阅读说明：本技术 用于光扩散膜的基膜、光扩散膜、显示装置及其制备方法 (Base film for light diffusion film, display device and preparation method thereof ) 是由 钟席红 杨勇 赵士军 金玉姣 龚钰 于 2019-09-29 设计创作，主要内容包括：本公开提供一种用于光扩散膜的基膜,所述基膜具有：透明聚合物层,所述透明聚合物层具有多个纳米微孔；和填充在所述多个纳米微孔中的液晶。本公开还提供了光扩散膜、显示器件、及它们的制备方法。(The present disclosure provides a base film for a light diffusion film, the base film having: a transparent polymer layer having a plurality of nanopores; and liquid crystal filled in the plurality of nano-pores. The present disclosure also provides a light diffusion film, a display device, and methods of making the same.)

1. A base film for a light diffusion film, the base film comprising:

a transparent polymer layer having a plurality of nanopores; and

liquid crystal filled in the plurality of nano-pores.

2. The base film according to claim 1, wherein the transparent polymer is a polyethylene terephthalate-based material.

3. The base membrane of claim 1, wherein the nanopores have a pore size in the range of 50-100 microns.

4. The base film of claim 1, wherein the nanopores in the base film have a porosity in the range of 10-50%.

5. A light diffusing film for homogenizing light emitted by a light source in a display device, the light diffusing film comprising:

the base film of claim 1;

a light diffusion layer on one side of the base film; and

a transparent printed circuit layer on the other side of the base film.

6. The light diffusion film according to claim 5,

the light diffusion layer is silica particles or microprisms.

7. The light diffusion film of claim 5, wherein the light diffusion film further comprises a transparent circuit protective coating.

8. The light diffusion film of claim 7, further comprising a transparent adhesive layer on the transparent circuit protective coating.

9. A display device comprising a display panel, a backlight, and the light diffusion film according to claim 5.

10. A method of making the base film of claim 1, the method comprising:

bombarding a transparent polymer layer with particles, optionally etching the bombarded transparent polymer layer with an alkaline solution to form a plurality of nanopores;

filling liquid crystal into the plurality of nano-pores.

11. The method of claim 10, wherein the alkali solution is a NaOH solution.

12. A method of making a light diffusing film for homogenizing light emitted by a light source in a display device, the method comprising:

preparing a base film by the method of claim 10;

forming a light diffusion layer on one side of the base film; and

and forming a transparent printed circuit layer on the other side of the base film.

13. The method of claim 12, wherein,

the transparent polymer is polyethylene terephthalate material, and

the light diffusion layer is formed by depositing silica particles or forming silica microprisms.

Technical Field

The disclosure relates to the field of light diffusion films, in particular to a base film for a light diffusion film, a display device and a preparation method of the display device.

Background

Currently, in a display device using a backlight unit, light emitted from the backlight unit is made more uniform by using a light diffusion film. The structure of the light diffusion film is generally a two-layer structure including a base film and a light diffusion layer formed on a surface of the base film.

A transparent polymer such as polyethylene terephthalate (PET) based material has been used as a base film of the light diffusion film. However, the transparent polymer base film has a characteristic of being easily warped, thereby affecting a display effect.

In addition, after the base film material of the light diffusion film is determined, the light transmittance is also determined. Can not be regulated according to the actual display requirement.

There is still a need for improvement in the base film for a light diffusion film.

Disclosure of Invention

In one aspect, the present disclosure provides a base film for a light diffusion film, the base film comprising:

a transparent polymer layer having a plurality of nanopores; and

liquid crystal filled in the plurality of nano-pores.

Optionally, the transparent polymer is a polyethylene terephthalate based material.

Optionally, the nanopores have a pore size in the range of 50-100 a.

Optionally, the nanopores in the base membrane have a porosity in the range of 10-50%.

In another aspect, the present disclosure provides a light diffusing film for homogenizing light emitted from a light source in a display device, the light diffusing film comprising:

the base film as described above;

a light diffusion layer on one side of the base film; and

a transparent printed circuit layer on the other side of the base film.

Optionally, the light diffusion layer is silica particles or microprisms.

Optionally, the light diffusion film further comprises a transparent circuit protection coating.

Optionally, the light diffusion film further comprises a transparent adhesive layer on the transparent circuit protection coating layer.

In yet another aspect, the present disclosure provides a display device comprising a display panel, a backlight, and the light diffusion film as described above.

In yet another aspect, the present disclosure provides a method of making a base film as previously described, the method comprising:

bombarding a transparent polymer layer with particles, optionally etching the bombarded transparent polymer layer with an alkaline solution to form a plurality of nanopores;

filling liquid crystal into the plurality of nano-pores.

Alternatively, the alkali solution is a NaOH solution.

In yet another aspect, the present disclosure provides a method of preparing a light diffusion film for homogenizing light emitted from a light source in a display device, the method comprising:

preparing a base film by the above method;

forming a light diffusion layer on one side of the base film; and

and forming a transparent printed circuit layer on the other side of the base film.

Optionally, the transparent polymer is a polyethylene terephthalate-based material, and

the light diffusion layer is formed by depositing silica particles or forming silica microprisms.

Drawings

Figure 1 schematically illustrates a method of one embodiment of the present disclosure.

Fig. 2 shows a light diffusion film of an embodiment of the present disclosure.

Fig. 3 schematically illustrates a light diffusion film according to another embodiment of the present disclosure.

Fig. 4 schematically shows a manner of fitting a light diffusion film of another embodiment of the present disclosure to a backlight.

Detailed Description

The light diffusion film typically consists of a transparent polymer base film and a transparent light diffusion layer on the polymer base film. The polymer-based film is mainly used to support the light diffusion layer. The light diffusion layer is typically a microstructure made of a transparent material having a specific refractive index, for example a granular transparent material layer. In the current field of light diffusion films, polyethylene terephthalate films are commonly used transparent polymer-based films.

However, one characteristic of such a light diffusion film is that warping easily occurs, and thus the display effect is affected.

The present disclosure proposes a base film for a light diffusion film, the base film including:

a transparent polymer layer having a plurality of nanopores; and

liquid crystal filled in the plurality of nano-pores.

The base film of the present disclosure includes a transparent polymer layer having a plurality of nano-pores. The inventors of the present disclosure found that warping of the base film can be effectively prevented by introducing nano-micro pores in the transparent polymer layer. Without being bound by any theory, this may be due to the presence of the nano-pores physically micro-damaging the transparent polymer layer, thereby reducing intermolecular van der waals forces in the transparent polymer layer, thereby preventing warping. In this way, the light diffusion layer prepared from the base film of the present disclosure is less prone to warping, and finally, a good display effect is obtained.

The base film host material of the present disclosure can be any suitable transparent polymer. From the viewpoint of display performance, the higher the light transmittance of the transparent polymer, the better. In the present disclosure, an example in which a polyethylene terephthalate-based material is often used as a base film main body material is illustrated. The polyethylene terephthalate-based material refers to a polyethylene terephthalate-based material, and may include polyethylene terephthalate and modified polyethylene terephthalate of various molecular weights. PET-based materials have been used for the preparation of conventional light diffusion films at present because of their high light transmittance. PET-based materials are preferred base film host materials. The present disclosure is not particularly limited to specific properties of the PET-based material as long as it is suitable for supporting the light diffusion layer.

Nano-pores are nano-scale pores in a transparent polymer layer. The micro-holes may be through holes or not. The nano-pores have two roles in the present disclosure, one of preventing warpage of the base film as described above and the other of accommodating liquid crystals as described in detail below.

The nano-micropores are filled with liquid crystal. The liquid crystal on one hand complements the space of the nanometer micropores and on the other hand endows the base film with variable light transmittance.

It is well known that liquid crystal materials can be turned by an electric field to change optical properties. Therefore, the liquid crystal can be optically switched by the electric field. The liquid crystal may be classified into nematic (nematic) liquid crystal, smectic (cholesteric) liquid crystal, cholesteric (cholesteric) liquid crystal, and the like. When the liquid crystal is filled in the nano-micropores, the light transmittance of the base film can be different from that of the pure transparent polymer layer, and the light transmittance of the base film can be further adjusted in real time through an external electric field. Cholesteric liquid crystals are preferably used.

The pore size of the nanopores may be in the range of 50-100 microns. If the aperture is less than 50 microns, the liquid crystal filling and light modulation effects are poor; if the aperture is larger than 100 micrometers, the liquid crystal module may have a granular sensation, which affects the display effect of the picture.

The nanopores may have a porosity in the range of 10-50%. The advantage of this range is. The porosity determines to some extent the content of liquid crystals in the base film. When the porosity is lower than 10%, the improvement effect of the liquid crystal on warping and light transmittance is not obvious; when the porosity is higher than 50%, it is not preferable to form a diffusion layer in the light diffusion film.

The base film for a light diffusion film of the present disclosure does not warp and light transmittance can be adjusted.

The present disclosure also provides a light diffusion film for homogenizing light emitted from a light source in a display device, the light diffusion film comprising:

the base film as described above;

a light diffusion layer on one side of the base film; and

a transparent printed circuit layer on the other side of the base film.

The function of the light diffusion layer is to uniformly scatter light emitted from the backlight. The light diffusion layer is positioned on one side of the base film and is positioned on the opposite side of the base film from the backlight source when installed in the backlight module. When light emitted from the backlight exits from the light diffusion layer, it becomes more uniform.

The light diffusion layer is made of a transparent material and has a specific microstructure. For example, the light diffusion layer may be particles or microprisms.

The transparent printed circuit layer is used to apply an electric field to the base film to adjust the light transmittance of the liquid crystal in the base film.

The light diffusion layer may be silica particles or microprisms. Silica is easy to form a light diffusion layer and is well matched with polyethylene terephthalate base materials in optical and mechanical properties.

The light diffusing film may further include a transparent circuit protection coating. Transparent circuit protective coatings are used to protect the circuit.

The light diffusion film may further include a transparent adhesive layer as long as the light diffusion effect is not affected. The transparent adhesive layer is used for assembling the light diffusion film to the backlight module. In order to facilitate storage, the transparent adhesive agent layer can be covered with a release layer.

The present disclosure also provides a display device including a display panel, a backlight, and the light diffusion film as described above.

The use of light diffusing films in conjunction with backlights is known in the art. For example, a light guide plate and a bottom reflection sheet may be provided on the opposite side of the diffusion film from the light diffusion layer, and light emitted from the backlight is made incident from the side of the light guide plate and finally emitted uniformly from the light diffusion layer side of the light diffusion film.

The present disclosure also provides a method of making a base film as previously described, the method comprising:

bombarding a polyethylene terephthalate material layer with particles, and optionally corroding the bombarded polyethylene terephthalate material layer with an alkali solution to form a plurality of nano micropores;

filling liquid crystal into the plurality of nano-pores.

The present disclosure employs mechanical means or a combination of mechanical and chemical means to form nanopores in a transparent polymer layer.

Purely mechanical means can be used to form the nanopores. Specifically, the particles are accelerated using a high-velocity gas or explosion to obtain high-velocity particles, and the transparent polymer layer is bombarded with the high-velocity particles to form nano-pores in the transparent polymer layer.

The particles of the present disclosure are fine particles that can cause micro-damage to the transparent polymer layer. Particles that can be used include fine particles having a high hardness such as silica particles. The appropriate size of the particles is related to their bombardment rate and the desired pore size to be obtained, and is not particularly limited herein.

Alternatively, the particles are first accelerated using a high velocity gas or explosion to obtain high velocity particles that bombard the transparent polymer layer, forming sub-nanometer scale micro-pits on the transparent polymer layer. Subsequently, the transparent polymer layer having the micro-pits is treated with an alkali solution. The transparent polymer layer is not resistant to strong bases. When the transparent polymer layer is treated with an alkali solution, the etching rate at the micro-pits is higher than that of a flat surface, and thus nano-micro pores are formed. Preferably, the alkali solution is a NaOH solution.

The formation of the nano-pores destroys the van der waals force between the polyethylene terephthalate molecules, so that the polyethylene terephthalate material film does not warp.

Finally, the nano-pores are filled with liquid crystal in a suitable manner. An example of the filling method may be a dropping method.

The present disclosure also provides a method of preparing a light diffusion film for homogenizing light emitted from a light source in a display device, the method comprising: preparing a base film by the above method; forming a light diffusion layer on one side of the base film; and forming a transparent printed circuit layer on the other side of the base film.

The light diffusion film is formed by the above method. The transparent circuit may be printed on the polymer layer in a conventional manner, and the light diffusion layer may be formed on the base film in a conventional manner.

Preferably, the transparent polymer is a polyethylene terephthalate-based material, and the light diffusion layer is formed by depositing silica particles or forming silica microprisms. Silica is easy to form a light diffusion layer and is well matched with polyethylene terephthalate base materials in optical and mechanical properties.

The technical scheme of the disclosure is further illustrated by the attached drawings and the embodiment.

Figure 1 schematically illustrates a method of one embodiment of the present disclosure. First, a polyethylene terephthalate layer is provided. And (3) performing particle bombardment on the polyethylene terephthalate layer to obtain the polyethylene terephthalate layer with nano micropores. Filling liquid crystal material into the polyethylene terephthalate layer with the nanometer micropores, and coating upper and lower protective coatings. Subsequently, a transparent circuit is printed on one side. An underlying protective coating is applied under the transparent circuit. And the opposite side of the polyethylene terephthalate layer was coated with diffusing particles. Thus, a light diffusion layer was produced.

Fig. 2 shows a light diffusion film of an embodiment of the present disclosure. Wherein the light diffusion layer is composed of silica diffusion particles.

Fig. 3 schematically illustrates a light diffusion film according to another embodiment of the present disclosure. Wherein, the light diffusion layer is composed of silicon dioxide micro prisms.

Fig. 4 schematically shows a manner of fitting a light diffusion film of another embodiment of the present disclosure to a backlight. The LED backlight source enters from the side face, passes through the light diffusion film under the action of the light guide plate and the bottom reflector plate, namely sequentially passes through the transparent printed circuit layer, the polyethylene terephthalate base film layer and the light diffusion layer, and finally is uniformly emitted.