KR100642489B1 - Apparatus and method for injecting liquid crystal of lcd device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for injecting liquid crystal into a liquid crystal panel and a method for injecting liquid crystal in manufacturing a liquid crystal display (LCD). In particular, the liquid crystal panel is heated to a uniform temperature by using a heating tank based on a bath. The present invention relates to a liquid crystal injecting device and a liquid crystal injecting method, which are capable of ensuring the injection property and the speed improvement and the uniformity of the quality when the liquid crystal is injected in a high temperature atmosphere.

The present invention provides a liquid crystal injection apparatus and method in which a non-thermal fluid (for example, water) is brought into contact with the outer surface of a liquid crystal panel, and the fluid is heated and circulated to allow heating to be performed at a uniform temperature over the entire surface of the liquid crystal panel. 3, a heating tank 24 is installed in the vacuum chamber 21, a fluid 23 having a large specific heat is filled in the heating tank, and a heater 27 for heating the fluid. And a device 30 for circulating, and a temperature sensor for sensing the temperature of the fluid and a controller for controlling temperature and circulation.

Liquid crystal display device, liquid crystal injection device, liquid crystal injection method

Description

Liquid crystal injection device and liquid crystal injection method {APPARATUS AND METHOD FOR INJECTING LIQUID CRYSTAL OF LCD DEVICE}

1 is a conventional liquid crystal injector, and shows a configuration of a liquid crystal injector of a liquid crystal panel direct heating method using a hot plate.

2 is a conventional liquid crystal injector, and shows a structure of a liquid crystal panel indirect heating method using a liquid crystal panel using an atmospheric heating method.

3 is a diagram showing the configuration of a liquid crystal injecting device as a first embodiment of the present invention.

4 is a perspective view of a heating tank of a liquid crystal injection apparatus as a first embodiment of the present invention;

5 is a view showing the configuration of a liquid crystal injection device as a second embodiment of the present invention.

The present invention relates to an apparatus for injecting liquid crystal into a liquid crystal panel and a method of injecting the same in a manufacturing process of a liquid crystal display (LCD), and in particular, comprising a heating tank based on a hot water method to inject a liquid crystal in a high temperature atmosphere. The fluid circulating to a high temperature in the heating tank contacts the surface of the liquid crystal panel to heat the liquid crystal panel, thereby ensuring temperature uniformity of the liquid crystal panel, and at the same time, the temperature difference between the liquid crystal panels when the liquid crystal is injected into a large amount of the liquid crystal panel. It relates to a liquid crystal injection device and a liquid crystal injection method to reduce the quality to ensure the uniformity of the quality.

A liquid crystal display generally consists of two substrates arranged to face each other at regular intervals and a liquid crystal injected between the two substrates.

In the case of a TFT color LCD, the first substrate includes a pixel electrode, a transistor for driving the pixel, an alignment layer, and the like, and the second substrate includes an alignment layer, an R, G, B color filter, a common electrode, and the like. The liquid crystal display device is completed by injecting liquid crystal between two substrates.

As is known, since liquid crystals have refractive index anisotropy with respect to short axis and long axis, it is essential for the liquid crystal display to control the arrangement of the liquid crystal molecules uniformly to obtain uniform brightness and high contrast ratio. An orientation film is applied to the surface, and an alignment treatment such as rubbing is applied to impart orientation to the liquid crystal.

However, when the liquid crystal is injected at room temperature, the trace of injection appears in the alignment layer due to the nematic properties of the liquid crystal, and in order to overcome this problem, the nematic transition temperature of the liquid crystal (the liquid crystal transitions to an isotropic phase in the nematic phase) The liquid crystal is raised to a higher temperature than the above-mentioned temperature, and at this temperature), and an isotropic liquid crystal is injected into the liquid crystal cell.

In addition, injecting the liquid crystal in a high temperature atmosphere is to lower the viscosity of the liquid crystal, so that the liquid crystal can penetrate between the liquid crystal panel (substrate) at a higher speed.                         

In particular, in the case of a large liquid crystal display device, the injection speed of the liquid crystal is an important problem that may affect the quality and productivity of the completed liquid crystal display device. The pressurization and pressure reduction techniques in a liquid crystal injection chamber are utilized.

The basic principle of the liquid crystal injection described above is based on the capillary phenomenon, and the factors determining the speed at which the liquid crystal is injected between the two substrates (panel) are the viscosity of the liquid crystal and the pressure inside and outside the liquid crystal panel when the liquid crystal is injected in the vacuum chamber. Tea etc. can be mentioned.

In particular, it is known that the injection speed is determined in inverse proportion to the viscosity of the liquid crystal, and the injection speed is determined in proportion to the pressure difference inside and outside the liquid crystal panel.

Therefore, as a means for increasing the injection speed of the liquid crystal (means for shortening the injection time), the viscosity of the liquid crystal can be lowered by the temperature rise.

Particularly, in the case of high viscosity smectic liquid crystals, high temperature injection is essential when selecting a liquid crystal injection method.

In addition to the liquid crystal injection technique in such a high temperature atmosphere, in order to increase the injection speed of the liquid crystal, as mentioned above, a method of increasing the difference between the pressure inside and outside the panel in the chamber can be used, and the pressure difference can be further increased. Artificial pressure and pressure reduction techniques may be used for this purpose.

As is known, a general liquid crystal injection method is as follows.

First, the liquid crystal panel, the heating means and the liquid crystal are prepared in the vacuum chamber, the liquid crystal panel is heated, and the chamber is brought into a low pressure state (vacuum state) using a vacuum pump or the like to make the inside of the liquid crystal panel in a low pressure state.

Next, the inlet of the liquid crystal panel is brought into contact with the liquid crystal in the container containing the liquid crystal, and the chamber is brought into an atmospheric pressure state by introducing air (or a predetermined gas such as nitrogen gas) into the chamber.

Then, while the inside of the liquid crystal panel maintains a vacuum state, pressure is applied to the liquid crystal by the gas introduced therein, and the liquid crystal is injected into the liquid crystal panel through the inlet of the liquid crystal panel by this pressure.

Conventionally, when injecting a liquid crystal into a large area LCD panel, the liquid crystal panel is directly heated by using a hot plate to increase the liquid crystal injection speed, or by indirectly heating the liquid crystal panel by heating the atmosphere inside the vacuum chamber. Injected.

However, the direct heating method is difficult to guarantee the temperature uniformity of the hot plate, the temperature difference is too great even in the hot plate, the injection characteristics are inferior, and the injection speed is different for each panel.In the case of the atmospheric heating method, the atmosphere inside the chamber is outside the chamber temperature. Temperature control was difficult because it was susceptible to changes.

Fig. 1 shows a conventional liquid crystal injecting apparatus, and shows a liquid crystal injecting apparatus of a direct heating method of a liquid crystal panel using a hot plate.

Inside the vacuum chamber 1, there is a liquid crystal container 3 containing a liquid crystal 2, and the liquid crystal injection by capillary phenomenon is performed by contacting the injection hole 4a of the liquid crystal panel 4 with the liquid crystal 2. .                         

At this time, the hot plate 5 is in close contact with the outer surface of the liquid crystal panel 4 for injection in a high temperature atmosphere, and the temperature controller 6 is connected to the hot plate 5 to heat the liquid crystal plate while controlling the hot plate 5 to an appropriate temperature. The panel 4 is kept heated to a predetermined temperature.

In addition, to improve the speed of liquid crystal injection, a vacuum pump 7 or the like is provided to make the inside of the chamber into a vacuum state or to introduce atmospheric air into an atmospheric pressure state.

When the liquid crystal is injected, the inside of the chamber is made into a vacuum state by operating the vacuum pump 7 to inject the liquid crystal 2. As a result, when the inside of the liquid crystal panel 4 also becomes a vacuum state, the liquid crystal injection hole of the liquid crystal panel 4 is injected. 4a is brought into contact with the liquid crystal 2 and outside air is introduced into the chamber.

Then, the inside of the chamber 1 is at atmospheric pressure, and the liquid crystal 2 is quickly moved into the liquid crystal panel 4 due to the pressure difference between the inside of the liquid crystal panel 4 in a vacuum state and the chamber at atmospheric pressure by the outside air. Is injected.

In this case, as described above, the liquid crystal injection may be performed in the steps of heating the liquid crystal panel, evacuating the inside of the chamber, inflowing outside air, injecting the liquid crystal by a pressure difference, and a capillary phenomenon.

However, when the liquid crystal panel is directly heated by the hot plate as described above, there are the following problems.

First, since the temperature uniformity of the hot plate 5 cannot be guaranteed, the temperature uniformity of the liquid crystal panel 4 is also impaired.

Second, when the temperature difference in the hot plate 5 is large, the liquid crystal injection characteristics may be deteriorated.                         

Third, when the liquid crystal injection operation is simultaneously performed in one chamber with respect to a plurality of liquid crystal panels, a temperature difference may occur for each hot plate in contact with each liquid crystal panel, and in this case, liquid crystal injection for each liquid crystal panel. The speed of is changed so that the uniformity of quality cannot be secured.

Fig. 2 shows a conventional liquid crystal injecting device, which shows a liquid crystal panel indirect heating method using a liquid crystal panel using an atmospheric heating method.

In the chamber 11, a liquid crystal container 13 containing liquid crystals 12 is provided, and a heating device 15 for heating the air inside the chamber 11 to indirectly heat the liquid crystal panel 14 is provided. A temperature controller 16 for adjusting the temperature of the heating device 15 is provided.

On the other hand, the liquid crystal injection device of FIG. 2 may also be provided with a vacuum pump.

The liquid crystal injection method by the liquid crystal injection device of FIG. 2 is performed as follows.

First, under the control of the temperature controller 16, the heating device 15 heats the air in the chamber 11, and the liquid crystal panel 14 is heated by the convection of the heated air.

When the liquid crystal panel 14 is heated to a predetermined desired temperature, the inside of the chamber 11 is brought into a vacuum state, and the injection hole 14a of the liquid crystal panel 14 is brought into contact with the liquid crystal 12.

In this state, the inside of the liquid crystal panel 14 maintains a vacuum state, and the outside air is introduced into the chamber 11 while the inside of the liquid crystal panel maintains a vacuum state.

When outside air flows into the chamber 11, the liquid crystal 13 is injected into the liquid crystal panel 14 through the liquid crystal injection hole 14a by a pressure difference between the inside and the outside of the liquid crystal panel 14 and a capillary phenomenon.                         

However, such an air-heated liquid crystal injection device has the following problems.

First, since the specific heat value of the air is small, it is easy to be affected by the external temperature change, and it is difficult to precisely control the temperature when the air temperature change suddenly occurs in accordance with the external temperature change.

Second, in the case of gas, the physical properties thereof are very difficult to warm up or down to a desired temperature, or to pressurize or depressurize to a desired pressure.

Third, in the case of gas, it is difficult to make fine adjustment in consideration of temperature and pressure at the same time because the physical property of the gas changes in pressure due to the temperature change, and also changes in temperature due to the pressure change.

The present invention provides a liquid crystal injecting device and a liquid crystal injecting method, wherein the liquid crystal panel is heated based on a hot water method in injecting liquid crystal into the liquid crystal panel in a high temperature atmosphere.

In another aspect, the present invention provides a liquid crystal injection device and a liquid crystal injection method characterized in that the liquid crystal panel is heated using a heating tank based on the hot water method in injecting the liquid crystal into the liquid crystal panel in a high temperature atmosphere.

In addition, the present invention has a heating tank based on the hot water method in injecting the liquid crystal into the liquid crystal panel in a high temperature atmosphere, and heats the liquid crystal panel by conducting the heat of the fluid circulating in the heating tank to the liquid crystal panel. A liquid crystal injection apparatus and a liquid crystal injection method are provided.

In addition, the present invention has a heating tank based on the bath method in injecting the liquid crystal into the liquid crystal panel in a high temperature atmosphere, when the heat of the fluid circulating inside the heating tank to the liquid crystal panel, the inside of the heating tank circulates It provides a liquid crystal injection device and a liquid crystal injection method characterized in that for heating the liquid crystal panel having a means for heating the fluid and means for forcibly circulating the heated fluid.

In another aspect, the present invention provides a liquid crystal injection device and a liquid crystal injection method to ensure a uniform temperature by the liquid crystal panel is heated to an even temperature across the entire surface by the fluid circulating in the heating tank.

In addition, the present invention may be at least one liquid crystal panel heated by a fluid circulating inside the heating tank, when at least one liquid crystal panel is injected at the same time, all of the at least one or more liquid crystal panel is said to be at least the same The present invention provides a liquid crystal injecting device and a liquid crystal injecting method capable of ensuring uniformity in quality and improved injection property in a plurality of liquid crystal panel simultaneous injection processes by heating with sufficient temperature uniformity.

The liquid crystal injecting apparatus of the present invention includes a chamber capable of adjusting air pressure, at least one liquid crystal panel installed inside the chamber, a heating tank for heating the liquid crystal panel based on a water bath method, the liquid crystal panel and Liquid crystal injection device, characterized in that consisting of the liquid crystal is installed at intervals of.                     

In the present invention, the heating tank is filled with a fluid having a predetermined specific heat value for heat conduction.

In the present invention, the fluid filled in the heating tank is characterized in that the water.

In the present invention, the heating tank is characterized in that the liquid crystal panel has a liquid crystal panel accommodating heating unit for heating the liquid crystal panel in contact with the accommodated liquid crystal panel.

In the present invention, the heating tank is characterized in that it comprises a heating means for heating the fluid filled in the heating tank.

In the present invention, the heating tank is characterized in that it comprises a circulation means for forcibly circulating the fluid filled in the heating tank.

In the present invention, the heating tank is characterized in that the wall other than the contact surface with the liquid crystal panel is insulated.

In the present invention, the liquid crystal panel accommodating heating part of the heating tank further includes a heat transfer medium having a predetermined thermal conductivity for closely contacting the liquid crystal panel and the accommodating heating part between the liquid crystal panel and the accommodating heating part.

The heat transfer medium in the present invention is characterized in that the pad is in close contact with the pad in front of the liquid crystal panel.

In the present invention, the close contact pad is characterized in that it has elasticity.

In the present invention, the adhesion pad is characterized in that the silicone rubber.

In the present invention, the liquid crystal injection device is characterized in that it has a temperature control means for maintaining the temperature of the fluid filled in the heating tank at a predetermined set temperature.

Hereinafter, with reference to the accompanying drawings, a liquid crystal injecting apparatus of the present invention and a liquid crystal injecting method made by the liquid crystal injecting apparatus will be described as examples.

First, Figure 3 is a view showing the configuration of a first embodiment of the liquid crystal injection device of the present invention, Figure 4 is a perspective view of an embodiment of a heating tank according to the first embodiment of the present invention.

As shown in Figs. 3 and 4, the liquid crystal injection device of the present invention is accommodated in the chamber 21.

The chamber 21 is equipped with intake and exhaust means 22 for adjusting the air pressure in the chamber to depressurize or pressurize the chamber 21 at an appropriate stage according to the liquid crystal injection process.

The chamber 21 is provided with a heating tank 24 filled with a fluid 23 therein.

The fluid 23 filled in the heating tank 24 is satisfied if the material has a specific heat of a predetermined value or more suitable for liquid crystal injection in a high temperature atmosphere, for example, water is sufficient.

The heating tank 24 accommodates the liquid crystal panel 25 in contact with the liquid crystal panel 25 so that the liquid crystal can be injected into the liquid crystal panel 25 in a high temperature atmosphere, and accommodates the liquid crystal panel 25. The heating part 26 is formed.

The accommodating heating part 26 may be formed, for example, as a rectangular hole penetrating vertically through the heating tank 24 as shown in the drawing, and the liquid crystal panel 25 corresponds to the accommodating heating part 26. Is stored in close contact with the tank wall surface.

In order to reduce heat loss of the heating tank 24 and to concentrate the heating of the liquid crystal panel 25 by the accommodating heating part 26, the wall surface of the heating tank 24 may be insulated.

Of course, even in this case, the tank wall surface corresponding to the storage heating part 26 is excluded from the heat treatment.

The heating tank 24 incorporates a heater 27 as a heating means for heating the fluid 23 filled therein.

In order to adjust the temperature of the fluid 23 heated by the heater 27, a temperature sensor 28 is built in the heating tank 24, and the temperature of the fluid 23 detected by the temperature sensor 28 Accordingly, a temperature controller 29 for controlling the drive of the heater 27 is provided as the temperature control means.

On the other hand, the circulation pump 30 is mounted to the heating tank 24 as a means for forcibly circulating the fluid 23 filled in the heating tank 24 in the tank.

The liquid crystal container 32 containing the liquid crystal 31 is placed inside the chamber 21. In the step before liquid crystal injection, the liquid crystal injection hole 25a of the liquid crystal panel 25 is predetermined with the liquid crystal 31. In the liquid crystal injection step, the liquid crystal container 32 rises and the liquid crystal 31 contacts the liquid crystal injection hole 25a of the liquid crystal panel 25 in the liquid crystal injection step.

The liquid crystal injection method according to the liquid crystal injection device of the present invention configured as described above is made as follows.

[One]. Preparation step

A liquid crystal container 32 containing a liquid crystal 31 in a chamber 21 in which a heating tank 24 in which at least one liquid crystal panel 25 is accommodated is installed, and in a chamber 21 in which a heating tank 24 is installed. Is provided at a predetermined interval from the liquid crystal injection port 25a of the liquid crystal panel 25.

[2]. Decompression stage

The inside of the chamber 21 is reduced in pressure by operating the intake and exhaust means 22 to discharge the atmosphere inside the chamber 21 to the outside.

For example, the inside of the chamber 21 is made into a vacuum state using a vacuum pump.

[3]. Heating stage

The heater 27 is driven by the temperature controller 29 to heat the fluid 23 inside the heating tank 24.

At this time, by detecting the temperature of the fluid 23 using the temperature sensor 28, the temperature controller 29 controls the driving of the heater 27 to maintain a predetermined set temperature.

As the heater 27 is driven, the fluid 23 is heated, and the heated fluid 23 may naturally circulate due to convection in the tank.

However, by operating the circulation pump 30, it is possible to keep the fluid 23 inside the heating tank 24 heated to a predetermined set temperature with a faster, more uniform temperature distribution.

In response to the driving of the heater 27 and the driving of the circulation pump 30, the fluid 23 circulates inside the tank 24 in a heated state and is in contact with the liquid crystal panel accommodating heating part 26. ) Will heat up.

At this time, the heating tank 24 may increase the thermal efficiency by heat-insulating the remaining wall surface except the storage heating portion 26, and may concentrate the heat possessed by the fluid 23 to the storage heating portion 26. .

When the liquid crystal panel 25 is heated through the receiving heating unit 26, the liquid 23 continues to supply heat while circulating in the tank, so that the liquid crystal panel 25 may be heated with an even temperature distribution over its entire surface. Also, even when several liquid crystal panels are heated simultaneously, the fluid 23 circulating in one same tank transfers heat to each liquid crystal panel, thereby minimizing a temperature difference heated for each liquid crystal panel.

In this way, the liquid crystal panel 25 is uniformly heated in the heating tank 24 to have a predetermined temperature distribution characteristic up to a predetermined temperature.

[4]. Liquid Crystal Injection Step

The liquid crystal container 32 is raised to bring the liquid crystal 31 into contact with the injection port 25a of the heated liquid crystal panel 25.

The intake and exhaust means 22 are operated in the state in which the injection port 25a of the liquid crystal panel 25 is in contact with the liquid crystal 31 so that outside air is introduced into the chamber 21.

When the outside air flows into the chamber 21, the pressure inside the chamber 21 increases, and a pressure difference between the inside and the outside of the liquid crystal panel 25 is generated. As a result, the pressure difference and the capillary phenomenon cause the liquid crystal ( 31 is injected into the liquid crystal panel 25 through the liquid crystal injection hole 25a.

At this time, the liquid crystal 31 will be injected into the liquid crystal panel 25 by the high temperature atmosphere by the heating tank 24 and the pressure difference by the intake and exhaust means 22.

In addition, as described above, since the temperature difference in one liquid crystal panel or between the plurality of liquid crystal panels is overcome by a series of heating means based on the water bath method, the liquid crystal injection rate injected into each liquid crystal panel is the same. This will keep the liquid crystal injection property good and ensure the quality uniformity of the liquid crystal display device to be completed after the liquid crystal is injected.

In the present invention, if the liquid crystal injection port 25a is pressed and the pressure is reduced in the opposite direction opposite to the liquid crystal injection port 25a, it is possible to further increase the liquid crystal injection speed by increasing the pressure difference in the liquid crystal injection step.

FIG. 5 is a view showing the configuration of a liquid crystal injection device as a second embodiment of the present invention. The same components as those of FIG. 3 are denoted by the same reference numerals and description thereof will not be repeated.

In the second embodiment of the liquid crystal injecting apparatus of the present invention shown in FIG. 5, the close contact pad 33 is made of a material having excellent thermal conductivity and sufficient elasticity, for example, silicone rubber, to the accommodating heating part 26. If it is installed.

The adhesion pad 33 receives heat from the fluid 23 in the heating tank 24 and transmits the heat to the liquid crystal panel 25.

In addition, the adhesion pad 33 is made of a material having elastic force, so that the entire outer surface of the liquid crystal panel 25 mounted between the adhesion pads 33 is in close contact with the adhesion pad 33 as a heat transfer medium. Allows it to be delivered and heated to an even temperature distribution.

The present invention secures a high-temperature atmosphere during liquid crystal injection using a heating tank based on the hot water bath method, thereby reducing the temperature difference between the liquid crystal panels during high temperature injection of the liquid crystal, thereby improving injection characteristics.

In addition, the present invention can reduce the temperature difference between the liquid crystal panel in the simultaneous liquid crystal injection process of a plurality of liquid crystal panel when applied to mass production to ensure uniformity of quality.

In addition, the present invention makes it easy to adjust the cooling rate when applied to the ferroelectric liquid crystal (FLC), thereby ensuring an excellent orientation.

Claims (16)

At least one liquid crystal panel installed inside the chamber, a heating tank for heating the liquid crystal panel based on a bath method, and a liquid crystal installed at a predetermined interval from the liquid crystal panel. Liquid crystal injection device, characterized in that made. The liquid crystal injection apparatus of claim 1, wherein the heating tank is filled with a fluid having a predetermined specific heat value for thermal conduction. The liquid crystal injection apparatus of claim 2, wherein the fluid filled in the heating tank is water. 2. The liquid crystal injection apparatus according to claim 1, wherein the heating tank has a liquid crystal panel accommodating heating portion for accommodating the liquid crystal panel and contacting the accommodated liquid crystal panel to heat the liquid crystal panel. The liquid crystal injection apparatus of claim 1, wherein the heating tank includes heating means for heating a fluid filled in the heating tank. The liquid crystal injection apparatus of claim 1, wherein the heating tank includes circulation means for forcibly circulating a fluid filled in the heating tank. The liquid crystal injection apparatus according to claim 1, wherein the heating tank is insulated from a wall other than a contact surface with the liquid crystal panel. The liquid crystal panel of claim 4, wherein the liquid crystal panel accommodating heating part of the heating tank further includes a heat transfer medium having a predetermined thermal conductivity for closely contacting the liquid crystal panel and the accommodating heating part between the liquid crystal panel and the accommodating heating part. Infusion device. 9. The liquid crystal injection apparatus according to claim 8, wherein the heat transfer medium is a pad that is in close contact with the entire surface of the liquid crystal panel. The liquid crystal injection apparatus of claim 8, wherein the heat transfer medium has elasticity. 9. The liquid crystal injection apparatus according to claim 8, wherein the heat transfer medium is silicon rubber. The liquid crystal injection apparatus according to claim 1, further comprising temperature control means for maintaining a temperature of the fluid filled in the heating tank at a predetermined temperature. A heating tank in which the liquid crystal panel is accommodated is installed in the chamber, and a liquid crystal is installed to face the liquid crystal inlet of the liquid crystal panel; Depressurizing the interior of the chamber; Uniformly heating the entire surface of the panel surface of the liquid crystal panel by the heating tank; And injecting a liquid crystal into the heated liquid crystal panel and pressurizing the inside of the chamber to inject a liquid crystal into the liquid crystal panel. The liquid crystal injection method according to claim 13, wherein the liquid crystal panel is heated and the liquid crystal injection is performed simultaneously on at least one liquid crystal panel. The liquid crystal injection method according to claim 13, wherein the heating of the liquid crystal panel by the heating tank is performed by a fluid circulating in the heating tank. The liquid crystal injection method according to claim 13, wherein the heating of the liquid crystal panel by the heating tank is performed by a fluid circulating in the heating tank, and the fluid is forcedly circulated by the circulation means.

Images