Optical brightening plate with surface microstructure and backlight module

Abstract

The utility model discloses an optical brightening plate with a surface microstructure and a backlight module, the optical brightening plate comprises a substrate layer, and the substrate layer is provided with a microprism structure layer. According to the utility model, microstructure coining is carried out on the surface of the optical plastic plate serving as a base material, so that the microstructure layer and the base material layer are made of the same material, the stiffness is higher, wrinkling and bending are not easy to occur, the optical path loss is effectively reduced, optical resin coating and volatile substance treatment are not needed, the production cost and the assembly difficulty are effectively reduced, and the production efficiency is improved. And the production efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of liquid crystal modules, and particularly relates to an optical brightness enhancement plate with a surface microstructure. Background Art

[0002] The main components of a flat liquid crystal module include: liquid crystal glass, a light source, a light guide plate, and various optical films. These optical films mainly include a reflective film, a brightness enhancement film, a diffusion film, etc. Among them, the brightness enhancement film is one of the most important optical films in the module. Its principle is to use the micro prism structure on the surface to refract and reflect light, so that the scattered light is concentrated at a certain angle and emitted from the backlight source, increasing the brightness of the light visible within the user's line of sight, and at the same time enabling the system to consume less energy when generating the required brightness.

[0003] At present, the main processing method for the surface microstructure of optical films in the domestic market is to coat an optical resin on the surface of a polyethylene terephthalate film substrate, process the surface through roll pressing, and at the same time cure the optical adhesive. When the curing is completed, roll demolding is carried out to make an optical film with a surface microstructure. Since the stiffness of polyethylene terephthalate is relatively low, it is prone to wrinkling and deformation, which easily causes water ripples and bright and dark stripes in the display device during application. At the same time, it may form friction with the lower surface of the liquid crystal glass, resulting in abrasion and defects of the optical film and the lower polarizer. Therefore, the backlight module needs to design a corresponding ear structure for optical film positioning, and the processing process steps are numerous. It is necessary to first make polyester chips (such as PET particles), then melt and biaxially stretch them into films (such as PET films), then coat and cure the optical resin to make a coil, and finally die-cut it into sheets, resulting in a relatively high production cost. Summary of the Utility Model

[0004] The purpose of the utility model is: to solve the above problems, the utility model provides an optical brightness enhancement plate with a surface microstructure and a backlight module.

[0005] The utility model specifically adopts the following technical solutions to achieve the above purpose. The optical brightness enhancement plate with a surface microstructure includes:

[0006] A base layer, on one end face of which a micro prism structure layer is provided.

[0007] As a further description of the above technical solution, the thickness of the base layer is 0.2 - 0.5 mm.

[0008] As a further description of the above technical solution, the material of the base layer is one of polymethyl methacrylate, polycarbonate, and polystyrene.

[0009] As a further description of the above technical solution, the micro prism structure layer is disposed on one end face of the base layer, and the micro prism structure layer is integrally formed by imprinting.

[0010] As a further description of the above technical solution, the micro prism structure layer includes a plurality of groups of micro prisms arranged in parallel.

[0011] As a further description of the above technical solution, the bottom angles of the cross section of the micro prism are equal.

[0012] As a further description of the above technical solution, the apex angle of the cross section of the micro prism is greater than or equal to 90°.

[0013] As a further description of the above technical solution, the height of the micro prism is 20-100 μm.

[0014] It further includes a backlight module, and the backlight module includes the optical brightness enhancement plate according to any one of the above technical solutions.

[0015] The beneficial effects of the present utility model are as follows:

[0016] In the present utility model, the surface of the optical plastic plate used as the base material is microstructured by imprinting, so that the microstructured layer has the same material as the base material layer and higher stiffness, is not prone to wrinkling and bending, effectively reduces the optical path loss, and does not require coating of optical resin and treatment of volatile substances, effectively reducing the production cost and assembly difficulty and improving the production efficiency.

[0017] To more clearly illustrate the structural features and functions of the present utility model, the present utility model will be described in detail below with reference to the drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of the optical brightness enhancement plate of the present utility model;

[0019] Figure 2 is a schematic diagram of the points taken by the uniformity test method of the present utility model;

[0020] Figure 3 is a comparison table of the stiffness test results of the PS material plate and the PET material film;

[0021] Figure 4 is an optical test comparison table of the combination of the PS material plate and the combination of the PET material film.

[0022] Reference numerals:

[0023] 1. Base layer; 2. Micro prism structure layer; 21. Micro prism. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model.

[0025] As Figure 1 shown, in one embodiment, an optical brightening plate with surface microstructures includes: a base layer 1, and a micro prism structure layer 2 is disposed on one end face of the base layer 1. Among them, the micro prism structure layer 2 is disposed on one end face of the base layer 1, and the micro prism structure layer 2 is integrally formed by imprinting.

[0026] Exemplarily, the material of the base layer 1 is any one of polymethyl methacrylate (PMMA), polycarbonate (PC), and polystyrene (PS). Preferably, polystyrene (PS) is selected as the plate base material to achieve higher stiffness.

[0027] Furthermore, an optical substrate is obtained through a melt extrusion technique, and then the micro prism structure layer 2 is directly imprinted on the surface of the plate base material by an imprinting technique. Exemplarily, the thickness of the base layer 1 is 0.2 - 0.5 mm.

[0028] Please continue to refer to Figure 1 , in this embodiment, the micro prism structure layer 2 includes multiple groups of micro prisms 21 arranged in parallel.

[0029] Exemplarily, the bottom angles of the cross-section of the micro prism 21 are equal, the apex angle of the cross-section of the micro prism 21 is greater than or equal to 90°, and the height of the micro prism 21 is 20 - 100 μm. Preferably, the cross-section of the micro prism 21 is an isosceles right triangle. During actual production, the height and angle of the micro prism 21 can be adjusted according to actual product parameters.

[0030] The embodiments of the present application provide a backlight module, including the backlight module with the optical brightening plate in any of the above embodiments. The type of the backlight module can be determined according to actual needs, and the embodiments of the present application do not limit this. Since the backlight module has the above optical brightening plate, warping deformation and scratch damage of the optical brightening plate can be eliminated or at least reduced, thereby improving the optical performance, and thus improving the display brightness uniformity and display visual effect.

[0031] Please continue to refer to Figures 2 - 4 , and conduct characteristic tests on the prepared products: physical property tests include stiffness tests and impact tests, and optical tests include center coordinate brightness and uniformity.

[0032] The prepared PS plates with surface microstructures of different materials and different thicknesses are subjected to stiffness tests and impact tests under the same experimental conditions as the PET film selected in the comparative example, and the center brightness and uniformity are tested under the same backlight conditions.

[0033] (1) Comparison of physical property tests

[0034] Physical property tests were carried out on the samples of the examples and comparative examples. The stiffness was tested using a bending stiffness tester CV-8550S: The sample preparation process included: preparing 80*38 mm samples, with 3 pieces in the length direction parallel to the structure horizontal direction and 3 pieces in the length direction perpendicular to the structure; The experimental conditions included: a bending length of 50 mm and a bending angle of 15°; Test according to the operation method of the bending stiffness tester, test 3 groups, and find the average value. The experimental results are as Figure 3 shown.

[0035] (2) Optical test comparison

[0036] Optical tests were carried out on the examples and comparative examples: The liquid crystal screen of a TCL 65S11H TV was removed as the backlight module, and the center coordinate brightness and uniformity were tested using a spectral color brightness meter SRC-200S. The experimental conditions included: A 1.2 mm ordinary PS diffusion plate (hereinafter referred to as the lower diffusion) was placed on the backlight module. There was a certain distance from the internal LED light bar, and the sample was covered on it as the test structure. The lens was vertically close to the surface of the sample to test the coordinates and brightness; The center coordinates and brightness were tested by positioning the central position of the module. The coordinates and brightness of 9 positions as Figure 2 shown were tested respectively. The uniformity was calculated according to the formula: Uniformity = minimum brightness / maximum brightness * 100%.

[0037] The test results are as Figure 4 shown. The brightness uniformity measured by the PS board combined with the lower diffusion was 57.37%, and the brightness uniformity measured by the PET film combined with the lower diffusion was 57.06%. The central brightness of the PS micro prism brightness enhancement plate combined with the lower diffusion was 5860.2, which was higher than the central brightness of the PET micro prism brightness enhancement film combined with the lower diffusion, which was beneficial to presenting a better visual effect.

[0038] Through the above technical solutions, in the present application, the surface of the optical plastic plate used as the base material is microstructured by stamping, so that the microstructured layer has the same material as the base material layer. Under the same conditions, the front brightness is higher after refracting the light path, and the stiffness is higher, and it is not easy to wrinkle and bend, effectively reducing the light path loss. And when assembling the structure, there is no need to separately involve hanging ears, no need to coat optical resin and handle volatile substances, effectively reducing the production cost and assembly difficulty, and improving the production efficiency.

[0039] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present utility model. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present utility model. Therefore, the present utility model will not be limited to the embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. An optical brightening plate with a surface microstructure, characterized in that, Comprising: A base layer (1), wherein a microprism structure layer (2) is provided on the base layer (1); The microprism structure layer (2) is disposed on one end face of the base layer (1), and the microprism structure layer (2) is integrally formed by imprinting; The microprism structure layer (2) includes a plurality of groups of microprisms (21) arranged in parallel.

2. The optical brightening plate with surface microstructure according to claim 1, wherein The thickness of the base layer (1) is 0.2 - 0.5 mm.

3. The optical brightening plate with surface microstructure according to claim 1, characterized in that, The material of the base layer (1) is one of polymethyl methacrylate, polycarbonate, and polystyrene.

4. The optical brightening plate with a surface microstructure according to claim 1, wherein The bottom angles of the cross-section of the microprism (21) are equal.

5. The optical brightening plate with a surface microstructure according to claim 1, wherein The apex angle of the cross-section of the microprism (21) is greater than or equal to 90°.

6. The optical brightening plate with surface microstructure according to claim 1, characterized in that, The height of the microprism (21) is 20 - 100 μm.

7. A backlight module, characterized in that, An optical brightening plate according to any one of claims 1 to 6.

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