Backlight device with double-sided LED light bar

Abstract

The utility model relates to the technical field of backlight source especially relates to a backlight source device with bilateral LED light bar, including the frame, the one side of frame is provided with the vertical edge, the one side of frame is provided with U type bending away from vertical edge, the backlight source subassembly contains upper layer light -enhancing film, lower layer light -enhancing film, diffusion film, light guide plate, reflection film and back cover, upper layer light -enhancing film, lower layer light -enhancing film, diffusion film, light guide plate, reflection film and back cover are fixed in turn from top to bottom and link to each other. This scheme adopts the LED light bar of left and right two sides symmetry distribution, and the light from light guide plate both sides is incident simultaneously, makes the light conduction distance shorten, and the attenuation of light energy in transmission process is greatly reduced, and light guide plate converts linear light source into uniform area light source through surface dot structure, ensures that the light distribution of entire display area is consistent, and bilateral light source converges in central area, effectively avoids the problem that the brightness of area far from light source is insufficient when the light is unilateral, and the overall brightness is obviously improved.

Description

Technical Field

[0001] This utility model relates to the field of backlight technology, and in particular to a backlight device with dual-sided LED light strips. Background Technology

[0002] LED backlight technology has been widely used in the lighting and display industries due to its advantages such as being environmentally friendly, having excellent color gamut display, and good mechanical vibration stability. Currently, the mainstream design for LED backlights is a single-sided light-incident structure, where the LED strip is only placed on one side of the light guide plate, which transmits light to the entire display area, thus providing uniform backlighting for the LCD panel. This design has become the preferred solution for mass-produced backlights due to its simple structure, low mold processing difficulty, and mature optical design and visual effects processing technologies. However, as users' requirements for display effects continue to increase, the limitations of the single-sided light-incident structure are gradually becoming apparent, especially in medium and large-sized display devices, where its brightness and visual effects performance are no longer sufficient to meet the needs of the high-end market.

[0003] In a single-sided light-incident structure, the number and layout of LED strips directly determine the backlight's brightness. Due to structural limitations, too many LED strips cannot be placed on one side, resulting in limited room for brightness improvement. Furthermore, after light enters the light guide plate from one side, it must travel a long distance to cover the entire display area. During this process, light energy gradually attenuates with increasing transmission distance, with greater energy loss in areas farther from the light source. To compensate for this attenuation, more microstructures are typically designed in areas far from the light source to optimize light distribution. However, this not only increases the complexity of optical design but may also lead to uneven visual effects, affecting the display's quality. This problem is particularly pronounced for medium to large-sized backlights, where low light transmission efficiency and poor visual effects become the main bottlenecks restricting performance improvement.

[0004] In existing technologies, to address the light energy attenuation problem in single-sided light-incident structures, some improvements have attempted to enhance luminance and uniformity by increasing the power of LED strips or optimizing the microstructure design of light guide plates. However, these methods are often limited by material properties and manufacturing processes, making it difficult to achieve a qualitative leap. For example, increasing LED power may lead to heat generation issues, while complex microstructure designs increase manufacturing costs and process difficulty. Therefore, how to overcome the limitations of single-sided light-incident structures based on existing technologies and achieve backlight designs with higher luminance and better visual effects has become an urgent problem to be solved by the industry. Utility Model Content

[0005] The purpose of this invention is to address the aforementioned shortcomings in the existing technology by proposing a backlight device with dual-sided LED light strips.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a backlight device with dual-sided LED light strips, including a frame, a vertical edge on one side of the frame, a U-shaped bend on the side of the frame away from the vertical edge, a backlight assembly embedded inside the frame, and light strip one and light strip two respectively on both sides of the backlight assembly.

[0007] The backlight assembly includes an upper brightness enhancement film, a lower brightness enhancement film, a diffusion film, a light guide plate, a reflective film, and a back cover. The upper brightness enhancement film, the lower brightness enhancement film, the diffusion film, the light guide plate, the reflective film, and the back cover are connected and fixed to each other in sequence from top to bottom.

[0008] Preferably, the frame is a glued iron frame structure.

[0009] Preferably, both the upper and lower brightness enhancement films are PET substrates with microprism structures on their surfaces and a thickness of 62-200 μm.

[0010] Preferably, the diffusion film is a PET substrate and its surface is coated with acrylic resin.

[0011] Preferably, the light guide plate is made of PMMA material.

[0012] Preferably, the reflective film is an ESP-enhanced specular reflective film with a thickness of 100-300 μm.

[0013] Preferably, the back cover is made of engineering plastic material and has a thickness of 1.5-3mm.

[0014] The design scheme proposed in this utility model has the following beneficial effects in application:

[0015] 1. This solution uses symmetrically distributed LED light strips on both sides, with light entering from both sides of the light guide plate simultaneously. This shortens the light transmission distance and significantly reduces the attenuation of light energy during transmission. The light guide plate transforms the line light source into a uniform surface light source through its surface dot structure, ensuring consistent light distribution throughout the display area. The dual light sources converge in the central area, effectively avoiding the problem of insufficient brightness in areas far from the light source when light enters from one side, resulting in a significant improvement in overall brightness.

[0016] 2. As described in 1, after the light passes through the light guide plate, it undergoes multi-stage processing through a diffusion film and two layers of brightness enhancement films. The diffusion film eliminates the dot marks and moiré patterns of the light guide plate, softens glaring light spots, and initially improves uniformity. The lower brightness enhancement film refracts large-angle light to the frontal viewing angle through a microprism structure, increasing axial brightness. The upper brightness enhancement film further converges the angle of scattered light, forming a cross-brightness enhancement effect with the lower brightness enhancement film. This layered design maximizes light utilization and outputs a highly uniform and high-brightness surface light source, effectively solving the problem of limited viewing angle of a single-layer brightness enhancement film.

[0017] 3. As described in section 2, the frame structure with U-shaped bending allows for convenient oblique insertion assembly of the light guide plate and LED strip. The back cover is made of lightweight engineering plastic, which ensures structural strength and protects internal components. The reflective film effectively reduces light leakage at the bottom of the light guide plate and isolates the heat generated by the LED. The closed structure of the frame ensures that each layer of film is tightly pressed together to avoid displacement. The overall design optimizes heat dissipation performance and extends the life of the LED through reasonable material selection and spatial layout. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0019] Figure 2 This is a schematic diagram showing the distribution of the light guide plate and the two light strips of this utility model;

[0020] Figure 3 For the present utility model Figure 1 Enlarged view of point A;

[0021] Figure 4 This is a schematic diagram of the backlight assembly of this utility model.

[0022] In the diagram: 1. Frame; 11. Vertical edge; 12. U-shaped bend; 13. Backlight assembly; 14. LED strip one; 15. LED strip two; 1301. Upper brightness enhancement film; 1302. Lower brightness enhancement film; 1303. Diffuser film; 1304. Light guide plate; 1305. Reflective film; 1306. Back cover. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0024] Example 1

[0025] Reference Figures 1-4 A backlight device with dual-sided LED light strips includes a frame 1, a vertical edge 11 on one side of the frame 1, a U-shaped bend 12 on the side of the frame 1 away from the vertical edge 11, a backlight assembly 13 embedded inside the frame 1, and light strip 14 and light strip 2 15 respectively on both sides of the backlight assembly 13.

[0026] The backlight assembly 13 includes an upper brightness enhancement film 1301, a lower brightness enhancement film 1302, a diffusion film 1303, a light guide plate 1304, a reflective film 1305, and a back cover 1306. The upper brightness enhancement film 1301, the lower brightness enhancement film 1302, the diffusion film 1303, the light guide plate 1304, the reflective film 1305, and the back cover 1306 are connected and fixed to each other in sequence from top to bottom.

[0027] Among them, frame 1 is a glued iron frame structure.

[0028] The upper brightness enhancement film 1301 and the lower brightness enhancement film 1302 are both PET substrates with microprism structures on their surfaces and a thickness of 62-200μm. The prism structure focuses light onto the frontal view, improving axial brightness, providing high light transmittance (>90%), reducing light loss, and making them thin, flexible, and easy to assemble. The lower brightness enhancement film 1302 and the upper brightness enhancement film 1301 have prisms perpendicular to each other and work together to further converge the light angle and improve overall uniformity.

[0029] Among them, the diffusion film 1303 is a PET substrate and is coated with acrylic resin. It scatters light, eliminates the moiré pattern of the brightness enhancement film and the dot marks of the light guide plate, improves uniformity, and softens glaring light spots.

[0030] The light guide plate 1304 is made of PMMA material, with a thickness of 0.5–3 mm for side-lit type and 3–10 mm for direct-lit type. The light transmittance of PMMA is >92%. It converts line light sources and point light sources into surface light sources through laser dots or printed dots.

[0031] Among them, the reflective film 1305 is an ESP-enhanced specular reflective film with a thickness of 100-300μm. It has high reflectivity, reduces light leakage at the bottom of the light guide plate, and provides heat insulation and reduces the impact of heat attenuation.

[0032] The back cover 1306 is made of engineering plastic material with a thickness of 1.5-3mm. The plastic back cover is lightweight, has high structural strength, and protects the internal components.

[0033] In practice

[0034] The dual-sided LED light strip design of this solution achieves efficient light transmission and uniform distribution by simultaneously introducing light from both sides of the light guide plate 1304 through light strip 14 and light strip 2 15. When light strip 14 and light strip 2 15 are powered on, the light emitted by the LED light source enters from the left and right sides of the light guide plate 1304 respectively. Since the light guide plate 1304 is made of PMMA material, the light is transmitted to the center of the display area through the principle of total internal reflection. The dual-sided light transmission structure shortens the light transmission distance to half that of single-sided light transmission, significantly reducing the attenuation of light energy during transmission. The laser dots or printed dots on the surface of the light guide plate 1304 convert the line light source into a uniform surface light source, ensuring the consistency of light distribution in the display area. In addition, the dual-sided light sources converge in the central area, further improving the overall brightness and avoiding the problem of insufficient brightness in areas far from the light source when using single-sided light transmission. This design not only improves optical efficiency but also reduces the complexity of optical debugging, making it suitable for the high brightness requirements of medium and large-sized backlights.

[0035] The layered design of the optical film material optimizes the uniformity and axial brightness of light through multi-stage processing. The light emitted from the light guide plate 1304 first passes through the diffuser film 1303, where scattering particles on its surface eliminate the dot marks on the light guide plate and the moiré patterns on the brightness enhancement film, softening glaring light spots and initially improving uniformity. Subsequently, the light enters the lower brightness enhancement film 1302, where the large-angle light is refracted to the front viewing angle through the microprism structure, improving axial brightness. Next, the upper brightness enhancement film 1301 further converges the angle of the remaining scattered light, enhancing the front brightness. The prisms of the two brightness enhancement films are arranged perpendicularly to form a cross-brightness enhancement effect, maximizing light utilization. This synergistic effect not only reduces light loss but also solves the problem of limited viewing angle of a single-layer brightness enhancement film, ultimately outputting a surface light source with high uniformity and high brightness, meeting the visual effect requirements of high-end display devices.

[0036] The mechanical structure design of the backlight device balances ease of assembly and thermal stability. The frame 1 adopts a glued iron frame structure, and its U-shaped bend 12 design allows the light guide plate 1304 and the first lamp strip 14 to be fixed after oblique insertion assembly. The second lamp strip 15 on the other side is directly fixed by adhesive strips, simplifying the assembly process. The back cover 1306 provides lightweight support and protects the internal components from external impacts. The reflective film 1305 is attached to the bottom of the light guide plate 1304 to reflect leaked light back into the light guide plate, reducing light energy waste, while isolating the heat generated by the LED and delaying the thermal decay of the material. The vertical edge 11 of the frame 1 and the U-shaped bend 12 form a closed structure to ensure that the layers of film are tightly pressed together and to avoid displacement. The overall structure ensures high brightness while optimizing heat dissipation through material selection and spatial layout, extending the LED life and making it suitable for display scenarios with long-term stable operation.

[0037] 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 backlight device with dual-sided LED light strips, comprising a frame (1), characterized in that: A vertical edge (11) is provided on one side of the frame (1), and a U-shaped bend (12) is provided on the side of the frame (1) away from the vertical edge (11). A backlight assembly (13) is embedded and installed inside the frame (1), and light strip one (14) and light strip two (15) are respectively provided on both sides of the backlight assembly (13). The backlight assembly (13) includes an upper brightness enhancement film (1301), a lower brightness enhancement film (1302), a diffusion film (1303), a light guide plate (1304), a reflective film (1305), and a back cover (1306). The upper brightness enhancement film (1301), the lower brightness enhancement film (1302), the diffusion film (1303), the light guide plate (1304), the reflective film (1305), and the back cover (1306) are connected and fixed to each other in sequence from top to bottom.

2. A backlight device with dual-sided LED light strips according to claim 1, characterized in that: The frame (1) is a glued iron frame structure.

3. A backlight device with dual-sided LED light strips according to claim 1, characterized in that: Both the upper brightening film (1301) and the lower brightening film (1302) are made of PET substrate, with a microprism structure on the surface and a thickness of 62-200μm.

4. A backlight device with dual-sided LED light strips according to claim 1, characterized in that: The diffusion film (1303) is a PET substrate and its surface is coated with acrylic resin.

5. A backlight device with dual-sided LED light strips according to claim 1, characterized in that: The light guide plate (1304) is made of PMMA material.

6. A backlight device with dual-sided LED light strips according to claim 1, characterized in that: The reflective film (1305) is an ESP-enhanced specular reflective film with a thickness of 100-300 μm.

7. A backlight device with dual-sided LED light strips according to claim 1, characterized in that: The back cover (1306) is made of engineering plastic material and has a thickness of 1.5-3mm.

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