JPH02275926A - Orienting film forming device for liquid crystal cell - Google Patents

Abstract

PURPOSE:To preclude a dielectric breakdown and the sticking of foreign matter due to the accumulation of static electricity and to improve the manufacture yield of liquid crystal cells by forming rubbing cloth of a conductive material, adhering this rubbing cloth to the outer periphery of a roller with a conductive adhesive material, and grounding the roller where the rubbing cloth is adhered through a resistor. CONSTITUTION:While the roller 2 wound with the rubbing cloth 8 is pressed against the surface of a transparent substrate 1 as shown by the arrow, the roller 2 or a stage 5 is moved. Consequently, the surface of an orienting film 1' on the transparent substrate 1 oriented and liquid crystal which is charged between substrates is oriented by this orienting film. At this time, the rubbing cloth 8 and its adhesive material 9 are conductive, so static electricity generated between the rubbing cloth 8 and orienting film 1' is not accumulated. Further, the roller 2 is grounded through the series circuit of a bearing plate 4 and a resistor 7 with a specific resistance value, so an excessive current due to the static electricity never flows through the surface of the substrate. Consequently, the liquid crystal orienting film is not broken electrostatically and the manufacture yield of liquid crystal cells can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an alignment film forming apparatus for a liquid crystal cell that forms an alignment film by a lahing process.

[Conventional technology]

Each liquid crystal cell of a liquid crystal display device has a structure in which a liquid crystal element is sealed between two transparent substrates, usually glass plates, and a transparent electrode and a protective film are provided inside each transparent substrate. In addition, an alignment film is formed on the surface of the substrate. FIG. 2 is a configuration diagram showing the main parts of a conventional alignment film forming apparatus for forming an alignment film on the inner surface of this transparent substrate. In the figure, 1 is a transparent substrate constituting a liquid crystal cell, 2 is a roller with a rubbing cloth 3 adhered to its outer periphery, and is grounded via a bearing plate 4, and the rubbing cloth 3 is made of an insulating material. 5 is a stage that supports the transparent substrate 1.

Further, FIG. 3 is a diagram showing details of the roller 2 to which the rubbing cloth 3 is adhered. The rubbing cloth 3 is adhered to the outer periphery of the roller 2 with an adhesive tape 6, and the adhesive tape 6 is made of an insulating material.

In the alignment film forming apparatus as described in L, the rubbing cloth 3
The roller 2 wrapped around the transparent substrate 1 is pressed against the surface of the transparent substrate 1 with a predetermined pressure, and the roller 2 or the stage 5 is moved in this state. As a result, a liquid crystal alignment film is formed on the surface of the transparent substrate 1.

[Problem to be solved by the invention]

However, in the conventional alignment film forming apparatus as described above, static electricity generated between the rubbing cloth and the transparent substrate is accumulated on both, resulting in damage to the alignment film and foreign matter adhering to the substrate. However, there was a problem in that the manufacturing yield decreased.

In other words, static electricity is generated when the rubbing cloth and transparent substrate are rubbed together, but at this time, since the rubbing cloth and adhesive tape are made of insulating materials, static electricity accumulates on both, and the accumulated static electricity ( If the charge) moves rapidly, an excessive current flows across the substrate surface, destroying the alignment film.

As a result, the liquid crystal is not oriented and the liquid crystal cell becomes an optical point defect.

In addition, the accumulated static electricity causes foreign matter such as rubbing cloth hair and dust to gather on the substrate, which causes problems such as gap defects.

This invention was made in view of these problems, and provides an alignment film forming apparatus for liquid crystal cells that prevents electrostatic damage due to accumulation of static electricity and adhesion of foreign matter, and improves the manufacturing yield of liquid crystal cells. The purpose is to obtain.

[Means to solve the problem]

The alignment film forming apparatus for a liquid crystal cell of the present invention is an alignment film forming apparatus that forms an alignment film on the surface of a substrate using a roller having a rubbing cloth adhered to its outer periphery. is adhered to the outer periphery of the roller using a conductive adhesive material, and the roller to which this rubbing cloth is adhered is grounded via a resistor, and the resistance value of the resistor is set to 100 to 109Ω. .

(Function) In the liquid crystal cell alignment film forming apparatus of the present invention, since the rubbing cloth and its adhesive have conductivity, static electricity generated between the rubbing cloth and the substrate is not accumulated. Also, since the roller wrapped with rubbing cloth is grounded via a resistor, an excessive current will not flow across the substrate surface.

〔Example〕

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, 1 is a transparent substrate to be aligned, 2 is a roller, and 4
is its bearing plate, and the roller 2 is connected to this bearing plate 4 by 100~1
It is grounded via a resistor 7 having a resistance value of 0.09Ω. A stage 5 supports the transparent substrate 1, and is grounded at one end. A rubbing cloth 8 is bonded to the outer periphery of the roller 2 and is made of a conductive material. Reference numeral 9 denotes a conductive adhesive (adhesive) material that adheres the rubbing cloth 8 to the outer periphery of the roller 2.

Note that, as the adhesive material 9, the following materials can be used, for example.

(a) "High-performance double-sided conductive tape" manufactured by Sumitomo 3M Limited (Development number X-7001) (b) "Conductive double-sided adhesive tape" manufactured by Teraoka Seisakusho Co., Ltd. (Tape No.
, 774 or 791) In the alignment film forming apparatus configured as described above, the roller 2 or the stage 5 is pressed against the surface of the transparent substrate 1 in the direction of the arrow, with the roller 2 wrapped with the rubbing cloth 8 pressed in the direction of the arrow as in the conventional case. Don't move.

As a result, an alignment film is formed on the surface of the transparent substrate 1, and the liquid crystal sealed between the substrates is oriented by this alignment film.

At this time, since the rubbing cloth 8 and its adhesive material 9 have conductivity, static electricity generated between the rubbing cloth 8 and the substrate 1 is not accumulated. Furthermore, since the roller 2 is grounded through a series circuit of a bearing plate 4 and a resistor 7 having a resistance value of 100 to 10<9 >[Omega], excessive current due to static electricity will not pass through the substrate surface. Therefore, the liquid crystal alignment film is not dielectrically broken down, and the manufacturing yield of liquid crystal cells is improved.

In addition, since there is no accumulation of static electricity as in the conventional case, foreign matter such as hair or dust from the rubbing cloth 8 does not adhere to the substrate, preventing defects such as gap defects, and improving the manufacturing yield of liquid crystal cells. will further improve.

〔Effect of the invention〕

As described above, according to the present invention, the rubbing cloth is formed of a conductive material, the rubbing cloth is adhered to the outer periphery of the roller with a conductive adhesive material, and the roller is grounded via a resistor. Static electricity generated between the cloth and the substrate is not accumulated, preventing electrostatic damage to the alignment film and foreign matter from adhering to the substrate, which has the effect of improving the manufacturing yield of liquid crystal cells. .

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a block diagram showing the main parts of a conventional device, and Fig. 3 is a detailed diagram of a roller with the rubbing cloth of Fig. 2 adhered to its outer periphery. . 1... Transparent substrate 2... Roller 4... Bearing plate 5... Stage 7... Resistor 8... Rubbing cloth 9...adhesive material

Claims (2)

[Claims] (1) In an alignment film forming apparatus that forms an alignment film on the surface of a substrate using a roller with a rubbing cloth bonded to its outer periphery, the rubbing cloth is formed of a conductive material, and the rubbing cloth is bonded to the roller with a conductive adhesive material. An apparatus for forming an alignment film for a liquid crystal cell, characterized in that a roller having a rubbing cloth adhered to its outer periphery is grounded via a resistor. (2) The apparatus for forming an alignment film for a liquid crystal cell according to claim 1, wherein the resistance value is a resistance value of 10^0 to 10^9 Ω.