JPH02208632A - Manufacture of liquid crystal panel - Google Patents

Abstract

PURPOSE:To enable uniform orientation over the entire liquid crystal panel by rubbing the orienting films of substrates by using extremely thin fibers of <=0.5 denier in thickness and then charging liquid crystal between the two substrates which have the orienting films face to face. CONSTITUTION:Transparent electrodes 3 and 4 are formed on the two transparent glass substrates 1 and 2, cleaned, and applied with the orienting films 5 and 6. Then the orienting films 5 and 6 are rubbed by using the fibers 10 of <=0.5 denier. Spacers 7 are scattered on the surface of the substrates 1 where the orienting film 5 is formed and seal resin 8 is printed at the edge part of the surface of the glass substrate 5 where the orienting film is formed. Then the glass substrates 1 and 2 are stuck having the orienting films 5 and 6 face to face and the ferroelectric liquid crystal 9 is charged between the glass substrates 1 and 2. Consequently, fine surface processing is performed and the liquid crystal panel which is nondefective and has uniform orientation is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a liquid crystal panel used in a liquid crystal display device.

BACKGROUND ART When manufacturing a liquid crystal panel, it is necessary to impart uniaxiality in order to align liquid crystal molecules in one direction, and for this purpose it is necessary to perform alignment treatment on a glass substrate. As the orientation method, rubbing method, oblique evaporation method, magnetic field application method, electric field application method, etc. have been devised, but the rubbing method is the best in terms of mass production and practicality. Conventional rubbing methods include a method of directly rubbing the substrate, a method of rubbing after providing an inorganic film on the substrate, a method of rubbing after depositing a surfactant, a coupling agent, etc. on the substrate,
There is a method of coating a substrate with a polymer such as polyimide and then rubbing it.

Rayon, polyester, nylon, etc. are used as materials for rubbing cloth, and the fibers used are several deniers thick.

The reason why the liquid crystal molecules are uniformly aligned by the rubbing process is that
This is thought to be due to the formation of microgroups on the substrate surface (microgroup orientation) and because the polymer chains on the surface of the alignment film are easily aligned in one direction by rubbing treatment (polymer chain orientation). .

Problems to be Solved by the Invention However, compared to orientation by rubbing or orientation by oblique evaporation, line defects are more likely to occur and lack uniformity. This is thought to be due to the fact that the alignment obtained by rubbing is very rough, and the order parameter of the molecular arrangement is smaller than that obtained by oblique evaporation.

It is an object of the present invention to overcome these conventional drawbacks and to provide uniform orientation across the entire panel.

Means for Solving the Problems In order to solve the above problems, the present invention forms an alignment film on the main surface of each of two substrates, and provides fibers with a thickness of 0 on the alignment film of at least one of the substrates. After performing a rubbing process using ultrafine fibers of .5 denier or less, liquid crystal is sealed between two substrates whose surfaces with alignment films face each other.

Effects According to the present invention, since the rubbing treatment is performed using ultrafine fibers, fine surface treatment can be performed, and a liquid crystal panel that exhibits uniform alignment over the entire panel can be obtained.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. The liquid crystal panel shown in FIG. 3 is manufactured using the manufacturing process shown in FIG.

First, a transparent conductive film (I
Transparent electrodes 3 and 4 made of (TO film) are formed. After cleaning the glass substrates 1 and 2, polyimide resin is applied thereon as alignment films 6 and 6 using a spinner. Thereafter, a rubbing process is performed on the alignment films 6, 6 using fibers of various thicknesses. The fiber thickness is 1,5, 1,0, 0
, 5, and 0.2.005 denier are used. Here, the 2-ping process is a process in which a rubbing cloth 1o for rubbing is attached around a roller as shown in FIG. 1, and the glass substrate 1 is rubbed by sliding it in the direction of the arrow.

Examples of ultra-fine fibers with a fiber thickness of 0.5 denier or less include Microstar (manufactured by Teijin Ltd.) and Miracle Silan (manufactured by Teijin Ltd.).
(manufactured by Toshi Co., Ltd.), Zaguina Mini Max (manufactured by Kanebo Co., Ltd.), etc., and a nylon rubbing cloth of 1.0 denier or more is used. After the rubbing treatment, 8102 with a diameter of 2 μm is sprinkled as a spacer 7 on the surface of one glass substrate 1 on which the alignment film 5 is provided, and a sealing resin 8 is applied on the edge of the surface of the other glass substrate 2 on which the alignment film is provided. Both glass substrates 1 and 2 are coated with an alignment film 5.
, are pasted together so that the six faces are facing each other, and the sealing resin 8 is cured by heating. Thereafter, vacuum evacuation is performed, and ferroelectric liquid crystal 9 is injected between the two glass substrates 1 and 2. Furthermore, polarizing plates are attached to the glass substrates 1 and 2.

Table 1 shows the results of examining the contrast of liquid crystal display devices using six types of liquid crystal panels manufactured in this way.

As is clear from Table 1, it can be seen that the panel using the rubbing cloth with fiber thickness of 0.5 denier or less has high contrast and exhibits good orientation without defects. Furthermore, as a result of observing the alignment films 5 and 6 rubbed with this ultra-fine rubbing cloth using a scanning line electron microscope, micro groups were observed that were smaller than those formed by conventional thick fiber diameters. ,
A detailed rubbing process was performed.

In this embodiment, at least one of the glass substrates 1 and 2 needs to be transparent, and although polyimide is used as the alignment film, other materials may be used. That is, the effect of the rubbing treatment using ultrafine fibers was observed regardless of the type of alignment films 6, 6. Furthermore, the method for applying the alignment film is not limited to spin code, but may also be printing, and the type of liquid crystal is not limited to ferroelectric liquid crystal, but may also be nematic liquid crystal.

Effects of the Invention As is clear from the above explanation, according to the present invention, by performing a rubbing treatment using ultra-fine fibers with a fiber thickness of 0.5 denier or less, a fine surface treatment can be achieved, resulting in no defects. A liquid crystal panel exhibiting uniform alignment can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the state of rubbing treatment in a method for manufacturing a liquid crystal panel according to an embodiment of the present invention, FIG. 2 is a flowchart showing a manufacturing process in a method for manufacturing a liquid crystal panel according to an embodiment of the present invention FIG. 3 is a sectional view of a liquid crystal panel manufactured according to an embodiment of the present invention. 1.2...Glass substrate, 6,6...Alignment film, 9...Liquid crystal, 10...Rubbing cloth. Name of agent: Patent attorney Shigetaka Awano and 1 other person1-
7j last 1 & oath 3-・fi811 electricity amount

Claims (2)

[Claims] (1) Forming an alignment film on the main surface of each of the two substrates,
After that, the fiber thickness is 0 on the alignment film of at least one substrate.
．． A method for manufacturing a liquid crystal panel, which comprises performing a rubbing treatment using ultrafine fibers of 5 deniers or less, and then sealing liquid crystal between two substrates whose surfaces provided with alignment films face each other. (2) The method for manufacturing a liquid crystal panel according to claim 1, wherein the liquid crystal to be sealed is a ferroelectric liquid crystal.