JPS5860780A - Color liquid crystal cell - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color liquid crystal cell in which two glass substrates are bonded together, and the inner surface of one of the substrates is coated with a white film and used as a reflective surface.

In conventional color liquid crystal cells, the phase change type, which uses liquid crystals containing dyes and optically active substances, has superior visibility and takes up less space when viewed with a reflective type than with a transmissive type. A white plate was pasted on it to serve as a reflector.

Figure 1 is a vertical cross-sectional view of this liquid crystal cell, in which 1 is an alignment treatment film, 2 is a transparent electrode, 8 is an insulating substrate, 4 is a liquid crystal, 5 is a dye, 7 is a reflective plate, and 8 is a sealant. be. However, with this method, the display turns are reflected by the back surface of the lower substrate of the liquid crystal cell for the viewer.

The image appeared to be partially doubled, the outline was blurred, and the display quality was degraded.

To overcome this drawback, there is a method of using opaque glass as the lower substrate. ■Method of depositing metal oxide on the inside of the lower substrate.

■Methods such as attaching a white scattering plate to the inside of the cell using adhesive have been proposed.

However, in method (2) above, when a transparent electrode film and an insulating film are coated on opaque glass, cracks occur in the film due to the difference in elongation between the glass plate and these films.

In the method (2) above, a completely opaque white film cannot be obtained. In the method @, because adhesive is used, there are process constraints on the conditions for coating the vapor deposition electrode and insulating film thereon.
The problem is that highly reliable liquid crystal cells cannot be manufactured.

The purpose of the present invention is to eliminate such drawbacks of the prior art,
To provide an inexpensive color liquid crystal cell with high visibility.

To achieve this object, the present invention provides a phase change color liquid crystal cell using a liquid crystal containing a dye and an optically active substance, and a mixed paste of an organometallic compound and white fine powder on one insulating substrate. It is characterized in that a white film obtained by coating and baking is used as a reflective film.

To be more specific, thickeners such as nitrocellulose and ethylcellulose, organic solvents such as ethanol, butylcarpitol, and butylcellosolve, and organometallic compounds such as aluminum, indium, silicon, and titanium. Alumina or titanium oxide fine powder (with a particle size of around 0.5μ) is uniformly added to the mixture.
Mix about 5 to 5%, make a paste, and print this on the entire surface of a glass substrate by a printing method. This board is 150
1: After pre-drying for 20 minutes, and firing in a 500 U belt furnace, an insulating film containing fine powder of alumina or titanium oxide is formed on the glass substrate, becoming an opaque white film. , it functions satisfactorily as a reflective film.

If you use the white substrate made in this way as one substrate and the other as an insulating substrate coated with only an insulating film and transparent electrode, and assemble a liquid crystal cell with the white film on the inside, the display pattern will be on the back side of the lower substrate. It is possible to provide a color liquid crystal cell that can be displayed clearly against a white film background without reflection, is inexpensive, has high visibility, and is of industrial value.

Next, an example will be described.

Examples The main components are organometallic compounds such as aluminum, indium, and silicon, such as aluminum acetylacetonate, indisember acetylacetonate, and vinyltris(2-methoxyethoxy)silane, and as a thickener, nitrocellulose is used as ethyl cellulose. A paste is prepared by combining the organic substances with the addition of butylcellosolve and butylcarpitol as organic solvents. Furthermore, add 1% of titanium oxide powder with a particle size of 0.25 to 0.45μ (manufactured by Ishihara Sangyo Co., Ltd., product name R530) or 1 granule of alumina.
Expected 0. R, , l'l powder (manufactured by Fujimi Abrasives Industry Co., Ltd., product name Alumikuron O, 5A) was mixed uniformly at 1%, and applied to the entire surface of one side of the glass substrate using the screen printing method. After pre-drying at 500°C for 20 minutes, the substrate was fired at 500°C in a belt furnace to obtain a white substrate.

A transparent electrode made of a metal oxide such as indium oxide is formed in a predetermined shape on the white substrate and transparent glass substrate by vapor deposition, and an insulating film containing no alumina or titanium oxide powder is printed to cover the transparent electrode. After that, it is immersed in a silane coupling agent, which is a vertical surface treatment agent, and dried at 180°C. These two substrates are placed facing each other and bonded together using an epoxy adhesive (manufactured by Naztar, product name: 5B4000) containing a 7 μm spacer to form a liquid crystal cell. A liquid crystal with negative dielectric anisotropy (manufactured by Chisso Corporation) made by mixing this cell with a phase change type guest host liquid crystal material.
Product name EN-80) is enclosed.

The liquid crystal cell thus obtained becomes a positive display Y projection type color liquid crystal cell in which a clear image is displayed on a white film.

FIG. 2 is a cross-sectional view of a liquid crystal cell obtained in this example, in which 1 is an alignment film, 2 is a transparent electrode, 8 is an insulating substrate, 4 is a liquid crystal, 5 is a dye, and 6 is a white reflection. The film 8 is a sealant. In this liquid crystal cell, since the reflective film 6 is located very close to the liquid crystal layer, only one image can be seen and a clear display can be obtained.

The present invention has the above-described configuration, and can provide a color liquid crystal cell that is inexpensive and has high visibility.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a conventional liquid crystal cell, and FIG. 2 is a vertical cross-sectional view of a liquid crystal cell according to an embodiment of the present invention. 1...Alignment treatment film, 2.Pa...
・Transparent electrode, 8...Insulating substrate, 4...
...Liquid crystal, 5...Pigment, 6...
・・・・・・Whiteness Lnni], ri,'

Claims (1)

[Claims] (1) In a phase change color liquid crystal cell, a mixed paste of an organic metal compound and white fine powder is coated on one insulating substrate and baked [the resulting white film is used as a reflective film]. A color liquid crystal cell characterized by: (2. In claim (1) [, said σ
A color liquid crystal cell characterized in that the color fine powder is alumina fine powder. (3) A color liquid crystal cell according to claim (1), wherein the white fine powder is a titanium oxide fine powder.