JPH08101382A - Two-layered type liquid crystal display device - Google Patents

Abstract

PURPOSE: To prevent the formation of interference fringes and to improve the yield of products by forming antireflection films on the opposite glass surfaces of a liquid crystal cell for compensation and a liquid crystal cell for display. CONSTITUTION: The antireflection films 12 are formed on at least either (both in Fig.) of the opposite glass surfaces of the two cells 1, 6. The formation of the interference fringes does not arise unless the reflection of light arises on the opposite surfaces. Fluororesins, etc., having a small refractive index are used as the antireflection films 12. Another method is to form ground surfaces 3a or 7a on at least either of the opposite glass surfaces of the two cells. The formation of these ground surfaces 3a, 7a is executed by spraying silica particles on the glass surfaces in the stage of the glass substrates alone and are fired. The light is irregularly reflected and since there is no regularity in reflection, the interference fringes do not appear any more by forming the ground surfaces 3a, 7a in such a manner.

Description

Detailed Description of the Invention

[0001]

This invention relates to STN (Super
The present invention relates to a two-layer liquid crystal display device using a Twisted Nematic liquid crystal, and particularly relates to prevention of interference fringes caused by the warpage of glass surfaces on the opposite sides of two cells.

[0002]

2. Description of the Related Art As shown in FIG. 2, a liquid crystal for compensating an optical phase difference, in which STN liquid crystals 5 and 10 are enclosed between a pair of glass substrates 2, 3 and 7, 8 respectively. A two-layer liquid crystal display device, in which the cell 1 and the display liquid crystal cell 6 are joined via a spacer 11 which also serves as a sealing material, has been put into practical use.

By the way, a slight warpage may occur on the glass surfaces of the two liquid crystal cells 1 and 6 which face each other. This warpage causes a problem that light is reflected on the glass surface and interference fringes appear, a defective product having a reduced display quality is formed, and the product yield is reduced. The present invention has been made in view of such circumstances, and an object thereof is to prevent the occurrence of interference fringes due to the warpage of the glass surface and improve the product yield.

[0004]

[Means for Solving the Problems]

(1) In the invention of claim 1, S is placed between two glass substrates.
TN (Super Twisted Nematic)
In a two-layer liquid crystal display device, in which a compensating liquid crystal cell and a display liquid crystal cell are bonded together via a spacer, in which a liquid crystal is sealed, at least one of glass surfaces of the compensating liquid crystal cell and the displaying liquid crystal cell facing each other is provided. The antireflection film is formed. (2) In the invention of claim 2, a ground glass surface is formed on at least one of the glass surfaces of the compensating liquid crystal cell and the displaying liquid crystal cell facing each other.

[0005]

EXAMPLE The interference fringes can be prevented if warpage of the glass surfaces of two cells facing each other can be prevented. However, even if this sled is very slight, interference fringes are generated, so by considering the manufacturing accuracy of components, the assembly accuracy, the temperature, the humidity, and the manufacturing environment such as dust, it is possible to suppress this sled sufficiently small not to affect it. Is difficult at present.

Therefore, in the present invention, as shown in FIG. 1A,
An antireflection film 12 is formed on at least one (both in the figure) of opposing glass surfaces of the two cells 1 and 6. By the antireflection film 12, no interference fringes are generated unless light is reflected on the facing surface. As the antireflection film 12, fluororesin or the like having a small refractive index is used. As another method, as shown in FIG. 1B, the ground glass surface 3a or 7a is formed on at least one of the glass surfaces facing each other of the two cells. To form the ground glass surface, silica particles may be sprinkled on the glass surface and fired or the glass surface may be treated with hydrofluoric acid at the stage of the glass substrate alone. By forming the frosted glass surface in this way, light becomes irregularly reflected, and since the reflection has no regularity, interference fringes do not appear.

The above two prevention methods can be used together.

[0008]

According to the present invention, since the antireflection film or the frosted glass surface is formed on the facing surfaces of the two cells, even if there is a warp on these facing surfaces, the reflection of light is suppressed or the light is diffusely reflected. It is possible to prevent the occurrence of interference fringes and improve the product yield. Further, the defective product in which the interference fringes are generated due to the warpage of the facing surfaces of the two cells can be relieved by applying the interference fringe prevention means of the present invention.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a conventional STN double-layer liquid crystal display device.

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[Procedure amendment]

[Submission date] November 9, 1994

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[0001]

BACKGROUND OF THE INVENTION This invention relates to two glass substrates.
Compensation liquid crystal cell and display liquid crystal cell with liquid crystal sealed between them
The present invention relates to a two-layer type liquid crystal display device in which and are joined via a spacer , and particularly relates to prevention of interference fringes caused by the warpage of glass surfaces of two cells facing each other.

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[0002]

2. Description of the Related Art As shown in FIG. 2, a pair of glass substrates 2, 3 and 7, 8 are provided between them.
Encapsulating liquid crystal 5,10 respectively, the optical phase difference compensation liquid crystal cell 1 and the display liquid crystal cell 6 were bonded through the spacer 11 which also serves as a sealing material double layer type liquid crystal display device has been put into practical use .

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[0004]

[Summary of (1) a first aspect of the invention, encapsulating liquid <br/> crystal between two glass substrates, a display liquid crystal cell and the compensation liquid crystal cell spacer In a two-layer liquid crystal display device bonded via
An antireflection film is formed on at least one of the opposing glass surfaces of the compensating liquid crystal cell and the displaying liquid crystal cell. (2) In the invention of claim 2, a ground glass surface is formed on at least one of the glass surfaces of the compensating liquid crystal cell and the displaying liquid crystal cell facing each other.

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FIG.

[Fig. 2]

Claims (2)

[Claims] 1. An STN (Sup) is provided between two glass substrates.
ER Twisted Nematic) A two-layer liquid crystal display device in which a compensating liquid crystal cell and a displaying liquid crystal cell are bonded together via a spacer, in which a glass surface facing the compensating liquid crystal cell and the displaying liquid crystal cell is provided. A two-layer liquid crystal display device, wherein an antireflection film is formed on at least one of the two. 2. A two-layer liquid crystal display device in which an STN liquid crystal is sealed between two glass substrates and a compensating liquid crystal cell and a displaying liquid crystal cell are joined via a spacer, wherein the compensating liquid crystal cell is A two-layer liquid crystal display device, characterized in that a ground glass surface is formed on at least one of the glass surfaces facing the display liquid crystal cell.