Backlight module capable of improving local dimming brightness and vehicle-mounted screen

Abstract

The backlight module comprises a closed supporting structure formed by wrapping a lower iron frame with an upper rubber frame, an LED lamp is fixed to a PCB in the lower iron frame, a light guide plate is located in front of the LED lamp and guides light rays, and a diffusion plate and a diffusion film sequentially cover the light guide plate to make the light rays uniform; a plurality of spherical bosses are arranged on the front face of the light guide plate, and the spherical bosses enable light to be diffused more evenly through refraction and condensation effects. The back surface of the light guide plate is provided with a plurality of spherical concave areas which can avoid an LED backlight source and carry out secondary focusing on light rays at the same time. Compared with the prior art, the light guide plate has the advantages that the spherical bosses are arranged on the front face of the light guide plate, light can be diffused more evenly through the refraction and condensation effects of the spherical bosses, meanwhile, the spherical inwards-concave areas are arranged on the back face of the light guide plate, an LED lamp is avoided, secondary focusing is conducted on the light, and the display quality problem caused by uneven backlight in the local dimming technology is effectively solved.

Description

Technical Field

[0001] This invention belongs to the field of display, specifically relating to a backlight module that can improve local dimming brightness and an in-vehicle screen containing the backlight module. Background Technology

[0002] Local dimming is a backlighting technology used to improve the contrast and picture quality of televisions and monitors. Its basic principle is to divide the backlight (usually LEDs) into multiple independently controlled areas or blocks, each of which can adjust its brightness independently according to the needs of the displayed content. This technology can reduce brightness in areas where deep blacks are needed and increase brightness in areas where bright details are needed, thus achieving a better visual effect.

[0003] However, existing local dimming backlight modules still have the following problems:

[0004] For example, patent CN208569259U discloses a display device with local dimming capability. It only describes a backlight module including a light guide plate, which is disposed between the backplate and the display screen. The light guide plate can reflect light emitted from multiple light sources, allowing the light to be evenly distributed onto the display screen. Traditional light guide plate designs mostly use planar or simple prism structures. When LED light sources propagate within the light guide plate, uneven light distribution can easily occur, resulting in areas that are too bright or too dark, affecting the uniformity of the displayed image. Furthermore, due to refraction losses during light transmission, some areas may lack sufficient brightness, making precise light control difficult, especially in applications requiring high-precision local dimming.

[0005] Existing backlight modules typically use a single brightness enhancement film or diffusion layer to optimize light. However, because light undergoes multiple refractions and scatterings during transmission within the light guide plate, some light is lost due to excessive refraction angles, thus reducing light output efficiency. Furthermore, traditional backlight modules fail to fully optimize the combination of optical film layers, resulting in wasted light energy and an inability to effectively improve brightness. This increases the power consumption of the LED light source, hindering energy-saving design. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art, provide a backlight module with uniform brightness and improved display effect that can enhance local dimming brightness, and provide a vehicle screen including the backlight module.

[0007] To solve the above technical problems, the technical method adopted by the present invention is as follows: The present invention discloses a backlight module that can improve local dimming brightness. An upper rubber frame wraps around a lower iron frame to form a closed support structure. An LED lamp is fixed on a PCB board inside the lower iron frame. A light guide plate is located in front of the LED lamp and guides the light. A diffuser plate and a diffuser film cover the light guide plate in sequence to uniformly distribute the light.

[0008] The front of the light guide plate is provided with multiple spherical protrusions, which make the light diffuse more evenly through refraction and light focusing.

[0009] The back of the light guide plate has multiple spherical concave areas, which can avoid the LED backlight and simultaneously refocus the light.

[0010] Furthermore, a lower brightness enhancement film and an upper brightness enhancement film are sequentially disposed above the diffusion film.

[0011] Furthermore, the upper brightness enhancement film is also provided with a dual brightness enhancement film.

[0012] Furthermore, the edge of the light guide plate is provided with a reflective layer.

[0013] Furthermore, the sidewall of the light guide plate is provided with a chamfered structure or a prism-shaped light guide structure to optimize the propagation path of light within the light guide plate.

[0014] Furthermore, the LED light is mounted on a PCB board.

[0015] Furthermore, the PCB board is fixed to the lower iron frame using thermally conductive double-sided adhesive.

[0016] Furthermore, the radius of curvature of the spherical boss is 1.5-4.0 mm; the radius of curvature of the spherical groove is 2.0-6.0 mm.

[0017] The present invention also discloses an in-vehicle screen, including any of the above-mentioned backlight modules that can improve local dimming brightness, and a liquid crystal display panel, wherein the liquid crystal display panel is disposed on the light-emitting side of the backlight module.

[0018] Furthermore, the vehicle screen also includes a touch layer, which is disposed in front of the liquid crystal display panel.

[0019] Beneficial effects:

[0020] 1. Compared to existing technologies, this invention utilizes multiple spherical protrusions on the front of the light guide plate to achieve more uniform light diffusion through refraction and focusing. Simultaneously, multiple spherical concave areas on the back avoid the LED lights and refocus the light. This reduces localized over-brightness or under-brightness and improves overall brightness uniformity, effectively addressing display quality issues caused by uneven backlighting in local dimming technology.

[0021] 2. By sequentially setting a lower brightness enhancement film, an upper brightness enhancement film, and a dual brightness enhancement film above the diffusion film, this invention optimizes the optical structure of the backlight module, enabling more light to be effectively transmitted to the liquid crystal display panel and improving light utilization efficiency. In particular, the addition of the dual brightness enhancement film further enhances the brightness output of light, allowing LEDs of the same power to provide higher luminous efficacy, thereby reducing power consumption and improving the energy efficiency ratio of the display device. Attached Figure Description

[0022] Figure 1 This is a cross-sectional structural diagram of the backlight module that can improve local dimming brightness in this invention;

[0023] Figure 2 This is a cross-sectional schematic diagram of the light guide plate in this invention. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0025] Example 1: Backlight module that can improve local dimming brightness

[0026] like Figure 1 As shown, this embodiment provides a backlight module that can improve local dimming brightness, including: an upper adhesive frame 11 wrapping a lower iron frame 12 to form a closed support structure to fix the various optical components of the backlight module;

[0027] LED light 3 is fixed on PCB board 2 and serves as the main light source; light guide plate 4 is located in front of LED light 3 to guide LED light and achieve uniform diffusion; diffuser plate 5 and diffuser film 6 cover light guide plate 4 in sequence to further uniformly emit light.

[0028] The front of the light guide plate 4 is provided with multiple spherical protrusions 41. The spherical protrusions 41 make the light diffuse more evenly through refraction and light focusing. The back of the light guide plate 4 is provided with multiple spherical concave areas 42, which can avoid the LED backlight and at the same time focus the light a second time.

[0029] Preferably, a lower brightness enhancement film 71 and an upper brightness enhancement film 72 are sequentially disposed above the diffusion film 6.

[0030] More preferably, the upper brightness enhancement film 72 is further provided with a dual brightness enhancement film 8 to further improve the light utilization efficiency.

[0031] Preferably, the edge of the light guide plate 4 is provided with a reflective layer to reduce light loss and improve light utilization efficiency.

[0032] The PCB board 2 is fixed to the lower iron frame 12 with thermally conductive double-sided adhesive tape 9 to enhance heat dissipation performance and improve the lifespan of the LED lamp 3.

[0033] Example 2: Backlight module with optimized light guide plate that improves local dimming brightness

[0034] like Figure 1 and 2 As shown, in this embodiment of the invention, the light guide plate 4 employs an optimized optical structure to improve light uniformity and local dimming effect. Specifically, the front side of the light guide plate 4 is provided with multiple spherical protrusions 41, with a radius of curvature set to 1.5mm-4.5mm, to optimize the refraction angle of light, enabling the light generated by the LED light source 3 to propagate more uniformly within the light guide plate 4 and achieve a softer light distribution on the light-emitting side.

[0035] Smaller radii of curvature, such as 1.5mm, are suitable for fine optical adjustments, making the refraction angle of light more concentrated and helping to improve local brightness; larger radii of curvature, such as 4.5mm, can reduce the number of light refractions and are suitable for large-size light guide plates, improving light transmission efficiency.

[0036] The distribution density of the spherical protrusions 41 is continuously distributed according to the size of the light guide plate 4. Specifically, the distribution density of the spherical protrusions 41 is higher near the LED lamp 3 to enhance the light scattering effect and reduce the light spot phenomenon in the near light source area; while the distribution density of the spherical protrusions 41 is appropriately reduced in the farthest position from the LED lamp 3 to ensure that the light can be evenly diffused to the entire light guide plate 4.

[0037] Furthermore, the back of the light guide plate 4 has multiple spherical concave areas 42, each with a depth of 0.3mm-1.0mm and a diameter of 3.0mm-7.0mm. This structure optimizes the secondary focusing effect of light, allowing some of the light emitted by the LED light source 3 to enter the light guide plate 4 at a more uniform angle after being reflected by the grooves, thereby reducing light energy loss and enhancing the uniformity of overall brightness. In addition, the grooves effectively avoid the direct illumination area of ​​the LED light source 3, reducing local overexposure and improving display uniformity.

[0038] Specifically, shallower grooves, such as 0.3mm, are suitable for high-brightness applications to avoid excessive light loss; deeper grooves, such as 1.0mm, can enhance light focusing and improve optical uniformity.

[0039] Smaller groove diameters, such as 3.0mm, are suitable for fine optical adjustments and enhance local dimming capabilities; larger groove diameters, such as 7.0mm, are suitable for large-area backlighting, enabling more efficient adjustment of light distribution and improved brightness uniformity.

[0040] Through the above-mentioned optimized design, the light guide plate 4 can achieve a more uniform light distribution while ensuring efficient light propagation. This enables the backlight module of the present invention to have higher brightness uniformity and better local dimming effect when applied to automotive screens, thereby improving display quality and enhancing user experience.

[0041] Example 2: A vehicle-mounted screen

[0042] This embodiment provides a vehicle screen, including a backlight module that can improve local dimming brightness as described in embodiment 1, and a liquid crystal display panel, wherein the liquid crystal display panel is disposed on the light-emitting side of the backlight module.

[0043] Preferably, the vehicle screen also includes a touch layer, which is located in front of the LCD display panel to enable interactive functions.

[0044] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A backlight module that can improve local dimming brightness, characterized in that, The upper frame (11) wraps the lower iron frame (12) to form a closed support structure. The LED lamp (3) is fixed on the PCB board (2) inside the lower iron frame (12). The light guide plate (4) is located in front of the LED lamp (3) and guides the light. The diffuser plate (5) and the diffuser film (6) cover the light guide plate (4) in sequence to uniformly distribute the light. The light guide plate (4) has multiple spherical protrusions (41) on its front side. The spherical protrusions (41) diffuse light more evenly through refraction and light focusing. The back of the light guide plate (4) is provided with multiple spherical concave areas (42) to avoid the LED backlight and to refocus the light.

2. The backlight module for improving local dimming brightness according to claim 1, characterized in that, Above the diffusion film (6), a lower brightness enhancement film (71) and an upper brightness enhancement film (72) are also provided in sequence.

3. The backlight module for improving local dimming brightness according to claim 2, characterized in that, The upper brightness enhancement film (72) is also provided with a dual brightness enhancement film (8).

4. The backlight module for improving local dimming brightness according to claim 1, characterized in that, The edge of the light guide plate (4) is provided with a reflective layer.

5. The backlight module for improving local dimming brightness according to claim 4, characterized in that, The sidewall of the light guide plate (4) is provided with a chamfered structure or a prism-shaped light guide structure to optimize the propagation path of light in the light guide plate (4).

6. The backlight module for improving local dimming brightness according to claim 4, characterized in that, The LED light (3) is mounted on the PCB board (2).

7. The backlight module for improving local dimming brightness according to claim 4, characterized in that, The PCB board (2) is fixed to the lower iron frame (12) by thermally conductive double-sided adhesive (9).

8. The backlight module for improving local dimming brightness according to claim 1, characterized in that, The radius of curvature of the spherical boss (41) is 1.5-4.0 mm; the radius of curvature of the concave region (42) is 2.0-6.0 mm.

9. A vehicle-mounted screen, characterized in that, The backlight module for improving local dimming brightness as described in any one of claims 1 to 8, and a liquid crystal display panel disposed on the light-emitting side of the backlight module.

10. The vehicle-mounted screen according to claim 9, characterized in that, The vehicle screen also includes a touch layer, which is disposed in front of the liquid crystal display panel.

Images