Backlight module and display device

Abstract

The application discloses a backlight module and a display device; wherein the light guide plate comprises a bottom surface, a first side surface and a second side surface, and the bottom surface is provided with a light guide structure; the first lamp strip comprises a first light emitting element arranged on one side of the first side surface, and the light emitting direction of the first light emitting element is arranged towards the first side surface and emits light along a first direction; the second lamp strip comprises a second light emitting element arranged on one side of the second side surface, and the light emitting direction of the second light emitting element is arranged towards the second side surface and emits light along a second direction, wherein the first direction is different from the second direction; the light guide structure comprises a first light guide surface arranged opposite to the first light emitting element and a second light guide surface arranged opposite to the second light emitting element, wherein the first light guide surface is a mirror surface, and the second light guide surface is a diffuse reflection surface; when the backlight module is configured in a first state, the first light emitting element emits light, and the second light emitting element does not emit light; when the backlight module is configured in a second state, at least the second light emitting element emits light; the application can realize a dynamic anti-peeping function, simplify the structure and reduce the cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a backlight module and a display device. BACKGROUND

[0002] Display is used in various aspects of people's daily life, and different application occasions have different requirements for the viewing angle of display. For example, when the user is in an open environment with privacy protection needs, such as inputting a password for withdrawing money, watching private information on public transportation or business negotiation, the display needs to have a narrow viewing angle to achieve the purpose of preventing peeping to protect personal privacy. When the user is in an environment with sharing needs, such as watching a display device with others, a wide viewing angle is needed to achieve the purpose of sharing.

[0003] At present, the dynamic anti-peeping purpose is often achieved by adding an anti-peeping film in the display, such as a liquid crystal anti-peeping film. However, the existing anti-peeping film structure is complex and greatly increases the cost of the display. SUMMARY

[0004] The embodiments of the present application provide a backlight module and a display device, which can achieve dynamic anti-peeping, simplify the structure of the backlight module, and reduce the cost.

[0005] The embodiments of the present application provide a backlight module, which comprises:

[0006] A light guide plate, comprising a bottom surface away from a light-out side of the backlight module, and a first side surface and a second side surface connected to the bottom surface, wherein the bottom surface is provided with a light guide structure;

[0007] A first lamp strip, comprising a first light-emitting element arranged on one side of the first side surface, wherein the light-emitting direction of the first light-emitting element is arranged towards the first side surface and emits light along a first direction;

[0008] A second lamp strip, comprising a second light-emitting element arranged on one side of the second side surface, wherein the light-emitting direction of the second light-emitting element is arranged towards the second side surface and emits light along a second direction, and the first direction is different from the second direction;

[0009] The light guide structure comprises a first light guide surface arranged opposite to the first light-emitting element, and a second light guide surface arranged opposite to the second light-emitting element, the first light guide surface is a mirror surface, the second light guide surface is a diffuse reflection surface, the backlight module is switched between a first state and a second state, when the backlight module is configured in the first state, the first light-emitting element emits light, and the second light-emitting element does not emit light, and when the backlight module is configured in the second state, at least the second light-emitting element emits light.

[0010] In one embodiment of the present invention, the angle between the first light guide surface and the first direction is smaller than the angle between the second light guide surface and the second direction.

[0011] In one embodiment of the present invention, the angle between the first light guide surface and the first direction is greater than or equal to 15° and less than or equal to 30°.

[0012] In one embodiment of the present invention, the first light guide surface is a plane and the second light guide surface is an arc surface.

[0013] In one embodiment of the present invention, the second light guide surface protrudes toward the side away from the first light guide surface.

[0014] In one embodiment of the present invention, the light guide plate further includes a third side surface connected to the bottom surface, and the backlight module further includes a third light strip. The third light strip includes a third light-emitting element disposed on one side of the third side surface. The light-emitting element emits light in a direction toward the third side surface and emits light along a third direction, and the third direction is different from both the first direction and the second direction.

[0015] The light guide structure includes a third light guide surface disposed opposite to the third light-emitting element. The third light guide surface is a specular reflective surface. The third light-emitting element emits light at least when the backlight module is configured in the first state.

[0016] In one embodiment of the invention, the third direction is opposite to the first direction.

[0017] In one embodiment of the present invention, the light guide plate further includes a fourth side surface connected to the bottom surface, and the backlight module further includes a fourth light strip. The fourth light strip includes a fourth light-emitting element disposed on one side of the fourth side surface. The light-emitting element emits light in a direction toward the fourth side surface and emits light along a fourth direction. The fourth direction is different from both the first direction and the second direction.

[0018] The light guide structure includes a fourth light guide surface disposed opposite to the fourth light-emitting element. The fourth light guide surface is a diffuse reflection surface. When the backlight module is configured in the first state, the fourth light-emitting element does not emit light. When the backlight module is configured in the second state, the fourth light-emitting element emits light.

[0019] In one embodiment of the present invention, the fourth direction intersects with the second direction, or the fourth direction is opposite to the second direction.

[0020] In one embodiment of the present invention, the first light strip includes a first circuit board, the first light-emitting element is disposed on the first circuit board, the first circuit board is located on the side of the light guide plate having the bottom surface, one end of the first circuit board is connected to the first light-emitting element, and the other end of the first circuit board overlaps with the light guide plate along the thickness direction of the light guide plate.

[0021] The second light strip includes a second circuit board, the second light-emitting element is disposed on the second circuit board, the second circuit board is located on the side of the light guide plate where the bottom surface is provided, one end of the second circuit board is connected to the second light-emitting element, and the other end of the second circuit board overlaps with the light guide plate along the thickness direction of the light guide plate.

[0022] In one embodiment of the present invention, the first circuit board has a first reflective layer on the surface opposite to the light guide plate, and the second circuit board has a second reflective layer on the surface opposite to the light guide plate.

[0023] According to the above-mentioned objectives of the present invention, an embodiment of the present invention also provides a display device, the display device including a display panel and the backlight module, wherein the display panel is disposed on the light-emitting side of the backlight module.

[0024] The beneficial effects of this invention are as follows: By designing the light guide structure of the light guide plate in the backlight module, the first light guide surface opposite to the first light-emitting element is a specular reflective surface, and the second light guide surface opposite to the second light-emitting element is a diffuse reflective surface. When the backlight module is configured in the first state, the first light-emitting element emits light, while the second light-emitting element does not. This results in a narrow viewing angle when the light from the first light-emitting element passes through the specular reflective surface of the first light guide surface, achieving a privacy protection effect. Therefore, the first state of the backlight module is a privacy protection state. When the backlight module is configured in the second state, at least the second light-emitting element emits light. This results in a wide viewing angle when the light from the second light-emitting element passes through the diffuse reflective surface of the second light guide surface, achieving a sharing effect. This makes the second state of the backlight module a sharing state, thus realizing a dynamic privacy protection function, simplifying the structure of the backlight module, and reducing costs. Attached Figure Description

[0025] The technical solution and other beneficial effects of the present invention will become apparent from the following detailed description of specific embodiments of the invention, in conjunction with the accompanying drawings.

[0026] Figure 1 This is a schematic diagram of a planar structure of a backlight module provided in an embodiment of the present invention;

[0027] Figure 2 Provided for embodiments of the present invention Figure 1 A schematic diagram of a cross-sectional structure obtained along line AA.

[0028] Figure 3 This is a schematic diagram of a light guide structure provided in an embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of another planar structure of the backlight module provided in an embodiment of the present invention;

[0030] Figure 5 Provided for embodiments of the present invention Figure 4 A schematic diagram of a cross-sectional structure obtained along line BB.

[0031] Figure 6 Provided for embodiments of the present invention Figure 4 A schematic diagram of a cross-sectional structure obtained along the CC line;

[0032] Figure 7 This is a schematic diagram of another planar structure of the backlight module provided in an embodiment of the present invention;

[0033] Figure 8 Provided for embodiments of the present invention Figure 7 A schematic diagram of a cross-sectional structure obtained along the DD line;

[0034] Figure 9 Provided for embodiments of the present invention Figure 7 A schematic diagram of a cross-sectional structure obtained along line EE;

[0035] Figure 10 This is a schematic diagram of another planar structure of the backlight module provided in an embodiment of the present invention;

[0036] Figure 11 Provided for embodiments of the present invention Figure 10 A schematic diagram of a cross-sectional structure obtained along the FF line;

[0037] Figure 12 Provided for embodiments of the present invention Figure 10 A schematic diagram of a cross-sectional structure obtained along line GG.

[0038] Figure 13 This is a schematic diagram of a display device provided in an embodiment of the present invention. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0040] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0041] This invention provides a backlight module, please refer to... Figure 1 and Figure 2 The backlight module includes a light guide plate 10, a first light strip 21, and a second light strip 22.

[0042] The light guide plate 10 includes a bottom surface 100 away from the light-emitting side of the backlight module and a first side surface 101 and a second side surface 102 connected to the bottom surface 100. The bottom surface 100 is provided with a light guide structure 11. The first light strip 21 includes a first light-emitting element 211 disposed on one side of the first side surface 101. The light-emitting direction of the first light-emitting element 211 is set towards the first side surface 101 and emits light along the first direction X. The second light strip 22 includes a second light-emitting element 221 disposed on one side of the second side surface 102. The light-emitting direction of the second light-emitting element 221 is set towards the second side surface 102 and emits light along the second direction Y. The first direction X and the second direction Y are different.

[0043] The light guide structure 11 includes a first light guide surface 111 disposed opposite to the first light-emitting element 211 and a second light guide surface 112 disposed opposite to the second light-emitting element 221. The first light guide surface 111 is a specular reflective surface and the second light guide surface 112 is a diffuse reflective surface. The backlight module switches between a first state and a second state. When the backlight module is configured in the first state, the first light-emitting element 211 emits light and the second light-emitting element 221 does not emit light. When the backlight module is configured in the second state, at least the second light-emitting element 221 emits light.

[0044] In practical application, this embodiment of the invention designs the light guide structure 11 of the light guide plate 10 in the backlight module such that the first light guide surface 111 opposite to the first light-emitting element 211 is a specular reflective surface, resulting in the light emitted by the first lamp strip 21 being a small-angle light emission, and the second light guide surface 112 opposite to the second light-emitting element 221 is a diffuse reflective surface, resulting in the light emitted by the second lamp strip 22 being a large-angle light emission. When the backlight module is configured in the first state, the first light-emitting element 211 emits light, and the second light-emitting element 221 does not emit light. When the light from the first light-emitting element 211 passes through the first light guide surface 111 of the specular reflective surface, it will produce light with a small viewing angle, achieving a privacy protection effect, making the first state of the backlight module a privacy protection state; when the backlight module is configured in the second state, at least the second light-emitting element 221 emits light, so that when the light from the second light-emitting element 221 passes through the second light guide surface 112 of the diffuse reflective surface, it will produce light with a large viewing angle divergence, achieving a sharing effect, making the second state of the backlight module a sharing state, thereby realizing a dynamic privacy protection function, simplifying the structure of the backlight module, and reducing costs.

[0045] Please continue to combine Figure 1 and Figure 2 The backlight module provided in this embodiment of the invention includes a light guide plate 10, and the light guide plate 10 includes a bottom surface 100 away from the light-emitting side of the backlight module and a first side surface 101 and a second side surface 102 connected to the bottom surface 100. For example, when the light guide plate 10 is a cuboid, the light guide plate 10 has four side surfaces 102. Figure 1 As shown.

[0046] The backlight module also includes a plurality of light strips disposed on the side of the light guide plate 10. Specifically, the backlight module includes a first light strip 21 and a second light strip 22 disposed on the periphery of the light guide plate 10. The first light strip 21 includes a first light-emitting element 211 disposed on one side of the first side 101 of the light guide plate 10. The first light-emitting element 211 emits light toward the first side 101 and emits light along the first direction X. The second light strip 22 includes a second light-emitting element 221 disposed on one side of the second side 102 of the light guide plate 10. The second light-emitting element 221 emits light toward the second side 102 and emits light along the second direction Y.

[0047] The first direction X and the second direction Y are different, that is, the first light-emitting element 211 and the second light-emitting element 221 are located on different sides of the light guide plate 10. For example, the first direction X may intersect with the second direction Y, or the first direction X may be opposite to the second direction Y.

[0048] In one embodiment, when the first direction X intersects the second direction Y, the first direction X may be perpendicular to the second direction Y.

[0049] It should be noted that the first light strip 21 may include a plurality of first light-emitting elements 211, and the first light-emitting elements 211 may be LEDs disposed on the first light strip 21, and the plurality of first light-emitting elements 211 may be arranged in a direction parallel to the first side surface 101 of the light guide plate 10; similarly, the second light strip 22 may include a plurality of second light-emitting elements 221, and the second light-emitting elements 221 may be LEDs disposed on the second light strip 22, and the plurality of second light-emitting elements 221 may be arranged in a direction parallel to the second side surface 102 of the light guide plate 10.

[0050] In one embodiment, the first light strip 21 includes a first circuit board 212, and a first light-emitting element 211 is located on the first side 101 of the light guide plate 10. The first circuit board 212 is located on the side of the light guide plate 10 near the bottom surface 100. The first light-emitting element 211 is disposed on the first circuit board 212, and one end of the first circuit board 212 is connected to the first light-emitting element 211. The other end of the first circuit board 212 overlaps with the light guide plate 10 along the thickness direction of the light guide plate 10. Further, the second light strip 22 includes a second circuit board 222, and a second light-emitting element 221 is located on the second side 102 of the light guide plate 10. The second circuit board 222 is located on the side of the light guide plate 10 near the bottom surface 100. The second light-emitting element 221 is disposed on the second circuit board 222, and one end of the second circuit board 222 is connected to the second light-emitting element 221. The other end of the second circuit board 222 overlaps with the light guide plate 10 along the thickness direction of the light guide plate 10.

[0051] Furthermore, to prevent the overlapping portions of the first circuit board 212 and the second circuit board 222 with the light guide plate 10 from affecting the light output of the backlight module, this embodiment of the invention provides a first reflective layer 213 on the side of the first circuit board 212 near the light guide plate 10, and a second reflective layer 223 on the side of the second circuit board 222 near the light guide plate 10. The first reflective layer 213 is disposed on the surface of the first circuit board 212 and the light guide plate 10 opposite to each other, and the second reflective layer 223 is disposed on the surface of the second circuit board 222 and the light guide plate 10 opposite to each other. This allows the light emitted by the first light-emitting element 211 and the second light-emitting element 221 to the bottom surface 100 of the light guide plate 10 to be reflected, thereby improving the light output efficiency of the backlight module.

[0052] In one embodiment, the backlight module further includes a reflective sheet disposed on the side of the light guide plate 10 with a bottom surface 100, a diffuser sheet and a prism sheet disposed on the light guide plate 10 near the light-emitting side of the backlight module, so as to further improve the light emission effect of the backlight module.

[0053] In this embodiment of the invention, the bottom surface 100 of the light guide plate 10 is provided with a light guide structure 11 to adjust the light emitted by the first light-emitting element 211 and the second light-emitting element 221 so that the light is emitted in a preset direction.

[0054] The light guide structure 11 includes a first light guide surface 111 disposed opposite to the first light-emitting element 211 and a second light guide surface 112 disposed opposite to the second light-emitting element 221. The first light guide surface 111 is a specular reflective surface so that the light emitted by the first light-emitting element 211 is collimated, and the second light guide surface 112 is a diffuse reflective surface so that the light emitted by the second light-emitting element 221 is diffuse.

[0055] It is understood that the first light guide surface 111 is the side of the light guide structure 11 facing the first light-emitting element 211, and the second light guide surface 112 is the side of the light guide structure 11 facing the second light-emitting element 221.

[0056] Furthermore, the backlight module includes a first state and a second state. When the backlight module is configured in the first state, the first light-emitting element 211 emits light, and the second light-emitting element 221 does not emit light, so that the backlight module emits light in a collimated manner in the first state. When the backlight module is configured in the second state, at least the second light-emitting element 221 emits light, so that the backlight module emits light in a divergent manner in the second state. This invention designs the light guide structure 11 of the light guide plate 10 in the backlight module so that the first light guide surface 111 opposite to the first light-emitting element 211 is a mirror reflective surface, so that the light emitted by the first lamp strip 21 is a small-angle light emission, and the light guide... The second light guide surface 112, which is opposite to the second light-emitting element 221, is a diffuse reflection surface, so that the light emitted by the second light strip 22 is a wide-angle light emission. When the backlight module is configured in the first state, the first light-emitting element 211 emits light and the second light-emitting element 221 does not emit light. When the backlight module is configured in the second state, at least the second light-emitting element 221 emits light. Thus, the first state of the backlight module is a privacy protection state and the second state is a shared state. The light emission angle range of the backlight module in the first state is smaller than that in the second state, so as to realize the dynamic privacy protection function, simplify the structure of the backlight module, and reduce the cost.

[0057] In one embodiment, such as Figure 3 As shown, the angle α between the first light guide surface 111 and the first direction X is smaller than the angle b between the second light guide surface 112 and the second direction Y, so that the light emitted by the first light-emitting element 211 can be emitted in a positive direction after being guided by the first light guide surface 111. Preferably, when the backlight module is configured in the first state, the light emission direction of the backlight module is positive.

[0058] In one embodiment, the angle between the first light guide surface 111 and the first direction X is greater than or equal to 15° and less than or equal to 30°.

[0059] It should be noted that the bottom surface 100 of the light guide plate 10 is provided with a plurality of light guide structures 11, and the plurality of light guide structures 11 can be arranged in a multi-row and multi-column array. Alternatively, in other embodiments of the present invention, the plurality of light guide structures 11 can also be arranged differently according to the brightness distribution of different areas, which is not limited here.

[0060] In one embodiment of the present invention, please continue to combine Figure 1 as well as Figure 2 In this embodiment, the first direction X is opposite to the second direction Y, that is, the first light-emitting element 211 and the second light-emitting element 221 are located on two opposite sides of the light guide plate 10 and emit light towards each other.

[0061] The first light guide surface 111 and the second light guide surface 112 of the light guide structure 11 are located on opposite sides of the light guide structure 11 to guide light to the first light-emitting element 211 and the second light-emitting element 221 respectively. When the backlight module is configured in the first state, the first light-emitting element 211 can be turned on and the second light-emitting element 221 can be turned off to achieve a small angle of light emission from the backlight module and realize the privacy function. When the backlight module is configured in the second state, the second light-emitting element 221 can be turned on and the first light-emitting element 211 can be turned off, or the second light-emitting element 221 and the first light-emitting element 211 can be turned on to achieve a large angle of light emission from the backlight module and realize the sharing function.

[0062] In another embodiment of the invention, please refer to Figure 4 , Figure 5 as well as Figure 6 In this embodiment, the light guide plate 10 further includes a third side surface 103 connected to the bottom surface 100, and the backlight module further includes a third light strip 23. The third light strip 23 includes a third light-emitting element 231 disposed on one side of the third side surface 103. The light emission direction of the third light-emitting element 231 is towards the third side surface 103, and the third light-emitting element 231 emits light along a third direction M. The third direction M is different from the first direction X and the second direction Y.

[0063] The third light strip 23 also includes a third circuit board 232, and a third light-emitting element 231 is disposed on the third circuit board 232. The third circuit board 232 is located on the side of the light guide plate 10 with a bottom surface 100. One end of the third circuit board 232 is connected to the third light-emitting element 231, and the other end of the third circuit board 232 overlaps with the light guide plate 10 along the thickness direction of the light guide plate 10. In order to avoid the overlapping part of the third circuit board 232 and the light guide plate 10 from affecting the light output of the backlight module, the present invention provides a third reflective layer 233 on the side of the third circuit board 232 close to the light guide plate 10. The third reflective layer 233 is disposed on the surface of the third circuit board 232 and the light guide plate 10 opposite to each other. In this way, the light emitted by the first light-emitting element 211, the second light-emitting element 221 and the third light-emitting element 231 to the bottom surface 100 of the light guide plate 10 can be reflected to improve the light output efficiency of the backlight module.

[0064] Optionally, the third direction M may intersect with the first direction X, or the third direction M may be opposite to the first direction X. In this embodiment, the example of the third direction M being opposite to the first direction X is used for explanation. That is, the first side 101 and the third side 103 are two opposite sides of the light guide plate 10, and the second side 102 is connected between the first side 101 and the third side 103.

[0065] The third light-emitting element 231 and the first light-emitting element 211 are located on two opposite sides of the light guide plate 10 and emit light towards each other. The second direction Y intersects with the first direction X and with the third direction M.

[0066] In this embodiment, the light guide structure 11 includes a third light guide surface 113 disposed opposite to the third light-emitting element 231, and the third light guide surface 113 is the side of the light guide structure 11 facing the third light-emitting element 231. The third light guide surface 113 is a mirror reflective surface, so that the light emitted by the third light-emitting element 231 can be guided by the third light guide surface 113 and emitted in a positive direction. Preferably, when the backlight module is configured in the first state, the light emission direction of the backlight module is positive.

[0067] It should be noted that since the light guide structure 11 can be patterned on the bottom surface 100 of the light guide plate 10 using a laser or a cutting tool, when the first light guide surface 111 and the third light guide surface 113 are the same surface, and the first light guide surface 111 and the third light guide surface 113 are located on opposite sides of the light guide structure 11, the processing difficulty of the light guide structure 11 can be reduced and the manufacturing process of the light guide plate 10 can be simplified.

[0068] In one embodiment, the depth of the light guide structure 11 can be greater than or equal to 5 micrometers and less than or equal to 15 micrometers, for example, it can be 5 micrometers, 6 micrometers, 7 micrometers, 8 micrometers, 9 micrometers, 10 micrometers, 11 micrometers, 12 micrometers, 13 micrometers, 14 micrometers, or 15 micrometers. The bottom width of the light guide structure 11 on the light-emitting side away from the backlight module can be greater than or equal to 30 micrometers and less than or equal to 70 micrometers, for example, it can be 30 micrometers, 35 micrometers, 40 micrometers, 45 micrometers, 50 micrometers, 55 micrometers, 60 micrometers, 65 micrometers, or 70 micrometers. The above values ​​are only for illustrative purposes and are not limited thereto.

[0069] In one embodiment, the angle between the third light guide surface 113 and the third direction M is greater than or equal to 15° and less than or equal to 30°. For example, it can be 15°, 20°, 25°, or 30°. The above values ​​are only for illustrative purposes and are not limited thereto.

[0070] Furthermore, the second direction Y can be perpendicular to the first direction X and the third direction M.

[0071] It is understood that the light guide structure 11 can have four surfaces, three of which are the first light guide surface 111, the second light guide surface 112 and the third light guide surface 113, and the remaining surface is opposite to the second light guide surface 112. The remaining surface can be a diffuse reflection surface to reduce the manufacturing difficulty of the light guide structure 11.

[0072] Continuing from the above, this embodiment of the invention designs the light guide structure 11 of the light guide plate 10 in the backlight module so that the first light guide surface 111 opposite to the first light-emitting element 211 is a specular reflective surface, so that the light emitted by the first light strip 21 is a small-angle light emission, and the second light guide surface 112 opposite to the second light-emitting element 221 is a diffuse reflective surface, so that the light emitted by the second light strip 22 is a large-angle light emission. In the first state, the backlight module is configured to emit light from the first light-emitting element 211 and the third light-emitting element 231, while the second light-emitting element 221 does not emit light. In the second state, the backlight module is configured to emit light from the second light-emitting element 221, or the first light-emitting element 211, the second light-emitting element 221, and the third light-emitting element 231 all emit light. Thus, the first state of the backlight module is a privacy protection state, and the second state is a shared state, so as to realize the dynamic privacy protection function, simplify the structure of the backlight module, and reduce the cost.

[0073] In another embodiment of the invention, please refer to Figure 7 , Figure 8 as well as Figure 9 This embodiment and Figure 5The difference in the embodiment shown is that the light guide plate 10 further includes a fourth side surface 104 connected to the bottom surface 100, and the backlight module further includes a fourth light strip 24. The fourth light strip 24 includes a fourth light-emitting element 241 disposed on one side of the fourth side surface 104. The light emission direction of the fourth light-emitting element 241 is disposed towards the fourth side surface 104 and emits light along the fourth direction N. The fourth direction N is different from the first direction X and the second direction Y.

[0074] In this context, the fourth direction N is opposite to the second direction Y, meaning that the fourth light-emitting element 241 and the second light-emitting element 221 are located on opposite sides of the light guide plate 10, and the fourth light-emitting element 241 and the second light-emitting element 221 emit light in opposite directions.

[0075] The light guide structure 11 includes a fourth light guide surface 114 disposed opposite to the fourth light-emitting element 241. The fourth light guide surface 114 is the side of the light guide structure 11 facing the fourth light-emitting element 241. The fourth light guide surface 114 is a diffuse reflection surface. When the backlight module is configured in the first state, the fourth light-emitting element 241 does not emit light. When the backlight module is configured in the second state, the fourth light-emitting element 241 emits light.

[0076] The fourth light strip 24 also includes a fourth circuit board 242, and a fourth light-emitting element 241 is disposed on the fourth circuit board 242. The fourth circuit board 242 is located on the side of the light guide plate 10 with a bottom surface 100. One end of the fourth circuit board 242 is connected to the fourth light-emitting element 241, and the other end of the fourth circuit board 242 overlaps with the light guide plate 10 along the thickness direction of the light guide plate 10. In order to avoid the overlapping part of the fourth circuit board 242 and the light guide plate 10 from affecting the light output of the backlight module, the present invention provides a fourth reflective layer 243 on the side of the fourth circuit board 242 close to the light guide plate 10. The fourth reflective layer 243 is disposed on the surface of the fourth circuit board 242 and the light guide plate 10 opposite to each other. In this way, the light emitted by the first light-emitting element 211, the second light-emitting element 221, the third light-emitting element 231 and the fourth light-emitting element 241 to the bottom surface 100 of the light guide plate 10 can be reflected to improve the light output efficiency of the backlight module.

[0077] Continuing from the above, this embodiment of the invention designs the light guide structure 11 of the light guide plate 10 in the backlight module so that the first light guide surface 111 opposite to the first light-emitting element 211 is a specular reflective surface, so that the light emitted by the first light strip 21 is a small-angle light emission, and the second light guide surface 112 opposite to the second light-emitting element 221 is a diffuse reflective surface, so that the light emitted by the second light strip 22 is a large-angle light emission. In the first state, the backlight module is configured to emit light from the first light-emitting element 211 and the third light-emitting element 231, while the second light-emitting element 221 does not emit light. In the second state, the backlight module is configured to emit light from the second light-emitting element 221 and the fourth light-emitting element 241, or the first light-emitting element 211, the second light-emitting element 221, the third light-emitting element 231, and the fourth light-emitting element 241 all emit light. Thus, the first state of the backlight module is a privacy protection state, and the second state is a shared state, so as to realize the dynamic privacy protection function, simplify the structure of the backlight module, and reduce the cost.

[0078] In another embodiment of the invention, please refer to Figure 10 , Figure 11 as well as Figure 12 This embodiment and Figure 1 The difference in the embodiment shown is that the light guide plate 10 also includes a fourth side surface 104 connected to the bottom surface 100 and a fifth side surface 105 connected to the bottom surface 100, and the backlight module also includes a fourth light strip 24 and a fifth light strip 25.

[0079] Specifically, the fourth light strip 24 includes a fourth light-emitting element 241 disposed on one side of the fourth side 104. The light-emitting direction of the fourth light-emitting element 241 is disposed towards the fourth side 104 and emits light along the fourth direction N, and the fourth direction N is different from the first direction X and the second direction Y; wherein the fourth direction N intersects with the second direction Y.

[0080] The light guide structure 11 includes a fourth light guide surface 114 disposed opposite to the fourth light-emitting element 241. The fourth light guide surface 114 is a diffuse reflection surface. When the backlight module is configured in the first state, the fourth light-emitting element 241 does not emit light. When the backlight module is configured in the second state, the fourth light-emitting element 241 emits light.

[0081] The fifth light strip 25 includes a fifth light-emitting element 251 disposed on one side of the fifth side 105. The light-emitting direction of the fifth light-emitting element 251 is disposed towards the fifth side 105 and emits light along the fifth direction P, which is different from the first direction X and the second direction Y. The fifth direction P is opposite to the fourth direction N, that is, the fourth light-emitting element 241 and the fifth light-emitting element 251 are respectively disposed on two opposite sides of the light guide plate 10, and the fourth light-emitting element 241 and the fifth light-emitting element 251 emit light towards each other.

[0082] The light guide structure 11 includes a fifth light guide surface 115 disposed opposite to the fifth light-emitting element 251. The fifth light guide surface 115 is the side of the light guide structure 11 facing the fifth light-emitting element 251. The fifth light guide surface 115 is a diffuse reflection surface. When the backlight module is configured in the first state, the fifth light-emitting element 251 does not emit light. When the backlight module is configured in the second state, the fifth light-emitting element 251 emits light.

[0083] In this embodiment, the first side 101 and the second side 102 are opposite sides of the light guide plate 10, and the fourth side 104 and the fifth side 105 are opposite sides of the light guide plate 10.

[0084] Furthermore, the fourth light strip 24 also includes a fourth circuit board 242, and a fourth light-emitting element 241 is disposed on the fourth circuit board 242. The fourth circuit board 242 is located on the side of the light guide plate 10 with a bottom surface 100. One end of the fourth circuit board 242 is connected to the fourth light-emitting element 241, and the other end of the fourth circuit board 242 overlaps with the light guide plate 10 along the thickness direction of the light guide plate 10. In order to avoid the overlapping part of the fourth circuit board 242 and the light guide plate 10 affecting the light output of the backlight module, the present invention provides a fourth reflective layer 243 on the side of the fourth circuit board 242 near the light guide plate 10. The fourth reflective layer 243 is disposed on the surface of the fourth circuit board 242 and the light guide plate 10 opposite to each other. In this way, the light emitted by the first light-emitting element 211, the second light-emitting element 221, the fourth light-emitting element 241 and the fifth light-emitting element 251 to the bottom surface 100 of the light guide plate 10 can be reflected to improve the light output efficiency of the backlight module.

[0085] The fifth light strip 25 also includes a fifth circuit board 252, and a fifth light-emitting element 251 is disposed on the fifth circuit board 252. The fifth circuit board 252 is located on the side of the light guide plate 10 with a bottom surface 100. One end of the fifth circuit board 252 is connected to the fifth light-emitting element 251, and the other end of the fifth circuit board 252 overlaps with the light guide plate 10 along the thickness direction of the light guide plate 10. In order to avoid the overlapping part of the fifth circuit board 252 and the light guide plate 10 from affecting the light output of the backlight module, the present invention provides a fifth reflective layer 253 on the side of the fifth circuit board 252 close to the light guide plate 10. The fifth reflective layer 253 is disposed on the surface of the fifth circuit board 252 and the light guide plate 10 opposite to each other. In this way, the light emitted by the first light-emitting element 211, the second light-emitting element 221, the fourth light-emitting element 241 and the fifth light-emitting element 251 to the bottom surface 100 of the light guide plate 10 can be reflected to improve the light output efficiency of the backlight module.

[0086] Continuing from the above, this embodiment of the invention designs the light guide structure 11 of the light guide plate 10 in the backlight module such that the first light guide surface 111 opposite to the first light-emitting element 211 is a specular reflective surface, resulting in the light emitted by the first lamp strip 21 being a small-angle light emission; the second light guide surface 112 opposite to the second light-emitting element 221 is a diffuse reflective surface, resulting in the light emitted by the second lamp strip 22 being a large-angle light emission. When the backlight module is configured in the first state, the first light-emitting element 211 emits light, and the second light-emitting element 221 emits light... When the light element 221, the fourth light element 241, and the fifth light element 251 do not emit light, and the backlight module is configured in the second state, the second light element 221, the fourth light element 241, and the fifth light element 251 emit light, or the first light element 211, the second light element 221, the fourth light element 241, and the fifth light element 251 all emit light, thereby making the first state of the backlight module a privacy protection state and the second state a shared state, so as to realize the dynamic privacy protection function, simplify the structure of the backlight module, and reduce the cost.

[0087] It is understood that the first light guide surface 111 and the third light guide surface 113 described in the above embodiments are smooth planes that can perform specular reflection, while the second light guide surface 112, the fourth light guide surface 114 and the fifth light guide surface 115 are arc-shaped rough surfaces that can perform diffuse reflection. The second light guide surface 112 protrudes towards the side away from the first light guide surface 111. In addition, the fourth light guide surface 114 and the fifth light guide surface 115 both protrude towards the side away from the center of the light guide structure 11, so that the light emitted by the second light-emitting element 221, the fourth light-emitting element 241 and the fifth light-emitting element 251 can be better dispersed and dispersed to a wider viewing angle range, thereby improving the viewing angle range and light emission effect of the backlight module in the second state.

[0088] It should be noted that, in this embodiment of the invention, the light guide plate 10 is described as having a quadrilateral shape when viewed from above. The light guide plate 10 can also be set as other polygons. Each light-emitting element is located on the side of the light guide plate 10 and emits light in a direction close to the light guide plate 10. The light guide structure 11 in the light guide plate 10 forms a light guide surface relative to one side of each light-emitting element, and at least one specular reflection surface and one diffuse reflection surface are required. The specular reflection surface can make the light emitted by the light-emitting element collimate to achieve light emission from a small viewing angle, and the diffuse reflection surface can make the light emitted by the light-emitting element diverge to achieve light emission from a large viewing angle. Thus, the backlight module can be switched between privacy mode and shared mode.

[0089] In one embodiment of the present invention, the light guide structure 11 is uniformly distributed in the light guide plate 10. In other embodiments of the present invention, the backlight module includes a first region and a second region. Since the brightness of the first region is originally less than that of the second region, the distribution density of the light guide structure 11 in the first region is set to be greater than that in the second region, so that the average brightness of the improved first region is equal to that of the second region, thereby improving the problem of uneven brightness distribution in the backlight module. For example, the first region can be the surrounding area of ​​the backlight module, and the second region can be the middle region of the backlight module. The surrounding area may suffer some light loss and reduced brightness due to the obstruction of the frame. The present invention can improve the brightness uniformity of the backlight module. In addition, the first region and the second region can also be other regions with uneven brightness distribution in the backlight module, which are not limited here.

[0090] In addition, embodiments of the present invention also provide a display device, please refer to... Figure 1 as well as Figure 13 The display device includes a display panel 40 and a backlight module 30 as described in the above embodiments, and the display panel 40 is disposed on the light-emitting side of the backlight module 30.

[0091] When the backlight module 30 is configured in the first state, it can emit light from a narrow viewing angle, thus enabling the display device to achieve a privacy mode. When the backlight module 30 is configured in the second state, it can emit light from a wide viewing angle, thus enabling the display device to achieve a sharing mode. Therefore, in this embodiment of the invention, by controlling the opening and closing of the light-emitting element on the side of the light guide plate 10, the display device can switch between the privacy mode and the sharing mode without the need for additional privacy films or other structures, thereby simplifying the process and reducing costs.

[0092] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0093] The foregoing has provided a detailed description of a backlight module and display device provided by the embodiments of the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of the present invention. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A backlight module, characterized in that, include: A light guide plate, the light guide plate including a bottom surface away from the light-emitting side of the backlight module and a first side surface and a second side surface connected to the bottom surface, the bottom surface being provided with multiple light guide structures; The first light strip includes a first light-emitting element disposed on one side of the first side, wherein the light-emitting element is disposed toward the first side and emits light along a first direction; The second light strip includes a second light-emitting element disposed on one side of the second side. The light-emitting element is disposed facing the second side and emits light along a second direction, and the first direction is different from the second direction. The light guide structure includes a first light guide surface disposed opposite to the first light-emitting element and a second light guide surface disposed opposite to the second light-emitting element. The first light guide surface is a specular reflective surface and the second light guide surface is a diffuse reflective surface. The backlight module switches between a first state and a second state. When the backlight module is configured in the first state, the first light-emitting element emits light and the second light-emitting element does not emit light. When the backlight module is configured in the second state, at least the second light-emitting element emits light.

2. The backlight module according to claim 1, characterized in that, The angle between the first light guide surface and the first direction is smaller than the angle between the second light guide surface and the second direction.

3. The backlight module according to claim 1 or 2, characterized in that, The angle between the first light guide surface and the first direction is greater than or equal to 15° and less than or equal to 30°.

4. The backlight module according to claim 1 or 2, characterized in that, The first light guide surface is a plane, and the second light guide surface is an arc surface.

5. The backlight module according to claim 4, characterized in that, The second light guide surface protrudes toward the side away from the first light guide surface.

6. The backlight module according to claim 1, characterized in that, The light guide plate also includes a third side surface connected to the bottom surface, and the backlight module also includes a third light strip. The third light strip includes a third light-emitting element disposed on one side of the third side surface. The light-emitting element is disposed towards the third side surface and emits light along a third direction, and the third direction is different from both the first direction and the second direction. The light guide structure includes a third light guide surface disposed opposite to the third light-emitting element. The third light guide surface is a specular reflective surface. The third light-emitting element emits light at least when the backlight module is configured in the first state.

7. The backlight module according to claim 6, characterized in that, The third direction is opposite to the first direction.

8. The backlight module according to claim 1, characterized in that, The light guide plate also includes a fourth side surface connected to the bottom surface, and the backlight module also includes a fourth light strip. The fourth light strip includes a fourth light-emitting element disposed on one side of the fourth side surface. The light-emitting element emits light in a direction toward the fourth side surface and emits light along a fourth direction. The fourth direction is different from the first direction and the second direction. The light guide structure includes a fourth light guide surface disposed opposite to the fourth light-emitting element. The fourth light guide surface is a diffuse reflection surface. When the backlight module is configured in the first state, the fourth light-emitting element does not emit light. When the backlight module is configured in the second state, the fourth light-emitting element emits light.

9. The backlight module according to claim 8, characterized in that, The fourth direction intersects with the second direction, or the fourth direction is opposite to the second direction.

10. The backlight module according to claim 1, characterized in that, The first light strip includes a first circuit board, the first light-emitting element is disposed on the first circuit board, the first circuit board is located on the side of the light guide plate where the bottom surface is provided, one end of the first circuit board is connected to the first light-emitting element, and the other end of the first circuit board overlaps with the light guide plate along the thickness direction of the light guide plate. The second light strip includes a second circuit board, the second light-emitting element is disposed on the second circuit board, the second circuit board is located on the side of the light guide plate where the bottom surface is provided, one end of the second circuit board is connected to the second light-emitting element, and the other end of the second circuit board overlaps with the light guide plate along the thickness direction of the light guide plate.

11. The backlight module according to claim 10, characterized in that, The first circuit board has a first reflective layer on its surface opposite to the light guide plate, and the second circuit board has a second reflective layer on its surface opposite to the light guide plate.

12. A display device, characterized in that, The display device includes a display panel and a backlight module as described in any one of claims 1 to 11, wherein the display panel is disposed on the light-emitting side of the backlight module.

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