Backlight module for liquid crystal display and collimating reflection structure thereof

Abstract

The utility model discloses a kind of backlight module of liquid crystal display and its collimating reflection structure, two protective layers are respectively equipped with on the both sides of reflecting layer, reflecting layer includes the reflecting array formed by multiple reflecting microstructures, the light-incident surface of being set towards first protective layer side is equipped on reflecting microstructure, the light-incident angle formed between the light-incident surface and second protective layer is in the range of 5-60 °.By optimizing design to collimating reflection structure, light leakage of light guide plate dot face large angle can be directly collimated and reflected back to light guide plate and emit from emitting surface, greatly improve the utilization of light, thereby greatly improve display brightness relative to traditional reflection film, relatively reduce the power consumption of backlight.

Description

Technical Field

[0001] This utility model relates to the field of liquid crystal display technology, and in particular to a backlight module for a liquid crystal display and its collimating reflection structure. Background Technology

[0002] Liquid crystal displays (LCDs) are widely used due to their advantages such as thinness, low power consumption, and low radiation. Because liquid crystal molecules themselves cannot emit light, LCDs require a backlight module behind the liquid crystal module in addition to the liquid crystal panel to provide a light source for display. As the requirements for thinner and lighter displays become increasingly stringent, some LCD devices have switched from direct-lit backlight modules to edge-lit backlight modules. In these edge-lit backlight modules, the light emitted from the backlight module enters a light guide plate at its end and exits from the light guide plate's emission surface, providing backlighting for the liquid crystal module.

[0003] To ensure efficient use of the light emitted by the backlight module, a reflective film is typically placed on the side of the light guide plate away from the emission surface. This film reflects the light leaking from the reflective surface of the light guide plate back into the light guide plate for reuse. For example... Figure 1-3 The common reflective films shown reflect light leaking from the LGP reflective surface using specular or diffuse reflection. While the collimating light guide plate reflects light (red), some light (green) leaks out through the reflective microstructure. The main characteristic of specular reflective films is high reflectivity, but the reflection angle remains unchanged. Matte reflective films can gradually pull large-angle light towards the vertical direction through diffuse reflection. When reflected light enters the light guide plate, there is a beam splitting phenomenon; some light enters the light guide plate through refraction, while some is returned to the reflective film, and this cycle of reflection, refraction, and reflection repeats. Furthermore, there is significant energy loss during large-angle refraction. Since most of the light leaking from the reflective surface of the front light guide plate is large-angle light, the ability of the light to be reused by the light guide plate is relatively small. Additionally, light leakage occurs on the far side of the collimating light guide plate's viewing angle. Utility Model Content

[0004] To address the technical problems existing in the background art, this utility model proposes a backlight module for liquid crystal display and its collimating reflection structure.

[0005] The present invention proposes a collimated reflection structure for a backlight module of a liquid crystal display, comprising: a reflective layer and a first protective layer and a second protective layer located on both sides of the reflective layer. The reflective layer includes a reflective array formed by multiple reflective microstructures. The reflective microstructures are provided with a light-facing surface facing the first protective layer. The light-facing angle formed between the light-facing surface and the second protective layer is in the range of 5-60°.

[0006] Preferably, the reflective microstructure also has a non-light-facing surface located away from the first protective layer, and the non-light-facing angle formed between the non-light-facing surface and the second protective layer is in the range of 15-90°.

[0007] Preferably, the reflective microstructure has a prismatic structure formed by a bottom surface, a light-facing surface, and a non-light-facing surface.

[0008] Preferably, adjacent layers of the reflective layer, the first protective layer, and the second protective layer are bonded together with optical adhesive.

[0009] Preferably, the reflective layer is white or silver.

[0010] Preferably, the surface facing the light is a mirror or a frosted surface.

[0011] This utility model also proposes a backlight module for a liquid crystal display, including the collimated reflection structure of the liquid crystal display backlight module described above.

[0012] Preferably, it also includes a light source and a light guide plate; The light guide plate has an incident end at one end and an exit surface on one side. The light source is located at the incident end of the light guide plate. The light guide plate is used to guide the incident light from the incident end through the exit surface. The reflective structure is located on the side of the light guide plate away from the emission surface, the second protective layer is located on the side of the first protective layer away from the light guide plate, and the light-facing surface of the prismatic microstructure faces the incident end.

[0013] In this invention, the proposed backlight module for a liquid crystal display and its collimated reflection structure have two protective layers on each side of the reflective layer. The reflective layer includes a reflective array formed by multiple reflective microstructures, and each reflective microstructure has a light-facing surface facing the first protective layer. The light-facing angle formed between the light-facing surface and the second protective layer is in the range of 5-60°. By optimizing the design of the collimated reflection structure, light rays leaking from the dot surface of the light guide plate at a large angle can be directly collimated and reflected back to the light guide plate and emitted from the exit surface, greatly improving the light utilization rate. This significantly increases the display brightness compared to traditional reflective films while relatively reducing the power consumption of the backlight. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the optical path using a mirror reflection structure in existing technology.

[0015] Figure 2 This is a schematic diagram of the optical path using a frosted reflective structure in existing technology.

[0016] Figure 3 This is a schematic diagram of the light field of a light guide plate in the far-light side.

[0017] Figure 4This is a schematic diagram of one embodiment of the collimation and reflection structure of the backlight module of a liquid crystal display proposed in this utility model.

[0018] Figure 5 This is a schematic diagram of one embodiment of a liquid crystal display backlight module proposed in this utility model.

[0019] Figure 6 This is a schematic diagram of the light leakage path of the light guide plate in one embodiment of the backlight module of a liquid crystal display proposed in this utility model.

[0020] Figure 7 This is a schematic diagram of the light field of the light guide plate from the far-light side in one embodiment of the backlight module of the liquid crystal display proposed in this utility model. Detailed Implementation

[0021] Reference Figure 4 The present invention proposes a collimated reflection structure for a backlight module of a liquid crystal display, comprising: a reflective layer 3 and a first protective layer 1 and a second protective layer 2 located on both sides of the reflective layer 3. The reflective layer 3 includes a reflective array formed by a plurality of reflective microstructures 31. The reflective microstructures 31 are provided with a light-facing surface 301 facing the first protective layer 1. The light-facing angle formed between the light-facing surface 301 and the second protective layer 2 is in the range of 5-60°.

[0022] To explain in detail the specific operation of the collimated reflection structure in this embodiment, please refer to... Figure 5 This embodiment also proposes a backlight module for a liquid crystal display, including the collimated reflection structure of the backlight module described above. Specifically, the backlight module further includes a light source 20 and a light guide plate 30; The light guide plate 30 has an incident end at one end and an exit surface on one side. The light source 20 is located at the incident end of the light guide plate 30. The light guide plate 30 is used to guide the incident light from the incident end through the light guide and then out through the exit surface. The reflective structure is located on the side of the light guide plate 30 away from the emission surface, the second protective layer 2 is located on the side of the first protective layer 1 away from the light guide plate 30, and the light-facing surface 301 of the prismatic microstructure faces the incident end.

[0023] During operation, light emitted from the backlight module enters the light guide plate from the incident end. After refraction by the light guide plate, it exits from the exit surface towards the liquid crystal module, thus achieving the liquid crystal display effect. During light transmission within the light guide plate, most of the light entering the plate exits directly from the light-facing surface. Simultaneously, a small portion of light leaks from the far-light side, and under the influence of the reflective layer's light-facing surface, is reflected back into the light guide plate and exits from the exit surface, improving the light utilization rate of the light source. Due to the optimized angle design of the light-facing surface, large-angle light leaking from the far-light side of the light guide plate can be reflected and re-enter the light guide plate at a perpendicular or near-perpendicular incident angle, and then transmitted through the exit surface of the light guide plate. Because this process involves perpendicular angle transmission, energy loss during light penetration is minimized. Furthermore, there is no light leakage on the far-light side of the light guide plate's viewing angle. Figure 6 and 7 As shown.

[0024] In this embodiment, the proposed backlight module and collimated reflection structure of the liquid crystal display have two protective layers on both sides of the reflective layer. The reflective layer includes a reflective array formed by multiple reflective microstructures. Each reflective microstructure has a light-facing surface facing the first protective layer, and the light-facing angle formed between the light-facing surface and the second protective layer is in the range of 5-60°. By optimizing the design of the collimated reflection structure, light rays leaking from the dot surface of the light guide plate at a large angle can be directly collimated and reflected back to the light guide plate and emitted from the exit surface, greatly improving the light utilization rate. This significantly increases the display brightness compared to traditional reflective films and relatively reduces the power consumption of the backlight.

[0025] In a specific embodiment, the reflective microstructure 31 is further provided with a non-light-facing surface 302 located away from the first protective layer 1. The non-light-facing angle formed between the non-light-facing surface 302 and the second protective layer 2 is in the range of 15-90°. By designing the non-light-facing surface to cooperate with the light-facing surface, the large-angle light entering the light guide plate is modulated, ensuring that the light exits from the exit surface at an angle as perpendicular or nearly perpendicular as possible, thereby further reducing the energy loss of the light during the penetration process.

[0026] In the specific design of the microstructure of the reflective layer, the reflective microstructure 31 has a prismatic structure formed by the bottom surface, the light-facing surface 301, and the non-light-facing surface 302.

[0027] In other specific embodiments, a first protective layer and a second protective layer are respectively provided on both sides of the reflective layer. The first protective layer is located above the reflective layer and is used to protect the 3D reflective structure from contamination and damage, ensuring the reflective effect of the light-facing surface. The second protective layer is located below the reflective layer and is used to protect and support the reflective layer. In actual design, in order to reduce the propagation loss of light in the reflective structure, adjacent layers of the reflective layer 3, the first protective layer 1, and the second protective layer 2 are bonded together with optical adhesive to avoid light refraction caused by air or other medium interfaces.

[0028] In addition, to ensure the reflection effect, the reflective layer 3 is white or silver, and the light-facing surface 301 can be mirrored or frosted.

[0029] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A collimated reflection structure for a backlight module of a liquid crystal display, characterized in that, include: The reflective layer (3) and the first protective layer (1) and the second protective layer (2) located on both sides of the reflective layer (3) respectively. The reflective layer (3) includes a reflective array formed by multiple reflective microstructures (31). The reflective microstructures (31) are provided with a light-facing surface (301) facing the first protective layer (1). The light-facing angle formed between the light-facing surface (301) and the second protective layer (2) is in the range of 5-60°.

2. The collimated reflection structure of the backlight module of the liquid crystal display according to claim 1, characterized in that, The reflective microstructure (31) is also provided with a non-light-facing surface (302) located away from the first protective layer (1), and the non-light-facing angle formed between the non-light-facing surface (302) and the second protective layer (2) is in the range of 15-90°.

3. The collimated reflection structure of the backlight module of the liquid crystal display according to claim 2, characterized in that, The reflective microstructure (31) has a prismatic structure formed by a bottom surface, a light-facing surface (301), and a non-light-facing surface (302).

4. The collimated reflection structure of the backlight module of the liquid crystal display according to claim 1, characterized in that, The two adjacent layers of the reflective layer (3), the first protective layer (1), and the second protective layer (2) are bonded together with optical adhesive.

5. The collimated reflection structure of the backlight module of the liquid crystal display according to claim 1, characterized in that, The reflective layer (3) is white or silver.

6. The collimated reflection structure of the backlight module of the liquid crystal display according to claim 1, characterized in that, The light-facing surface (301) is either mirror-like or frosted.

7. A backlight module for a liquid crystal display, characterized in that, Includes the collimated reflection structure of the backlight module of the liquid crystal display according to any one of claims 1-6.

8. The backlight module of the liquid crystal display according to claim 7, characterized in that, It also includes a light source (20) and a light guide plate (30); The light guide plate (30) has an incident end at one end and an exit surface on one side. The light source (20) is located at the incident end of the light guide plate (30). The light guide plate (30) is used to guide the incident light from the incident end through the light guide and then out through the exit surface. The reflective structure is located on the side of the light guide plate (30) away from the emission surface, the second protective layer (2) is located on the side of the first protective layer (1) away from the light guide plate (30), and the light-facing surface (301) of the prismatic reflective microstructure faces the incident end.

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