JPS63231416A - Production of liquid crystal cell - Google Patents

Abstract

PURPOSE:To make cell gaps of a liquid crystal cell uniform eliminating unevenness of surface of a substrate by bonding plastic substrates to each other by heating under pressure, then heating the bonded substrates again without applying a pressure. CONSTITUTION:A sealing resin 2 is interposed between plastic substrates 1, 2 constituted of polyester film, etc. having a transparent electroconductive film formed on the surface. The plastic substrates 1, 2 are pressed with pressing glass plates 4, 4 interposing a buffer material 3, 3 having unevenness on the surface, and heated. Thus, two plastic substrates 1, 1 are bonded to each other by setting the sealing resin 2. If the substrates 1, 2 are mounted on a flat plate and heated at 100 deg.C for 30min, the substrates 1, 2 are expanded by the heat, and uneven parts thereon are stretched, and the condition for forming flat surface is maintained even if the surface is cooled back to ordinary temp. By this method, cell gaps are made uniform, and unevenness of contrast and color tone of a display pattern can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for manufacturing a liquid crystal cell having a flexible plastic substrate.

<Summary of the Invention> The present invention achieves bonding by heating and bonding two plastic substrates with a sealing resin interposed therebetween while applying pressure, and then reheating the plastic substrates without applying pressure. The purpose is to eliminate the unevenness of the plastic substrate that occurs during pressing by reheating, equalize the cell gap, and improve the display quality of the liquid crystal cell.

<Prior Art> Generally, a liquid crystal cell has a structure in which a pair of glass substrates on which transparent conductive films are formed are bonded together with a sealing resin, and a liquid crystal is sandwiched between the glass substrates. - In order to make this liquid crystal cell flexible and thin, a plastic substrate such as a polyester film (hereinafter referred to as PET) is used as a base for the glass substrate.

<Problems to be Solved by the Invention> However, since the PET film has a low heat resistance temperature of about 120 degrees, unevenness occurs when pressing the substrates together.

In general, the method of bonding 2 to 2 substrates is to put a spacer between the substrates in order to make the cell thickness uniform, and heat is applied while pressing from the outside to harden the sealing resin. Press plates and cushioning materials with uneven surfaces are used to ensure uniform pressure, and the unevenness of these press plates and cushioning materials causes uneven deformation of the plastic substrate itself, making the display pattern very uneven. Contrast unevenness occurred and color unevenness occurred, making it impossible to obtain good display quality.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a method for manufacturing a liquid crystal cell that eliminates unevenness of a plastic substrate, equalizes the cell gap, and improves display quality.

Means for Solving the Problems> The present invention is made by pressing a pair of plastic substrates together by pressing and heating with a sealing resin interposed therebetween, and then reheating the plastic substrates without applying pressure.

Effect> As described above, the unevenness of the plastic substrate is eliminated by reheating, and the cell gap becomes uniform.

<Example> Hereinafter, an example of the present invention will be described in detail using the drawings.

In FIG. 1, a sealing resin 2 is interposed between plastic substrates 1.1, such as polyester film, on which a transparent conductive film is formed, and a cushioning material 3.1 with uneven surfaces is interposed between the plastic substrates 1.1. 3 to press glass plate 4,
4 and heat to harden the sealing resin 2 and bond the two plastic substrates 1.1 together.

Note that 5 is a spacer for making the cell gap uniform. In the liquid crystal cell in this state, the plastic substrate 1.1 is uneven as shown in FIG. Place these deformed plastic substrates 1, 1 on a flat plate and heat them at 100°C for 30 minutes.
When heated for about 0 minutes, the plastic substrate 1.1 expands due to the heat, and the uneven state becomes a stretched shape, and even when the temperature is returned to room temperature, the flat state is maintained as shown in FIG. 3. If the liquid crystal 6 is then injected, the cell gap will be uniform and uneven contrast and color tone will not occur.

Further, the table below shows the temperature range for reheating. From the table above, it can be seen that the reheating temperature is preferably about 80°C to 150°C.

<Effects of the Invention> As described above, according to the present invention, a useful liquid crystal cell that eliminates contrast unevenness and color tone unevenness in display patterns is obtained by reheating to eliminate unevenness of the plastic substrate and uniformizing the cell gap. can provide a manufacturing method.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing the pressed state of the liquid crystal cell, Figure 2,
FIG. 3 is a sectional view showing the liquid crystal cell before and after reheating. 1.1...Plastic substrate, 2...Seal resin,
6...Liquid crystal.

Claims (1)

[Claims] In a method for manufacturing a liquid crystal cell in which one or two plastic substrates are bonded together with a sealing resin interposed therebetween, after bonding is performed by heating the plastic substrates while applying pressure, A method for manufacturing a liquid crystal cell, characterized in that the plastic substrate is reheated without applying pressure.