JPS6347728A - Orienting method for liquid crystal display device - Google Patents

Abstract

PURPOSE:To minimize the electric charge of electrode substrates and to improve yield, quality stability and workability by subjecting the substrates to a rubbing treatment with a conductive material to orient the substrates. CONSTITUTION:This orienting method for a liquid crystal display device consists in sealing a liquid crystal material between at least two sheets of the electrode substrates which are provided with the electrodes and are subjected to the orientation treatment, and making prescribed display by impressing a voltage to the electrodes. The orientation treatment in said method is executed by subjecting the substrates to the rubbing treatment with the conductive material. A roller 11 is made of a metal such as SUS and a fork 11b for supporting the roller is formed of a metal as well and is grounded by a grounding lead 13. An example of a cloth 12 to be wound on the roll surface of the roller 11 is a cloth formed by weaving conductive monofilaments of acrylic fibers chemically bonded with copper to the cyano group thereof so as to have some cushion property.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a method for manufacturing a liquid crystal display, and is particularly applied to a method for aligning an electrode substrate in manufacturing a liquid crystal display.

(Prior Art) As shown in FIG. 2, a field-effect liquid crystal display has two electrode substrates 101, 101 that have been subjected to alignment treatment and are held with a substantially constant gap between them. It is constructed by sealing a liquid crystal compound between opposing surfaces.

This alignment treatment is essential for regularly aligning the molecules of the liquid crystal compound.
It has the effect of preventing deterioration of appearance quality and reduction of contrast when no voltage is applied to .... As the orientation treatment, the following methods are conventionally known.

(a) A so-called oblique evaporation method in which a thin film of silicon oxide or the like is formed by performing vacuum evaporation from an oblique direction on the main surface of an electrode substrate.

(b) A so-called rubbing method in which the surface of the electrode substrate (made of glass) is rubbed in one direction with cloth or paper.

(c) A method of applying a surfactant onto an electrode substrate.

However, method (b) above is simple and widely used. For this purpose, for example, there is a rubbing method using a brush as disclosed in Japanese Patent Laid-Open No. 55-13309.

Furthermore, for example, Japanese Patent Application Laid-Open No. 61-67022 discloses a method in which at least one of the alignment film or the rubbing material is coated with a conductive liquid and the liquid is grounded to perform rubbing. Ill. First, as shown in FIG. 4, a conductive liquid film 104 is deposited on the alignment film 103.

The base 105 on which the electrode substrate 101 is mounted is moved in the direction of the arrow A in the figure on the guide part 107 made of a conductive material and grounded (ground lead 106), and rubbed with a rotating roller 109 wrapped with rubbing material 108. This is a method of applying Furthermore, as shown in FIG. 5, the above method does not provide a conductive liquid film on the alignment film 103, but instead applies a film 114 to the rubbing material 108 wound around the rotating roller 109.
The alignment film 103 is rubbed. in this case,
The guide part 107 is also grounded and the roller 109 rotates once.
A grounding means (grounding lead 116) is provided on the rotating shaft 110 that supports this.

(Problems to be Solved by the Invention) The present invention solves the following problems with the rubbing method (b) of the above method.

The first problem with the rubbing method is that it is not elegant to rub the surface of the electrode substrate uniformly. In addition, cloth or paper is usually wrapped around a roller and rubbed while applying pressure, but the cloth or paper tends to deteriorate, causing problems such as uneven quality and poor productivity.

Next, in recent years, the display format of liquid crystal displays has become extremely fine.
During the rubbing alignment process, cloth and paper waste is generated, which is a major hindrance to display definition.

Furthermore, there is a serious problem in that static electricity generated during the rubbing process adversely affects the surface of the electrode substrate. This static electricity charge is 5000~c when velvet is used as the cloth.
The dust attracted by this charging becomes interposed between the electrode substrates 101 and 101 during the assembly process, resulting in defects and a decrease in yield.Next, when the electrode substrate is removed from the rubbing stage, discharge is caused. The discharge occurs at the transparent electrode 102.10 as shown by the dashed arrow in FIG.
Sparks are generated between the two, leaving a surface defect. This defect is fatal to the display, and if it is strong enough, it can also cause electrode breakage.

According to the technique disclosed in Japanese Patent Application Laid-open No. 61-67022, which takes measures against static electricity charging, the conductive material sprinkled on the alignment film remains on the film surface even after rubbing, impairing reliability and quality after assembly into a cell. There are some drawbacks. Further, even when a conductive substance is applied to a rubbing material wound around a rotating roller and subjected to rubbing, the conductive substance is transferred to the alignment film, which has the same negative effect as described above. Furthermore, when a liquid is used, post-treatment is required, and at least a drying process is required, resulting in a complicated process.

The present invention addresses the above-mentioned problems and provides a lapping treatment method that specifically takes measures against static electricity generated on an electrode substrate during rubbing treatment and does not leave any adverse effects on the product.

[Structure of the invention]

(Means for Solving the Problems) The alignment direction of the liquid crystal display according to the present invention is such that a liquid crystal substance is sealed between at least two electrode substrates provided with electrodes and subjected to alignment treatment, and a voltage is applied to the electrodes. The alignment treatment in manufacturing a liquid crystal display device that performs a predetermined display by applying is characterized in that it is performed by rubbing with a conductive material. .

(Function) According to the present invention, since the amount of charge generated on the electrode substrate by the rubbing treatment is significantly reduced, discharge between the electrodes and adsorption of dust can be prevented.

(Example) An example of the present invention will be described below with reference to FIG. In addition, in the description, parts that are the same as in the prior art are indicated by the same reference numerals as in the prior art in the drawings, and the description thereof will be omitted.

FIG. 1 shows a partial cross section of an alignment processing apparatus that performs alignment processing on an electrode substrate 111. The roller 11 is made of metal such as SUS, and the fork 1lb that supports it is also made of metal. It is grounded with a ground lead 13. The cloth 12 wound around the roll surface of the roller 11 is made of, for example, a conductive fabric made by chemically bonding copper to the cyano group of acrylic fibers, and woven with conductive fibers to provide some cushioning properties. *The electric voltage is very small (for example, 10
Abnormalities in the electrodes caused by voltage (less than 0 V) and defects due to dust were prevented, and the yield was improved by more than 30%. Also,
Since this cloth is woven from single fibers, there is no dust (short fibers) generated from the cloth itself.Furthermore, when the electrode substrate is in the form of a film, there is no clinging due to electrostatic charge, improving the efficiency of one work by 20 times. , and the yield improved as well. Note that during the rubbing process of the electrode substrate 101, the rubbing stage 100 (for example, SU
The effect will be further improved if the conductor (made of metal such as S) is also grounded with the ground lead 23.

〔Effect of the invention〕

By the rubbing treatment with the conductive material according to this invention,
The electrostatic charge on the electrode substrate, which was unavoidable with conventional technology, can be minimized, improving yield.

Stable quality 9. Has a remarkable effect on improving workability.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a rubbing device for explaining rubbing according to an embodiment of the present invention, FIG. 2 is a perspective view showing a partially cut away liquid crystal display, and FIG. 3 is a 4 and 5 are cross-sectional views of an apparatus for explaining conventional rubbing, respectively. 12------1 conductive material cloth 13, 23-m-ground lead 101--1--electrode substrate 102--1--transparent electrode 103--1--orientation film

Claims (1)

[Claims] In a method for aligning a liquid crystal display, in which a liquid crystal substance is sealed between at least two electrode substrates provided with electrodes and subjected to an alignment treatment, and a predetermined display is performed by applying a voltage to the electrodes, the alignment treatment A method for aligning a liquid crystal display, characterized in that the method is performed by rubbing with a conductive material.