JPH05333349A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To uniformly maintain a cell thickness even if mechanical and electrical forces act on the cell and to prevent the degradation in quality by spraying hard plastic beads on the insulating film of one substrate and baking the beads, thereby fixing the beads as the spacers in the cell. CONSTITUTION:The insulating film 4 is provided on the upper substrate 2 provided with transparent electrodes 3 and the hard plastic beads 5 are sprayed on the insulating film 4 by a solvent consisting of a liquid mixture composed of alcohol and water and are baked at a prescribed temp. An oriented film 6 is thereafter formed, baked and subjected to an orientation treatment by rubbing. The upper and lower substrates 2, 2 are stuck to each other and a liquid crystal material 8 is injected therebetween. Namely, the uniform cell gap is obtd. by using the hard plastic beads 5. Since the hard plastic beads 5 are fixed by the insulating film 4 and are provided only on the one side substrate 2 and, therefore, there is no need for a special adhesive in the stage and the clouding of the insulating film is obviated. In addition, the movement of the plastic beads by the mechanical and electrical stresses does not arise.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is for measuring liquid crystal televisions, digital clocks, personal word processors, etc.
The present invention relates to a liquid crystal element used for a display device of office automation (hereinafter referred to as OA) equipment.

[0002]

2. Description of the Related Art As shown in FIG. 2, a conventional liquid crystal display device A'has a pair of glass substrates or acrylic or epoxy plastic substrates 2 with plastic beads 5 formed by molding an adhesive resin in a spherical shape as spacers. The structure was fixed inside or the spacer was not fixed to the glass substrate or the plastic substrate. Further, spacers are formed by printing by mixing the plastic beads with the orientation material. In the figure, 3 is a transparent electrode, 4 is an insulating film, and 6
Is an alignment film, 7 is a sealing material, and 8 is a liquid crystal material. The cell is a small chamber surrounded by the alignment film 6 and the sealing material 7.

In the structure in which the plastic beads 5 are fixed to the glass substrate 2 as a spacer, the hardness of the plastic beads 5 is low and it is difficult to obtain a uniform particle size distribution as a spacer.
Therefore, it is difficult to obtain a uniform cell gap of the liquid crystal display element A ′, and variations in color tone increase. Further, the plastic beads 5 which have a large plastic deformation at a high temperature and are spherical at a low temperature, that is, the plastic beads 5, cannot endure the thermal expansion of the liquid crystal in the cell at a high temperature, become a vertically long shape, and are returned to a low temperature again. Since the vertically long shape is maintained, even if the cell expanded at a high temperature is returned to a low temperature, the inside of the cell remains in a decompressed state and bubbles are generated.

In the structure in which the spacer of the plastic beads is not fixed to the glass substrate or the plastic substrate 2,
The spacer moves due to electrical and mechanical stress,
There are problems that the cell thickness is changed, the display quality is remarkably deteriorated due to local concentration of the spacers, or the alignment surface is damaged when the spacers are moved.
Further, it is impossible to obtain a uniform dispersion of the plastic beads by a method of forming a spacer by mixing and printing the plastic beads in the orientation material.

[0005]

The problem to be solved by the present invention is that the liquid crystal display element of the prior art has a color tone especially for measurement under an environment where various mechanical and electrical external stresses are applied and for use as an OA device. Therefore, it is difficult to obtain a uniform and high-quality liquid crystal display device due to various problems such as dispersion of liquid crystal and generation of bubbles.

[0006]

According to the present invention, a liquid crystal display device is constructed by printing an insulating film on one of a pair of substrates, spraying hard plastic beads on the insulating film and fixing the beads by baking. It is characterized by.

[0007]

[Function] By scattering the hard plastic beads on one insulating film and fixing the beads with the alignment film,
The beads are always in a fixed position even when a mechanical or electrical external force is applied, and the cell thickness of each part is kept uniform to prevent deterioration of quality.

[0008]

EXAMPLE FIG. 1 is a schematic view showing an example of the liquid crystal display element A of the present invention. The flow of the manufacturing process of the liquid crystal display element A is as follows: Substrate 2 (upper substrate in the figure)
Printing the insulating film 4 composed mainly of Ti (titanium) -Si (silicon),
Immediately after the hard plastic beads 5 were sprayed on the printed insulating film 4 with a solvent composed of a mixture of alcohol and water, calcination was performed at 70 ° C. for 1 minute on a hot plate. After that, UV (ultraviolet) irradiation of 4 J / cm ² is performed at 150 ° C.
The main firing was performed for 1 hour. Further, an alignment film 6 having a basic skeleton of thermoplastic polyether amide is printed, calcination is performed on a hot plate at 70 ° C for 1 minute, and then at 150 ° C for 1.5.
After the main firing for a certain period of time, an alignment treatment was performed by a rubbing method, the upper and lower substrates 2, 2 ′ were bonded together, and the liquid crystal material 8 was injected. 7 is a sealing material.

Here, the main curing temperature for bonding is 140
The temperature is lower than the baking temperature of the insulating film or the alignment film in ° C. 0.4mm thick for acrylic and epoxy substrates,
The thickness of the glass substrate is 0.7 mm, and the plastic beads 5
Has a particle size of 6 μmφ.

The operation of the liquid crystal display element A according to the above flow is such that a uniform cell gap is obtained because the hard plastic beads are used, and the variation in the color tone of the cells is eliminated. Since the material is fixed and provided by the insulating film, the insulating film does not absorb moisture and become cloudy during the process, and the pair of substrates 2 and 2'is not adhered to each other. Does not occur. No special adhesive is required to fix the hard plastic beads, it can be sprayed with a solvent containing water, and the dispersibility of the plastic beads is very good and mechanical compared to the method of printing by mixing with the alignment material. , Does not move due to electrical stress.

[0011]

The liquid crystal display device of the present invention having the structure and operation as described above is fixed to only one of the pair of substrates by using the hard plastic beads and is used as the spacer in the cell. By providing the liquid crystal display element, it is possible to prevent movement of the spacer in the cell due to mechanical or electrical external stress, and to destroy the alignment film by the conventional movement.
Fluctuation of cell thickness, deterioration of display quality due to aggregation of spacers,
It became possible to solve problems such as the generation of bubbles, and it was possible to obtain a high-quality liquid crystal display element, particularly showing excellent effects in a display element in which the substrate is soft and the in-cell spacer is easy to move.

[Brief description of drawings]

FIG. 1 is a schematic view of a liquid crystal display element.

FIG. 2 is a schematic view of a conventional liquid crystal display element.

[Explanation of Codes] A liquid crystal display device 1 polarizing plate 2, 2'substrate 3 transparent electrode 4 insulating film 5 plastic beads 6 alignment film 7 sealing material 8 liquid crystal material

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Makoto Iwamoto 22-22 Nagaike-cho, Abeno-ku, Osaka City, Osaka Prefecture Sharp Corporation (72) Kyohei Isohata 22-22 Nagaike-cho, Abeno-ku, Osaka City, Osaka Prefecture Inside Sharp Corporation (72) Inventor Yasuyuki Nagano 22-22 Nagaike-cho, Abeno-ku, Osaka City, Osaka Prefecture Inside Sharp Corporation

Claims (1)

[Claims] 1. A hard plastic bead is sprinkled and fired on an insulating film printed on one of a pair of substrates to form the insulating film.
A liquid crystal display element characterized in that hard plastic beads are completely fixed as spacers in the cell only on one substrate.