JPH05289036A - Liquid crystal supply device into which deaeration device is integrated and its operating method - Google Patents

Abstract

PURPOSE:To inject a liquid crystal in which air is not dissolved to a cell. CONSTITUTION:Between a deaeration device 1 and a liquid crystal injecting device 2, a receiving tank 3 for storing temporarily a deaerated liquid crystal, and a feed liquid pump 4 for supplying the liquid crystal in this receiving tank 3 to the liquid crystal injecting device 2 are provided, and in a liquid crystal reservoir 17 contained in a pressure reducing tank 14 of the liquid crystal injecting device 2, a three-way cock 18 is provided, and this three-way cock 18 is connected to the feed liquid pump 4. when the liquid crystal injecting device 2 is vacuum, the deaerated liquid crystal is fed into the liquid crystal reservoir 17, and after injecting the liquid crystal to a cell 15, the liquid crystal injecting device 2 is filled with the air and the three-way cock 18 is opened, and when the liquid crystal is discharged from the liquid crystal reservoir 17, the deaerated liquid crystal can always be injected to the cell 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal supply device incorporating a degassing device for separating and removing a gas dissolved in a liquid crystal and injecting the liquid crystal into an empty cell, and a method of operating the same. ..

[0002]

2. Description of the Related Art In recent years, liquid crystal display devices have become widespread in office automation equipment, home appliances and the like.

In this type of liquid crystal display device, an empty cell is formed by connecting a pair of transparent substrates each having an electrode on each inner surface with a frame-shaped encapsulating material sandwiched between them, and the empty cell is formed inside the cell. It is manufactured by injecting liquid crystal.

By the way, in the process of injecting liquid crystal into the cell, if the liquid crystal is injected into the cell without sufficiently removing the gas dissolved in the liquid crystal, bubbles are generated in the cell, which hinders the display of images and the like. ..

Therefore, conventionally, a method has been adopted in which the liquid crystal is placed in a dish or beaker, placed in a decompression tank, the tank is evacuated to remove dissolved gas in the liquid crystal, and then the liquid crystal is injected into the cell. It was being done.

However, such an injecting method is complicated and inefficient, and since it is returned to atmospheric pressure when it is carried out from the decompression tank, it is unavoidable that air is redissolved in the degassed liquid crystal. ..

As another injection method, a method of supplying liquid crystal to the injection device while continuously degassing has been proposed.

This is performed by using a deaerator (Japanese Patent Laid-Open No. 62-205317) using a polyolefin type microporous membrane,
The degassed liquid crystal is sent to a liquid crystal reservoir provided in a decompression tank for injecting liquid crystal.

[0009]

However, although the above-mentioned filling method can supply the degassed liquid crystal to the liquid crystal reservoir, since the inside of the container is returned to the atmospheric pressure at the time of filling the cell, the liquid crystal reservoir is filled at this time. Air is dissolved in the liquid crystal inside.

Therefore, at the time of the next injection, it is inevitable that the liquid crystal in which air is re-dissolved is mixed with the liquid crystal supplied from the degassing device, and the effect that the originally degassed liquid crystal has is not achieved. there were.

In the injection method as described above, the liquid crystal in which air is re-dissolved when the pressure is returned to the atmospheric pressure can be degassed by sending it again to the degassing device, but the inside of the container is in a vacuum state. Even if you try to transfer the liquid crystal with a liquid-sending pump at times, if the liquid crystal is in a vacuum state, 0.1 To
Since the pressure was reduced to about rr, the liquid crystal was not sucked in even when the liquid feed pump was operated, and there was a problem that the liquid crystal could not be sent to the deaerator.

Therefore, according to the present invention, the degassed liquid crystal can be injected into the cell, and the liquid crystal in the liquid crystal pool after the injection can be sent again to the degassing device to be degassed, and the air is redissolved. An object of the present invention is to provide a liquid crystal supply device incorporating a degassing device that can always inject degassed liquid crystal without mixing liquid crystal, and an operating method thereof.

[0013]

In order to solve the above problems, the first invention is a deaeration in which a deaeration tube formed of a non-porous film having gas permeability is incorporated in a vacuum chamber. A device and a liquid crystal injection device that stores a liquid crystal reservoir in the decompression tank and connects the liquid crystal reservoir to the inlet and outlet of the degassing device via a three-way cock, and is located between the degassing device and the liquid crystal filling device. Then, a structure is adopted which comprises a receiving tank for temporarily storing the degassed liquid crystal, and a liquid feed pump for supplying the liquid crystal in the receiving tank to the liquid crystal injecting device.

Similarly, in the second invention, the liquid crystal deaerated by passing through the deaeration tube in a depressurized state is temporarily stored in a receiving tank capable of depressurizing, and a required amount of liquid crystal is then supplied to a liquid crystal injection device by a liquid feed pump. When the pressure is reduced, it is sent to the liquid crystal reservoir through the three-way cock, and when the liquid crystal is injected and sealed by the liquid crystal injection device, the liquid crystal is discharged from the liquid crystal reservoir through the three-way cock during pressurization. ..

[0015]

[Function] After the liquid crystal degassed by the degassing device is temporarily stored in the receiving tank, it is sent to the liquid crystal reservoir by the liquid sending pump when the liquid crystal injecting device is in a vacuum, and the liquid crystal is injected and sealed in the cell under the vacuum condition. By setting the liquid crystal injection device to atmospheric pressure and operating the three-way cock, the liquid crystal discharged from the liquid crystal reservoir is sent to the degassing device again to be degassed, so that the liquid crystal in which air is re-dissolved does not mix, and it is constantly degassed. The liquid crystal can be injected into the cell.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in the figure, the liquid crystal supply device includes a degassing device 1, a liquid crystal injecting device 2, a receiving tank 3 arranged between the outlet of the degassing device 1 and the liquid crystal injecting device 2, and the receiving tank 3 and the liquid crystal. A liquid feed pump 4 arranged between the injecting device 2, a receiving tank 5 arranged between the liquid crystal injecting device 2 and the inlet of the degassing device 1, and a liquid sending pump arranged between the receiving tank 5 and the inlet of the degassing device 1. Liquid pump 6
It is composed of and.

The degassing apparatus 1 has a deaeration tube 8 housed inside a vacuum chamber 7. The vacuum chamber 7 is connected to a vacuum pump 9 to reduce the pressure inside, and the degassing tube 8 has a valve 10 at the inlet side. It is connected to the liquid sending pump 6 via the outlet side and is connected to the receiving tank 3 on the outlet side.

The degassing tube 8 is formed of a non-porous film having gas permeability. As the degassing tube 8, for example, an inner diameter of 0.5 mm, a wall thickness of 0.1 mm, and a length of 1 m are made of polytetrafluoroethylene resin. An element in which 150 tubes are joined is used.

The tube size of the degassing tube 8,
The length and the number can be freely selected.

The receiving tank 3 is for temporarily storing degassed liquid crystal, has a structure capable of being hermetically sealed, is internally connected to the vacuum pump 9 via a valve 11, and has a lower outlet at the valve. It is connected to the inlet of the liquid feed pump 4 via 12.

The receiving tank 3 is provided between the receiving tank 3 and the valve 11.
A valve 13 for weakening the vacuum state is branched and connected.

The liquid crystal injecting device 2 has a structure in which the decompression tank 14 can seal and take in and out the empty cell 15, and the inside thereof is connected to the vacuum pump 16 and the liquid crystal is injected into the empty cell 15 inside. A liquid crystal reservoir 17 for incorporating the liquid crystal reservoir 17 is incorporated, and a three-way cock 18 is provided below the liquid crystal reservoir 17.

The three-way cock 18 is for switching the piping for supplying the liquid crystal to the liquid crystal reservoir 17 and discharging the liquid crystal in the liquid crystal reservoir 17 to the outside of the decompression tank 14, and the inlet port is a liquid feed pump. 4 is connected to the outlet via a valve 19, and the outlet port is connected to the receiving tank 5, so that the switching operation can be performed from the outside of the decompression tank 14.

The liquid crystal reservoir 17 reduces the amount of air dissolved in the liquid crystal when the pressure reducing tank 14 is returned to atmospheric pressure.
By reducing the surface area within the range that does not hinder the workability when injecting the liquid crystal into the cell 15, and making the bottom into an inverted conical shape, the amount of the liquid crystal remaining after one injection into the cell 15 is reduced. ing.

When a plurality of liquid crystals are injected into the empty cell 15 at the same time, it is possible to deal with the liquid crystal reservoir 17 having the sectional shape shown in the drawing and having a wide width in the longitudinal direction.

A pipe 20 for replenishing liquid crystal is connected to the receiving tank 5, and an inlet of the liquid feed pump 6 is provided with a valve 21.
Connected through.

The liquid crystal supply device of the present invention has the above-mentioned structure, and the operation method thereof will be described below.

First, the vacuum pump 9 is operated to bring the vacuum chamber 7 of the degassing apparatus 1 to a vacuum state of about 1 Torr, and the liquid crystal stored in the receiving tank 5 is introduced into the degassing tube 8 by the liquid sending pump 6. ..

The degassing tube 8 is formed of a non-porous film having gas permeability, and the inside of the vacuum chamber 7 is depressurized. Therefore, when the liquid crystal is introduced into the degassing tube 8, The gas dissolved in is separated by the pressure difference,
It is removed through the wall surface of the degassing tube 8. The degassed liquid crystal is stored in the receiving tank 3 which is kept in a vacuum state so that the air is not redissolved during storage.

Next, in order to feed the liquid crystal into the liquid feed pump 4,
Close the valve 11 and slightly open the valve 13 to receive the tank 3
After weakening the vacuum state of, the liquid feed pump 4 is operated. In addition, when the liquid delivery pump 4 is stopped, the receiving tank 3 is brought into a vacuum state again.

In the liquid crystal injecting device 2, in order to inject the liquid crystal into the empty cell 15, the vacuum pump 16 is operated to bring the decompression tank 14 into a vacuum state, and then the valve 12 is closed to open the valve 1.
9 is opened to set the three-way cock 18 to the “liquid feeding” position as shown in FIG. 2C, and the liquid feeding pump 4 feeds a predetermined amount of liquid crystal into the liquid crystal reservoir 17.

Next, the three-way cock 18 is set to the "injection" position as shown in FIG. 2B, the inlet of the empty cell 15 is immersed in the liquid crystal reservoir 17, and then the decompression tank 14 is opened to the atmosphere to apply pressure. Then, liquid crystal is injected into the empty cell 15.

After that, the inlet of the cell 15 is sealed, and then the three-way cock 18 is set to the "discharging" position as shown in FIG. 2A, and the liquid crystal remaining in the liquid crystal reservoir 17 is discharged to the receiving tank 5. .. This discharge is performed by a head or a liquid feed pump (not shown).

The liquid crystal stored in the receiving tank 5 is again introduced into the degassing device 1 by the liquid sending pump 6, and the degassed liquid crystal is sent to the liquid crystal injecting device 2.

As described above, the liquid crystal degassed by the degassing device 1 may also be sent to the liquid crystal reservoir 17 in a vacuum state by the liquid crystal injecting device 2 and may not be discharged every time depending on the dissolved state of air, but the liquid crystal injecting device 2 Since the liquid crystal in the liquid crystal reservoir 17 is discharged after the air is opened, stable liquid crystal injection can be performed without air or gas being dissolved in the liquid crystal.

[0037]

As described above, according to the present invention, the liquid crystal deaerated by the deaeration device is sent to the liquid crystal reservoir when the liquid crystal injecting device is in a vacuum, and the liquid crystal in the liquid crystal reservoir is discharged after the liquid crystal is injected into and sealed in the cell. Since this is done, the liquid crystal to be supplied to the liquid crystal reservoir does not mix with the liquid crystal in which air is re-dissolved, and the degassed liquid crystal can be constantly injected into the cell with a simple structure and operation.

[Brief description of drawings]

FIG. 1 is a flow sheet of a liquid crystal supply device according to the present invention.

FIG. 2 shows different states at the time of switching operation of a three-way cock, (A) during cell injection, (B) during discharge, and (C) during liquid transfer.

[Explanation of symbols]

 1 Degassing device 2 Liquid crystal injecting device 3,5 Receiving tank 4,6 Liquid sending pump 7 Vacuum chamber 8 Degassing tube 9,16 Vacuum pump 14 Pressure reducing tank 15 Cell 17 Liquid crystal reservoir 18 Three-way cock

Claims (2)

[Claims] 1. A degassing apparatus incorporating a degassing tube formed of a non-porous film having gas permeability in a vacuum chamber, and a liquid crystal reservoir housed in a decompression tank. The liquid crystal reservoir is equipped with a three-way cock. A liquid crystal injection device connected to the inlet and outlet of the degassing device via, and located between the degassing device and the liquid crystal injection device,
A liquid crystal supply device incorporating a degassing device, comprising a receiving tank for temporarily storing degassed liquid crystal and a liquid feed pump for supplying the liquid crystal in the receiving tank to a liquid crystal injecting device. 2. The degassed liquid crystal that has passed through the degassing tube in a depressurized state is temporarily stored in a depressurizable receiving tank, and a necessary amount of liquid crystal is then supplied by a liquid feed pump to the liquid crystal injecting device by a three-way cock when depressurizing. Incorporated with a degassing device characterized by discharging liquid crystal from the liquid crystal reservoir through a three-way cock when pressure is applied after the liquid crystal is injected and sealed by the liquid crystal injecting device via the three-way cock. Operation method of liquid crystal supply device.