Backlight module and direct type LED backlight display screen

Abstract

The utility model relates to a backlight module and direct type LED backlight display screen, utilize the backlight module of following to make direct type LED backlight display screen, the backlight module includes the diffusion plate of taking PS material as base material, the glass fiber aerogel heat insulation sheet of diffusion plate one side, and the LED lamp plate of one side of heat insulation sheet back to diffusion plate side, diffusion plate side to glass fiber aerogel heat insulation sheet is the light entrance, the distance between LED lamp plate and light entrance is 4.065mm 4.637mm, wherein the thickness of glass fiber aerogel heat insulation sheet is 1.065mm 3.637mm. The utility model adds the heat insulation layer between LED lamp pearl and diffusion plate, can reduce the light mixing distance greatly, reduces display equipment thickness.

Description

Technical Field

[0001] This utility model relates to the field of LED display technology, and in particular to a backlight module and a direct-lit LED backlight display. Background Technology

[0002] Currently, the mainstream display technology in the market is LED display technology, which is the most important flat panel display technology and drives the continuous updating and upgrading of flat panel display technology.

[0003] Currently, LED displays are mainly used in LCD TVs. With the increasing popularity of TVs, ultra-thin and intelligent designs will become inevitable development trends for LCD TVs. Traditional direct-lit backlights, with the light source located at the bottom of the module, offer excellent brightness and uniformity. However, the LED chips generate significant heat on their surface, and the diffuser plate's substrate is typically made of PS material. Figure 1 As shown, if the light mixing distance between the LED light board and the diffuser plate is reduced, the diffuser plate is prone to warping and rapid aging. This requires increasing the distance between the LED beads and the diffuser plate so that the light mixing distance is not less than 12mm, which increases the thickness of the display and does not meet the application requirements of modern thinness and aesthetics.

[0004] A three-layer diffuser plate is fabricated using polymer extrusion technology. The middle layer is a quantum dot layer, while the top and bottom layers are diffusion layers. The diffusion layers include a light diffusing agent and silica aerogel particles, utilizing their thermal insulation properties to address the poor thermal stability of quantum dot diffusers. The silica aerogel composite plate utilizes the ultra-low density of silica aerogel to solve the settling problem of particle-filled light-transmitting composite panels. Glass is used as the diffuser plate substrate, and the diffusion effect is achieved through the layering of different refractive indices. Glass diffusers offer excellent diffusion, thermal insulation, and heat resistance, and can be directly applied above LED circuits without the need for a separator.

[0005] The technical challenge lies in the fact that while adding silica aerogel to the polymer can increase its thermal stability, the surface temperature of LED beads exceeds 120°C, making the polymer prone to damage when the light mixing distance is reduced. The fragility and weight of glass substrates limit their use as diffuser materials, not only increasing the weight of the display device but also imposing more stringent requirements on assembly and transportation. Summary of the Invention

[0006] The purpose of this utility model is to provide a backlight module and a direct-lit LED backlight display screen that reduce the mixing distance and thus the thickness of the display screen, which is achieved by the following technical solutions:

[0007] A backlight module:

[0008] The device includes a diffuser plate with PS material as the substrate; a glass fiber aerogel heat insulation sheet located on one side of the diffuser plate; and an LED light panel located on the side of the glass fiber aerogel heat insulation sheet facing away from the diffuser plate; the side of the diffuser plate facing the glass fiber aerogel heat insulation sheet is the light incident surface, and the distance between the LED light panel and the light incident surface is 4.065mm-4.637mm; wherein the thickness of the glass fiber aerogel heat insulation sheet is 1.065mm-3.637mm.

[0009] The backlight module is further designed to use glass fiber as a substrate and composite it with silica aerogel to form the glass fiber aerogel heat insulation sheet.

[0010] The backlight module is further designed such that: the glass fiber aerogel heat insulation sheet is bonded to the light-incident surface of the diffuser plate using UV adhesive or thermosetting adhesive, and there is an air layer of 1mm-3mm between the glass fiber aerogel heat insulation sheet and the LED light board.

[0011] The backlight module is further designed such that the glass fiber aerogel heat insulation sheet is placed on the LED lamp board, and the distance between the glass fiber aerogel heat insulation sheet and the light incident surface is an air layer of 1mm-3mm.

[0012] A direct-lit LED backlight display screen, using any of the aforementioned backlight modules.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0014] By utilizing the advantages of silica aerogel, such as good thermal insulation performance, high porosity, low density, and good thermal insulation properties, the thermal conductivity of the insulation material can be effectively reduced, thereby improving the thermal insulation capacity and reducing the weight of the backlight system.

[0015] Glass fiber aerogel insulation sheets are prepared by supercritical drying process using glass fiber as the base material and composite silica aerogel. They have the characteristics of low thermal conductivity, strong hydrophobicity, and excellent fire resistance and flame retardancy, and can isolate the diffuser plate from the damage caused by high temperature lamp beads.

[0016] Adding a heat insulation layer between the LED beads and the diffuser plate can significantly reduce the light mixing distance and reduce the thickness of the display device. Attached Figure Description

[0017] Figure 1 These are thermal distortion temperature data graphs for three types of diffusion plates made with PS substrate.

[0018] Figure 2 This is a data sheet for the prepared glass fiber aerogel insulation sheet.

[0019] Figure 3 This is a schematic diagram of a brightness test.

[0020] Figure 4 This is a schematic diagram of the product structure for comparison.

[0021] Figure 5 This is a schematic diagram of the structure of the first product in the embodiment.

[0022] Figure 6 This is a schematic diagram of the product structure of the second embodiment.

[0023] Figure 7 This is a schematic diagram of the third product structure in the embodiment.

[0024] Figure 8 This is a data table for an example. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0026] A backlight module as shown in the figure includes a diffuser plate; a glass fiber aerogel heat insulation sheet located on one side of the diffuser plate; and an LED light panel located on the side of the glass fiber aerogel heat insulation sheet facing away from the diffuser plate; the side of the diffuser plate facing the glass fiber aerogel heat insulation sheet is the light incident surface, and the distance between the LED light panel and the light incident surface is 4.065mm-4.637mm; wherein the thickness of the glass fiber aerogel heat insulation sheet is 1.065mm-3.637mm.

[0027] Glass fiber aerogel insulation sheet is prepared by composite silica aerogel with glass fiber as the substrate.

[0028] Specifically, the preparation of glass fiber aerogel insulation sheets involves: a silica aerogel matrix of 40-50 wt%, glass fibers of 10-35 wt%, and the remainder as a binder. The average diameter of the glass fibers is 10-20 μm, preferably 10-16 μm. The silica aerogel matrix comprises one or more of the following: tetraethoxysilane (TEOS), methyltrimethoxysilane (MTMS), hexamethyldisiloxane (HMDSO), tetraethyl orthosilicate (TEOS), methyl orthosilicate (TMOS), ethyltrimethoxysilane (ETMS), and propyltriethoxysilane (PTES). The aerogel particles are 100-300 μm in size.

[0029] The adhesives include one or more of the following: silicone adhesives, siloxane emulsions, acrylic adhesives, fumigated silica, or silica gel. Preparation process: 1) One or more silica aerogel matrices are dissolved in ethanol in a specific ratio (40% hexamethyldisiloxane, 10% tetraethoxysilane), and an appropriate amount of acid catalyst (0.1 M hydrochloric acid) is added. The temperature is controlled at 50-60°C, and the mixture is stirred for 30-40 minutes to form a homogeneous sol. 2) Fibers and adhesives (40% glass fiber, 10% adhesive) are added to the sol, and the mixture is gently stirred to ensure uniform fiber distribution and a stable dispersion. 3) The dispersion is poured into a mold, sealed, and kept at room temperature to allow gelation and aging for 24 hours. 4) The aged gel material is placed in a supercritical CO2 drying apparatus, first soaked in ethanol, then the ethanol is replaced with liquid CO2 at 4-8°C to gradually reach supercritical drying conditions, preventing gel collapse. After drying, a glass fiber aerogel insulation sheet is obtained.

[0030] Prepared Figure 2 The patent application describes the preparation process of glass fiber aerogel insulation sheets, aiming to clarify the selection of existing glass fiber aerogel insulation sheets and form a specific structural relationship. It is important to emphasize that glass fiber aerogel insulation sheets are known prior art in this field.

[0031] The diffuser plate in the embodiment has a thickness of 1-3 mm, preferably 1.5 mm, a haze of >99%, and a transmittance of 20-60%, preferably 25-35%.

[0032] like Figure 7 As shown, the glass fiber aerogel insulation sheet is bonded to the light-incident surface of the diffuser plate using UV adhesive or thermosetting adhesive, and there is an air layer of 1mm-3mm between the glass fiber aerogel insulation sheet and the LED light panel. This embodiment forms the structural relationship (d) between the glass fiber aerogel insulation sheet, the diffuser plate, and the LED light panel.

[0033] like Figure 6 As shown, the glass fiber aerogel insulation sheet is placed on the LED lamp panel, and the distance between the glass fiber aerogel insulation sheet and the light-incident surface is an air layer of 1mm-3mm. This embodiment forms the structural relationship (c) between the glass fiber aerogel insulation sheet, the diffuser plate, and the LED lamp panel.

[0034] As a comparison, such as Figure 4-5 As shown, in the structural relationship (a), no glass fiber aerogel insulation sheet is placed between the diffuser plate and the LED light panel, only an air layer is retained. In the structural relationship (b), the glass fiber aerogel insulation sheet, the diffuser plate, and the LED light panel are bonded together.

[0035] like Figure 3As shown, glass fiber aerogel insulation sheets A (i.e., glass fiber aerogel insulation sheets 3-8) of different thicknesses are used as the insulation layer between the backlight LED and the diffuser plate B. The luminous intensity of the LED as the blue backlight C is 400W / m. 2 The sample was placed above the LED beads, with the bottom of the diffuser plate in close contact with the thermometer. After being continuously lit for 1.5 hours, the temperature between the glass fiber aerogel insulation sheet and the diffuser plate was tested, forming Examples 1-12.

[0036] In addition, no heat insulation layer is placed between the diffuser plate and the LED light panel, and the above steps are repeated to form control group 1. Control groups 2-4 are formed using the glass fiber aerogel heat insulation sheet 3 in combination with diffuser plates of different thicknesses, as described in the example. The final result is... Figure 8 The example data table is shown.

[0037] In control group 1, the surface temperature of the diffuser plate was 76.3℃, which is higher than the heat distortion temperature of the diffuser plate substrate, and long-term use may cause deformation of the diffuser plate. Control groups 2-4 show that when the LED beads are in contact with the glass fiber aerogel insulation sheet, although increasing the thickness of the diffuser plate can achieve a better light mixing effect due to heat conduction, the surface temperature of the diffuser plate still does not meet the usage requirements. Examples 1-12 can effectively solve the problem of diffuser plate uniformity, and the surface temperature is lower than the heat distortion temperature. Therefore, using the solution of this invention can effectively shorten the light mixing distance of direct-lit flat panel displays, making it suitable for direct-lit LED backlight displays.

Claims

1. A backlight module, characterized in that: The device includes a diffuser plate with PS material as the substrate; a glass fiber aerogel heat insulation sheet located on one side of the diffuser plate; and an LED light panel located on the side of the glass fiber aerogel heat insulation sheet facing away from the diffuser plate; the side of the diffuser plate facing the glass fiber aerogel heat insulation sheet is the light incident surface, and the distance between the LED light panel and the light incident surface is 4.065mm-4.637mm; wherein the thickness of the glass fiber aerogel heat insulation sheet is 1.065mm-3.637mm.

2. The backlight module according to claim 1, characterized in that: Glass fiber aerogel insulation sheet is prepared by composite silica aerogel with glass fiber as the substrate.

3. The backlight module according to claim 1, characterized in that: The glass fiber aerogel heat insulation sheet is bonded to the light-incident surface of the diffuser plate using UV adhesive or thermosetting adhesive, and there is an air layer of 1mm-3mm between the glass fiber aerogel heat insulation sheet and the LED light panel.

4. The backlight module according to claim 1, characterized in that: The glass fiber aerogel heat insulation sheet is placed on the LED light panel, and the distance between the glass fiber aerogel heat insulation sheet and the light incident surface is an air layer of 1mm-3mm.

5. A direct-lit LED backlight display screen, characterized in that, The backlight module of any one of claims 1-4 is used.

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