Light diffusion sheet, light source module and projection display system
By designing multiple micro -structured light diffusers set in parallel, it solves the problem of light diffusion effects that are difficult to achieve in the existing technology, and achieve efficient light use and low -cost large -sized products.
Patent Information
- Application Number
- CN202420354810.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-26
- Publication Date
- 2025-01-28
- Estimated Expiration
- 2034-02-26
AI Technical Summary
The prior art is difficult to effectively realize the light diffusion effect of rectangular angular distribution, resulting in low light energy utilization efficiency, difficult to produce large-sized products and high cost.
Design a type of light diffuser, including the first substrate, the first diffusion structure, and the second diffusion structure. The first diffusion structure and the second diffusion structure are set up in the direction of the light transmission through multiple micro -structures. By adjusting the angle of the microstructure, different diffusion effects can be achieved.
The light diffusion effect of rectangular angle distribution is achieved, the efficiency of light energy utilization is improved, the production of large -sized products is simplified, the cost is reduced, and the advantages of simple and convenient adjustment are provided.
Smart Images
Figure CN222420580U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of light diffusion devices, and in particular to a light diffusion sheet, a light source module and a projection display system. Background Art
[0002] HUD stands for Head Up Display, also known as "head-up digital display". AR stands for Augmented Reality, also known as "augmented reality". ARHUD combines the above two technologies and uses AR imaging technology to overlay digital graphics on the real world we see, so that the information projected by HUD is integrated with the real driving environment.
[0003] ARHUD includes a picture generation unit PGU (Picture Generation Unit), and PGU mostly uses a liquid crystal display LCD (Liquid Crystal Display). The LCD-PGU is provided with a nearly collimated backlight by a backlight source, which is evenly distributed through a diffusion film or a diffusion sheet and provides a certain diffusion angle. The image is then formed after liquid crystal modulation, and the image is imaged to the human eye through the optical path of the ARHUD. The area near the human eye that can ensure the viewing effect is the eyebox. In order to ensure the viewing effect of the human eye, technicians generally shape the eyebox into a rectangle, such as a 130mm×50mm rectangular eyebox. In order to improve the efficiency of light energy utilization, it is necessary to use a diffusion film or a diffusion sheet to adjust the angular distribution of the PGU to a similar shape.
[0004] The diffusion effect of a conventional diffusion structure is an elliptical Gaussian, and its diffusion effect angular distribution is an ellipse. As mentioned above, in applications such as ARHUD, a rectangular angular distribution is closer to the ideal diffusion effect. To achieve the diffusion effect of a rectangular angular distribution, the diffusion structure needs to be specially designed (such as microlens arrays and computer-generated holograms, etc.), and the processing technology is also complex and time-consuming. It is difficult to produce large-size products and the cost is high. Utility Model Content
[0005] The present application provides a light diffuser, the present application also provides a light source module, and the present application also provides a projection display system.
[0006] In a first aspect, the present application provides a light diffuser, which includes a first substrate, a first diffusion structure, and a second diffusion structure. The first substrate includes a first surface and a second surface, the first diffusion structure is attached to the first surface, the first diffusion structure includes a plurality of first microstructures protruding relative to the first surface, the first microstructures have a first length extension direction, the angle between the first length extension direction of the plurality of first microstructures and the first specified direction is less than or equal to a preset value, and the first substrate and the first diffusion structure define a light propagation direction. The second diffusion structure is arranged in parallel with the first diffusion structure in the light propagation direction, the second diffusion structure includes a plurality of second microstructures, the second microstructures have a second length extension direction, the angle between the second length extension direction of the plurality of second microstructures and the second specified direction is less than or equal to a preset value, and the angle between the second specified direction and the first specified direction is greater than 0°.
[0007] Optionally, in some embodiments, the second diffusion structure is attached to the second surface and protrudes relative to the second surface, and the light propagation direction is from the first surface to the second surface, or from the second surface to the first surface.
[0008] Optionally, in some embodiments, the light diffuser further includes a second substrate, and the second diffusion structure is attached to a surface of the second substrate.
[0009] Optionally, in some embodiments, the first substrate and the second substrate are stacked, and a light-transmitting adhesive is disposed between the first substrate and the second substrate.
[0010] Optionally, in some embodiments, the first microstructure has a first width direction perpendicular to the first length extension direction, and the structural parameters of the first microstructures of a part of the multiple first microstructures are different from those of the other first microstructures, and the structural parameters include at least one of the following parameters: the height of the protrusion relative to the first surface, the size in the first length extension direction, and the size in the first width direction; or / and, the second microstructure has a second width direction perpendicular to the second length extension direction, and the structural parameters of the second microstructures of a part of the multiple second microstructures are different from those of the other second microstructures, and the structural parameters include at least one of the following parameters: the size in the second length extension direction and the size in the second width direction.
[0011] Optionally, in some embodiments, the average value of the dimensions of the plurality of first microstructures in the first length extension direction is in the range of greater than or equal to 10 μm and less than or equal to 1000 μm; or / and the first microstructure has a first width direction perpendicular to the first length extension direction, and the ratio of the dimension of each first microstructure in the first length extension direction to the dimension in the first width direction is in the range of greater than or equal to 1:1000 and less than or equal to 1:1; or / and the average value of the height of the plurality of first microstructures protruding relative to the first surface is in the range of greater than or equal to 2 μm and less than or equal to 10 μm.
[0012] Optionally, in some embodiments, the light diffuser also includes at least one third diffusion structure, and in the direction of light propagation, the first diffusion structure, the second diffusion structure and the third diffusion structure are arranged in parallel, the third diffusion structure includes a plurality of third microstructures, the third microstructures have a third length extension direction, and the angle between the third length extension direction of the plurality of third microstructures and the third specified direction is less than or equal to a preset value; the angles between the third specified direction, the second specified direction and the first specified direction are all greater than 0°, and the three intersect at the same point.
[0013] In a second aspect, the present application further provides a light source module, which includes a light source and the above-mentioned light diffuser, and the light diffuser is located on the light path of the light source.
[0014] In a third aspect, the present application further provides a projection display system, which includes a display chip and the above-mentioned light source module, wherein the display chip is located on the light path of the light source module.
[0015] In the light diffuser provided by the present application, the first diffuser structure and the second diffuser structure are provided with respective corresponding microstructures, and each of them can produce a diffuse light spot of a specific shape when receiving light. In the light diffuser provided by the present embodiment, the second diffuser structure is arranged in parallel with the first diffuser structure in the light propagation direction. When the light penetrates the light diffuser along the light propagation direction, the light diffuser can combine the light spots of the specific shapes corresponding to the first diffuser structure and the second diffuser structure to obtain a diffuse light spot of a desired shape. Specifically, since the angle between the first length extension side of the multiple first microstructures and the first specified direction is less than or equal to the preset value, the first length extension direction of the multiple first microstructures is roughly the same as the first specified direction. Since the angle between the second length extension side of the multiple second microstructures and the second specified direction is less than or equal to the preset value, the second length extension direction of the multiple second microstructures is roughly the same as the second specified direction. Since the angle between the first specified direction and the second specified direction is greater than 0°, the first microstructure intersects with the second microstructure corresponding to itself. When the incident light passes through, the cross-arranged first microstructure and the second microstructure can homogenize the light and control the diffusion angle. By adjusting the angle between the first microstructure and the second microstructure, images with different diffusion effects can be obtained to meet various usage requirements. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the implementation manner will be briefly introduced below. Obviously, the drawings described below are only some implementation manners of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0017] Figure 1 It is a schematic diagram of the structure of the light diffuser in some embodiments of the present application.
[0018] Figure 2 It is a schematic diagram of the structure of the light diffuser in other embodiments.
[0019] Figure 3 Schematic diagram of length distribution statistics of multiple microstructures of the light diffuser in some embodiments of the present application (the curve in the figure is a fitted Gaussian distribution curve).
[0020] Figure 4 (A) is a schematic diagram of contour line size simulation of protruding structures of a plurality of first microstructures in some embodiments of the present application; Figure 4 (B) is a schematic diagram of the arrangement simulation of multiple first microstructures in the first diffusion structure in some embodiments of the present application.
[0021] Figure 5 is a side view of a light diffuser in some other embodiments.
[0022] Figure 6 It is a schematic diagram of the structure of the light diffuser in some embodiments of the present application.
[0023] Figure 7 Schematic diagram of the microstructure (A) and diffusion effect (B) of the light diffuser in some embodiments of the present application.
[0024] Figure 8 Schematic diagram of the microstructure (A) and diffusion effect (B) of the light diffuser in some other embodiments of the present application.
[0025] Fig. 9 Schematic diagram of the microstructure (A) and diffusion effect (B) of the light diffuser in some other embodiments of the present application.
[0026] Fig.10 is a side view of a light diffuser in some other embodiments.
[0027] Fig.11 4 is a cross-sectional view of light diffusers in some other embodiments.
[0028] Fig.12 is a side view of a light diffuser in some other embodiments.
[0029] Fig.13 Schematic diagram of the structure of light diffusers in some other embodiments.
[0030] Fig.14 yes Fig.13 Side view of the structure of the light diffuser.
[0031] Fig.15 It is a schematic diagram of the structure of the light source module in some embodiments of the present application.
[0032] Fig.16 It is a schematic diagram of the structure of the projection display system in some embodiments of the present application.
[0033] Fig.17 yes Figure 6 A magnified view of the first microstructure and the second microstructure.
[0034] Explanation of reference numerals: 100, light diffuser; 10, first substrate; 101, first surface; 102, second surface; 20, first diffusion structure; 201, first microstructure; 30, second diffusion structure; 301, second microstructure; 40, third diffusion structure; 401, third microstructure; 50, second substrate; 501, third surface; 502, fourth surface; 200, light source module; 21, light source; 300, projection display system; 31, display chip. DETAILED DESCRIPTION
[0035] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application.
[0036] In the description of the present application, it should be understood that the terms "length", "width", "thickness", "up", "down", "left", "right", "front", "back", "top", "bottom", "inside", "outside", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate positions or state relationships based on the positions or state relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.
[0037] In addition, some of the above terms may be used to express other meanings in addition to indicating a position or state relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.
[0038] In addition, the terms "first", "second", etc. are mainly used to distinguish different devices, elements or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, elements or components. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0039] In addition, unless otherwise expressly specified or limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can be internal communication between two elements, or it can be only surface contact. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0040] If certain words are used in the specification and claims to refer to specific components, those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. The specification and claims do not use differences in names as a way to distinguish components, but use differences in components' functions as the criteria for distinction. For example, "including" mentioned throughout the specification and claims is an open term, so it should be interpreted as "including but not limited to"; "substantially" means that those skilled in the art can solve technical problems within a certain error range and basically achieve technical effects.
[0041] See also Figure 1 and Figure 2 , an embodiment of the present application provides a light diffuser 100, which is used to homogenize incident light and adjust the diffusion angle, so as to obtain an ideal light diffusion effect. The light diffuser 100 includes a first substrate 10, a first diffusion structure 20 and a second diffusion structure 30. The first substrate 10 is made of a light-transmitting material, which is generally a sheet-like structure, and includes a first surface 101 and a second surface 102 that are arranged opposite to each other. The first diffusion structure 20 is attached to the first surface 101, and the first diffusion structure 20 includes a plurality of first microstructures 201 protruding relative to the first surface 101, and the first microstructure 201 has a first length extension direction X, and the angle between the first length extension direction X of the plurality of first microstructures 201 and the first designated direction A is less than or equal to a preset value. In the present embodiment, the preset value ranges from 0 to 10° (including the endpoints). As an example, the preset value may be any value, such as 3°, 5°, 7°, etc. The angle between the first length direction X and the first designated direction A is limited to be less than the preset value, which can ensure that the first length extension direction X of the plurality of first microstructures 201 is arranged roughly along the first designated direction A, that is, the plurality of first microstructures 201 are arranged roughly along the same direction, so as to facilitate the formation of a diffuse light spot of a specific shape. As a specific example, in the drawings of the specification of the present embodiment, the first designated direction A is roughly the same as the length direction or width direction of the first substrate 10, that is, the plurality of first microstructures 201 are arranged roughly along the length direction or width direction of the first substrate 10. In other embodiments, the first designated direction A may also be any other direction, and ensure that the first designated direction A is basically arranged along the planar extension direction of the first substrate 10. It should be understood that, Figure 1 The multiple first microstructures 201 shown in the figure are only schematic diagrams for auxiliary explanation, and their specific structures should not be limited by the diagram. For example, the length dimension and length extension direction of each first microstructure 201 in the figure are consistent, but in some specific examples, the length dimensions of the multiple first microstructures 201 may be different or only partially the same, or the length extension directions of the multiple first microstructures 201 may be different or only partially the same.
[0042] It should be noted that the above-mentioned "first microstructure 201" refers to a structure whose surface diffusion structure cross section is similar to a Gaussian distribution, the three-dimensional structure is a conical "peak" structure, and the top view of the structure is approximately elliptical or spindle-shaped. The characteristic dimensions (length, width, height, etc.) of the multiple first microstructures 201 in the first diffusion structure 20 are not fixed values, but the length size distribution of the multiple first microstructures 201 conforms to the Gaussian distribution (see Figure 3 Schematic diagram of the distribution of lengths of multiple microstructures). The multiple first microstructures 201 in the first diffusion structure 20 are staggered and arranged without periodic features, fixed intervals, and macroscopically without periodic boundaries. As an example, see Figure 4 , Figure 4 (A) shows a schematic diagram of contour line size simulation of protruding structures of a plurality of first microstructures 201 in some embodiments, Figure 4 (B) shows a schematic diagram of the arrangement simulation of the plurality of first microstructures 201 in the first diffusion structure 20. The "plurality of second microstructures 301 of the second diffusion structure 30, the plurality of third microstructures 401 of the third diffusion structure 40" appearing below all meet the above definition. In the embodiment of the present application, the preparation of the first microstructure 201 can be made by stamping the first substrate 10 with an adapted mold, and the preparation method of the second microstructure 301 and the third microstructure 401 is the same as above.
[0043] The first substrate 10 and the first diffusion structure 20 define a light propagation direction O (see Figure 5 ), the light propagation direction O is the propagation direction of the incident light, which is substantially perpendicular to the first substrate 10. In actual use, the incident light can be emitted from the first surface 101 to the second surface 102 along the light propagation direction O, or from the second surface 102 to the first surface 101 along the light propagation direction O. The above two light incident directions do not affect the diffusion effect of the light diffuser 100 on the incident light.
[0044] Please also see Figure 2 and Figure 6The second diffusion structure 30 is arranged in parallel with the first diffusion structure 20 in the light propagation direction O. Therefore, when the incident light propagates along the light propagation direction O, it can sequentially transmit the first diffusion structure 20 and the second diffusion structure 30, or sequentially transmit the second diffusion structure 30 and the first diffusion structure 20. The second diffusion structure 30 includes a plurality of second microstructures 301, and the second microstructures 301 have a second length extension direction Y. The angle between the second length extension direction Y of the plurality of second microstructures 301 and the second specified direction B is less than or equal to a preset value. In this embodiment, the preset value ranges from 0 to 10° (including the end points). As an example, the preset value can be any value, such as 3°, 5°, 7°, etc. The angle between the second length direction Y and the second specified direction B is limited to less than the preset value, which can ensure that the second length extension direction Y of the plurality of second microstructures 301 is arranged substantially along the second specified direction B, that is, the plurality of second microstructures 301 are arranged substantially along the same direction, so as to facilitate the formation of a diffuse light spot of a specific shape. The angle between the second designated direction B and the first designated direction A is greater than 0° (i.e., the second designated direction B is arranged to intersect with the first designated direction A). Furthermore, the angle between the second designated direction B and the first designated direction A is less than 90°. It should be understood that Figure 2 The multiple second microstructures 301 shown in the figure are only schematic diagrams for auxiliary explanation, and their specific structures should not be limited by the diagram. For example, the length dimension and length extension direction of each second microstructure 301 in the figure are consistent, but in some specific examples, the length dimensions of the multiple second microstructures 301 may be different or only partially the same, or the length extension directions of the multiple second microstructures 301 may be different or only partially the same.
[0045] In the embodiment of the present application, the implementation of the second diffusion structure 30 being arranged in parallel with the first diffusion structure 20 in the light propagation direction O may include but is not limited to: the second diffusion structure 30 and the first diffusion structure 20 are stacked, or the second diffusion structure 30 and the first diffusion structure 20 are spaced apart, or the second diffusion structure 30 and the first diffusion structure 20 are spaced apart by an optical medium (such as a transparent substrate), etc. Through the above arrangement, the first diffusion structure 20 and the second diffusion structure 30 are provided with their respective corresponding microstructures, and each of them can generate a specific shape of diffuse light spot when receiving light. In the light diffuser 100 provided in the present embodiment, the second diffusion structure 30 is arranged in parallel with the first diffusion structure 20 in the light propagation direction O. When the light penetrates the light diffuser 100 along the light propagation direction O, the light diffuser 100 can combine the specific shapes of the light spots corresponding to the first diffusion structure 20 and the second diffusion structure 30 to obtain a desired shape of diffuse light spot. Specifically, since the first microstructure 201 intersects with the second microstructure 301 corresponding to the first microstructure 201, when the incident light passes through, the first microstructure 201 and the second microstructure 301 arranged crosswise can homogenize the light and adjust the diffusion angle, and by adjusting the angle between the first microstructure 201 and the second microstructure 301, images with different diffusion effects (for example, roughly rectangular, square or polygonal) can be obtained to meet various usage requirements. Therefore, the above-mentioned light diffuser 100 has the advantages of simple structure preparation, convenient adjustment, high degree of freedom, low structural precision requirements, and the ability to achieve a variety of different diffusion effects.
[0046] See also Figure 6 In some embodiments, the second diffusion structure 30 and the first diffusion structure 20 can be arranged on the same surface of the same light-transmitting substrate. For example, the second diffusion structure 30 is also attached to the first surface 101 of the first substrate 10 and protrudes relative to the first surface 101. The light propagation direction O is from the first surface 101 to the second surface 102, or from the second surface 102 to the first surface 101. Through the above arrangement, in the process of preparing the above-mentioned light diffuser 100, the first diffusion structure 20 and the second diffusion structure 30 can be obtained by once stamping the first substrate 10 through an adapting mold, which can simplify the production process and improve production efficiency. And no matter whether the incident light is emitted from the first surface 101 to the second surface 102, or from the second surface 102 to the first surface 101, it will not affect the diffusion effect of the light diffuser 100 on the incident light. As an example, please refer to Figure 7 , Figure 7 (A) shows a schematic diagram of structural simulation when the second diffusion structure 30 and the first diffusion structure 20 are attached to the same surface and the angle between the second designated direction B and the first designated direction A is 20°; Figure 7(B) shows a schematic diagram of the corresponding diffusion effect in this structure. As another example, see Figure 8 , Figure 8 (A) shows a schematic diagram of structural simulation when the second diffusion structure 30 and the first diffusion structure 20 are attached to the same surface and the angle between the second designated direction B and the first designated direction A is 90°; Figure 8 (B) shows a schematic diagram of the corresponding diffusion effect in this structure. As another example, see Fig. 9 , Fig. 9 (A) shows a schematic diagram of structural simulation when the second diffusion structure 30 and the first diffusion structure 20 are attached to the same surface and the angle between the second designated direction B and the first designated direction A is 60°; Fig. 9 (B) shows a schematic diagram of the corresponding diffusion effect in this structure.
[0047] See also Fig.10 In some embodiments, the second diffusion structure 30 and the first diffusion structure 20 can be arranged on different surfaces of the same light-transmitting substrate. For example, the second diffusion structure 30 is attached to the second surface 102 of the first substrate 10 and protrudes relative to the second surface 102. The light propagation direction O is from the first surface 101 to the second surface 102, or from the second surface 102 to the first surface 101. Through the above arrangement, in the process of preparing the above light diffuser 100, the first diffusion structure 20 can be obtained by a first stamping of the first substrate 10 through an adapting mold, and then the first substrate 10 is turned over and a second stamping is performed on the first substrate 10 through an adapting mold to obtain the second diffusion structure 30. Although the first diffusion structure 20 and the second diffusion structure 30 are respectively located on different surfaces of the first substrate 10, the cross arrangement of the two can still achieve an ideal diffusion effect on the incident light.
[0048] See also Fig.11 In some embodiments, the second diffusion structure 30 and the first diffusion structure 20 can be respectively disposed on different light-transmitting substrates. Specifically, the light diffuser 100 can further include a second substrate 50, and the second diffusion structure 30 is attached to the surface of the second substrate 50. The second substrate 50 and the first substrate 10 have substantially the same shape and size. The first substrate 10 and the second substrate 50 are stacked, a light-transmitting adhesive is disposed between the first substrate 10 and the second substrate 50, and the second diffusion structure 30 is attached to the surface of the second substrate 50.
[0049] Through the above-mentioned arrangement, in the process of preparing the above-mentioned light diffuser 100, the first substrate 10 and the second substrate 50 can be prepared separately, and the first diffusion structure 20 and the second diffusion structure 30 can be prepared on the first substrate 10 and the second substrate 50 respectively, and then the first substrate 10 and the second substrate 50 are pasted correspondingly, which can not only improve the preparation speed and preparation efficiency, but also increase the thickness of the light diffuser 100, so as to improve the stability and reliability of the light diffuser 100.
[0050] Please continue reading Fig.11 In some embodiments, the second substrate 50 has a third surface 501 and a fourth surface 502 that are disposed opposite to each other, the third surface 501 is bonded to the second surface 102 of the first substrate 10, and the second diffusion structure 30 is disposed on the third surface 501. Through the above arrangement, the first diffusion structure 20 can be prepared on the first surface 101 of the first substrate 10, and the second diffusion structure 30 can be prepared on the third surface 501 of the second substrate 50, and then the second surface 102 of the first substrate 10 and the third surface 501 of the second substrate 50 are bonded to obtain the first diffusion structure 20 and the second diffusion structure 30 that are disposed crosswise, thereby achieving an ideal diffusion effect on the incident light. Please refer to Fig.12 In some other embodiments, the second diffusion structure 30 can also be arranged on the fourth surface 502. Through the above arrangement, the first diffusion structure 20 can be prepared on the first surface 101 of the first substrate 10, and the second diffusion structure 30 can be prepared on the fourth surface 502 of the second substrate 50, and then the second surface 102 of the first substrate 10 and the third surface 501 of the second substrate 50 are bonded, and the light diffusion sheet 100 with an ideal diffusion effect can also be obtained.
[0051] Please also see Figure 6 and Fig.17In some embodiments, the first microstructure 201 has a first width direction M perpendicular to the first length extension direction X, and the structural parameters of a part of the first microstructures 201 and other first microstructures 201 in the multiple first microstructures 201 in the first diffusion structure 20 are different, and the structural parameters include at least one of the following parameters: the height protruding relative to the first surface 101, the size in the first length extension direction X, and the size in the first width direction M. For example, the height of any one of the multiple first microstructures 201 in the first diffusion structure 20 protruding relative to the first surface 101 is different from the height of the other microstructures protruding relative to the first surface 101; or, the size of any one of the multiple first microstructures 201 in the first diffusion structure 20 in the first length extension direction X is different from the size of the other microstructures in the first length extension direction X; or, the size of any one of the multiple first microstructures 201 in the first diffusion structure 20 in the first width direction M is different from the size of the other microstructures in the first width direction M. It should be noted that the size of the multiple first microstructures 201 in the first length extension direction X should satisfy Figure 8 The Gaussian distribution curve is shown in . Through the above configuration, the multiple first microstructures 201 are not completely the same in morphology, thus greatly reducing the manufacturing precision requirements of the first microstructures 201 and facilitating the manufacturing of the light diffuser 100 .
[0052] Please continue reading Figure 6 and Fig.17 In some other embodiments, the second microstructure 301 has a second width direction N perpendicular to the second length extension direction Y, and the structural parameters of a part of the second microstructures 301 in the plurality of second microstructures 301 in the second diffusion structure 30 are different from those of the other second microstructures 301, and the structural parameters include at least one of the following parameters: the size in the second length extension direction Y, the size in the second width direction N. For example, the size of any one of the plurality of second microstructures 301 in the second diffusion structure 30 in the second length extension direction Y is different from the size of the other microstructures in the second length extension direction Y; or, the size of any one of the plurality of second microstructures 301 in the second diffusion structure 30 in the second width direction N is different from the size of the other microstructures in the second width direction N. It should be noted that the size of the plurality of second microstructures 301 in the second length extension direction Y should satisfy Figure 8 The Gaussian distribution curve is shown in . Through the above configuration, the multiple second microstructures 301 are not completely the same in morphology, thus greatly reducing the manufacturing precision requirements of the second microstructures 301 and facilitating the manufacturing of the light diffuser 100 .
[0053] See also Fig.13In some embodiments, the light diffuser 100 further includes a third diffusion structure 40. In the light propagation direction O, the first diffusion structure 20, the second diffusion structure 30 and the third diffusion structure 40 are arranged in parallel. The third diffusion structure 40 includes a plurality of third microstructures 401. The third microstructures 401 have a third length extension direction Z. The angle between the third length extension direction Z of the plurality of third microstructures 401 and the third designated direction C is less than or equal to a preset value. In this embodiment, the preset value ranges from 0 to 10° (including the end points). As an example, the preset value can be any value, such as 3°, 5°, 7°, etc. The angle between the third length direction Z and the third designated direction C is limited to less than the preset value, which can ensure that the third length extension direction Z of the plurality of third microstructures 401 is arranged substantially along the third designated direction C, that is, the plurality of third microstructures 401 are arranged substantially along the same direction, so as to facilitate the formation of a light spot of a specific shape. The angles between the third designated direction C, the second designated direction B and the first designated direction A are all greater than 0, and the three intersect at the same point.
[0054] Through the above arrangement, the first diffusion structure 20, the second diffusion structure 30 and the third diffusion structure 40 are arranged in pairs and intersect at one point. The three cooperate to homogenize the incident light and adjust the diffusion angle, thereby obtaining an ideal light diffusion effect.
[0055] It should be noted that the third diffusion structure 40 and the first diffusion structure 20 can be disposed on the same light-transmitting substrate. For example, the third diffusion structure 40 can be disposed on the first surface 101 of the first substrate 10 (see Fig.14 ) or the second surface 102 (this situation is not shown in the figure); the third diffusion structure 40 can also be arranged on the same light-transmitting substrate as the second diffusion structure 30. For example, the third diffusion structure 40 can also be arranged on the third surface 501 or the fourth surface 502 of the second substrate 50 (the above two situations are not shown in the figure); or, the third diffusion structure 40 can also be arranged alone on any surface of the third substrate (not shown in the figure).
[0056] In other embodiments, the light diffuser 100 may also include any number of diffusion structures such as a fourth diffusion structure and a fifth diffusion structure (not shown in the figures), as long as the length extension directions of the microstructures corresponding to the respective diffusion structures are staggered in pairs and intersect at one point.
[0057] In some embodiments, the average value of the size of the plurality of first microstructures 201 in the first diffusion structure 20 in the first length extension direction X is in the range of greater than or equal to 10 μm and less than or equal to 1000 μm. The first microstructure 201 has a first width direction M perpendicular to the first length extension direction X, and the ratio of the size of each first microstructure 201 in the first length extension direction X to the size in the first width direction M is in the range of greater than or equal to 1:1000 and less than or equal to 1:1. The average value of the height of the plurality of first microstructures 201 in the first diffusion structure 20 protruding relative to the first surface 101 is in the range of greater than or equal to 2 and less than or equal to 10 μm. The average value of the size of the plurality of second microstructures 301 in the second diffusion structure 30 in the second length extension direction Y is in the range of greater than or equal to 10 μm and less than or equal to 1000 μm. The second microstructure 301 has a second width direction N perpendicular to the second length extension direction Y, and the ratio of the size of each second microstructure 301 in the second length extension direction Y to the size in the second width direction N is in the range of greater than or equal to 1:1000 and less than or equal to 1:1. The average value of the sizes of the plurality of third microstructures 401 in the third diffusion structure 40 in the third length extension direction Z is in the range of greater than or equal to 10 μm and less than or equal to 1000 μm. The third microstructure 401 has a third width direction P (not shown in the figure) perpendicular to the third length extension direction Z, and the ratio of the size of each third microstructure 401 in the third length extension direction Z to the size in the third width direction P is in the range of greater than or equal to 1:1000 and less than or equal to 1:1.
[0058] By setting the above parameters, the first microstructure 201 , the second microstructure 301 and the third microstructure 401 can all satisfy the structural characteristics of the Gaussian microstructure, so that the three can cooperate with each other to achieve an ideal light diffusion effect.
[0059] In summary, the light diffuser 100 provided in this embodiment has the following beneficial effects:
[0060] (1) The structure is simple, the precision requirement is low, and the tolerance is high. Since the microstructure (the first microstructure 201, the second microstructure 301, the third microstructure 401, etc.) itself has a random distribution feature, the tolerance to microstructure errors is high, some small defects have little effect on the diffusion effect, and the stability in actual use is better;
[0061] (2) High degree of freedom. Different angles and numbers of combined structures can be selected according to different effect requirements. When the angle between the first microstructure 201 and the second microstructure 301 is 90° (i.e., the angle between the first length extension direction X and the second length extension direction Y is 90°, see Figure 8(A)), the light diffusion effect of the light diffusion sheet 100 on the incident light (see Figure 8 (B)) is approximately square; when the angle between the first microstructure 201 and the second microstructure 301 is 20° (ie, the angle between the first length extension direction X and the second length extension direction Y is 20°, see Figure 7 (A)), the light diffusion effect of the light diffusion sheet 100 on the incident light (see Figure 7 (B)) is approximately rectangular; when the angle between the first microstructure 201 and the second microstructure 301 is 60° (ie, the angle between the first length extension direction X and the second length extension direction Y is 60°, see Fig. 9 (A)), the light diffusion effect of the light diffusion sheet 100 on the incident light (see Fig. 9 (B)) Approximately hexagonal;
[0062] (3) The process is simple and easy to reuse. The Gaussian speckle structure can be prepared as a mold. When a combined structure is needed, the structure can be stamped in sequence according to the designed angle by stamping. The stamped structure is then used as a master mold for mass production through a mold-turning process.
[0063] See also Fig.15 Based on the light diffuser 100, the embodiment of the present application further provides a light source module 200, which includes a light source 21 and the light diffuser 100, wherein the light diffuser 100 is located on the optical path of the light source 21 to diffuse the light emitted by the light source 21. The light source module 200 can conveniently adjust the light diffusion effect, and has the advantages of high light diffusion freedom and strong diversity.
[0064] See also Fig.16 , based on the above light source module 200, the embodiment of the present application also provides a projection display system 300, which includes a display chip 31 and the above light source module 200, and the display chip 31 is located on the light path of the light source module 200. The above projection display system 300 can easily adjust the light diffusion effect, and has the advantages of high light diffusion freedom and strong diversity. As a specific example, the above projection display system 300 can be an augmented reality head-up display system (Augmented Reality-Head Up Display, AR-HUD) used in a car, which can clearly project the information on the car dashboard onto the front windshield of the car, so that the driver can obtain the vehicle driving information without lowering his head. Among them, the light diffuser 100 used on optical parts such as LCD can homogenize the backlight of the LCD and adjust the diffusion angle, and can form an angular distribution in a shape such as a rectangle to match the needs of AR-HUD, thereby having higher energy utilization efficiency and better display effect.
[0065] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. 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 application. 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. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.
[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application is described in detail with reference to the above embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features can be replaced by equivalents. However, these modifications or replacements do not drive the essence of the corresponding technical solutions out of the spirit and scope of the technical solutions of the embodiments of the present application.
Claims
1. A light diffuser, comprising: A first substrate including a first surface and a second surface; a first diffusion structure attached to the first surface; The first diffusion structure includes a plurality of first microstructures protruding relative to the first surface, the first microstructures having a first length extension direction, and an angle between the first length extension direction of the plurality of first microstructures and a first specified direction is less than or equal to a preset value; the first substrate and the first diffusion structure define a light propagation direction; as well as The second diffusion structure is arranged in parallel with the first diffusion structure in the light propagation direction. The second diffusion structure includes multiple second microstructures. The second microstructures have a second length extension direction. The angle between the second length extension direction of the multiple second microstructures and the second specified direction is less than or equal to a preset value, and the angle between the second specified direction and the first specified direction is greater than 0°.
2. The light diffuser according to claim 1, wherein: The second diffusion structure is attached to the first surface and protrudes relative to the first surface. The light propagation direction is from the first surface to the second surface, or from the second surface to the first surface.
3. The light diffuser according to claim 1, wherein: The second diffusion structure is attached to the second surface and protrudes relative to the second surface. The light propagation direction is from the first surface to the second surface, or from the second surface to the first surface.
4. The light diffuser according to claim 1, wherein: The light diffusion sheet further includes a second substrate, and the second diffusion structure is attached to a surface of the second substrate.
5. The light diffuser according to claim 4, wherein: The first substrate and the second substrate are stacked, and a light-transmitting adhesive is disposed between the first substrate and the second substrate.
6. The light diffuser according to any one of claims 1 to 5, characterized in that: The first microstructure has a first width direction perpendicular to the first length extension direction, and structural parameters of a part of the first microstructures and other first microstructures in the plurality of the first microstructures are different, and the structural parameters include at least one of the following parameters: a height protruding relative to the first surface, a size in the first length extension direction, and a size in the first width direction; or / and, The second microstructure has a second width direction perpendicular to the second length extension direction, and the structural parameters of a part of the second microstructures and other second microstructures are different, and the structural parameters include at least one of the following parameters: the size in the second length extension direction and the size in the second width direction.
7. The light diffuser according to any one of claims 1 to 5, characterized in that: The average value of the sizes of the plurality of first microstructures in the first length extension direction is in the range of: greater than or equal to 10 μm and less than or equal to 1000 μm; or / and, The first microstructure has a first width direction perpendicular to the first length extension direction, and the ratio of the size of each of the first microstructures in the first length extension direction to the size in the first width direction is in the range of: greater than or equal to 1:1000 and less than or equal to 1:1; or / and, An average value of heights of the plurality of first microstructures protruding relative to the first surface is in a range of greater than or equal to 2 μm and less than or equal to 10 μm.
8. The light diffuser according to any one of claims 1 to 5, characterized in that: The light diffuser also includes a third diffusion structure. In the light propagation direction, the first diffusion structure, the second diffusion structure and the third diffusion structure are arranged in parallel. The third diffusion structure includes a plurality of third microstructures. The third microstructures have a third length extension direction. The angle between the third length extension direction of the plurality of third microstructures and the third designated direction is less than or equal to a preset value. The angles between the third designated direction, the second designated direction and the first designated direction are all greater than 0°, and the three intersect at the same point.
9. A light source module, comprising: Light source, and The light diffuser according to any one of claims 1 to 8, wherein the light diffuser is located on the light path of the light source.
10. A projection display system, comprising: Display chip; as well as The light source module as claimed in claim 9, wherein the display chip is located on the light path of the light source module.