Novel backlight module with high light source utilization rate

Abstract

The invention relates to the technical field of semiconductor display, in particular to a novel light source high-utilization-rate backlight module which comprises a back plate, an LED set, a light guide plate and a rubber frame, and the top face of the light guide plate is covered with a high-light-source-diffusivity nanometer coating which is used for replacing a traditional diffusion sheet; the bottom face, the left side face, the right side face and the light-emitting side face of the light guide plate are covered with high-diffuse-reflection nanometer coatings used for replacing a traditional reflector plate. The high-diffusivity nano-coating and the high-diffuse-reflection nano-coating are directly printed on the surface of the light guide plate, and traditional PET film material physical superposition is replaced. The thickness of the nano coating is only 0.1-5 microns, so that the thickness of the backlight module is obviously reduced. The high-diffusivity coating realizes the balance that the light transmittance is greater than 90% and the haze is greater than 80% by using nano-particles; the high diffuse reflection coating forms full-angle diffuse reflection through a nano-porous structure and a high-refractive-index material, and light energy loss is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor display, in particular to a novel light source high utilization backlight module. BACKGROUND

[0002] In the current backlight module architecture, the diffusion sheet is a key optical element on the upper layer of the light guide plate, made of PET substrate, mainly responsible for light source diffusion function; the reflection sheet is an optical medium between the light guide plate and the back plate, also made of PET substrate, and its core function is to reflect light. As shown in Figure 1 and Figure 2 , the system composition includes: ① back plate structure ② LED array ③ LED shading tape ④ LED fixing tape ⑤ light guide plate main body ⑥ diffusion sheet assembly ⑦ reflection sheet assembly ⑧ light guide plate & reflection sheet fixing tape ⑨ frame assembly ⑩ frame fixing tape.

[0003] Through system analysis, the design has the following technical bottlenecks: 1. Component stacking thickness limitation: the material stacking characteristics of the diffusion sheet and the reflection sheet will restrict the further compression of the backlight module thickness, making it difficult to meet the engineering needs of the ultra-thin development trend.

[0004] 2. Light diffusion efficiency degradation: the physical gap between the diffusion sheet and the light guide plate not only leads to light diffusion efficiency decay (light flux loss of about 12-15%), but also forms a foreign matter penetration channel, which may cause micro scratches on the upper surface of the light guide plate, ultimately leading to white spot defects and foreign matter display failure in the backlight module.

[0005] 3. Light reflection performance degradation: the interface gap between the reflection sheet and the light guide plate causes a decrease in reflection efficiency (reflectivity decreases by about 8-10%), and the foreign matter particles penetrating the gap are easy to cause mechanical damage to the lower surface of the light guide plate, thereby causing subsurface light scattering effect, leading to degradation of display brightness and uniformity indicators.

[0006] 4. Assembly process defects: there are component offset tolerances (typical value ±0.3mm) and mechanical stress damage in the module assembly process, the former can induce optical abnormal phenomena such as light leakage, bright line, shadow, etc., and the latter directly leads to component breakage and scrap (scrap rate of about 1.2-1.8%). SUMMARY

[0007] In view of the deficiencies of the prior art, the present application discloses a novel light source high utilization backlight module to solve the above problems.

[0008] This invention is achieved through the following technical solution: This invention provides a novel high-utilization backlight module, comprising a backplate, LED assembly, light guide plate, and frame. The top surface of the light guide plate is covered with a high light source diffusion nano-coating, which is used to replace the traditional diffuser sheet; The bottom, left and right sides, and light-emitting side of the light guide plate are covered with a high diffuse reflection nano-coating, which is used to replace the traditional reflective sheet.

[0009] Furthermore, the high light diffusion nanocoating comprises silicon dioxide, zinc oxide, or titanium dioxide with a nanoparticle concentration of 1-5wt% and a particle size of 50-500nm, and has a light transmittance of >90% and a haze of >80%, achieving light diffusion through a micron / nano-scale porous structure.

[0010] Furthermore, the high diffuse reflection nanocoating contains high refractive index nanomaterials, which form diffuse reflection at all angles through a nanoporous structure or layered design. The high refractive index nanomaterials are TiO2 or ZnO.

[0011] Furthermore, the thickness of the nano-coating is 0.1-5μm, formed by a microgravure coating process, with the coating line speed controlled at 10-30m / min and the mesh count at 150-200 lines / inch.

[0012] Furthermore, the coating thickness fluctuation of the micro-gravure coating process is less than ±3%, and local coating of the brightening area at the edge of the light guide plate can be achieved by customizing the gravure pattern.

[0013] Furthermore, the high light diffusion nano-coating has an anti-glare function, which can eliminate ultraviolet / infrared radiation and flicker; the high diffuse reflection nano-coating has a smooth surface and is wear-resistant.

[0014] Furthermore, the light guide plate and the frame are connected by light guide plate fixing tape and frame fixing tape, and there is no assembly gap like that of traditional diffuser sheets and reflective sheets.

[0015] The beneficial effects of this invention are as follows: This invention employs a highly diffusive nano-coating (replacing the diffuser sheet) and a highly diffuse reflective nano-coating (replacing the reflector sheet), which are directly printed onto the surface of the light guide plate, eliminating the need for physical layering of traditional PET film materials. The nano-coating thickness is only 0.1-5μm, significantly reducing the overall thickness of the backlight module and meeting the requirements for ultra-thin designs.

[0016] The high-diffusivity coating of this invention utilizes the Mie scattering or Rayleigh scattering principle of nanoparticles (such as SiO2, ZnO, TiO2) to achieve a balance between transmittance >90% and haze >80%, thereby enhancing the uniformity of light diffusion. The high-diffusivity coating, through its nanoporous structure and high-refractive-index materials such as TiO2, forms multiple scattering, increasing the reflectivity to diffuse reflection at all angles and reducing light energy loss.

[0017] This invention eliminates the physical gap (originally about 0.1-0.3mm) between the diffuser / reflector and the light guide plate, avoiding problems such as foreign object intrusion and scratches on the light guide plate caused by the gap. At the same time, it reduces assembly steps (such as tape fixing steps) and reduces the defect rate of misalignment, light leakage, and breakage.

[0018] The nano-coating of this invention improves surface smoothness and has better wear and corrosion resistance than traditional PET film materials. The coating thickness fluctuation is less than ±3% through micro-gravure coating process (linear speed 10-30m / min, mesh 150-200 lines / inch), ensuring optical uniformity. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is the original design's AA sectional view of the light-receiving side; Figure 2 These are the left and right side BB sectional views of the original design; Figure 3 This is a newly designed light-incident side AA sectional view; Figure 4 These are the left and right side BB sectional views of the new design; The labels in the diagram represent: ① Backplate; ② LED assembly; ③ LED light-shielding tape; ④ LED fixing tape; ⑤ Light guide plate; ⑥ Diffuser sheet; ⑦ Reflector sheet; ⑧ Light guide plate & reflector sheet fixing tape; ⑨ Frame; ⑩ Frame fixing tape; ⑪ High-diffusivity nano-coating; ⑫ High-diffusivity nano-coating. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Reference Figure 2 and Figure 3 As shown, this embodiment provides a novel high-utilization backlight module, including a back plate, an LED group, a light guide plate, and a frame. The top surface of the light guide plate is covered with a high light-diffusing nano-coating to replace the traditional diffuser sheet; the bottom surface, left and right sides, and light-emitting side of the light guide plate are covered with a high-diffusing nano-coating to replace the traditional reflector sheet.

[0023] In this embodiment, the high light diffusion nanocoating contains silicon dioxide, zinc oxide, or titanium dioxide with a nanoparticle concentration of 1-5wt% and a particle size of 50-500nm. Its light transmittance is >90% and haze is >80%, and light diffusion is achieved through a micron / nano-scale porous structure.

[0024] This embodiment of the high diffuse reflection nanocoating contains high refractive index nanomaterials, which form diffuse reflection at all angles through a nanoporous structure or layered design. The high refractive index nanomaterials are TiO2 or ZnO.

[0025] In this embodiment, the thickness of the nano-coating is 0.1-5μm, formed by a microgravure coating process, with the coating line speed controlled at 10-30m / min and the mesh count at 150-200 lines / inch.

[0026] In this embodiment, the coating thickness fluctuation of the micro-gravure coating process is less than ±3%, and local coating of the brightening area at the edge of the light guide plate can be achieved by customizing the gravure pattern.

[0027] The high light source diffusion nano-coating of this embodiment has anti-glare function and can eliminate ultraviolet / infrared radiation and flicker; the surface of the high diffuse reflection nano-coating is smooth and wear-resistant.

[0028] In this embodiment, the light guide plate and the frame are connected by light guide plate fixing tape and frame fixing tape, and there is no assembly gap like in traditional diffuser sheets and reflective sheets.

[0029] The diffusion coating in this embodiment is prepared as follows: Composition: 3wt% silica nanoparticles (200nm particle size) dispersed in UV-curable resin; Optical performance: 92% light transmittance, 85% haze; Coating process: microgravure coating, mesh count 180 lines / inch, linear speed 20m / min, coating thickness 2μm (fluctuation ±2.5%).

[0030] The diffuse reflection coating in this embodiment is prepared as follows: Composition: 4wt% TiO2 nanoparticles (100nm particle size) dispersed in acrylic resin; Coating process: same as diffusion layer, thickness 1.5μm (fluctuation ±2.8%).

[0031] The assembly process in this embodiment is as follows: Step 1: After plasma cleaning, the light guide plate is sequentially printed with a diffusion coating (top surface) and a diffuse reflection coating (bottom and side surfaces). Step 2: The LED assembly is attached to the light-incident side of the light guide plate using fixing tape (④); Step 3: The light guide plate is embedded in the frame (⑨) and locked to the back plate by fixing tape (⑧, ⑩), without additional diffuser / reflector.

[0032] This embodiment features a partial coating design: To address the need for brightening the edges of the light guide plate, a custom intaglio pattern was created, and the thickness of the diffuse reflection coating was increased to 3μm in a 5mm wide area on the bottom edge of the light guide plate (1.5μm in the remaining areas), thereby improving the uniformity of edge brightness.

[0033] The process parameters for this implementation were verified as follows: Coating process parameter test comparison table The technical effects of this embodiment are compared and verified as follows: Comparison table of optical module performance The optical effects of this embodiment are as follows: the diffuse reflection coating achieves omnidirectional scattering (reflectivity > 95%), the diffusion coating eliminates glare (flicker frequency > 3125Hz); there are no gaps between the films, and the surface of the light guide plate is free of scratches and white spots (verified by 1000 hours of aging test).

[0034] In summary, this invention utilizes a highly diffusive nano-coating (replacing the diffuser sheet) and a highly diffuse reflective nano-coating (replacing the reflector sheet) directly printed onto the surface of the light guide plate, eliminating the need for physical layering of traditional PET films. The nano-coating thickness is only 0.1-5 μm, significantly reducing the overall thickness of the backlight module and meeting the requirements for ultra-thin designs.

[0035] The high-diffusivity coating of this invention utilizes the Mie scattering or Rayleigh scattering principle of nanoparticles (such as SiO2, ZnO, TiO2) to achieve a balance between transmittance >90% and haze >80%, thereby enhancing the uniformity of light diffusion. The high-diffusivity coating, through its nanoporous structure and high-refractive-index materials such as TiO2, forms multiple scattering, increasing the reflectivity to diffuse reflection at all angles and reducing light energy loss.

[0036] This invention eliminates the physical gap (originally about 0.1-0.3mm) between the diffuser / reflector and the light guide plate, avoiding problems such as foreign object intrusion and scratches on the light guide plate caused by the gap. At the same time, it reduces assembly steps (such as tape fixing steps) and reduces the defect rate of misalignment, light leakage, and breakage.

[0037] The nano-coating of this invention improves surface smoothness and has better wear and corrosion resistance than traditional PET film materials. The coating thickness fluctuation is less than ±3% through micro-gravure coating process (linear speed 10-30m / min, mesh 150-200 lines / inch), ensuring optical uniformity.

[0038] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, 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. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A novel high-utilization backlight module, comprising a backplate, an LED assembly, a light guide plate, and a frame, characterized in that: The top surface of the light guide plate is covered with a high light source diffusion nano-coating, which is used to replace the traditional diffuser sheet; The bottom, left and right sides, and light-emitting side of the light guide plate are covered with a high diffuse reflection nano-coating, which is used to replace the traditional reflective sheet.

2. The novel high-utilization backlight module for light sources according to claim 1, characterized in that: The high light-diffusing nanocoating contains silicon dioxide, zinc oxide, or titanium dioxide with a nanoparticle concentration of 1-5wt% and a particle size of 50-500nm. Its light transmittance is >90% and haze is >80%, and light diffusion is achieved through a micron / nano-scale porous structure.

3. The novel high-utilization backlight module for light sources according to claim 1, characterized in that: The high diffuse reflection nanocoating contains high refractive index nanomaterials, which form diffuse reflection at all angles through a nanoporous structure or layered design. The high refractive index nanomaterials are TiO2 or ZnO.

4. The novel high-utilization backlight module for light sources according to any one of claims 1-3, characterized in that: The thickness of the nano-coating is 0.1-5μm, formed by a microgravure coating process, with the coating line speed controlled at 10-30m / min and the mesh count at 150-200 lines / inch.

5. The novel high-utilization backlight module for light sources according to claim 4, characterized in that: The coating thickness of the micro-gravure coating process fluctuates by less than ±3%, and local coating of the brightening area at the edge of the light guide plate can be achieved by customizing the gravure pattern.

6. The novel high-utilization backlight module for light sources according to claim 1, characterized in that: The high light-diffusing nano-coating has anti-glare function and can eliminate ultraviolet / infrared radiation and flicker; the high diffuse reflection nano-coating has a smooth surface and is wear-resistant.

7. The novel high-utilization backlight module for light sources according to claim 1, characterized in that: The light guide plate and the frame are connected by light guide plate fixing tape and frame fixing tape, and there is no assembly gap like in traditional diffuser sheets and reflective sheets.

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