JPS62272225A - Production of liquid crystal display device - Google Patents

Abstract

PURPOSE:To form a uniform orientation of a large tilt angle by electrostatically implanting pulverized particles of <=5mu diameter to the surface of a high-polymer resin coated on a substrate and subjecting the coating to a rubbing treatment. CONSTITUTION:The pulverized particles 3 electrified by a static electricity generator are penetrated into the high-polymer film 2 formed on the substrate 1 and the surface of the film 2 is subjected to the rubbing treatment to incline the pulverized particles 3 in one direction by which fine ruggedness is generated. The pulverized particles 3 having <=5mu diameter are implanted at 100 pieces/mm<2>. Liquid crystal molecules 4 are thus stably arranged in the specified direction at 0-20 deg. pretilt angle theta and are uniformly oriented at >=90 deg. twist angle thereof.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for manufacturing a liquid crystal display device, particularly to a method for forming an alignment layer.

[Conventional technology]

As a conventional method for forming an alignment layer of a liquid crystal display device, Si
Inclined vapor deposition method of n, Au, etc. (Japanese Patent Application Laid-open No. 17746/1983)
Alternatively, after coating a polyimide polymer resin on the substrate, rubbing it in a certain direction with cloth etc.
No. 525) etc.

[Problem that the invention seeks to solve]

However, although the above-mentioned tilted evaporation method is very advantageous in giving a predetermined pretilt angle to the liquid crystal, on the other hand, since it is a vacuum evaporation method, a high vacuum of about 10-” Torr is required.
In addition, since the substrate must be tilted, mass productivity is poor.

Furthermore, with the rubbing method, it is difficult to freely set the pretilt angle of the liquid crystal, especially to increase the pretilt angle.

The present invention is intended to solve these problems, and its purpose is to provide uniform alignment with a large tilt angle.

[Means for solving problems]

The method for manufacturing a liquid crystal display device according to the present invention includes a step of forming an alignment layer on a substrate, a step of applying a polymer resin on the substrate to form a polymer resin film, and a diameter of 5 μm on the surface of the polymer resin film. The step of electrostatically implanting fine particles as described below, and the step of rubbing the surface of the polymer resin coating in a certain direction with a cloth, or the step of forming the alignment layer on the substrate with a diameter of 5 μm or less. The method is characterized by comprising a step of applying a polymer resin into which fine particles have been incorporated, and a step of rubbing the surface of the polymer resin in a fixed direction with a cloth or the like.

[Effect]

The operation of the present invention will be explained based on FIG. A polymer resin is applied onto the substrate 1 to form a polymer coating 2, and the substrate is grounded.Next, the fine particles 3 are charged with an electrostatic generator and immersed in the polymer liquid 1) a2. (Fig. 1-fa+) Alternatively, a polymer resin into which fine particles are incorporated is applied onto the substrate 1 to form a polymer coating 2 (Fig. 1-fa+).
tb+)*Next, when the surface of the polymer film is rubbed in a certain direction with a cloth or the like, the fine particles 3 are tilted in one direction, producing fine irregularities, as shown in FIG. 1-1el. In this case, the size, density, and inclination of the uneven shape are determined by the size, amount, and rubbing pressure of the fine particles 3. A particle size range of 5 μm or less is desirable.

As a result of the above processing, the liquid crystal molecules 4 are stably aligned in a certain direction with a pretilt angle θ, as shown in Figure 1-(dl).
Using the present invention, the pretilt angle can be controlled in the range of about 0 to 20@.

[Example 1] After coating a polyimide-based polymer resin on a substrate on which a transparent electrode was patterned into a predetermined shape, 2.0 g of glass fiber with a diameter of 3 μm on the zero-order, on which a polyimide film was formed by heat treatment, was placed on the surface of the polyimide film. Then, rubbing treatment was performed in a fixed direction with a total pressure cuff of 0 kg using zero-order saran electrostatically implanted with an electrostatic generator to form an alignment layer. A liquid crystal was sandwiched between such substrates, and the pretilt angle of the liquid crystal was measured to be approximately 10°. Also, using the above substrate, super TN
When a type liquid crystal display device was constructed, a display having uniform alignment over the entire display area was obtained.

[Example 2] The pretilt angle of the liquid crystal was measured in the same manner as in Example 1 except that 2.0 g of glass fiber with a diameter of 4 μm was electrostatically implanted and the total pressure of the rubbing treatment was increased to 100 + r. 15'''. When a liquid crystal display device was constructed in the same manner as in Example 1, a display having uniform alignment over the entire display area was obtained.

[Example 3] Aj with a diameter of 2 pm! The pretilt angle of the liquid crystal was measured in the same manner as in Example 1, except that 4.0 g of xOs was electrostatically implanted and the total pressure of the rubbing treatment was 100 kir, and the result was about 10°. Further, when a liquid crystal display device was constructed in the same manner as in Example 1, a display having uniform alignment over the entire display area was obtained.

[Example 4] The same process as in Example 1 was carried out except that the total pressure of the rubbing process was 150 kg, and the pretilt angle of the liquid crystal was measured to be about 20@. Further, when a liquid crystal display device was constructed in the same manner as in Example 1, a display having uniform alignment over the entire display area was obtained.

[Example 5] A polyimide polymer resin in which 2.0 g of glass fiber with a diameter of 3 μm was kneaded was applied onto a substrate on which a transparent electrode was patterned into a predetermined shape, and then a polyimide film was formed by heat treatment. Using Saran, the total pressure cuff was rubbed at +r in a constant direction at 0 to form an alignment layer. A liquid crystal was sandwiched between such substrates, and the pretilt angle of the liquid crystal was measured to be approximately 5°. Further, when a liquid crystal display device was constructed in the same manner as in Example 1, a display having uniform alignment over the entire display area was obtained.

〔effect〕

As described above, according to the present invention, the step of forming an alignment layer includes a step of forming a polymer resin film on a substrate, a step of electrostatically implanting fine particles into the polymer resin film, and a step of electrostatically implanting fine particles into the polymer resin film. The step of forming the alignment layer consists of a step of rubbing the film in a certain direction, or a step of forming a polymer resin film in which fine particles are incorporated on the substrate, and a step of rubbing the polymer resin in a certain direction. By this process, the fine particles are tilted in a certain direction, forming fine irregularities, and the liquid crystal pretilt angle can be controlled in the range of 00 to 20@ without reducing mass production unlike the tilted deposition method. Therefore, even if the twist angle of the liquid crystal molecules is increased by 90° or more, stable and uniform alignment can be provided.

As a result, the present invention is particularly effective for large-scale display type liquid crystal display devices using birefringence mode, which has been attracting attention in recent years.

[Brief explanation of the drawing]

Fig. 1 +a+, +bl, (C1, +d+ are schematic diagrams showing the effects of the present invention. Fig. 2 is a cross-sectional view of a liquid crystal display device according to the present invention. l......Substrate 2・・・・・・・・・・・・Alignment layer 3・・・・・・・・・Fine particles 4・・・・・・・・・Liquid crystal molecules 4'... ......Liquid crystal layer 5...Transparent electrode 6...Sealant 7.7'...Polarizing plate or more Applicant: Seiko Epson Corporation (C') (Fig. 1)

Claims (2)

[Claims] (1) In a liquid crystal display device in which a liquid crystal is sandwiched between a pair of substrates each having a transparent electrode on the substrate and an alignment layer on the electrode,
The step of forming at least one of the alignment layers includes a step of applying a polymer resin on at least the substrate, and a step of electrostatically implanting fine particles having a diameter of 5 μm or less onto the surface of the polymer resin.
and a rubbing process. (2) Claims characterized in that the step of forming the alignment layer consists of at least a step of applying a polymer resin into which fine particles with a diameter of 5 μm or less are incorporated onto the substrate, and a step of performing a rubbing treatment. 2. A method for manufacturing a liquid crystal display device according to item 1.