JPS59125714A - Structure and production of liquid crystal displaying element - Google Patents

Abstract

PURPOSE:To obtain a large-sized liquid crystal displaying element without gap unevenness and having high displaying quality by dispersing internal spacers in a cell and setting up the pressure in the cell smaller than the atmospheric pressure. CONSTITUTION:After forming a cell by arranging the internal spacers 18 between upper and lower base plates 16, 17, liquid crystal 19 is injected from a liquid crystal injecting port. Then, a part of the liquid crystal injected into the cell is forcibly sucked from the liquid crystal injecting port by a vacuum pump 20. Consequently, the inside of the cell of the liquid crystal displaying element is reduced down to a pressure lower than atmospheric pressure and the upper and lower base plates 16, 17 are pressed by the atmospheric pressure in the direction reducing the gap. Then, the evacuated liquid crystal injecting port is sealed by a sealing agent, so that the liquid crystal element having a uniform gap over the whole display surface is obtained. Thus, the upper and lower base plates 11, 12 are pressed by P1-P2 pressure in the direction reducing the gap by reducing the pressure P2 inside the liquid crystal element lower than the atmospheric pressure P1 under the status sealing the injected liquid crystal.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a structure of a liquid crystal display element and a method for manufacturing the same, which can make the "upper and lower substrate spacing" (hereinafter referred to as gear knob) uniform over the entire display surface.

Glass that faces each other with a liquid crystal interposed in a liquid crystal display element,
The upper and lower substrates made of plastic or the like have a display pattern made of a transparent conductive film formed on their opposing surfaces, and an alignment treatment is applied thereon, and a sealing agent is applied to the outer periphery while keeping the gap uniform. The parts are glued together.

In a liquid crystal display element, it is particularly important to make the gap -f uniform; if the gap is non-uniform, various problems such as those described below will occur.

■Response time becomes uneven. ■Multiple interference colors appear on the display screen. ■In guest-host type liquid crystal display elements,
Color unevenness occurs because the thickness of the pigment layer is different. (2) In a multi-segment drive type liquid crystal display element, the display cannot be distinguished. ■Make it impossible to realize multicolor display (DAP) due to birefringence.

As mentioned above, the unevenness of gear knobs not only degrades display quality, but also becomes an obstacle to the realization of new display technology (
・Ru.

Uniform caps in the manufacturing of conventional liquid crystal display elements
The method for doing this will be described according to the drawings.

FIG. 1 is a cross-sectional view of a general liquid crystal display element, in which 1.2 indicates the upper and lower substrates, 6 indicates the sealant, 4 indicates the seal spacer, 5 indicates the internal spacer, 6 indicates the liquid crystal, 7 indicates the sealant, and P indicates the external pressure applied when the upper and lower substrates are overlapped and the sealant is cured.

After forming a sealing agent 6 consisting of a seal spacer 4 such as glass fiber or plastic beads on the upper and lower substrates 1.2 by printing, the upper and lower substrates are placed one on top of the other, and the sealing agent 6 is applied while applying an external pressure P. Let it harden. (tsu, fall,
A cell is formed by stacking the upper and lower substrates and curing the sealant to form a cavity. ) By hardening the sealant 3 while applying a large external pressure P, uniformity of the gear knob is obtained based on the seal part spacer 4 and the internal spacer 5.

Thereafter, the external pressure P is removed, the liquid crystal 6 is injected into the cell, and the liquid crystal injection port is sealed with a sealant 7.

FIG. 2 is a partially enlarged sectional view of a conventional large-sized liquid crystal display element. If we look at the state of the upper and lower substrates 1.2, they have undulations, as shown in Figure 2.

Even if an attempt is made to obtain uniformity of the gear knob using the undulating upper and lower substrates 1.2 using the conventional method described above, the lower limit can be limited by the internal spacer 5 (state A), but the upper limit is limited (state B, Condition C) Cannot be done. However, in the vicinity of the sealant, the adhesive force will correct the gap, and a certain degree of uniformity of the gap will be achieved.

The cell also has non-uniform gaps due to overall strain.

As described above, the conventional method causes unevenness of the gear knob, lowers the display quality of the liquid crystal display element, and makes it difficult to realize new technologies such as multi-segment drive and multi-color display.

The purpose of the present invention is to solve the above-mentioned drawbacks and improve the display quality even in large-sized liquid crystal display elements, and also to improve the display quality of multi-segment drive type liquid crystal display elements, multicolor type liquid crystal display elements, liquid crystal display elements using plastic substrates, etc. The aim is to realize a new type of liquid crystal display element.

The present invention will be explained below with reference to the drawings.

FIG. 3 shows a cross-sectional view of a liquid crystal display element according to the present invention, 1
1. 12 indicates the upper and lower substrates, 16 indicates the internal spacer, 14 indicates the liquid crystal, 15 indicates the sealant, P indicates the atmospheric pressure, and P2 indicates the pressure within the cell of the liquid crystal display element.

Similar to the conventional method, the liquid crystal 14 is injected and sealed after a cell is formed by interspersing internal spacers 16 in the area where the liquid crystal is injected and becomes the display part, but in the present invention, the liquid crystal is injected and sealed. By making the pressure P2 inside the liquid crystal display element smaller than the atmospheric pressure P in the stopped state, the upper and lower substrates 11
．． 12 is pressed in the direction where the gap becomes smaller by the pressure of Pl-P2. This pressure corrects the undulations and distortions of the upper and lower substrates 11 and 12, eliminates the non-uniformity of the gap, and provides a uniform cap based on the internal spacers over the entire surface of the liquid crystal display element.

Next, FIG. 4 is a model diagram showing a method of manufacturing a liquid crystal display element according to an embodiment of the present invention.

After forming a cell by interposing an internal spacer 18 between the upper and lower substrates 16 and 17, liquid crystal 19 is injected from a liquid crystal injection port.

Thereafter, a portion of the liquid crystal that has once entered the cell is forcibly sucked out from the liquid crystal injection port using the vacuum pump 20. As a result, the pressure inside the cell of the liquid crystal display element is reduced to a pressure lower than atmospheric pressure, and the upper and lower substrates 16 and 17 are pressed by the atmospheric pressure in a direction that reduces the gap. Thereafter, by sealing the evacuated liquid crystal injection port with a sealant, a liquid crystal display element having a uniform cap over the entire display surface can be obtained.

When the present invention was implemented on a large liquid crystal display element using a glass substrate with a size of 240 x 200 mm, the gear knob variation was around 25 μm in the conventional method, but the camp variation was reduced by the present invention. It was possible to obtain a liquid crystal display element with a thickness of 0.05 μm or less.

As described above, by utilizing the present invention, a large-sized liquid crystal display element with no gear knob unevenness and high display quality can be obtained.

It is clear that the present invention is also applicable to making the gap uniform in a multi-segment drive type liquid crystal display element, a multicolor type liquid crystal display element, a liquid crystal display element using a plastic substrate, and the like.

In order to obtain a liquid crystal display element in which the pressure inside the cell is lower than atmospheric pressure, after injecting the liquid crystal, pressurize the upper and lower substrates in the direction that the cap becomes smaller, and force a part of the liquid crystal through the liquid crystal injection port. It is also possible to adopt a method in which the liquid crystal inlet is discharged, and then the liquid crystal injection port is sealed with a sealant while the pressure is maintained.

[Brief explanation of drawings]

Figures 1 and 2 are cross-sectional views showing conventional liquid crystal display elements;
FIG. 3 is a sectional view of a liquid crystal display element according to an embodiment of the present invention, and FIG. 4 is a model diagram showing a method of manufacturing a liquid crystal display element according to an embodiment of the present invention. 1.11.16-Upper substrate, 2.12.17...Lower substrate, 6...Seal Qll, i-Seal part spacer, 5
．． 16.18 - Internal spacer, 7.15 - Sealing agent, 20 - Vacuum pump, Pl - Atmospheric pressure, P2 - Pressure inside the cell. Figure 1 Figure 2. Figure 3

Claims (2)

[Claims] (1) In a liquid crystal display element in which a cell is formed by bonding the outer peripheries of upper and lower substrates together with a sealant, and liquid crystal is injected and sealed into the cell, A structure of a liquid crystal display element, characterized in that internal spacers are scattered and the pressure inside the cell is set to be lower than atmospheric pressure. (2) In a liquid crystal display element in which a cell is formed by bonding the outer peripheries of upper and lower substrates to each other with a sealant, and a flic liquid crystal is injected and sealed within the cell, when forming the cell, the inside of the cell is It consists of interspersed with internal spacers,
and a step of injecting liquid crystal into the cell through a liquid crystal injection port, a step of forcibly discharging a part of the injected liquid crystal from the injection port, and a step of sealing the injection port after the liquid crystal is filled. A method for manufacturing a liquid crystal display element, characterized in that: