TWI459084B - Diffusion sheet and method for making same - Google Patents

Description

Diffuser and manufacturing method thereof

The present invention relates to the field of backlight modules, and in particular, to a diffusion sheet and a method of fabricating the same.

The backlight module is one of the key components of the LCD panel. Since the liquid crystal itself cannot emit light by itself, the main function of the backlight module is to provide a light source with sufficient brightness and uniform distribution for the liquid crystal panel. The basic principle is to convert the commonly used point light source or linear light source into high brightness and uniform brightness through the optical mechanism. Surface light source products.

The backlight module can be divided into a direct type and a side light type according to its configuration. For these two backlight modules, in order to effectively eliminate the phenomenon of light and dark staggered or dot, a diffusing film must be disposed above the light guide plate to homogenize the light to provide a uniform surface light source for the LCD panel.

The conventional diffusion film is coated on a transparent substrate with a resin binder and chemical particles as diffusion particles to form a diffusion layer. When the light passes through the diffusion layer, the refractive index is different to cause refraction, reflection and scattering, which can be effectively diffused. Light, which in turn achieves the effect of light homogenization. However, the optical diffusion particles are not easily uniformly dispersed in the solvent-type resin, and a large-scale baking resin device is required in mass production, and the cost is high.

In view of the above, it is necessary to provide a diffusion sheet having a lower mass production cost and a method of manufacturing the same.

A diffusion sheet comprising a light transmissive substrate, a diffusion layer formed on the light transmissive substrate, wherein the diffusion layer is a titanium dioxide film layer having a porous structure.

A method for manufacturing a diffusion sheet, comprising the steps of: providing a transparent substrate and a titanium n-butoxide solution; coating the titanium n-butoxide solution on the transparent substrate by a sol-gel method to form a porous A diffusion layer of a titanium dioxide film.

Compared with the prior art, the titanium dioxide film layer prepared by the sol-gel method is used as a diffusion layer, and does not require a large baking equipment, and the mass production cost is low.

100‧‧‧Diffuser

20‧‧‧Transmissive substrate

40‧‧‧Diffusion layer

1 is a cross-sectional view of a diffusion sheet according to an embodiment of the present invention.

2 is a schematic flow chart of a method for manufacturing a diffusion sheet according to an embodiment of the present invention.

The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

Referring to FIG. 1 , an embodiment of the present invention provides a diffusion sheet 100 including a light transmissive substrate 20 , a diffusion layer 40 formed on the light transmissive substrate 20 , and the diffusion layer 40 having a porous structure. Titanium dioxide film layer.

The material of the transparent substrate 20 is polymethyl methacrylate (PMMA), polycarbonate (Polycarbonate, PC) or polyethylene terephthalate (PET). In the example, the material of the light-transmitting substrate 20 is made of PET. The light transmissive substrate 20 has a thickness of from 10 micrometers to 250 micrometers.

In the porous structure of the titanium dioxide film layer, the pores (not shown) have a spherical shape, and the pores have a diameter of 50 to 200 nm. The diffusion layer 40 has a thickness of 50 to 250 nm.

Referring to FIG. 2, an embodiment of the present invention provides a method for fabricating the diffusion sheet 100, which includes the following steps:

In the first step, a light transmissive substrate and a titanium n-butoxide solution are provided.

In the second step, the titanium n-butoxide solution is coated on the light-transmissive substrate by a sol-gel method to form a diffusion layer of a porous titania film.

The solvent of the titanium n-butoxide solution is n-propanol, and the concentration ratio of the titanium n-butoxide to n-propanol is 1:10. The principle of the sol-gel method is to apply a titanium n-butoxide solution to the surface of the light-transmitting substrate 20, and the surface of the transparent substrate 20 is gelled by hydrolysis and polycondensation, and then dried to obtain a porous titanium dioxide film. Diffusion layer 40. The coating method may be a centrifugal spinning method, an immersion pulling method or a sputtering method. In this embodiment, the coating method is an immersion pulling method; a chemical reaction such as hydrolysis or polycondensation is carried out in a water vapor atmosphere having a humidity of 30% to 50%; and the drying temperature is 25 to 80 degrees Celsius.

The diffusion layer 40 is a uniform and dense porous titanium dioxide film layer, so that when the light passes through the film layer, the light is reflected in the film pores, and the light is uniformly diffused.

Compared with the prior art, the titanium dioxide film layer prepared by the sol-gel method is used as the diffusion layer 40, and does not require a large baking equipment, and the mass production cost is low.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

100‧‧‧Diffuser

20‧‧‧Transmissive substrate

40‧‧‧Diffusion layer

Claims (2)

A method for manufacturing a diffusion sheet, comprising the steps of: providing a transparent substrate and a titanium n-butoxide solution; coating the titanium n-butoxide solution on the transparent substrate by a sol-gel method to form a porous a diffusion layer of the titanium dioxide film, the material of the light-transmitting substrate is polymethyl methacrylate, polycarbonate or polyethylene terephthalate, and the solvent of the titanium n-butoxide solution is n-propanol, the positive The concentration ratio of titanium butoxide to n-propanol is 1:10, and the drying temperature in the sol-gel method is 25 to 80 degrees Celsius. The method for producing a diffusion sheet according to the first aspect of the invention, wherein the coating method is a centrifugal rotation method, an immersion pulling method or a sputtering method.