JPS5918685B2 - lcd cell - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid crystal cell that does not easily bulge, and particularly relates to a large area liquid crystal cell.

A liquid crystal cell has a liquid crystal sandwiched between a pair of substrates via a 10-20μ spacer. When an electric field is applied to this cell, the arrangement of the liquid crystal molecules changes, producing a so-called electro-optic effect, and the electric field Numbers, letters, etc. are displayed based on the difference in contrast between the areas to which the voltage is applied and the areas to which the voltage is not applied.

In general, a method for manufacturing a liquid crystal cell is to arrange a pair of substrates with their electrode surfaces facing each other at a predetermined distance using spacers, etc.
After sealing the periphery, liquid crystal was injected through a pre-prepared hole, and then the hole was sealed.

Such liquid crystal cells normally contain a spacer of a certain size in the sealing material to form a seal of a certain thickness, but as there is no support inside the cell, the thickness becomes uneven and the appearance is poor. Sometimes things got worse.

In addition, to prevent this, spacers identical to the seal part were sprinkled inside the cell, or island-shaped seals were partially provided as spacers inside the cell, but in the former case, the spacer was attached to the seal part. Since the same material was used as in the latter, it is possible to prevent the cell from becoming thinner, but it is not possible to prevent the cell from becoming thicker due to swelling.Also, in the latter case, the spacer is fixed, so the spacer is visible and when liquid crystal is injected. It had drawbacks such as the liquid crystal not being injected smoothly.
An object of the present invention is to provide a liquid crystal cell that does not adversely affect the injection of liquid crystal and can obtain uniform cell gaps.

As a result of repeated research for this purpose, the present inventor arrived at the present invention, in which a pair of substrates are placed with their electrode surfaces facing each other, spaced at a predetermined distance by spacers, the periphery is sealed, and liquid crystal is injected. In a liquid crystal cell whose injection port is sealed by
The thickness of the spacer placed inside the cell is made smaller than the thickness of the sealing material around the cell, and the inside of the cell is brought into a reduced pressure state, so that the spacer inside the cell is thinner than the cell gap at the sealing part around the cell. This liquid crystal cell is characterized in that the cell gap between the two parts is narrowed.

In the liquid crystal cell of the present invention, the thickness (fiber diameter, particle size) of the spacer inside the cell is thinner than the thickness of the sealing material around the cell, so the liquid crystal cell Cells are less likely to bulge and uniform cell gaps can be easily obtained.

Further, in the present invention, since the spacer inside the cell is not fixed with a sealing material, the liquid crystal does not become difficult to inject when liquid crystal is injected, and even a large liquid crystal cell can be injected smoothly.

Furthermore, by reducing the pressure inside the cell, the substrate is brought into close contact with the thin spacer inside the cell, making it difficult for bulges to occur and further improving uniformity.

The spacer placed inside this cell is different from the one on the periphery because it does not fix the two substrates, so it is influenced by the thickest spacer and increases its thickness, which immediately works to widen the gap between the liquid crystal display panels. Therefore, in the conventional example, the entire cell tends to swell into a convex lens shape, whereas in the present invention, the thickness of the spacer inside the cell is thin, and the inside of the cell is placed under reduced pressure, so that the substrate tends to adhere to the spacer. Therefore, the cell gap inside the cell becomes narrower than the cell gap in the seal area around the cell, resulting in a slightly concave shape, but in most of the display area, except for the periphery, the spacer maintains a constant gap, so it is uniform. A gap is obtained and display unevenness does not occur.

FIG. 1 is a cross-sectional view of an example of a liquid crystal cell in which the spacer inside the cell is made thinner than the peripheral part, and a sealing material 3 A spacer 6 is provided inside the cell to seal it, and a liquid crystal 5 is injected into the inside of the cell.

In this example, the thickness of the spacer 6 inside this cell is made thinner than the thickness of the sealing material 3, but since the internal spacer does not sufficiently support the electrode plate, the liquid crystal cell has a partially uneven shape. ′ shape, and sufficient uniformity cannot be obtained. FIG. 2 is a cross-sectional view of an example of a liquid crystal cell according to the present invention. Since the inside of the cell is kept in a reduced pressure state, the two substrates are regulated by a spacer 6, making the gap narrower than the peripheral sealing part. 1
A much more uniform cell gap can be obtained than in the example shown.

An example of injecting liquid crystal into the liquid crystal cell of the present invention will be described.

A spacer is placed inside and the liquid crystal cell sealed at the periphery is pulled using a vacuum chuck to slightly widen the cell gap and liquid crystal is injected under pressure.

Next, the external force is removed, and if necessary, the substrate is pressurized or the pressure is reduced from the outlet (inlet) to discharge excess liquid crystal and seal the inlet. In this case, as shown in FIG. 2, the inside is kept under reduced pressure, that is, the gap inside the cell is narrower than the surrounding area of the cell. Therefore, in the present invention, the thickness of the spacer inside the cell is made thinner than the thickness of the peripheral sealing part, and since the inside is kept under reduced pressure, the cell does not unilaterally bulge into a convex lens shape and transmit waves. No uneven shape like this will occur. Particularly in the case of a large liquid crystal cell, the structure of the present invention has a great effect in regulating the bulge of the cell, and this effect is especially great when the liquid crystal cell is used in a vertical position.

On the other hand, in conventional liquid crystal cells where the spacer and the seal part have the same thickness, they tend to bulge out into a convex lens shape due to the influence of the thickest spacer inside the cell, and even if the liquid crystal is depressurized and discharged from the discharge port (filling port), Even when the spacer is sealed, since the thickness of the spacer is the same as that of the peripheral sealing portion, it is difficult to achieve a sufficient pressure reduction state, and a bulging state is likely to occur.

As the spacer 6 used in the present invention, a fibrous spacer or a spherical spacer is used. The spacer of the present invention does not form an island-shaped seal inside the cell, so even when liquid crystal is injected, it does not cause uneven liquid crystal molecular arrangement or leave bubbles at the seal inside the cell, and it is smooth. Liquid crystal is injected into the cell, and it is also possible to widen the cell gap during injection. In the above explanation, a cell having electrodes has been described, but it goes without saying that electrodes are not required if the liquid crystal is of a temperature effect type.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a comparative example. FIG. 2 is a sectional view of an embodiment of the invention. 1, 2...
・Substrate, 3... Seal material, 5... Liquid crystal, 6... Spacer.

Claims (1)

[Claims] 1. In a liquid crystal cell in which a pair of substrates are arranged with their electrode surfaces facing each other at a predetermined distance using a spacer, the periphery is sealed, liquid crystal is injected, and the injection port is sealed, the thickness of the spacer placed inside the cell. is made to be smaller than the thickness of the sealing material around the cell, and the inside of the cell is brought into a reduced pressure state, so that the cell gap at the spacer part inside the cell is narrower than the cell gap at the sealing part at the cell periphery. A liquid crystal cell characterized by: