Front light source and display device

Abstract

The embodiment of the present invention provides a front light source and a display device, the front light source comprising: a light source; a light guide layer, the light guide layer comprising a light incident surface, a first surface and a second surface; wherein the second surface comprises a plurality of first inclined surfaces connected to each other; the plurality of first inclined surfaces are arranged in parallel in a first direction; the side of the first inclined surface close to the light source is the first side; the side of the first inclined surface away from the light source is the second side; the first vertical distance from the first side to the first surface is greater than the second vertical distance from the second side to the first surface. The embodiment of the present invention sets the second surface as a plurality of first inclined surfaces connected to each other, so that when a large-angle light is incident on the first inclined surface, the reflection direction of the large-angle light is changed, the incident angle of the large-angle light is reduced, and the light can be incident on the display panel in a direction away from the light source, thereby improving the uniformity of the light from the front light source incident on the display panel and the light utilization rate of the front light source.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a front light source and a display device. Background Art

[0002] Compared with transmissive display devices, reflective display devices have softer images and lower power consumption, and can achieve better display effects outdoors, so they are increasingly favored in fields such as e-readers and public displays. However, reflective display devices are greatly affected by external ambient light. Figure 1 When the external ambient light enters the display panel 01 nearly perpendicularly, the display effect of the reflective display device is better. Figure 1 The display effect of the middle H area is better; when the incident angle of the external ambient light incident on the display panel is large, less light enters the display panel 01, and the display effect of the reflective display device is poor, such as Figure 1 The display effect in the middle C area is poor.

[0003] To solve the above problems, the current method is to add a front light source to the reflective display device. When the external ambient light is insufficient, the front light source can be used to improve the display effect of the reflective display device; Figure 2 , is a front light source of the prior art, including a light source 02 and a light guide layer 03, wherein the light guide layer 03 is arranged on the display panel 01. It can be seen that the small-angle light a and light b directed to the display panel 01 will be incident on the display panel 01, and the large-angle light c directed to the display panel 01 will be totally reflected. It can be seen that Figure 2 There is a problem that the amount of light incident on the display panel becomes less and less in the direction X away from the light source 02, and there is a problem that the light distribution range is uneven, and the incident angle distribution range of the light incident on the display panel is wide; in addition, the light incident on the surface of the light guide layer 03 will partially appear to be emitted from the display panel, resulting in a problem of low effective utilization of light, and ultimately leading to a problem of poor display effect of the display panel. Summary of the invention

[0004] The present invention provides a display device to solve the problems of uneven light distribution and low light efficiency caused by the existing front light source.

[0005] A first aspect of the present invention provides a front light source, the front light source comprising:

[0006] light source;

[0007] A light guide layer, the light guide layer comprising a light incident surface, a first surface, and a second surface; the light source is arranged on the light incident surface side of the light guide layer, and the light emitted by the light source enters the light guide layer through the light incident surface; the first surface is perpendicular to the light incident surface; the first surface and the second surface are arranged opposite to each other;

[0008] Among them, the second surface includes a plurality of first inclined surfaces connected to each other; the plurality of first inclined surfaces are arranged in parallel in a first direction; the first direction is a direction perpendicular to the light incident surface; the side of the first inclined surface close to the light source is the first side; the side of the first inclined surface away from the light source is the second side; the first vertical distance from the first side to the first surface is greater than the second vertical distance from the second side to the first surface.

[0009] Optionally, it also includes: a first structural layer; the first structural layer is arranged on the first surface or the second surface of the light-guiding layer; the third surface of the first structural layer away from the light-guiding layer includes a plurality of interconnected second inclined surfaces; the side of the second inclined surface close to the light source is a third side; the side of the second inclined surface away from the light source is a fourth side; the third vertical distance from the third side to the fourth surface of the first structural layer is smaller than the fourth vertical distance from the fourth side to the fourth surface; the fourth surface is arranged opposite to the third surface.

[0010] Optionally, an angle between the first inclined surface and the light incident surface is greater than or equal to 80° and less than 90°.

[0011] Optionally, an angle between the second inclined surface and the plane where the light incident surface is located is greater than or equal to 55° and less than 90°.

[0012] Optionally, it further includes: a bonding layer; the bonding layer is arranged on a side of the light guide layer away from the first structural layer.

[0013] Optionally, it further includes: a protective layer; the protective layer is arranged on the third surface of the first structural layer, and the fifth surface of the protective layer facing the first structural layer is in line with the third surface.

[0014] Optionally, the refractive index of the bonding layer is smaller than the refractive index of the light guiding layer.

[0015] Optionally, the refractive index of the protective layer is smaller than the refractive index of the first structural layer.

[0016] Optionally, in the first direction, the distance from the third side to the fourth side is a first distance; the distance from the first side to the second side is a second distance; and the first distance is smaller than the second distance.

[0017] Optionally, it also includes a second structural layer; the second structural layer is arranged between the light guiding layer and the first structural layer; a plurality of optical structures are arranged in the second structural layer for adjusting the light incident on the optical structures; the optical structures are arranged at intervals along the first direction; each of the optical structures includes a groove located in the second structural layer, and the groove forms an opening on the sixth surface; the sixth surface is a side of the second structural layer facing away from the light guiding layer.

[0018] Optionally, the refractive index of the second structure layer, the refractive index of the first structure layer, and the refractive index of the light guide layer are the same.

[0019] Optionally, the thickness of the front light source ranges from 50 μm to 400 μm.

[0020] A second aspect of the present invention provides a display device, comprising a front light source as described in any one of the above items, and further comprising: a display panel; the display panel is arranged on a side of the bonding layer away from the light guide layer.

[0021] An embodiment of the present invention provides a front light source, which includes: a light source; a light guide layer, the light guide layer including a light incident surface, a first surface and a second surface; the light source is arranged on the light incident surface side of the light guide layer, and the light emitted by the light source enters the light guide layer through the light incident surface; the first surface is perpendicular to the light incident surface; the first surface and the second surface are arranged opposite to each other; wherein the second surface includes a plurality of first inclined surfaces connected to each other; the plurality of first inclined surfaces are arranged side by side in a first direction; the first direction is a direction perpendicular to the light incident surface; a side of the first inclined surface close to the light source is a first side; a side of the first inclined surface away from the light source is a second side; a first vertical distance from the first side to the first surface is greater than a second vertical distance from the second side to the first surface. The embodiment of the present invention sets the second surface as a plurality of interconnected first inclined surfaces. When a large-angle light is incident on the first inclined surface, the reflection direction of the large-angle light is changed, and the incident angle of the large-angle light is reduced. After the incident angle of the large-angle light is reduced multiple times by the plurality of first inclined surfaces, the large-angle light can be incident on the display panel in a direction away from the light source, thereby improving the uniformity of the front light source light incident on the display panel and the light utilization rate of the front light source, thereby ultimately improving the display effect of the display device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0023] Figure 1 It is a schematic diagram of a structure of a reflective display panel receiving light provided by the prior art;

[0024] Figure 2 It is a structural schematic diagram of a front light source provided by the prior art;

[0025] Figure 3 is a schematic diagram of a front light source structure provided by an embodiment of the present invention;

[0026] Figure 4 is a schematic diagram of the distribution of a first inclined surface on a second surface provided by an embodiment of the present invention;

[0027] Figure 5 is a schematic diagram of distribution of another first inclined surface on the second surface provided by an embodiment of the present invention;

[0028] Figure 6 is a schematic structural diagram of another front light source provided by an embodiment of the present invention;

[0029] Figure 7 is a partially enlarged structural schematic diagram of a first structural layer provided by an embodiment of the present invention;

[0030] Figure 8 is a schematic structural diagram of another front light source provided by an embodiment of the present invention;

[0031] Fig. 9 is a schematic structural diagram of an optical structure provided by an embodiment of the present invention;

[0032] Fig.10 is a partially enlarged structural schematic diagram of a second structural layer provided by an embodiment of the present invention;

[0033] Fig.11 is a schematic structural diagram of another optical structure provided by an embodiment of the present invention;

[0034] Fig.12 It is a structural schematic diagram of a display device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Reference Figure 3, shows a schematic structural diagram of a front light source according to an embodiment of the present invention, the front light source specifically comprises:

[0037] Light source 10;

[0038] The light guide layer 20 includes a light incident surface 21, a first surface 22, and a second surface 23; the light source 10 is disposed on the light incident surface 21 side of the light guide layer 20, and the light emitted by the light source 10 enters the light guide layer 20 through the light incident surface 21; the first surface 22 is perpendicular to the light incident surface 21; the first surface 22 and the second surface 23 are disposed opposite to each other;

[0039] Among them, the second surface 23 includes a plurality of interconnected first inclined surfaces 231; the plurality of first inclined surfaces 231 are arranged in parallel in a first direction Y; the first direction Y is a direction perpendicular to the light incident surface 21; the side of the first inclined surface 231 close to the light source 10 is a first side 2311; the side of the first inclined surface 231 away from the light source 10 is a second side 2312; a first vertical distance h1 from the first side 2311 to the first surface 22 is greater than a second vertical distance h2 from the second side 2312 to the first surface 22.

[0040] The light source 10 is a side-entry light source, which can further reduce the total thickness of the front light source.

[0041] Furthermore, the light source 10 may include a light emitting diode (LED for short) or a light strip composed of multiple light emitting diodes, but the embodiments of the present disclosure are not limited to this. In other embodiments, the light source 10 may also include organic light emitting diodes, quantum dot light emitting diodes, micro light emitting diodes, sub-millimeter light emitting diodes and other elements suitable for emitting light.

[0042] exist Figure 3 In the embodiment, the first vertical distances h1 from the first side 2311 of each first inclined surface 231 to the first surface 22 are equal, and the second vertical distances h2 from the second side 2312 of each first inclined surface 231 to the first surface 22 are also equal. The second side 2312 of the first inclined surface 231 is inclined toward the direction of the first surface 22 relative to the first side 2311.

[0043] In addition, the second edge 2312 of a first inclined surface is connected to the first edge 2311 of another adjacent first inclined surface via a vertical surface 232, which is parallel to the light incident surface 21, and the length L3 of the vertical surface 232 in the perpendicular first direction Y can be calculated based on the angle α1 and L2.

[0044] In the embodiment of the present invention, the second side 2312 of the first inclined surface 231 is inclined toward the first surface 22, and the angle α1 between the first inclined surface and the light incident surface is greater than or equal to 80° and less than 90°. Preferably, α1 can be selected to be 88°.

[0045] Specifically, Figure 3 The working principle of the front light source is as follows: the large-angle light g incident on the first inclined surface 231 has an incident angle of γ1, is totally reflected by the first inclined surface 231, and is incident on the first surface 22. After being reflected by the first surface 22, it is again incident on another first inclined surface 231 with an incident angle of γ2, wherein γ2 is smaller than the total reflection angle, and the light g1 is emitted from the second surface. If the second surface in the prior art is a plane perpendicular to the incident surface 21, the incident angle of the incident light g incident on the second surface is β1, and is totally reflected on the second surface, forming Figure 3 Therefore, compared with the prior art, the first inclined surface 231 provided in the embodiment of the present invention can increase the probability of large-angle light being emitted from the second surface, thereby improving the light utilization rate of the front light source.

[0046] In addition, γ1=β1-(90°-α1); γ2=β1-2(90°-α1); when the incident light is reflected n times on the first inclined surface 231, γn=β1-n(90°-α1), until γn is smaller than the total reflection angle, and then it is emitted from the second surface. It can be seen that by providing multiple first inclined surfaces 231, the light can be emitted from the second surface away from the light source 10, thereby improving the uniformity of the light and improving the angle concentration of the light incident from the light guide layer to the display panel.

[0047] Further, in Figure 3 In the embodiment, the high-angle light i incident on the first surface 22 is reflected by the first surface 22 and then incident on the first inclined surface 231 with an incident angle of θ1, and then incident on another first inclined surface 231 with an incident angle of θ2, and then forms an outgoing light i1, which is incident on the display panel; if the second surface in the prior art is a plane perpendicular to the incident surface 21, the incident angle of the incident light i incident on the first surface is β2, and total reflection occurs on the first surface, and after multiple total reflections, an outgoing light i1 is formed. Figure 3 The light i2 in the first surface cannot be emitted from the second surface, and thus cannot be effectively utilized. Therefore, the embodiment of the present invention can further utilize the large-angle light emitted to the first surface, thereby improving the light utilization rate of the front light source.

[0048] In addition, θ1=β2-(90°-α1); θ2=β2-2(90°-α1); then when the incident light is reflected n times on the first inclined surface 231, θn=β2-n(90°-α1), until θn is less than the total reflection angle, and then it is emitted from the second surface. It can be seen that by providing multiple first inclined surfaces 231, more light can be emitted from the second surface away from the light source 10, thereby improving the uniformity of the light and increasing the angle concentration of the light incident from the light guide layer to the display panel.

[0049] In an embodiment of the present invention, the display panel is arranged on the second surface 23 of the light guide layer 20, so that the light emitted from the second surface can be directly emitted to the display panel; in addition, the display panel can also be arranged on the first surface 23 of the light guide layer 20. In this case, it is necessary to set a subsequent first structural layer and a second structural layer to reflect the light emitted from the first surface back to the light guide layer to achieve the utilization rate of large-angle light.

[0050] In the embodiment of the present invention, large-angle light refers to light whose incident angle is greater than the total reflection angle when the light is incident from the incident surface to the first surface and the second surface for the first time; further, the total reflection angle means that when the incident angle is greater than or equal to the total reflection angle, the light is totally reflected on the surface of the light-guiding layer, and when the incident angle is less than the total reflection angle, the light is refracted on the surface of the light-guiding layer and emitted from the light-guiding layer.

[0051] In the embodiment of the present invention, the first inclined surface 231 can be arranged in a one-dimensional manner or in a two-dimensional manner. For details, refer to Figure 4 , is a view toward the second surface 23 of the light guide layer 20, Figure 4 The first inclined surfaces are arranged in a one-dimensional manner, that is, arranged along the first direction Y. Figure 5 , is another view toward the second surface 23 of the light guide layer 20, Figure 5 The first inclined surfaces are arranged in a two-dimensional manner, that is, multiple rows are arranged along the first direction on the second surface 23. In the embodiment of the present invention, the first inclined surfaces 231 can also be arranged at intervals and arranged in an array on the second surface. The specific arrangement can be adjusted according to actual conditions and is not limited here.

[0052] Reference Figure 6 and Figure 8The front light source also includes: a first structure layer 30; the first structure layer 30 is arranged on the first surface 22 or the second surface 23 of the light guide layer 20; the third surface 31 of the first structure layer 30 away from the light guide layer 20 includes a plurality of second inclined surfaces 311 connected to each other; the side of the second inclined surface 311 close to the light source 10 is a third side 3111; the side of the second inclined surface 311 away from the light source 10 is a fourth side 3112; the third vertical distance h3 from the third side 3111 to the fourth surface 32 of the first structure layer is smaller than the fourth vertical distance h4 from the fourth side 3112 to the fourth surface 32; the fourth surface 32 is arranged opposite to the third surface 31.

[0053] Among them, Figure 6 In the embodiment, the angle α2 between the second inclined surface 311 and the plane where the light incident surface 21 is located is greater than or equal to 55° and less than 90°. The first structure layer 30 is disposed on the first surface 22 of the light guide layer 20, and the second surface 23 of the light guide layer 20 faces the display panel. When the light k emitted from the light guide layer 20 enters the first structure layer, it will be reflected by the second inclined surface 311 and return to the light guide layer 20, thereby improving the utilization rate of the light.

[0054] Specifically, the working principle of the first structural layer 30 is as follows Figure 7 In the prior art, the third surface 31 of the first structure layer 30 is a plane, and the incident angle of the light ray k is is smaller than the total reflection angle of the third surface, and refraction occurs, and the light k2 is emitted from the third surface; and in the embodiment of the present invention, a second inclined surface 311 is provided, and the incident angle of the light k toward the second inclined surface 311 is in, Then the incident angle of light k increases, and the incident angle The total reflection angle is greater than that of the third surface, so that the light K is reflected, and the reflected light k1 re-enters the light guide layer 20, thereby increasing the utilization rate of the light.

[0055] It can be seen that compared with the prior art in which the third surface is set as a plane, the embodiment of the present invention sets the third surface 31 as a plurality of interconnected second inclined surfaces 311, which can reflect light within a partial range of the incident angle; for example, when the total reflection angle of the third surface is 70°, α2=80°, then in the prior art, light with an incident angle less than 70° will be refracted, while in the embodiment of the present invention, light with an incident angle of 60°-70° relative to the plane will be totally reflected and directed to the light guide layer for utilization.

[0056] Reference Figure 8, the first structure layer 30 is arranged on the second surface 23 of the light guide layer 20, and the first surface 21 of the light guide layer 20 faces the display panel. In the prior art, the second surface is a plane. After the large-angle light p is reflected by the second surface of the plane, it is reflected multiple times in the light guide layer and the reflected light p2 cannot be utilized. In the embodiment of the present invention, the second surface 23 is a plurality of first inclined surfaces 231. The incident light p is incident on the first inclined surface 231, and the incident angle is reduced. It is emitted from the first inclined surface 231 of the light guide layer 20 and can be returned to the light guide layer 20 for utilization again through the action of the first structure layer 30 and the second structure layer 60. Therefore, the utilization rate of the light is also improved.

[0057] In the embodiment of the present invention, the second inclined surface 311 may also be arranged on the third surface 31 according to Figure 4 and Figure 5 The one-dimensional or two-dimensional arrangement is performed in a manner, which will not be described in detail here.

[0058] In the embodiment of the present invention, refer to Figure 6 and Figure 8 The front light source further includes: a bonding layer 40 ; the bonding layer 40 is arranged on a side of the light guide layer 20 away from the first structural layer 30 .

[0059] Specifically, the laminating layer 40 may be a transparent adhesive layer, and the material of the laminating layer 40 includes a pressure sensitive adhesive (PSA) or an optically clear adhesive (OCA). The refractive index of the laminating layer 40 is less than the refractive index of the light guide layer 20. Figure 6 , light o with an incident angle greater than or equal to the total reflection angle of the bonding layer 40 will be reflected back to the light guide layer 20, and light with an incident angle less than the total reflection angle of the bonding layer will exit the bonding layer 40 and enter the display panel. The bonding layer 40 serves to bond the front light source and the display panel.

[0060] Reference Figure 6 and Figure 8 The front light source further includes: a protective layer 50 ; the protective layer 50 is disposed on the third surface 31 of the first structural layer 30 , and a fifth surface of the protective layer 50 facing the first structural layer 30 is aligned with the third surface 31 .

[0061] Among them, since the third surface 31 is composed of a plurality of second inclined surfaces 311 connected to each other, the fifth surface is completely in contact with the third surface, and the fifth surface is also composed of a plurality of inclined surfaces.

[0062] In addition, the refractive index of the protective layer 50 is smaller than the refractive index of the first structural layer 30. The material of the protective layer 50 includes: polymethyl methacrylate (PMMA) or other transparent high refractive index materials. Fig.11The upper side (in the above) is called the display side of the display module, and the side of the display panel 200 away from the protective layer 50 (i.e., Fig.11 the lower side in the above) is called the back side of the display module.

[0063] Referring to Figure 6 In the first direction Y, the distance from the third side 3111 to the fourth side 3112 is the first distance L1; the distance from the first side 2311 to the second side 2312 is the second distance L2; the first distance L1 is less than the second distance L2.

[0064] Specifically, L1 is less than L2. In the second direction perpendicular to the first direction Y, the vertical distance H1 from the third side 3111 to the fourth side 3112 can be set according to L1 and the angle of α2. L2 is less than 500 μm; in the second direction perpendicular to the first direction Y, the distance from the first side 2311 to the second side 2312, which is the vertical distance H2, can be set according to L2 and the angle of α1. The specific lengths of L1 and L2 can be set according to actual needs and are not limited herein.

[0065] Referring to Figure 6 and Figure 8 it further includes a second structural layer 60; the second structural layer 60 is disposed between the light guide layer 20 and the first structural layer 30; a plurality of optical structures 61 are disposed in the second structural layer 60 for adjusting the light incident on the optical structures 61; the optical structures 61 are arranged at intervals along the first direction Y; each of the optical structures 61 includes a groove in the second structural layer 60, and the groove forms an opening on the sixth surface 62; the sixth surface 62 is the side of the second structural layer 60 facing away from the light guide layer 20.

[0066] Referring to Fig. 9 the optical structure 61 includes a first optical surface 611, a second optical surface 612, a third optical surface 613, a fourth optical surface 614, and a fifth optical surface 615. Combining Figures 6 to 8 as shown, the first optical surface 611, the second optical surface 612, the third optical surface 613, and the fourth optical surface 614 are successively away from the light incident surface 21, and the four are successively connected. The fifth optical surface 615 connects the first optical surface 611 and the fourth optical surface 614. The fifth optical surface 615 can be substantially parallel to the fourth surface 32 of the first structural layer 30. Among them, when the groove of the optical structure 61 is filled with a low refractive index material, the fifth optical surface 615 can be the top surface of the low refractive index material and be coplanar with the fourth surface 32 of the first structural layer 30. In some embodiments, when the groove is not filled with a low refractive index material, that is, when the groove is filled with air, the fifth optical surface 615 is a virtual surface coplanar with the fourth surface 32 of the first structural layer 30.

[0067] like Fig. 9 As shown, the angle between the first optical surface 611 and the fifth optical surface 615 is the first angle α3, the angle between the first optical surface 611 and the second optical surface 612 is the second angle α4, the angle between the second optical surface 611 and the third optical surface 612 is the third angle α5, and the angle between the third optical surface 613 and the fourth optical surface 614 is the fourth angle α6. The first angle α3, the second angle α4, the third angle α5 and the fourth angle α6 satisfy the following formula:

[0068] 0°<α3, α4, α5, α6<90°,

[0069] That is, the first angle α3, the second angle α4, the third angle α5 and the fourth angle α6 are all acute angles.

[0070] Reference Fig.10 , is a partial enlarged view of the second structural layer 60, refer to Fig.10 The light m shown in the figure, the light m traveling in the second structure layer 60 is incident on the first optical surface 611 of the optical structure 61, and is totally reflected at the first optical surface 611. When the angle between the light incident on the first optical surface 611 and the normal direction at the first optical surface 611 is greater than or equal to the critical angle of total reflection, the light m will be totally reflected at the first optical surface 611. The angle between the light m and the normal direction at the first optical surface 611 is greater than or equal to the critical angle, and after being totally reflected at the first optical surface 611, it travels toward the first surface 22 of the light guide layer 20. It can then be incident on the display panel to provide display light for the display panel.

[0071] Reference Fig.10 As shown, the light ray n traveling in the second structure layer 60 is incident on the first optical surface 611 of the optical structure 61. The angle between the light ray n and the normal direction at the first optical surface 611 is less than the critical angle. The light ray n is refracted at the first optical surface 611 and enters the optical structure 61. After propagating in the optical structure 61, the light ray n is refracted at the second optical surface 612 of the optical structure 61 and enters the second structure layer 60 again. Since the refraction at the second optical surface 612 is from the optically sparse medium to the optically dense medium, the light ray n emitted from the second optical surface 612 can be emitted to the third optical surface 613 at a larger angle. The angle between the light ray n and the normal direction at the first optical surface 613 is greater than or equal to the critical angle. The light ray n is totally reflected at the third optical surface 613 and then travels toward the first surface 22 of the light guide layer 20. Then, it can be incident on the display panel to provide display light for the display panel.

[0072] Reference Fig.11, is another optical structure 61 that can be selected in the embodiment of the present invention. The optical structure 61 is a triangular structure. For example, Fig.11 Among the light rays u, some of the light rays are incident on the optical structure 61 and are refracted at the optical surface of the optical structure 61. After being refracted by the two optical surfaces, the light rays propagate toward the display side and are incident on the first structural layer. Fig.11 The light w in the optical structure 61 is totally reflected at an optical surface and reflected back to the light guide layer. Fig.11 The light v in is incident on the optical structure 61 , and is refracted at the two optical surfaces of the optical structure 61 . After being refracted by the two optical surfaces, the light propagates toward the back side and is incident on the light guide layer 20 .

[0073] In the embodiment of the present invention, the optical structure 61 can be configured to have other shapes as required, which is not limited here. In addition, the optical structure 61 can be distributed linearly or in an array in the second structural layer.

[0074] The refractive index of the second structure layer 60, the refractive index of the first structure layer 30, and the refractive index of the light guide layer 20 are the same. Specifically, the refractive indexes of the second structure layer 60, the first structure layer 30, and the light guide layer 20 are all in the range of 1.3-1.8, preferably 1.58; if the refractive indexes of the second structure layer 60, the first structure layer 30, and the light guide layer 20 are set to be the same, the light will not be refracted when propagating between the second structure layer 60, the first structure layer 30, and the light guide layer 20, which facilitates the design of the optical structure 61 in the second structure layer 60, the second inclined surface 311 in the first structure layer 30, and the first inclined surface 231 in the light guide layer 20.

[0075] In addition, the refractive index of the protective layer 50 and the laminating layer 40 is also in the range of 1.3-1.8, wherein the refractive index of the protective layer 50 is preferably 1.3, and the refractive index of the laminating layer 40 is preferably 1.49. In the embodiment of the present invention, the refractive index of the protective layer 50 and the laminating layer 40 can be adjusted according to specific needs.

[0076] Specifically, the thickness T of the front light source ranges from 50μm to 400μm. Among them, the thickness range of the protective layer 50 is from 10μm to 55μm; the thickness range of the first structural layer 30 is from 5μm to 10μm; the thickness range of the second structural layer 60 is from 5μm to 20μm; the thickness range of the light guide layer 20 is from 20μm to 310μm; the thickness range of the bonding layer 40 is from 5μm to 12μm; it can be seen that the front light source provided by the embodiment of the present invention meets the design thinning requirements, the thickness T of the front light source is lower than the thickness of the conventional front light source, and it can be equipped with any display module of different shapes, with strong matching. In addition, the specific thickness of the front light source can be adjusted according to the display panel to be matched, and is not limited here.

[0077] In the embodiment of the present invention, the protective layer 50, the first structural layer 30, the second structural layer 60, the light guide layer 20 and the bonding layer 40 can all be made of flexible materials with high light transmittance, such as PC (polycarbonate), PMMA polymethyl methacrylate, and UV (light-curing material).

[0078] The present invention provides a front light source, which includes: a light source; a light guide layer, the light guide layer includes a light incident surface, a first surface and a second surface; the light source is arranged on the light incident surface side of the light guide layer, and the light emitted by the light source enters the light guide layer through the light incident surface; the first surface is perpendicular to the light incident surface; the first surface and the second surface are arranged opposite to each other; wherein the second surface includes a plurality of first inclined surfaces connected to each other; the plurality of first inclined surfaces are arranged side by side in a first direction; the first direction is a direction perpendicular to the light incident surface; a side of the first inclined surface close to the light source is a first side; a side of the first inclined surface away from the light source is a second side; a first vertical distance from the first side to the first surface is greater than a second vertical distance from the second side to the first surface. The embodiment of the present invention sets the second surface as a plurality of interconnected first inclined surfaces. When a large-angle light is incident on the first inclined surface, the reflection direction of the large-angle light is changed, and the incident angle of the large-angle light is reduced. After the incident angle of the large-angle light is reduced multiple times by the plurality of first inclined surfaces, the large-angle light can be incident on the display panel in a direction away from the light source, thereby improving the uniformity of the front light source light incident on the display panel and the light utilization rate of the front light source, thereby ultimately improving the display effect of the display device.

[0079] Reference Fig.12 , an embodiment of the present invention provides a display device, including a front light source 100 as any one of the above items, and also including: a display panel 200; the display panel 200 is arranged on a side of the bonding layer 40 away from the light guide layer 20.

[0080] In the embodiment of the present invention, the display panel 200 may be a liquid crystal display panel (LCD).

[0081] exist Fig.12 In the figure, when the light r reflected from the display panel 200 is incident on the front light source 100 at an incident angle of 30°, it is refracted by the front light source 100 and emitted from the display device as the light r1, wherein the emission angle of r1 is 45°. When the first inclined surface 231 and the second inclined surface 311 are not provided, the emission light corresponding to the light r is r2, and the emission angle of r2 is 48°. It can be seen that the front light source provided in the embodiment of the present invention also has a gathering effect on the light reflected from the display panel.

[0082] Furthermore, when the light s reflected from the display panel 200 is incident on the front light source 100 at an incident angle of 35°, it is reflected by the optical structure 61 in the front light source 100 and reflected back to the light guide layer as the light s1. When the first inclined surface 231 and the second inclined surface 311 are not set, the light s is refracted by the front light source and emitted from the display device as the light s2. The emission angle of the light s2 is 85°, and the large angle of the light s2 is not conducive to display. It can be seen that the front light source provided in the embodiment of the present invention has a significant effect on improving the utilization rate of light in the display device.

[0083] In addition, in the embodiment of the present invention, the contrast CR of the front light source is calculated as follows:

[0084]

[0085] Among them, in the above formula, L255 brightness (brightness of white screen) refers to the brightness when the front light source is set to the brightest, and L0 brightness (brightness of black screen) refers to the brightness when the front light source is set to the darkest; the upper surface light refers to the light emitted from the side of the protective layer 50 away from the display panel 200, and the lower surface light refers to the light emitted by the front light source toward the display panel 200; Ref.L255 refers to the light reflected back to the front light source after being emitted to the display panel 200 when the screen is white; Ref.L0 refers to the light reflected back to the front light source after being emitted to the display panel 200 when the screen is black; and the transmittance refers to the light transmittance of the front light source. It can be seen from the above formula that reducing the upper surface light and increasing the lower surface light can improve the contrast of the display device. As can be seen from the above, the front light source provided in the embodiment of the present invention can reduce the light output on the upper surface and increase the light output intensity and angle concentration of the lower surface. Therefore, the display device provided in the embodiment of the present invention has a higher contrast and enhances the display effect of the display device.

[0086] In summary, the display device provided by the embodiment of the present invention has a high light utilization rate, the light emitted by the display device during display is relatively concentrated, the contrast is relatively high, and the display device has a better display effect.

[0087] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described device and structure can refer to the corresponding process in the aforementioned front light source embodiment, and will not be repeated here.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0089] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A front light source, It is characterized in that include: light source; A light guide layer, the light guide layer comprising a light incident surface, a first surface, and a second surface; the light source is arranged on the light incident surface side of the light guide layer, and the light emitted by the light source enters the light guide layer through the light incident surface; the first surface is perpendicular to the light incident surface; the first surface and the second surface are arranged opposite to each other; Wherein, the second surface includes a plurality of first inclined surfaces connected to each other; the plurality of first inclined surfaces are arranged in parallel in a first direction; the first direction is a direction perpendicular to the light incident surface; a side of the first inclined surface close to the light source is a first side; a side of the first inclined surface away from the light source is a second side; a first vertical distance from the first side to the first surface is greater than a second vertical distance from the second side to the first surface; a first structural layer; the first structural layer is arranged on the first surface or the second surface of the light guide layer; the third surface of the first structural layer away from the light guide layer includes a plurality of second inclined surfaces connected to each other; the side of the second inclined surface close to the light source is a third side; the side of the second inclined surface away from the light source is a fourth side; a third vertical distance from the third side to the fourth surface of the first structural layer is less than a fourth vertical distance from the fourth side to the fourth surface; the fourth surface is arranged opposite to the third surface; A protective layer; the protective layer is disposed on the third surface of the first structural layer, and a fifth surface of the protective layer facing the first structural layer is aligned with the third surface; The bonding layer is arranged on a side of the light guide layer away from the first structural layer; a second structural layer; the second structural layer is arranged between the light-guiding layer and the first structural layer; a plurality of optical structures are arranged in the second structural layer for adjusting the light incident on the optical structures; the optical structures are arranged at intervals along the first direction; each of the optical structures includes a groove located in the second structural layer, and the groove forms an opening on the sixth surface; the sixth surface is a side of the second structural layer away from the light-guiding layer.

2. The front light source according to claim 1, It is characterized in that An included angle between the first inclined surface and the light incident surface is greater than or equal to 80° and less than 90°.

3. The front light source according to claim 1, It is characterized in that An angle between the second inclined surface and the plane where the light incident surface is located is greater than or equal to 55° and less than 90°.

4. The front light source according to claim 1, It is characterized in that The refractive index of the bonding layer is smaller than the refractive index of the light guiding layer.

5. The front light source according to claim 1, It is characterized in that The refractive index of the protection layer is smaller than the refractive index of the first structure layer.

6. The front light source according to claim 1, It is characterized in that In the first direction, the distance from the third side to the fourth side is a first distance; the distance from the first side to the second side is a second distance; and the first distance is smaller than the second distance.

7. The front light source according to claim 1, It is characterized in that The refractive index of the second structure layer, the refractive index of the first structure layer, and the refractive index of the light guide layer are the same.

8. The front light source according to claim 1, It is characterized in that The thickness of the front light source ranges from 50 μm to 400 μm.

9. A display device, It is characterized in that The front light source comprises any one of claims 1 to 8, further comprising: a display panel; the display panel is arranged on a side of the bonding layer away from the light guide layer.

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