Surface light source module and bidirectional transparent display device

Abstract

The utility model provides an area light source module which comprises a light guide plate, a light source assembly, a covering layer and an optical adhesive layer. The first surface of the light guide plate is provided with a plurality of microstructures. The optical adhesive layer is arranged between the light guide plate and the covering layer. Each microstructure is provided with a symmetry plane and a first structural plane, the boundary of the first structural plane and the symmetry plane is provided with a first boundary line, and the first boundary line comprises a first part line segment, a second part line segment and a third part line segment. The first part line segment or the third part line segment is connected with the first surface, and the second part line segment is connected between the first part line segment and the third part line segment. And a third included angle of 50-90 degrees is formed between the tangent line of each position on the third part line segment and the first surface. The ratio of the third length of the third part line segment to the total length of the first boundary line is greater than or equal to 5%.

Description

Technical Field

[0001] The utility model relates to a light source module, in particular to a surface light source module and a bidirectional transparent display device. Background Art

[0002] Reflective display devices can reflect ambient light to allow users to see the display screen. However, when the ambient light is insufficient, a front light module is often required to provide light. Existing front light modules often use a light guide plate to make the light output uniform. For example, multiple microstructures are set on the surface of the light guide plate to achieve the purpose of uniform light output. However, in order to avoid affecting the optical effect of the microstructure, existing front light modules often retain an air gap between the light guide plate and the glass plate or touch panel. However, this will make the interface between the front light module and the air gap prone to strong reflection under strong ambient light, thereby reducing the visibility of the reflective display device.

[0003] The "background technology" section is only used to help understand the content of the utility model, so the content disclosed in the "background technology" section may contain some prior art that is not known to those skilled in the art. The content disclosed in the "background technology" section does not mean that the content or the problem to be solved by one or more embodiments of the utility model has been known or recognized by those skilled in the art before the application of the utility model. Utility Model Content

[0004] The utility model provides a light guide plate of a surface light source module, which is provided with a plurality of microstructures, wherein each microstructure has a first structural surface, so that the surface light source module can provide a uniform and forward illuminating light beam transmitted toward a display element. In addition, the surface light source module of the utility model uses an optical adhesive layer with a second refractive index to cover the plurality of microstructures, which helps to improve the visibility of the display device under strong ambient light.

[0005] Other purposes and advantages of the utility model can be further understood from the technical features disclosed in the utility model.

[0006] To achieve one or part or all of the above purposes or other purposes, a surface light source module of an embodiment of the utility model includes a light guide plate, a light source assembly, a covering layer and an optical adhesive layer. The light guide plate has a first surface and a second surface opposite to each other, and a light incident surface connecting the first surface and the second surface, and the first surface is provided with a plurality of microstructures. The light source assembly is arranged opposite to the light incident surface. The covering layer is arranged opposite to the first surface. The optical adhesive layer is arranged between the light guide plate and the covering layer, and covers a plurality of microstructures. Each microstructure has a first structural surface connected to the first surface, and each microstructure has a symmetry plane, which is perpendicular to the first surface and has an angle with the light incident surface between 45 degrees and 90 degrees. The intersection of the first structural surface and the symmetry plane has a first intersection line, and the first intersection line includes a first partial line segment, a second partial line segment and a third partial line segment. The first partial line segment or the third partial line segment is connected to the first surface, and the second partial line segment is connected between the first partial line segment and the third partial line segment. The optical adhesive layer at least contacts the second partial line segment of the first intersection line of the first structural surface. The tangents at various positions on the first part of the line segment have a first angle with the first surface, and the tangents at various positions on the third part of the line segment have a third angle with the first surface. The first angle is greater than 0 degrees and less than or equal to 30 degrees, the third angle is greater than or equal to 50 degrees and less than or equal to 90 degrees, and the second part of the line segment is a curve. The first length of the first part of the line segment accounts for a proportion of greater than or equal to 5% of the total length of the first boundary line, and the third length of the third part of the line segment accounts for a proportion of greater than or equal to 5% of the total length of the first boundary line.

[0007] In one embodiment of the utility model, the surface light source module includes a light guide plate, a light source assembly, a covering layer and an optical adhesive layer. The light guide plate has a first surface and a second surface opposite to each other, and a light incident surface connecting the first surface and the second surface, and the first surface is provided with a plurality of microstructures. The light source assembly is arranged opposite to the light incident surface. The covering layer is arranged opposite to the first surface. The optical adhesive layer is arranged between the light guide plate and the covering layer, and covers a plurality of microstructures. Each microstructure has a first structural surface connected to the first surface, and each microstructure has a symmetry plane, the symmetry plane is perpendicular to the first surface and the angle with the light incident surface is between 45 degrees and 90 degrees, and the intersection of the first structural surface and the symmetry plane has a first intersection line, and the first intersection line includes a first partial line segment, a second partial line segment and a third partial line segment. The first partial line segment or the third partial line segment is connected to the first surface, and the second partial line segment is connected between the first partial line segment and the third partial line segment. The optical adhesive layer at least contacts the second partial line segment of the first intersection line of the first structural surface. There is a first angle between the tangent at each position on the first part of the line segment and the first surface, there is a second angle between the tangent at each position on the second part of the line segment and the first surface, and there is a third angle between the tangent at each position on the third part of the line segment and the first surface. The first angle has a first angle maximum value, the third angle has a third angle minimum value, the first angle maximum value is greater than 0 degrees and less than or equal to 40 degrees, and the third angle minimum value is greater than or equal to 50 degrees and less than or equal to 90 degrees. The first length of the first part of the line segment accounts for a proportion of greater than or equal to 5% of the total length of the first boundary line, and the third length of the third part of the line segment accounts for a proportion of greater than or equal to 5% of the total length of the first boundary line. The second angle increases gradually from the first angle maximum value to the third angle minimum value.

[0008] In an embodiment of the present invention, the bidirectional transparent display device comprises a transparent display panel and two surface light source modules, and the transparent display panel is disposed between the two surface light source modules.

[0009] The surface light source module and the bidirectional transparent display device of the embodiment of the utility model have the advantages of uniform light emission and good forward light emission effect because they use the microstructure with the first structural surface. In addition, the surface light source module of the embodiment of the utility model uses an optical adhesive layer to cover multiple microstructures, which helps to improve the visibility of the display device under strong ambient light when applied to a display device (such as the bidirectional transparent display device of the utility model or other unidirectional display device).

[0010] In order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a cross-sectional schematic diagram of a display device according to an embodiment of the present invention.

[0012] Figure 2 for Figure 1 Enlarged schematic diagram of box F.

[0013] Figure 3 The figure is a top view of a light guide plate according to an embodiment of the present invention.

[0014] Figure 4 FIG. 1 is a schematic cross-sectional view of a single microstructure in a light guide plate according to another embodiment of the present invention.

[0015] Figure 5 FIG. 1 is a schematic cross-sectional view of a single microstructure in a light guide plate according to another embodiment of the present invention.

[0016] Figure 6 FIG. 1 is a schematic cross-sectional view of a single microstructure in a light guide plate according to another embodiment of the present invention.

[0017] Figure 7 FIG. 1 is a cross-sectional schematic diagram of a display device according to another embodiment of the present invention.

[0018] Figure 8 It is a cross-sectional schematic diagram of a bidirectional transparent display device according to an embodiment of the utility model.

[0019] Reference numerals list

[0020] 1.1d: Display device

[0021] 1e: Bidirectional transparent display device

[0022] 10, 10b, 10d, 10e: Surface light source module

[0023] 20, 20d: Display components

[0024] 20e: Transparent display panel

[0025] 100, 100a, 100b, 100c, 100d: light guide plate

[0026] 101: First surface

[0027] 102: Second surface

[0028] 103: Light-entering surface

[0029] 110, 110a, 110b, 110c: microstructure

[0030] 111, 111a, 111c: first structural surface

[0031] 112: Second structural surface

[0032] 113, 113b: third structural surface

[0033] 210: Light source component

[0034] 211a, 211b, 211d: light

[0035] 220, 220d, 220e: Covering layer

[0036] 230: Optical adhesive layer

[0037] A: Symmetrical plane

[0038] A1, A1a, A1c: First Junction

[0039] a1: the first part of the line segment

[0040] a2: the second segment

[0041] a3: the third segment

[0042] D: Maximum depth

[0043] F: Box

[0044] H: Maximum height

[0045] L1: First length

[0046] L2: Second length

[0047] L3: The third length

[0048] L4: Total length

[0049] W: Width

[0050] X, Y, Z: direction

[0051] θ1: first angle

[0052] θ2: first angle

[0053] θ3: The third angle

[0054] θ4: The fourth angle

[0055] ψ: maximum width. DETAILED DESCRIPTION

[0056] The above and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of a preferred embodiment with reference to the drawings. The directional terms (e.g., up, down, left, right, front or back, etc.) mentioned in the following embodiments are only referenced to the directions of the attached drawings. Therefore, the directional terms used are used to illustrate and not to limit the present invention.

[0057] Figure 1It is a cross-sectional schematic diagram of a display device according to an embodiment of the present invention. Figure 2 for Figure 1 Enlarged view of box F. Please refer to Figure 1 and Figure 2 A display device 1 of one embodiment of the present invention includes a surface light source module 10 and a display element 20, wherein the surface light source module 10 includes a light guide plate 100, a light source assembly 210, a covering layer 220 and an optical adhesive layer 230. The light guide plate 100 has a first surface 101 and a second surface 102 opposite to each other, and a light incident surface 103 connecting the first surface 101 and the second surface 102, and the first surface 101 is provided with a plurality of microstructures 110. The light source assembly 210 is arranged opposite to the light incident surface 103. The covering layer 220 is arranged opposite to the first surface 101. The optical adhesive layer 230 is arranged between the light guide plate 100 and the covering layer 220. The light source assembly 210 of this embodiment, for example, includes a plurality of light-emitting elements, and the light-emitting elements are, for example, light-emitting diodes, but the present invention does not impose specific limitations on this. The display element 20 is, for example, a reflective liquid crystal panel.

[0058] Figure 3 This is a top view of a light guide plate according to an embodiment of the present invention. Figure 2 and Figure 3 In the present embodiment, each microstructure 110 has, for example, a first structural surface 111 connected to the first surface 101, and each microstructure 110 has a symmetry plane A. The boundary between the first structural surface 111 and the symmetry plane A has a first boundary line A1, and the first boundary line A1 includes a first partial line segment a1, a second partial line segment a2, and a third partial line segment a3. The first partial line segment a1 is connected to the first surface 101, and the second partial line segment a2 is connected between the first partial line segment a1 and the third partial line segment a3. Specifically, the microstructure 110 of the present embodiment is, for example, a concave microstructure recessed from the first surface 101, and the outer contour of the microstructure 110 in a top view (that is, the projection of the microstructure 110 on the first surface 101) is, for example, a long strip, such as Figure 3 As shown, the symmetry plane A, for example, passes through the geometric center of the microstructure 110, and the microstructure 110 is symmetrical about the symmetry plane A (for example, mirror symmetry). The symmetry plane A is, for example, perpendicular to the first surface 101 and the angle between it and the light incident surface 103 is, for example, between 45 degrees and 90 degrees. For example, the angle between the symmetry plane A and the light incident surface 103 in this embodiment is 90 degrees, but the utility model does not impose a specific limitation on this. The utility model also does not impose a specific limitation on the shape of the microstructure 110. In another embodiment, the outer contour of the projection of the microstructure 110 on the first surface 101 can be a fan-shaped or arc-shaped shape.

[0059] Please continue to refer to Figure 1 and Figure 2In this embodiment, the first partial line segment a1 is adjacent to the light incident surface 103, and the tangent at each position on the first partial line segment a1 has a first angle θ1 with the first surface 101, the tangent at each position on the second partial line segment a2 has a second angle θ2 with the first surface 101, and the tangent at each position on the third partial line segment a3 has a third angle θ3 with the first surface 101. The first angle θ1 is greater than 0 degree and less than or equal to 30 degrees, the third angle θ3 is greater than or equal to 50 degrees and less than or equal to 90 degrees, and the second angle θ2 increases gradually from 30 degrees to 50 degrees, for example. Specifically, the first angle θ1 is an acute angle, and the farther away from the light incident surface 103, the larger the angle of the first angle θ1 (the line segment is, for example, a curve) or remains unchanged (the line segment is, for example, a straight line). The second angle θ2 is an acute angle, and the farther away from the light incident surface 103, the larger the angle of the second angle θ2. The third angle θ3 is an acute angle, and the further away from the light incident surface 103, the larger or constant the angle of the third angle θ3. In other words, the further away the first boundary line A1 is from the light incident surface 103, the larger or constant the angle between the first boundary line A1 and the first surface 101, the maximum value of the first angle θ1 is less than or equal to the minimum value of the second angle θ2, and the maximum value of the second angle θ2 is less than or equal to the minimum value of the third angle θ3. In addition, in one embodiment, the first partial line segment a1 is, for example, a curve, a straight line, or a combination of a curve and a straight line, the second partial line segment a2 is, for example, a curve, and the third partial line segment a3 is, for example, a curve, a straight line, or a combination of a curve and a straight line. Specifically, the first partial line segment a1, the second partial line segment a2, and the third partial line segment a3 of this embodiment are, for example, all curves, but the utility model does not impose specific limitations on this. In this embodiment, the difference between the third angle θ3 and the first angle θ1 (for example, the difference between the maximum value of the third angle θ3 of the third partial line segment a3 and the minimum value of the first angle θ1 of the first partial line segment a1) is, for example, greater than or equal to 30 degrees, greater than or equal to 50 degrees, or greater than or equal to 70 degrees, and can be 40 degrees or 50 degrees, but the utility model does not impose specific limitations on this.

[0060] Continuing from the above, in this embodiment, the first length L1 of the first partial line segment a1 accounts for a ratio of greater than or equal to 5% of the total length L4 of the first intersection line A1, the second length L2 of the second partial line segment a2 accounts for a ratio of less than or equal to 90% of the total length L4 of the first intersection line A1, and the third length L3 of the third partial line segment a3 accounts for a ratio of greater than or equal to 5% of the total length L4 of the first intersection line A1. Specifically, the total length L4 of the first intersection line A1 is, for example, the sum of the first length L1, the second length L2, and the third length L3. In other embodiments, the first partial line segment a1 is, for example, a combination of a straight line (the first angle θ1 is, for example, 15 degrees) and a curve (the first angle θ1 is, for example, 15 degrees and gradually increases to 30 degrees), and the third partial line segment a3 is, for example, a combination of a curve (the third angle θ3 is, for example, 50 degrees and gradually increases to 75 degrees) and a straight line (the third angle θ3 is, for example, 75 degrees). In another embodiment, the first partial line segment a1 is, for example, a curve (the first angle θ1 is, for example, 5 degrees and gradually increases to 30 degrees), and the third partial line segment a3 is, for example, a curve (the third angle θ3 is, for example, 50 degrees and gradually increases to 80 degrees). In another embodiment, the third partial line segment a3 accounts for a proportion of the total length L4 of the first boundary line A1 that is greater than or equal to 20%, and the line segment with the third angle θ3 greater than 65 degrees accounts for a proportion of the total length L4 of the first boundary line A1 that is greater than or equal to 15%.

[0061] From another point of view, in the present invention, the first angle θ1 of the first partial line segment a1, for example, has a first angle maximum value, the third angle θ3 of the third partial line segment a3, for example, has a third angle minimum value, the first angle maximum value, for example, is greater than 0 degrees and less than or equal to 40 degrees, the third angle minimum value, for example, is greater than or equal to 50 degrees and less than or equal to 90 degrees, the first length L1 of the first partial line segment a1 accounts for a proportion of greater than or equal to 5% of the total length L4 of the first boundary line A1, the third length L3 of the third partial line segment a3 accounts for a proportion of greater than or equal to 5% of the total length L4 of the first boundary line A1, and the second angle θ2, for example, gradually increases from the first angle maximum value to the third angle minimum value. In other embodiments, the first angle maximum value is, for example, 40 degrees, the third angle minimum value is, for example, 65 degrees, the first length L1 of the first partial line segment a1 accounts for a proportion of greater than or equal to 15% of the total length L4 of the first boundary line A1, and the third length L3 of the third partial line segment a3 accounts for a proportion of greater than or equal to 15% of the total length L4 of the first boundary line A1. In another embodiment, the first angle θ1 of the first partial line segment a1, for example, has a first angle average value, the first angle average value, for example, is greater than 0 degrees and less than or equal to 40 degrees, and the first length L1 of the first partial line segment a1 accounts for a ratio of greater than or equal to 5% of the total length L4 of the first boundary line A1. It is particularly noted that the remaining details are similar to those of the above display device embodiment and are not repeated here.

[0062] Please refer to Figure 1 and Figure 2 When the light provided by the light source assembly 210 is transmitted to the first structural surface 111, part of the light may be partially reflected or fully reflected once or multiple times on the first structural surface 111, thereby correcting the transmission path of the light, which helps to improve the forward light emission effect of the surface light source module 10. For example, the light 211a is transmitted to the second partial line segment a2 of the first structural surface 111, and is then reflected and transmitted to the third partial line segment a3 and the second surface 102 in sequence, so that the light 211a is close to the forward light emission when it is emitted from the light guide plate 100. The light 211b is transmitted to the second partial line segment a2 of the first structural surface 111, and is reflected and transmitted to the second surface 102, so that the light 211b is also close to the forward light emission when it is emitted from the light guide plate 100.

[0063] The optical adhesive layer 230 of this embodiment covers a plurality of microstructures 110. The light guide plate 100 has a first refractive index, and the optical adhesive layer 230 has a second refractive index, wherein the second refractive index is less than the first refractive index. Specifically, the difference between the first refractive index and the second refractive index is, for example, between 0.1 and 0.15. The first refractive index is, for example, between 1.5 and 1.6, for example, 1.57, and the second refractive index is, for example, between 1.4 and 1.5, for example, 1.42 or 1.47, but the utility model does not make specific restrictions on this. When the surface light source module 10 is applied to a display device 1 (such as a reflective display device), and the display device 1 is in a place where the ambient light is strong, because the optical adhesive layer 230 covers and fills a plurality of microstructures 110, the difference between the second refractive index of the optical adhesive layer 230 and the first refractive index is much smaller than the difference between the air and the first refractive index, so that the reflection of the ambient light at the interface between the light guide plate 100 and the optical adhesive layer 230 can be reduced, thereby improving the visibility of the display device 1. On the other hand, since the first structure surface 111 has the first partial line segment a1, the second partial line segment a2 and the third partial line segment a3, even if the difference in refractive index between the light guide plate 100 and the optical adhesive layer 230 is small, the light beam can still be totally reflected to a near forward direction.

[0064] As mentioned above, the optical adhesive layer 230 of the present embodiment at least contacts the second partial line segment a2 of the first boundary line A1 of the first structural surface 111. The optical adhesive layer 230 of the present embodiment, for example, fully fills (or fully adheres) between the light guide plate 100 and the cover layer 220, that is, the optical adhesive layer 230 further contacts the first partial line segment a1 and the third partial line segment a3 of the first boundary line A1. The full filling of the optical adhesive layer 230 can make the cover layer 220 and the light guide plate 100 more firmly adhered, make the structure stronger, and reduce stray light. Furthermore, when the cover layer 220 is, for example, a touch panel, the touch sensation can be enhanced.

[0065] Please continue to refer to Figure 2, each microstructure 110 of the present embodiment further has, for example, a second structural surface 112 and a third structural surface 113. The second structural surface 112 is, for example, connected between the first structural surface 111 and the third structural surface 113, the third structural surface 113 is, for example, connected to the first surface 101, and the third partial line segment a3 is, for example, connected to the second structural surface 112. For example, the microstructure 110 and the symmetry plane A have a boundary line, and the angle between the tangent of the boundary line and the first surface 101 exceeds 50 degrees and then becomes less than 50 degrees, which can be defined as the intersection of the third partial line segment a3 and the second structural surface 112. The third structural surface 113 and the first surface 101 have, for example, a fourth angle θ4, which is, for example, greater than or equal to 50 degrees and less than or equal to 90 degrees. Specifically, the third structural surface 113 of the present embodiment is, for example, a plane (that is, the boundary between the third structural surface 113 and the symmetry plane A is, for example, a straight line), and the fourth angle θ4 is preferably close to 90 degrees.

[0066] Continuing from the above, the angle between the second structural surface 112 of the present embodiment and the first surface 101 is, for example, greater than or equal to 0 degrees and less than or equal to 30 degrees, the second structural surface 112 has, for example, a width W in the direction X perpendicular to the light incident surface 103, and each microstructure 110 has, for example, a maximum depth D in the direction Z perpendicular to the first surface 101, and the width W is, for example, greater than or equal to one-tenth of the maximum depth D, and, for example, less than or equal to one-half of the maximum depth D. For example, the width W is, for example, 2μm, but the present invention does not impose specific limitations on this. In addition, the second structural surface 112 of the present embodiment is, for example, a plane, but the present invention is not limited to this. In another embodiment, the second structural surface 112 may be a curved surface.

[0067] The display device 1 of the present embodiment is, for example, a reflective display device, the cover layer 220 is, for example, glass or a touch panel, and the surface light source module 10 is, for example, a front light module. The display element 20 is, for example, disposed opposite to the second surface 102, and the optical adhesive layer 230 is further, for example, disposed between the light guide plate 100 and the display element 20. In addition, the surface light source module 10 of the present embodiment may further include an optical film (not shown) disposed between the optical adhesive layer 230 and the cover layer 220, and the optical film is, for example, a polarizer, a brightness enhancement film, or a combination thereof, which can reduce stray light and improve contrast and viewing angle.

[0068] The surface light source module 10 of the present embodiment uses a microstructure 110 having a first structure surface 111, so the surface light source module 10 can provide a uniform and forward emitting illumination light beam transmitted toward the display element 20. In addition, the surface light source module 10 of the present embodiment uses an optical adhesive layer 230 having a second refractive index to cover the plurality of microstructures 110, which helps to improve the visibility of the display device 1 under strong ambient light.

[0069] Figure 4This is a cross-sectional schematic diagram of a single microstructure in a light guide plate of another embodiment of the present invention. Figure 2 and Figure 4 . Figure 4 and Figure 2 Similarly, the main difference is that the microstructure 110a of the light guide plate 100a is different from the microstructure 110 of the light guide plate 100. In detail, the first length L1 of the first partial line segment a1 accounts for a smaller proportion on the first junction line A1a than on the first junction line A1, for example, greater than 0% and less than 5%, and the third length L3 of the third partial line segment a3 accounts for a larger proportion on the first junction line A1a than on the first junction line A1, for example, greater than or equal to 20% and less than or equal to 75%.

[0070] Figure 5 This is a cross-sectional schematic diagram of a single microstructure in a light guide plate according to another embodiment of the present invention. Figure 2 and Figure 5 , Figure 5 and Figure 2 Similar, the main difference is Figure 5 The third structural surface 113b and the first structural surface 111 are, for example, symmetrical. Specifically, the boundary between the third structural surface 113b and the symmetry plane A has, for example, a third boundary line A3, and the third boundary line A3 and the first boundary line A1 are, for example, mirror-symmetrical. In other words, the third structural surface 113b also has, for example, a first partial line segment a1, a second partial line segment a2, and a third partial line segment a3 as those of the first structural surface 111, but the utility model does not impose specific restrictions on this. The microstructure 110b of the light guide plate 100b of this embodiment has a third boundary line A3 and a first boundary line A1 that are mirror-symmetrical, and therefore can be applied to a surface light source module 10b with bidirectional light input.

[0071] Figure 6 This is a cross-sectional schematic diagram of a single microstructure in a light guide plate according to another embodiment of the present invention. Figure 6 , each microstructure 110c of the present embodiment, for example, protrudes from the first surface 101, the first partial line segment a1, for example, is far away from the first surface 101, and the third partial line segment a3, for example, is connected to the first surface 101. Specifically, the first boundary line A1c is the same as the first boundary line A1, and will not be repeated here. In addition, each microstructure 110c has, for example, a maximum width ψ in the direction X perpendicular to the light incident surface 103 on the surface connected to the first surface 101, and each microstructure 110c has, for example, a maximum height H in the direction Z perpendicular to the first surface 101, and the maximum height H is, for example, less than or equal to three tenths of the maximum width ψ. When the microstructure 110c, for example, protrudes from the first surface 101, the flat microstructure 110c (that is, the ratio of the maximum height H to the maximum width ψ is small) helps light (such as Figure 1 As shown) is transferred to the first structural surface 111c.

[0072] Figure 7 This is a cross-sectional schematic diagram of a display device according to another embodiment of the present invention. Figure 1 and Figure 7 The surface light source module 10d of this embodiment is similar to the surface light source module 10, and the main difference is that the second surface 102 of the surface light source module 10d is, for example, the light emitting surface of the surface light source module 10d, and the cover layer 220d is, for example, a reflective sheet. In this case, the surface light source module 10d is, for example, a backlight module. Figure 1 The microstructure 110 also helps to guide the transmission path of part of the light (e.g., light 211d) of the light source assembly 210, so that the surface light source module 10d can provide a forward light beam that is transmitted toward the display element 20d and has uniform light output. In addition, the display element 20d of this embodiment is, for example, a transmissive liquid crystal panel. In addition, the surface light source module 10d may also include an optical film (not shown), which is disposed between the light guide plate 100d and the display element 20d, wherein the light guide plate 100d and the optical film may be fully bonded or have an air gap.

[0073] Figure 8 This is a cross-sectional diagram of a bidirectional transparent display device according to an embodiment of the present invention. Figure 1 and Figure 8 The bidirectional transparent display device 1e of one embodiment of the utility model comprises a transparent display panel 20e and two surface light source modules 10e, wherein the transparent display panel 20e is disposed between the two surface light source modules 10e. Figure 1 The main difference is that the cover layer 220e of the surface light source module 10e is, for example, a transparent substrate, and the transparent display panel 20e is equivalent to Figure 1 The display element 20 is a transparent display panel 20e, but the transparent display panel 20e can display the two surface light source modules 10e respectively, and the other details are similar to the surface light source module 10, which will not be repeated here. The microstructure 110 of the surface light source module 10e of this embodiment is the same as the microstructure 110 of the surface light source module 10, but the present invention is not limited to this. In another embodiment, the microstructure 110 of the surface light source module 10e may be a microstructure 110a, a microstructure 110b or a microstructure 110c. In addition, the microstructures 110 of the two surface light source modules 10e of this embodiment are, for example, the same, but the present invention does not impose specific restrictions on this. In another embodiment, the microstructures 110 of the two surface light source modules 10e may be different. It should be noted that the light source assemblies 210 of the two surface light source modules 10e of this embodiment are, for example, arranged relative to each other. However, the present invention does not impose specific restrictions on this. In another embodiment, the light source assemblies 210 of the two surface light source modules 10e may be arranged on the same side, for example, the same Figure 8 to the left or right side of the

[0074] To summarize, since the surface light source module of the embodiment of the utility model and the microstructure of the light guide plate of the bidirectional transparent display device have both small-angle partial line segments and large-angle partial line segments, it has at least one of the following advantages: uniform light output and good forward light output effect, and when the surface light source module is applied to a display device (such as the bidirectional transparent display device or other unidirectional display device of the utility model), it helps to improve the visibility of the display device under strong ambient light.

[0075] The above description is only the preferred embodiment of the utility model, and it cannot be used to limit the scope of implementation of the utility model. That is, all simple equivalent changes and modifications made in accordance with the claims of the utility model and the specification of the utility model are still within the scope of the utility model patent. In addition, any embodiment or claim of the utility model does not have to achieve all the purposes, advantages or features disclosed in the utility model. In addition, the abstract of the specification and the name of the utility model are only used to assist in the retrieval of patent documents, and are not used to limit the scope of rights of the utility model. In addition, the terms "first", "second", etc. mentioned in this specification or claims are only used to name the name of the element or distinguish different embodiments or scopes, and are not used to limit the upper or lower limit of the number of elements.

Claims

1. A surface light source module, characterized in that: The surface light source module includes a light guide plate, a light source assembly, a cover layer and an optical adhesive layer, wherein: The light guide plate has a first surface and a second surface opposite to each other, and a light incident surface connecting the first surface and the second surface, and the first surface is provided with a plurality of microstructures; The light source assembly is arranged opposite to the light incident surface; The covering layer is arranged opposite to the first surface; The optical adhesive layer is disposed between the light guide plate and the cover layer, and covers the plurality of microstructures; Each of the plurality of microstructures has a first structural surface connected to the first surface, each of the plurality of microstructures has a symmetry plane, the symmetry plane is perpendicular to the first surface and has an angle with the light incident surface between 45 degrees and 90 degrees, the first structural surface and the symmetry plane have a first boundary line at their junction, the first boundary line includes a first partial line segment, a second partial line segment and a third partial line segment, the first partial line segment or the third partial line segment is connected to the first surface, the second partial line segment is connected between the first partial line segment and the third partial line segment, the optical adhesive layer at least contacts the second partial line segment of the first boundary line of the first structural surface, a tangent at each position on the first partial line segment has a first angle with the first surface, a tangent at each position on the third partial line segment has a third angle with the first surface, the first angle is greater than 0 degree and less than or equal to 30 degrees, the third angle is greater than or equal to 50 degrees and less than or equal to 90 degrees, and the second partial line segment is a curve; The first length of the first partial line segment accounts for a proportion greater than or equal to 5% of the total length of the first boundary line, and the third length of the third partial line segment accounts for a proportion greater than or equal to 5% of the total length of the first boundary line.

2. The surface light source module according to claim 1, characterized in that: The third length of the third portion of line segments accounts for more than or equal to 20% of the total length of the first boundary line, and the line segments with the third angle greater than 65 degrees account for more than or equal to 15% of the total length of the first boundary line.

3. The surface light source module according to claim 1, characterized in that: Each of the multiple microstructures is recessed from the first surface, and a second angle is formed between the tangent of each position on the second partial line segment of the first boundary line of the first structural surface and the first surface; the farther the positions on the first partial line segment are from the light incident surface, the larger the first angle is or remains unchanged; the farther the positions on the second partial line segment are from the light incident surface, the larger the second angle is; the farther the positions on the third partial line segment are from the light incident surface, the larger the third angle is or remains unchanged; the maximum value of the first angle is less than or equal to the minimum value of the second angle, and the maximum value of the second angle is less than or equal to the minimum value of the third angle.

4. The surface light source module according to claim 1, characterized in that: The first part of the line segments is a curve, a straight line or a combination of a curve and a straight line, and the third part of the line segments is a curve, a straight line or a combination of a curve and a straight line.

5. The surface light source module according to claim 1, characterized in that: Each of the plurality of microstructures is recessed from the first surface, and each of the plurality of microstructures further has a second structure surface and a third structure surface, wherein the second structure surface is connected between the first structure surface and the third structure surface, the third structure surface is connected to the first surface, and the third partial line segment is connected to the second structure surface; A fourth angle is formed between the third structural surface and the first surface, and the fourth angle is greater than or equal to 50 degrees and less than or equal to 90 degrees.

6. The surface light source module according to claim 5, characterized in that: The second structure surface has a width along a direction perpendicular to the light incident surface, each of the plurality of microstructures has a maximum depth, and the width is greater than or equal to one tenth of the maximum depth.

7. The surface light source module according to claim 1, characterized in that: Each of the plurality of microstructures is recessed from the first surface, and each of the plurality of microstructures further has a second structure surface and a third structure surface, wherein the second structure surface is connected between the first structure surface and the third structure surface, the third structure surface is connected to the first surface, and the third partial line segment is connected to the second structure surface; The junction of the third structural surface and the symmetry plane has a third boundary line, the third boundary line is mirror-symmetrical to the first boundary line, and the second structural surface has a width along a direction perpendicular to the light incident surface, each of the multiple microstructures has a maximum depth, and the width is greater than or equal to one tenth of the maximum depth.

8. The surface light source module according to claim 1, characterized in that: Each of the plurality of microstructures protrudes from the first surface, the first portion of line segments is away from the first surface, and the third portion of line segments is connected to the first surface.

9. The surface light source module according to claim 8, characterized in that: Each of the multiple microstructures has a maximum width on a surface connected to the first surface in a direction perpendicular to the light incident surface, and each of the multiple microstructures has a maximum height, which is less than or equal to three tenths of the maximum width.

10. The surface light source module according to claim 1, characterized in that: The covering layer is glass or a touch panel.

11. The surface light source module according to claim 1, characterized in that: The second surface is the light emitting surface of the surface light source module, and the covering layer is a reflective sheet.

12. The surface light source module according to claim 1, characterized in that: The difference between the maximum value of the third angle and the minimum value of the first angle is greater than or equal to 30 degrees.

13. A surface light source module, characterized in that: The surface light source module includes a light guide plate, a light source assembly, a cover layer and an optical adhesive layer, wherein: The light guide plate has a first surface and a second surface opposite to each other, and a light incident surface connecting the first surface and the second surface, and the first surface is provided with a plurality of microstructures; The light source assembly is arranged opposite to the light incident surface; The covering layer is arranged opposite to the first surface; The optical adhesive layer is disposed between the light guide plate and the cover layer, and covers the plurality of microstructures; Each of the plurality of microstructures has a first structural surface connected to the first surface, each of the plurality of microstructures has a symmetry plane, the symmetry plane is perpendicular to the first surface and the angle between the symmetry plane and the light incident surface is between 45 degrees and 90 degrees, the first structural surface and the symmetry plane have a first boundary line at their junction, the first boundary line includes a first partial line segment, a second partial line segment and a third partial line segment, the first partial line segment or the third partial line segment is connected to the first surface, the second partial line segment is connected between the first partial line segment and the third partial line segment, the optical adhesive layer at least contacts the second partial line segment of the first boundary line of the first structural surface, and the tangent line at each position on the first partial line segment and the first surface is between tangent line It has a first angle, a second angle is formed between the tangent at each position on the second part of the line segment and the first surface, a third angle is formed between the tangent at each position on the third part of the line segment and the first surface, the first angle has a first angle maximum value, the third angle has a third angle minimum value, the first angle maximum value is greater than 0 degree and less than or equal to 40 degrees, the third angle minimum value is greater than or equal to 50 degrees and less than or equal to 90 degrees, the first length of the first part of the line segment accounts for a proportion of greater than or equal to 5% of the total length of the first boundary line, the third length of the third part of the line segment accounts for a proportion of greater than or equal to 5% of the total length of the first boundary line, and the second angle increases gradually from the first angle maximum value to the third angle minimum value.

14. A bidirectional transparent display device, characterized in that: The bidirectional transparent display device comprises a transparent display panel and two surface light source modules, wherein the transparent display panel is arranged between the two surface light source modules, and each of the two surface light source modules comprises a light guide plate, a light source assembly, a cover layer and an optical adhesive layer, wherein: The light guide plate has a first surface and a second surface opposite to each other, and a light incident surface connecting the first surface and the second surface, the second surface is adjacent to the transparent display panel, and the first surface is a light emitting surface and is provided with a plurality of microstructures; The light source assembly is arranged opposite to the light incident surface; The covering layer is arranged opposite to the first surface; The optical adhesive layer is disposed between the light guide plate and the cover layer, and covers the plurality of microstructures; Each of the plurality of microstructures has a first structural surface connected to the first surface, each of the plurality of microstructures has a symmetry plane, the symmetry plane is perpendicular to the first surface and has an angle with the light incident surface between 45 degrees and 90 degrees, the first structural surface and the symmetry plane have a first boundary line at their junction, the first boundary line includes a first partial line segment, a second partial line segment and a third partial line segment, the first partial line segment or the third partial line segment is connected to the first surface, the second partial line segment is connected between the first partial line segment and the third partial line segment, the optical adhesive layer at least contacts the second partial line segment of the first boundary line of the first structural surface, a tangent at each position on the first partial line segment has a first angle with the first surface, a tangent at each position on the third partial line segment has a third angle with the first surface, the first angle is greater than 0 degree and less than or equal to 30 degrees, the third angle is greater than or equal to 50 degrees and less than or equal to 90 degrees, and the second partial line segment is a curve; The first length of the first partial line segment accounts for a proportion greater than or equal to 5% of the total length of the first boundary line, and the third length of the third partial line segment accounts for a proportion greater than or equal to 5% of the total length of the first boundary line.

15. The bidirectional transparent display device according to claim 14, characterized in that: Each of the cover layers is a transparent substrate.

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