JPH052172A - Production of liquid crystal display element - Google Patents

Abstract

PURPOSE:To provide the process for production of the liquid crystal display element which reduces the time required for packing a liquid crystal material into a liquid crystal cell and improves productivity and the process for production of the liquid crystal display element which can deal with the future trend toward larger-sized screens. CONSTITUTION:This process for production of the liquid crystal display element by packing the liquid crystal material into the liquid crystal consists in sucking the liquid crystal material from a liquid crystal suction port 7 of the liquid crystal cell and discharging gases from a gas discharge port 10 of the liquid crystal, thereby packing the liquid crystal material into the liquid crystal cell.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display device used for displays, televisions and the like.

[0002]

2. Description of the Related Art As shown in FIG. 4, a liquid crystal display element used for a display, a television or the like is basically a liquid crystal cell 421 and a polarizing plate 422, a reflector 423 placed behind it, an illuminating device, etc. Composed of. A liquid crystal cell is one in which a liquid crystal substance is filled between two substrates having a transparent electrode on the inside and a liquid crystal alignment film.
Spacers are placed to control the cell thickness. Further, in order to prevent deterioration of the liquid crystal due to moisture or oxidation, the peripheral portion is sealed by a seal portion.

As a method of filling a liquid crystal cell with a liquid crystal,
As a conventional method, first, an empty liquid crystal cell is assembled and the peripheral portion is sealed. Next, in a chamber that has been degassed in vacuum for about 5 to 6 hours, a small hole (liquid crystal injection port) left in the seal part is immersed in a liquid crystal sump to introduce the liquid crystal substance by utilizing the capillary action of the cell. It takes about 4 hours to inject, and finally the liquid crystal injection port is sealed with an adhesive or the like.

[0004]

Conventionally, a liquid crystal cell is filled with a liquid crystal substance by the above method, and a large amount of time is required for the process of vacuum degassing the chamber and the process of introducing the liquid crystal substance into the liquid crystal cell. Was needed.

Further, when the liquid crystal cell becomes large, if a method of introducing a liquid crystal substance into the liquid crystal cell by utilizing a capillary phenomenon in a vacuum is used, the vacuum chamber to be used also becomes large. However, it also takes time when the liquid crystal substance is filled in the liquid crystal cell, which causes a problem of increasing difficulty. In view of the above problems, the present invention provides a method for manufacturing a liquid crystal display device, which reduces the time taken to fill a liquid crystal cell with a liquid crystal substance and has good productivity. Further, the present invention provides a method for manufacturing a liquid crystal display device capable of dealing with a large screen.

[0006]

The present invention uses a liquid crystal cell having a liquid crystal substance suction port and a gas suction port, in which gas is sucked from the gas suction port of the liquid crystal cell and liquid crystal substance is sucked from the liquid crystal substance suction port. A method of manufacturing a liquid crystal display device, comprising a step of filling a liquid crystal cell with liquid crystal.

That is, according to the present invention, a liquid crystal cell suction port (liquid crystal substance suction port) and a gas in the liquid crystal cell are sucked into the liquid crystal cell without utilizing vacuum deaeration and capillarity of the entire liquid crystal cell. A gas suction port is provided, the liquid crystal substance suction port is immersed in a liquid crystal reservoir, and the gas suction port is connected to a vacuum system to introduce the liquid crystal substance into the liquid crystal cell. These series of operations can be performed under atmospheric pressure.

The liquid crystal substance suction port and the gas suction port are provided as a liquid crystal substance suction port and a gas suction port, respectively, between the two substrates constituting the liquid crystal cell, preferably at a peripheral seal portion.
It is formed by providing holes in more than one place.

Further, a valve made of an elastic body may be attached to the peripheral seal portion between the two substrates of the liquid crystal cell as the liquid crystal substance suction port and the gas suction port. 1 and 2 are schematic views showing an example of a state in which a valve made of an elastic material is attached to a liquid crystal substance suction port or a gas suction port of a liquid crystal cell. FIG. 1 is a sectional view of a liquid crystal cell, showing a state before liquid crystal injection. Valves 8 and 9 made of an elastic material are attached to the liquid crystal substance inlet 7 and the gas inlet 10 of the liquid crystal cell, respectively. The valve 8 or the valve 9 is in a closed state. A joint connected to a liquid crystal reservoir or a vacuum system is inserted into each of the valves 8 and 9 for use. Since the valve 8 and the valve 9 have a triangular notch at the position where the joint is inserted, a tubular joint is easily inserted.
In FIG. 2, the joints 11 and 12 are inserted into the valves 8 and 9, the gas in the liquid crystal cell is sucked from the gas suction port 10 in the direction of arrow 14, and the liquid crystal substance is sucked from the liquid crystal substance suction port 7 in the direction of arrow 13. Indicates that On the other hand, the inlets of the joints 11 and 12 are tapered so that the joints can be easily inserted into the valve. After injecting the liquid crystal, if the joint is removed, the valve will be at atmospheric pressure against the reduced pressure inside.
It returns to the closed state and the sealing is completed. After the liquid crystal is injected, the liquid crystal substance suction port and the gas suction port may be sealed with a suitable resin or the like, or the elastic body of the valve itself may be melted and sealed by an operation such as heating or light irradiation. The material of the elastic body used for the valve preferably withstands pressure and has appropriate elasticity. For example, natural rubber, synthetic rubber, silicone rubber, or the elastic body of the valve itself can be operated by heating or light irradiation. There are thermosetting resins and photocurable resins that can be fused and sealed.

Further, the elastic body is made of a resin called a so-called ceramic cap or a septum cap, and may be a type of plug which can be opened and closed by inserting or removing a needle-like tube.

To inject a liquid crystal substance into the liquid crystal cell having the above structure, for example, a device having the following structure is used. FIG. 3 shows an overall view of a liquid crystal injection device using the present invention. As the liquid crystal cell, the one shown in FIGS. 1 and 2 is used. The liquid crystal substance 15 is a liquid crystal sump 21 with an oil bath jacket 16 that can be heated to a temperature at which fluidity is sufficient.
It has been put in. On top of this, there is a joint 11 for inhaling the liquid crystal substance, and the liquid crystal substance suction port 7 of the liquid crystal cell is connected to the joint 11. The liquid crystal cell is connected to the valve 8 made of an elastic material at the liquid crystal substance inlet 7.
In addition, the joint 11 is pierced. Further, the gas suction port 10 of the liquid crystal cell is connected to a vacuum line 18 which maintains a high vacuum. Gas suction port 1
Similarly to the liquid crystal suction port, 0 also has a valve 9 made of an elastic body and is connected by inserting a joint 12 connected to a vacuum line. The entire device is a support 20
Supported by. Further, the liquid crystal cell may be equipped with a jacket 19 for heating so that the flow of the liquid crystal substance is improved.

[0012]

When the liquid crystal substance is introduced into the liquid crystal cell by the above method, it is possible to inject the liquid crystal into the liquid crystal cell under atmospheric pressure, so that it is not necessary to use a vacuum chamber, and the liquid crystal injecting process can be performed efficiently. It can be carried out.

[0013]

【Example】

(Example 1) A liquid crystal injection device as shown in FIG.
Liquid crystal was injected into a 0.4-inch empty liquid crystal cell. As the liquid crystal, 2LI-1132 (manufactured by Merck) was used.

The liquid crystal cell shown in FIGS. 1 and 2 was used, and the elastic valve portion was made of synthetic rubber. An intravenous injection needle of 0.6 × 30 mm was used as the joint, and the connection portion was fixed to the vacuum line portion with an adhesive.

In the liquid crystal cell, a liquid crystal suction port and a gas suction port are provided in the seal portion for sealing between the two substrates in a diagonal direction. The liquid crystal suction port had a gas suction port with a diameter (inner diameter) of 1 mm.

An empty liquid crystal cell was fixed to the apparatus shown in FIG. 3, the valve of the vacuum line was opened, and the liquid crystal was sucked. The valve of the vacuum line was adjusted so that suction could be completed in about 15 minutes.
After suction in the cell, the needle was removed first from the suction port, and the suction port was later removed. An adhesive was attached and fixed to the synthetic rubber valve. It was confirmed that there were no bubbles inside.

It was also found that it is possible to change the structure of the elastic valve so that no bubbles remain. For example, if the elastic portion is made long and the portion to which atmospheric pressure is applied is made large, bubbles will be pushed out when the needle is pulled out while sucking gas. It was also possible to apply pressure to the liquid crystal sump portion of FIG. 3 instead of atmospheric pressure. (Example 2) A device as shown in FIG.
Liquid crystal was injected into an empty liquid crystal cell of inch. 2 for liquid crystal
LI-2293 (manufactured by Merck) was used.

The liquid crystal cell has a structure as shown in FIGS. 1 and 2, and the material of the valve is natural rubber.
An intravenous injection needle of 0.6 × 30 mm was used as the joint, and the connection portion was fixed to the vacuum line portion with an adhesive. In the liquid crystal cell, a liquid crystal suction port and a gas suction port were respectively provided in a seal portion that seals between two substrates in a diagonal direction. The liquid crystal suction port and the gas suction port each had a diameter (inner diameter) of 1 mm. An empty liquid crystal cell was fixed to the apparatus of FIG. 3, the valve of the vacuum line was opened, and the liquid crystal was sucked so that the suction force was the same as in Example 1. In order to improve the flow of liquid crystal, an experiment was conducted while heating the liquid crystal cell by sandwiching it with a jacket containing a heater. The time from the start of suction to the completion was 3 minutes and 20 seconds.

In the method of performing the capillary phenomenon, in order to inject liquid crystal into the same 10.4 inch liquid crystal cell as in this embodiment,
It can be seen that it takes 6 to 7 hours to degas the inside of the chamber, and 3 to 4 hours to inject the liquid crystal, which is very short.

[0020]

As described above, according to the present invention, the time required for the liquid crystal injection step is significantly shortened, and the chamber deaeration step is not required. Correspondence is also possible. Therefore, the contribution of the present invention to the industry is great.

[Brief description of drawings]

FIG. 1 is a sectional view of a liquid crystal cell.

FIG. 2 is a sectional view of a liquid crystal cell.

[Fig. 3] Overall view of the liquid crystal material injection device

FIG. 4 is a schematic diagram of a liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Glass substrate 2 ... Alignment film 3 ... Spacer 4 ... Alignment film 5 ... Transparent electrode 6 ... Glass substrate 7 ... Liquid crystal substance intake port 8 ... Valve 9 ... Valve 10 ... Gas suction port 11 ... Joint 12 ... Joint 13 ... Liquid crystal substance Flow direction 14 ... Gas flow direction 15 ... Liquid crystal substance 16 ... Oil bath jacket 17 ... Support stand 18 ... Vacuum line 19 ... Jacket 20 ... Pillar 21 ... Liquid crystal sump 421 ... Liquid crystal cell 422 ... Polarizing plate 423 ... Reflector plate

Claims (1)

Claim: What is claimed is: 1. A liquid crystal cell having a liquid crystal substance suction port and a gas suction port is used, and gas is sucked out from the gas suction port of the liquid crystal cell.
A method of manufacturing a liquid crystal display device, comprising the step of filling a liquid crystal cell with liquid crystal by sucking a liquid crystal substance from a liquid crystal substance inlet.