (1) according to claim 4, characterized in that: The intersection lines of each second microlens (112a) and the base surface (110) of the transparent substrate (11) form a rectangle, the rectangles of all the second microlenses (112a) in each column are the same, the rectangles of the second microlenses (112a) in multiple columns are the same, and all the rectangles of the second microlenses (112a) in multiple columns form rows aligned along the length direction (L) and columns aligned along the width direction (W).

11. The lens unit (1) according to claim 1, characterized in that: The fifth oblique plane (F5) is configured to converge the light after being homogenized by the first microlens array (111) along the width direction (W) toward the direction in which the second microlens array (112) and the third microlens array (113) are opposite to each other.

12. The lens unit (1) according to claim 11, characterized in that: The fifth inclined plane (F5) is inclined only in the width direction (W) relative to the base surface (110).

13. The lens unit (1) according to claim 11, characterized in that: The fifth oblique planes (F5) of the third microlenses (113a) in each column are coplanar; The fifth oblique planes (F5) of the third microlenses (113a) in each column are arranged so that the light rays emerging from the fifth oblique planes (F5) of the third microlenses (113a) in the column are coplanar.

14. The lens unit (1) according to claim 11, characterized in that: The inclination angle of the fifth inclined plane (F5) of the third microlenses (113a) in the plurality of columns and the highest height along the thickness direction T gradually decrease as the columns approach the second microlens array (112) along the width direction (W).

15. The lens unit (1) according to claim 11, characterized in that: The sixth oblique plane (F6) is configured to converge the light after being homogenized by the first microlens array (111) toward the direction in which the second microlens array (112) and the third microlens array (113) are opposite to each other; In each third microlens (113a), the light rays coming out of the sixth oblique plane (F6) and the light rays coming out of the fifth oblique plane (F5) are not parallel.

16. The lens unit (1) according to claim 15, characterized in that The sixth oblique planes (F6) of the third microlenses (113a) in each column are parallel; The sixth oblique planes (F6) of the third microlenses (113a) in each column are arranged so that the light rays emerging from the sixth oblique planes (F6) of the third microlenses (113a) in the column are coplanar.

17. The lens unit (1) according to claim 11, characterized in that: The intersection lines of each third microlens (113a) and the base surface (110) of the transparent substrate (11) form a rectangle, the rectangles of all the third microlenses (113a) in each column are the same, the rectangles of the third microlenses (113a) in multiple columns are the same, and all the rectangles of the third microlenses (113a) in multiple columns form rows aligned along the length direction (L) and columns aligned along the width direction (W).

18. The lens unit (1) according to claim 1, characterized in that The second microlens array (112) and the third microlens array (113) are mirror images.

19. A lighting device (M21), comprising a light source (2), characterized in that: The lighting device (M21) further comprises a lens unit (1) according to any one of claims 1 to 18, The light source (2) is a plurality of Lambertian light sources arranged at least along a length direction (L) of a transparent substrate (11) of the lens unit (1); The light source (2) faces the first microlens array (111) of the lens unit (1) and is centrally located relative to the first microlens array (111) of the lens unit (1); Along the projection in the thickness direction (T) of the transparent substrate (11) of the lens unit (1), the light source (2) is located in the interval between the projection of the second microlens array (112) and the projection of the third microlens array (113).

20. A color sorter (100), comprising: Identification device (M2), the identification device (M2) is used to identify the material (P), It is characterized in that The identification device (M2) comprises an illumination device (M21) according to claim 19, and the illumination device (M21) is used for illuminating the material (P).

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