JPH08122797A - Method for injecting liquid crystal and device therefor - Google Patents

Abstract

PURPOSE: To prevent damage of a panel by controlling swelling of a liquid crystal panel and to improve reliability of the liquid crystal panel by maintaining flatness of the panel. CONSTITUTION: A liquid crystal, liquid crystal panels 12, a master panel 16 equivalent to the liquid crystal panels 12 and a precision displacement gauge 17 installed on the master panel surface are provided in a vacuum vessel 11. Change of panel swelling caused by pressure difference between the pressure in the vacuum vessel 11 and the pressure in the liquid crystal panels 12 is measured by the precision displacement gauge 17 and is sent to a control box 19. The control box 19 regulates a ventillation speed by a rotation speed of a pump 21 for evacuating the inside of the vacuum vessel 11 and closing extent of an electrically variable valve 20 and also controls filling pressure of minute quantity of an inactive gas into the vacuum vessel 11 when necessary. Consequently, the swelling of the liquid crystal panels 12 is suppressed below normal value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal injection method and a liquid crystal injection device for injecting liquid crystal into a liquid crystal panel used in a liquid crystal display device or the like.

[0002]

2. Description of the Related Art Conventionally, liquid crystal display devices have excellent characteristics such as thinness, light weight, low voltage drive, and low power consumption. Personal computers, personal word processors, liquid crystal television devices, liquid crystal video cameras, projectors, car navigation systems. In-vehicle display such as system,
Mobile phones, portable information terminals, display devices for various devices, etc.
Widely used as a flat-panel display device.

As shown in FIG. 7, in general, a liquid crystal panel 1 which is a display element of a liquid crystal display device has a pair of substrates 1a and 1b arranged so as to face each other. These substrates 1a,
The substrate 1b is attached with a sealing material 1c interposed at the peripheral portion of the substrate at a predetermined distance.
A liquid crystal material is injected between a and 1b. Further, the sealing material on one side of the liquid crystal panel 1 is partially removed,
A liquid crystal injection port 1d for injecting a liquid crystal material is formed between the substrates 1a and 1b at the portion where the sealing material is removed.

A liquid crystal injecting device for injecting a liquid crystal material into the liquid crystal panel 1 is, as shown in FIG.
Then, the liquid crystal panel 1 is installed so that the inlet 1d faces downward, and the inside of the vacuum container 2 is evacuated. Along with that, the inside of the liquid crystal panel 1 is also evacuated through the injection port 1d, and when a constant vacuum pressure is maintained, as shown in FIG. Inlet 1 of liquid crystal panel 1
d is dipped. Then, the vacuum container 2 is filled with an inert gas, and the atmospheric pressure in the vacuum container 2 is returned to normal pressure. At this time,
Since the inside of the liquid crystal panel 1 is kept in a vacuum state, the liquid crystal material inside the container 3 is filled with the liquid from the inlet 1 of the liquid crystal panel 1 due to the pressure difference between the inside of the vacuum container 2 and the inside of the liquid crystal panel 1.
It is injected from d into the liquid crystal panel 1.

[0005]

However, in the above-mentioned conventional liquid crystal injecting apparatus, when the liquid crystal panel 1 and the container 3 containing the liquid crystal are installed in the vacuum container 2 and the vacuum container 2 is evacuated, The inside of the liquid crystal panel 1 gradually becomes a vacuum,
The evacuation speed from the inlet 1d of the liquid crystal panel 1 is very slow as compared with the evacuation speed from the inside of the vacuum container 2, so that there is a difference in the degree of vacuum between the inside of the liquid crystal panel 1 and the inside of the vacuum container 2. This pressure difference becomes higher inside the liquid crystal panel 1, and the liquid crystal panel 1 expands as shown in FIG. 9A.

In such expansion of the liquid crystal panel 1,
The expansion amount increases as the panel becomes larger, and becomes 200 to 300 times the cell gap of the liquid crystal panel 1 depending on the exhaust speed.

As shown in FIG. 9 (b), as the liquid crystal panel 1 becomes larger, the sealing material 1c is attached to the upper and lower substrates 1a, 1b of the liquid crystal panel 1 due to the expansion of the liquid crystal panel 1 during vacuum evacuation. The pressure applied to the sealing material 1c increases, the adhesion between the sealing material 1c and the upper and lower substrates 1a, 1b decreases, and the sealing material 1c
And the upper and lower substrates 1a and 1b are separated from each other at any position of X, Y, and Z of the sealing material 1c, the liquid crystal panel 1 itself is cracked, and the flatness of the panel is increased due to the expansion of the liquid crystal panel 1. There are problems that have not been seen in conventional small LCD panels, such as the problem of being lost.

FIG. 10 shows the relationship between the degree of vacuum and the expansion displacement amount of the liquid crystal panel 1 when the inside of the vacuum container 2 is evacuated by the conventional liquid crystal injection device. As shown in FIG. 10, the panel displacement amount indicated by the thick line C increases as the degree of vacuum indicated by the thin line D increases, and exceeds the predetermined value A as a safety value that may damage the liquid crystal panel 1. I know that

The present invention solves the above-mentioned conventional problems. When the inside of the vacuum container is evacuated, the expansion of the liquid crystal panel is controlled to prevent the panel from being damaged, and the flatness of the panel is maintained to maintain the liquid crystal. An object of the present invention is to provide a liquid crystal injection method and a liquid crystal injection device that can improve the reliability of a panel.

[0010]

According to the liquid crystal injection method of the present invention, a container containing liquid crystal and a liquid crystal panel are installed in a vacuum container, the interior of the vacuum container is evacuated, and then the liquid crystal is placed in the vacuum container. Liquid crystal injection in which the opening of the panel is immersed in liquid crystal, the vacuum container is filled with, for example, an inert gas to restore the pressure inside the vacuum container, and the liquid crystal is injected into the liquid crystal panel due to the pressure difference between the inside and outside of the liquid crystal panel. In the method, a liquid crystal panel according to a pressure difference between an air pressure inside the liquid crystal panel and an air pressure outside the liquid crystal panel due to a difference between an exhaust speed for exhausting the inside of the vacuum container to a vacuum and an exhaust speed from the inside of the liquid crystal panel. The pressure in the vacuum container is controlled so that the expansion of the vacuum chamber does not exceed a predetermined limit, and thereby the above-mentioned object is achieved.

In the liquid crystal injecting method of the present invention, a container containing liquid crystal and a liquid crystal panel are installed in a vacuum container, the inside of the vacuum container is evacuated, and the opening of the liquid crystal panel is opened in the vacuum container. In the liquid crystal injection method of immersing the liquid crystal in the liquid crystal, filling the vacuum container with, for example, an inert gas to restore the internal pressure of the vacuum container, and injecting the liquid crystal into the liquid crystal panel by the pressure difference between the inside and the outside of the liquid crystal panel, Displacement of the expansion of the liquid crystal panel due to the difference between the air pressure inside the liquid crystal panel and the air pressure outside the liquid crystal panel due to the difference between the exhaust speed for exhausting the inside of the container to a vacuum and the exhaust speed from the inside of the liquid crystal panel. Based on the measurement data measured by a measuring means, at least the exhaust speed of the exhaust speed from the inside of the vacuum container and the filling of a small amount of gas into the vacuum container is determined by the expansion of the liquid crystal panel. Is the predetermined limit Is intended to control so as not to exceed the above-described object can be achieved.

Further, according to the liquid crystal injection method of the present invention, a container containing liquid crystal and a liquid crystal panel are installed in a vacuum container, the interior of the vacuum container is evacuated, and the opening of the liquid crystal panel is opened in the vacuum container. In the liquid crystal injection method of immersing the liquid crystal in the liquid crystal, filling the vacuum container with, for example, an inert gas to restore the internal pressure of the vacuum container, and injecting the liquid crystal into the liquid crystal panel by the pressure difference between the inside and the outside of the liquid crystal panel, A liquid crystal panel due to a pressure difference between an air pressure inside the liquid crystal panel and an air pressure outside the liquid crystal panel in the vacuum container due to a difference between an exhaust speed for exhausting the inside of the container to a vacuum and an exhaust speed from the inside of the liquid crystal panel. Of the expansion of the vacuum container based on the measurement data measured in advance by using a displacement measuring unit, and at least the exhaust speed of the exhaust rate in the vacuum container and the filling of a small amount of gas into the vacuum container,
The expansion is controlled so that the expansion of the liquid crystal panel does not exceed a predetermined limit, whereby the above object is achieved.

In the above liquid crystal injection method of the present invention, preferably, the control of the exhaust speed in the pressure control in the vacuum container is performed by at least one of the rotation speed of the exhaust pump and the opening / closing amount of the exhaust valve. Control.

Further, in the liquid crystal injecting apparatus of the present invention, at least the liquid crystal and the liquid crystal panel are installed in a vacuum container, the inside of the vacuum container is evacuated, and the opening of the liquid crystal panel is immersed in the liquid crystal, In a liquid crystal injecting apparatus for injecting the liquid crystal into the liquid crystal panel by a pressure difference between the inside and the outside of the liquid crystal panel in the vacuum container, for example, an inert gas is filled in the vacuum container to restore the pressure in the vacuum container, The liquid crystal due to the difference between the atmospheric pressure inside the liquid crystal panel and the atmospheric pressure outside the liquid crystal panel inside the vacuum container due to the difference between the exhaust speed for exhausting the inside of the vacuum container to a vacuum and the exhaust speed inside the liquid crystal panel. The panel has a control unit for controlling the pressure in the vacuum container so that the expansion of the panel does not exceed a predetermined limit, thereby achieving the above object.

Further, in the liquid crystal injecting apparatus of the present invention, at least the liquid crystal and the liquid crystal panel are installed in a vacuum container, the inside of the vacuum container is evacuated, and the opening of the liquid crystal panel is immersed in the liquid crystal, In a liquid crystal injecting apparatus for injecting the liquid crystal into the liquid crystal panel by a pressure difference between the inside and the outside of the liquid crystal panel in the vacuum container, for example, an inert gas is filled in the vacuum container to restore the pressure in the vacuum container, A panel displacement measuring unit for measuring expansion of the liquid crystal panel due to a difference in air pressure between the inside and outside of the liquid crystal panel due to a difference between an exhaust speed for exhausting the inside of the vacuum container to a vacuum and an exhaust speed from inside the liquid crystal panel, and the panel displacement Based on the measurement data from the measuring unit, the expansion speed of the liquid crystal panel is determined by the exhaust speed from the vacuum container and at least the exhaust speed of filling a small amount of an inert gas into the vacuum container. Are those having a control unit for controlling so as not to exceed the limit, the objects can be achieved.

Further, in the liquid crystal injecting apparatus of the present invention, at least the liquid crystal and the liquid crystal panel are installed in a vacuum container, the inside of the vacuum container is evacuated, and the opening of the liquid crystal panel is immersed in the liquid crystal, In a liquid crystal injecting apparatus for injecting the liquid crystal into the liquid crystal panel by a pressure difference between the inside and the outside of the liquid crystal panel in the vacuum container, for example, an inert gas is filled in the vacuum container to restore the pressure in the vacuum container, A panel member for measuring panel expansion / displacement provided in the vacuum container, displacement measuring means for measuring panel expansion displacement of the panel member, and exhaust gas in the vacuum container based on displacement data from the displacement measuring means. A control means for controlling the speed and at least the evacuation speed of filling a small amount of gas into the vacuum container so that the expansion of the liquid crystal panel does not exceed a predetermined limit. Ri the above-mentioned object can be achieved.

Further, in the liquid crystal injecting apparatus of the present invention, at least the liquid crystal and the liquid crystal panel are installed in a vacuum container, the inside of the vacuum container is evacuated, and the opening of the liquid crystal panel is immersed in the liquid crystal, In a liquid crystal injecting apparatus for injecting the liquid crystal into the liquid crystal panel by a pressure difference between the inside and the outside of the liquid crystal panel in the vacuum container, for example, an inert gas is filled in the vacuum container to restore the pressure in the vacuum container, Measurement data obtained by previously measuring the expansion of the liquid crystal panel due to the difference in the air pressure inside and outside the liquid crystal panel due to the difference between the gas exhaust speed for evacuating the inside of the vacuum container and the gas exhaust speed from the liquid crystal panel using a panel displacement measuring unit. Based on the above, a control means for controlling at least the exhaust speed of the exhaust speed in the vacuum container and the filling of a small amount of gas into the vacuum container so that the liquid crystal panel expansion does not exceed a predetermined limit. It is those having the above objects can be achieved.

[0018]

With the above structure, the expansion of the liquid crystal panel is prevented from exceeding a predetermined limit due to the pressure difference between the inside and outside of the liquid crystal panel due to the difference between the exhaust speed for exhausting the inside of the vacuum container to a vacuum and the exhaust speed from the liquid crystal panel. Since the pressure in the vacuum container is controlled, the expansion of the liquid crystal panel is controlled to prevent the panel from being damaged, and the flatness of the panel is maintained to improve the reliability of the liquid crystal panel.

For example, when the vacuum container is evacuated to be evacuated, the displacement amount of the panel expansion due to the difference between the pressure inside the vacuum container and the pressure inside the liquid crystal panel is measured by the displacement measuring unit or the displacement measuring means. When the measured data exceeds a predetermined value, the rotation speed of the pump is reduced and the exhaust speed is adjusted by controlling the opening / closing amount of the electric variable valve to suppress the panel expansion. Also,
For example, if the displacement amount of panel expansion exceeds a predetermined value after adjusting the exhaust speed, fill the vacuum container with a small amount of, for example, an inert gas to reduce the degree of vacuum in the vacuum container and expand the panel. Suppress. The above-mentioned predetermined value as a safety value is a panel expansion displacement amount that does not impair the adhesiveness of the sealing material that adheres the upper and lower substrates.

Further, as described above, based on the measurement data measured by the displacement measuring unit, the displacement measuring means, etc., a program is preliminarily prepared which defines a procedure for reducing the pressure of the vacuum container, By inputting this program into the control unit or control means, control of exhaust such as increase / decrease in the number of rotations of the pump and opening / closing of the valve, if necessary, a small amount of inert gas is filled in the vacuum container to control the pressure. By doing
The panel expansion is suppressed without using the displacement measuring unit or the displacement measuring means, and the work efficiency is improved.

[0021]

Embodiments of the present invention will be described below.

(Embodiment 1) FIG. 1 is a block diagram of a liquid crystal injection device showing Embodiment 1 of the present invention. In FIG. 1, a plurality of liquid crystal panels 12 are provided in a vacuum container 11 and a liquid crystal injection port 12 is provided.
It is held by a holder 13 so that it can move up and down with d facing downward. Further, the liquid crystal panel 1 held by the holder 13
A container 15 in which the liquid crystal material 14 is housed is arranged below 2 so that the liquid crystal injection ports 12 d of the plurality of liquid crystal panels 12 are respectively immersed in the liquid crystal material 14 by the downward movement of the holder 13. ing. Further, in the vacuum container 11, a master panel 16 of the same type as the liquid crystal panel 12 is arranged, and on the surface of the master panel 16,
A precision displacement meter 17 as a displacement measuring means such as a micrometer or a dial gauge for measuring the panel thickness is arranged, and the master panel 16 and the precision displacement meter 17 are provided.
To measure the amount of expansion of the panel. This precision displacement meter 17
The output terminal of is connected to the control box 19 via the signal converter 18, and the data output from the precision displacement meter 17 is converted into a signal by the signal converter 18 and the information is input to the control box 19.

Further, the vacuum container 11 is an electrically variable valve 20.
It is connected to the depressurizing pump 21 through a pipe. Further, a vacuum gauge 22 for measuring the degree of vacuum in the vacuum container 11 is provided. Further, the vacuum container 11 includes the vacuum container 1
A nitrogen gas cylinder 23 for supplying nitrogen gas as an inert gas is connected to the inside of the pipe 1 through an electric variable valve 24. A signal line for a control signal is provided between the electric variable valves 20, 24 and the pump 21 and the control box 19. Further, signal lines for control signals are provided between the vacuum gauge 22 and the control box 19, respectively.

A master panel 16 as a panel member for measuring the expansion and displacement of the panel and a precision displacement meter 17 as a displacement measuring means constitute a panel displacement measuring section. The panel displacement measuring section and a control box 19 as a control means. , The signal converter 18, the electric variable valve 20,
24, the pump 21 and the vacuum gauge 22 constitute a control unit, and the control unit controls the liquid crystal according to the difference between the exhaust speed for exhausting the vacuum container 11 to a vacuum and the exhaust speed from the liquid crystal panel 12. The pressure in the vacuum container 11 is controlled so that the expansion of the liquid crystal panel 12 due to the pressure difference between the inside and outside of the panel 12 does not exceed a predetermined limit. The control of the exhaust speed in the pressure control in the vacuum container 11 controls at least one of the rotation speed of the pump 21 for exhaust and the opening / closing amount of the electric variable valve 20 for exhaust.

Here, an example of the structure of the liquid crystal panel 12 for injecting liquid crystal by the liquid crystal injecting apparatus of the present invention will be described.

FIG. 2A is a perspective view showing a schematic structure of the liquid crystal panel 12 of FIG. 1, and FIG. 2B is a sectional view thereof. In FIG. 2A and FIG. 2B, the liquid crystal panel 12
Is a pair of substrates 12 made of glass or plastic.
a and 12b. This substrate 12a is a so-called TF in which a plurality of pixel electrodes, TFTs (thin film transistors) for selectively driving the pixel electrodes, and wirings thereof are formed on one surface.
The substrate 12b is a T active matrix substrate, and the substrate 12b is a counter substrate having a counter electrode formed on one surface thereof. The substrate 12a is formed to be slightly larger than the substrate 12b in order to form an electrode for connecting a drive circuit. On both of these substrates 12a and 12b, the sealing material 1 is provided on the periphery thereof.
Substrate 1 in which 2c is interposed and is opposed to the inside of the display unit
Spacers (not shown) are scattered so as to keep the distance between 2a and 12b constant, and the electrodes are adhered so that their electrode forming surfaces face each other. A partially removed opening is formed in the sealing material 12c on one side of the liquid crystal panel 12, and a liquid crystal injection port for injecting the liquid crystal material between the openings 12a and 12b is formed in the opening. 12d is formed.

With the above configuration, the operation will be described below.

FIG. 3 is a control flow chart showing the operation of the liquid crystal injection device of FIG. In FIG. 3, first, in step S1, the pump 21 is turned on and driven, and then in step S2
Then, the electric variable valve 20 is fully opened to evacuate the inside of the vacuum container 11 to a vacuum state. At this time, the vacuum container 1
1 inside, liquid crystal panel 12 and master panel 16
9A, the liquid crystal panel 12 expands toward the center in the thickness direction and expands in the thickness direction toward the center, and the seal sections at both ends expand in a fan-shaped cross section. The larger the liquid crystal panel 12 becomes, the larger the expansion amount becomes, and the expansion amount becomes 200 to 300 times as large as the panel cell gap in the central portion of the panel depending on the exhaust speed and the seal pattern. In particular, the thinner the substrates 12a and 12b are plastic substrates, and the more easily the material is deformed, the larger the expansion amount becomes. In this embodiment, the central portion of the panel is controlled to be within 10 times the cell gap of the panel.

The displacement amount in the thickness direction due to this expansion is measured by using a precision displacement gauge 17. This precision displacement meter 17
The displacement amount of the master panel 16 due to is converted into an electric signal by the signal converter 18 and transmitted to the control box 19.

In step S3, the control box 19
Determines whether the displacement amount X is larger than a predetermined value A. That is, when the pumping speed in the liquid crystal panel 12 becomes slower than the pumping speed in the vacuum container 11, the panel displacement amount X becomes large.
Exceeds a predetermined value A shown in FIG. 4 (a panel expansion displacement amount as a safety value that does not impair the adhesiveness of the sealing material 12c that adheres the upper and lower substrates 12a and 12b). When the displacement amount X exceeds the predetermined value A (predetermined value A <displacement amount X), it is determined in step S4 whether the control variable (I) is smaller than n (n is a natural number), and if smaller, in step S5. The electric variable valve 20 is closed by one step. If the displacement amount X exceeds the predetermined value A even after repeating this operation n times, it is determined in step S6 whether the control variable (I) is smaller than n ′ (n ′ is a natural number, n ′> n). If it is smaller, the rotation speed of the pump 21 is set to one slow rotation in step S7 to control the exhaust speed. If the displacement amount X exceeds the predetermined value A even if this operation is repeated n ′ times, that is, if the panel displacement amount does not become the predetermined value A or less by this exhaust speed control, the electric variable valve 20 is determined in step S8.
Completely close.

Further, when the displacement amount X exceeds the predetermined value A, the control variable (I) is n ″ in step S6.
It is determined whether or not (n "is a natural number, n"> n '> n), the electric variable valve 20 is fully closed until the control variable (I) = n ", and in step S9 the electric variable valve 2
4 is opened for a moment to fill the vacuum container 11 with nitrogen gas, which is an inert gas, to reduce the degree of vacuum by one step. Then, in step S3, it is determined whether the displacement amount X is larger than the predetermined value A. By repeating this, the liquid crystal panel 12
The pressure difference between the inside and the outside is reduced to control the panel displacement amount to be equal to or lower than the upper predetermined value A. As described above, in the case of filling the inert gas, when the panel displacement amount decreases to the predetermined value B on the lower side of FIG. 4, the filling of the inert gas in step S9 is stopped and the process returns to step S1. The rotation speed of the pump 21 is increased in step S1, and the electric variable valve 20 is fully opened in step S2.

Further, when the displacement amount X does not exceed the predetermined value A in step S3, the atmospheric pressure data Z from the vacuum gauge 22 is determined to be the predetermined vacuum pressure (10 in the case of this embodiment) in step S10.
^-2 torr) Judge whether it is V or less. This vacuum gauge 2
The electric variable valve 20 is fully opened and exhausted in step S11 until the atmospheric pressure data Z from 2 reaches the predetermined vacuum pressure V. Then, the process returns to step S3, and the exhaust speed is repeatedly controlled and if necessary, the inert gas is filled. Further, when the atmospheric pressure data Z from the vacuum gauge 22 is equal to or lower than the predetermined vacuum pressure V in step S10, the liquid crystal panel 12 is lowered together with the holder in step S12, and the liquid crystal inlet 12 of the liquid crystal panel 12 is lowered.
After d is dipped in the liquid crystal material 14, the electric variable valve 24 is fully opened and the vacuum container 11 is filled with nitrogen gas which is an inert gas so that the pressure becomes normal pressure. Injection of the liquid crystal material 14 into the gap is started via the inlet 12d.

FIG. 4 shows an example of changes in the panel displacement amount and the degree of vacuum when the vacuum control of the liquid crystal injecting apparatus according to the first embodiment of the present invention is performed. The displacement amount of the liquid crystal panel is set to a predetermined value A or less. Can be kept automatically. In the case of FIG. 4, the filling of the inert gas has not been reached.

As described above, the liquid crystal panel 12 and the container 15 accommodating the liquid crystal 14 are installed in the vacuum container 11, the vacuum container 11 is evacuated, and the injection port 12d as the opening of the liquid crystal panel 12 is opened. Immerse in the liquid crystal material 14 in the container 15,
Liquid crystal injection configured to fill the vacuum container 11 with nitrogen gas, which is an inert gas, to restore the pressure in the vacuum container 11 and to inject the liquid crystal material 14 from the liquid crystal container 15 into the liquid crystal panel 12 by the pressure. In the apparatus, the vacuum container 11
When evacuating the chamber, a precision displacement gauge 17
Is set, the amount of change in panel expansion due to the pressure difference between the pressure in the vacuum container 11 and the pressure in the liquid crystal panel 12 is measured by the precision displacement meter 17, and the pump 21 for evacuating the vacuum container 11 is set.
Of the liquid crystal panel 12 by adjusting the exhaust speed by controlling the number of rotations of the electric variable valve 20 and the opening / closing amount of the electric variable valve 20 and by controlling the recompression pressure of the minute amount of the inert gas filling the vacuum container 11.
The expansion of the liquid crystal panel 12 can be suppressed and the reliability of the liquid crystal panel 12 can be obtained.

Here, the exhaust speed is (exhaust volume) /
(Time / volume to be evacuated), and if the evacuation speed of the vacuum container 11 and the evacuation speed of the liquid crystal panel 12 are equal, the atmospheric pressure in the vacuum container 11 and the atmospheric pressure in the liquid crystal panel 12 become equal, but in reality, Since the liquid is exhausted from the liquid crystal panel 12 by exhausting from the vacuum container 11, the exhaust from the liquid crystal panel 12 is slower.

In the first embodiment, the precision displacement meter 17 such as a micrometer or a dial gauge is used as the liquid crystal panel expansion displacement amount measuring device, but it is not limited to the precision displacement meter 17 and the optical system sensor or the electrostatic sensor. It is possible to use a gap change measuring method by capacitance measurement.

In the first embodiment, the displacement X does not exceed the predetermined value A by comparing the displacement X of the liquid crystal panel 12 in vacuum with the predetermined value A and varying the exhaust speed. Although the control is performed, the pressure in the vacuum container 11 may be controlled by using the measured value of the displacement amount X and performing feedback control so that there is no difference between the measured value and the allowable set value of the displacement. .

Further, in the first embodiment, as shown in FIG. 3, when the control variable (I) is smaller than n'in step S6, the rotation speed of the pump 21 is set to one step slow rotation in step S7. The exhaust speed is controlled, and then it is determined in step S3 whether or not the displacement amount X exceeds a predetermined value A. In step S7, the rotation speed of the pump 21 is set to one slow rotation, and then the process returns to step S2. The electric variable valve 20 may be fully opened to control the exhaust only by the rotation speed of the pump 21.

Further, in the first embodiment, first, the electric variable valve 20 is throttled step by step, then the rotational speed of the pump 21 is gradually decreased by one step, and the electric variable valve 20 is fully closed. Was filled and the pressure was controlled,
This order is not limited to this embodiment.

(Embodiment 2) FIG. 5 is a constitutional view of a liquid crystal injecting apparatus showing Embodiment 2 of the present invention. Members having the same effects as those of Embodiment 1 of FIG. And its description is omitted.

In FIG. 5, the configuration is different from that of the first embodiment shown in FIG. 1 in that a vacuum panel 11 is provided with a master panel 16 of the same type as the liquid crystal panel 12 and a precision displacement gauge 17 for measuring the panel thickness. That is, the signal converter 18 is not provided. In addition, the control box 19 of FIG.
Used a displacement signal from the signal converter 18 to control the pressure by adding a determination function. However, a control box 31 is provided so that the memory in the control box 31 has a panel displacement amount indicated by a thick line in FIG. 4, for example. Data of the number of revolutions of the pump 21 for exhaust control and measured data of the throttles of the electric variable valves 20 and 24 are input to the liquid crystal panel 12, and pressure control is performed by sequence control or the like based on the measured data. Expansion can be suppressed.

That is, the panel displacement amount X is the vacuum degree V and the time T.
, The same size, the same substrate material, the same seal pattern, and the same master panel 16 under the same conditions.
A precision displacement gauge 17 or the like is installed on the same panel substrate as the above, and an experiment is conducted in advance, and instead of the control portion of the judgment function of the flowchart shown in FIG. For example, as shown in FIG. 4, a program defining a procedure for reducing the pressure is input to the memory in the control box 31. With this pressure control program, the control box 31 automatically executes the pressure control of the throttle of the electric variable valve 20, the rotation speed of the pump 21, and if necessary, the pressure control means such as the electric variable valve 24 for filling the inert gas. Then, the pressure in the vacuum container 11 is controlled to suppress the panel expansion.

FIG. 6 is a control flowchart showing an example of a program operated by the liquid crystal injection device of FIG. Figure 6
In step S101, first, the pump 21 is turned on and driven to start exhausting, and in step S102, the electric variable valve 20 is fully opened. Next, the predetermined time t1
After that, in step S103, the electric variable valve 20 is closed by 1/2. Further, after a predetermined time t2, step S104.
The rotation speed of the pump 21 is reduced to ⅔, and after a predetermined time t3, the electric variable valve 20 is completely closed in step S105. Furthermore, after a predetermined time t4, step S106.
To return the rotational speed of the pump 21 to the initial state, and step S1
At 07, the electric variable valve 20 is fully opened. Further, after a predetermined time t5, a certain degree of vacuum Z is reached. Step S108
If the pressure inside the vacuum container 11 is monitored by the vacuum gauge 22 and the control box 31 detects the constant vacuum degree Z,
The electric variable valve 20 is controlled to fill the vacuum container 11 with nitrogen gas, which is an inert gas, to bring it to normal pressure, and step S109
Then the liquid crystal injection is started. In this way, the control box 31 can also monitor the pressure inside the vacuum container 11 to check the depressurization process inside the vacuum container 11.

As described above, when the constant vacuum pressure Z is maintained, the injection port 12d of the liquid crystal panel 12 is immersed in the container 15 containing the liquid crystal 14 in advance, and then the nitrogen gas is supplied to the vacuum container 11.
Since the inside of the liquid crystal panel 12 inside the vacuum container 11 is kept vacuum, the inside of the vacuum container 11 and the liquid crystal panel 12 are filled.
The liquid crystal 14 in the container 15 is injected into the liquid crystal panel 12 through the injection port 12d due to the pressure difference generated therebetween.

Since the panel displacement amount varies depending on the size of the liquid crystal panel 12 even if the pumping speed is the same, actual measurement data is obtained for each size of the liquid crystal panel 12 and a program corresponding to each liquid crystal panel 12 is obtained. To create. In addition, for example, the set value of the pressure in the vacuum container 11 and the vacuum gauge 22 which change with time based on the data taken in advance.
The pressure in the vacuum container 11 may be controlled by feedback control so as to eliminate the pressure difference by comparing the measured value with the above.

Further, in this embodiment, the pressure control program is input to the memory in the control box 31, data is taken out from the memory, and the rotation speed of the pump 21 and the throttles of the electric variable valves 20, 24 are extracted based on the data. The pressure control program is stored in an external memory such as a tape device, and the rotation speed of the pump 21 and the throttles of the electric variable valves 20 and 24 are controlled based on the data from the external memory. You may.

As described above, according to the first and second embodiments, the control boxes 19 and 31 automatically move to the pump 21.
And the control signal is sent to the electric variable valve 20, and the pump 2
The number of rotations of 1 is decreased, and the electric variable valve 20 is closed stepwise to about half, for example, to reduce the exhaust speed in the vacuum container 11. Even if the exhaust speed is slowed, the panel displacement X
Does not fall below the predetermined value A, a control signal for closing the electric variable valve 20 is sent to the control boxes 19 and 3.
1 to the electric variable valve 20. When the panel displacement amount X does not fall below the predetermined value A due to the control of the exhaust speed, the electric variable valve 24 for filling the inert gas is momentarily opened to lower the degree of vacuum in the vacuum container 11,
By controlling the pressure difference between the inside and the outside of the panel, the panel displacement amount X is controlled to a predetermined value A or less. At this time, the panel displacement amount X is shown in FIG.
When the value becomes smaller than the predetermined value B, the rotational speed of the pump 21 is increased to exhaust the gas. It is possible to automatically keep the displacement amount of the liquid crystal panel at a predetermined value A or less by repeatedly controlling the evacuation speed and filling the inert gas if necessary, until the vacuum gauge 22 reaches a constant vacuum pressure. it can. For this reason,
Decrease in adhesion of the sealing material 12c to which the upper and lower substrates 12a and 12b of the liquid crystal panel 12 are adhered and the sealing material 12c
It is possible to prevent damage such as peeling of the panel, maintain flatness of the panel, improve reliability of the liquid crystal panel, and improve yield of the liquid crystal panel.

The present invention is particularly effective for large-sized panels and liquid crystal panels that do not use glass substrates, for example, those that use plastic substrates.

[0049]

As described above, according to the present invention, the pressure in the vacuum container is controlled so that the expansion of the liquid crystal panel, which occurs when the vacuum container is evacuated, does not exceed a predetermined value. It is possible to improve the reliability of the liquid crystal panel by preventing this, and also improve the yield of the liquid crystal panel.

Further, expansion of the liquid crystal panel that occurs when the inside of the vacuum container is evacuated can be suppressed, a flat liquid crystal panel can be produced, and the display quality is improved. In particular, the effect is great for a large-sized panel that generates a large force due to panel expansion and a liquid crystal panel that does not use a glass substrate and that is easily deformed, such as a plastic substrate.

Further, since the displacement measuring means is provided and the expansion of the liquid crystal panel is measured, the control means has a simple structure.
The pressure in the vacuum container can be reliably controlled according to the displacement of the panel, and the panel expansion can be suppressed. Further, it is possible to easily deal with the change of the panel size, for example, by changing the set value of the displacement amount.

Further, if the pressure in the vacuum container is controlled by a control program created in advance, the pressure in the vacuum container can be controlled with a simpler configuration without using displacement measuring means, etc., and panel expansion is suppressed. It is possible to work efficiently. Further, the panel size can be easily changed only by replacing the control program created in advance for each panel size.

Further, it is not necessary to perform the liquid crystal injection work at the evacuation speed in view of the safety of the panel expansion, and the work can always be performed quickly within the panel expansion limit.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a liquid crystal injection device showing a first embodiment of the present invention.

2A is a perspective view showing a schematic configuration of a liquid crystal panel 12 of FIG. 1, and FIG. 2B is a sectional view thereof.

FIG. 3 is a control flowchart showing the operation of the liquid crystal injection device of FIG.

FIG. 4 is a diagram showing an example of changes in a panel displacement amount and a degree of vacuum when vacuum control of the liquid crystal injection device according to the first embodiment of the present invention is performed.

FIG. 5 is a configuration diagram of a liquid crystal injection device showing Embodiment 2 of the present invention.

FIG. 6 is a control flowchart showing an example of a program operated by the liquid crystal injection device of FIG.

7A is a perspective view showing a schematic configuration of a conventional liquid crystal panel 1, and FIG. 7B is a sectional view thereof.

FIG. 8 shows a schematic configuration of a conventional liquid crystal injection device, (a)
Is a state diagram at the time of exhaust, and (b) is a state diagram at the time of injecting liquid crystal.

9A and 9B show a panel expansion state due to a pressure difference between the inside and outside of the liquid crystal panel, FIG. 9A is a sectional view of the liquid crystal panel, and FIG. 9B is an enlarged view of one end thereof.

10 is a diagram showing the relationship between the degree of vacuum and the amount of expansion displacement of the liquid crystal panel 1 when the inside of the vacuum container 2 is evacuated by the conventional liquid crystal injection device.

[Explanation of symbols]

 11 Vacuum Container 12 Liquid Crystal Panels 12a and 12b Substrate 12c Sealing Material 12d Liquid Crystal Inlet 14 Liquid Crystal Material 16 Master Panel 17 Precision Displacement Meter 19, 31 Control Box 20, 24 Electric Variable Valve 21 Pump 22 Vacuum Gauge 23 Nitrogen Gas Cylinder

Claims (8)

[Claims] 1. After the inside of the vacuum container is evacuated, the opening of the liquid crystal panel is immersed in the liquid crystal inside the vacuum container, gas is filled in the vacuum container to restore the internal pressure of the vacuum container, and the liquid crystal panel In a liquid crystal injection method for injecting the liquid crystal into the liquid crystal panel by a pressure difference between the inside and the outside, the inside and the outside of the liquid crystal panel depending on a difference between an exhaust speed for exhausting the inside of the vacuum container to a vacuum and an exhaust speed from the inside of the liquid crystal panel. A liquid crystal injection method for controlling the pressure in the vacuum container so that the expansion of the liquid crystal panel due to the atmospheric pressure difference does not exceed a predetermined limit. 2. After the inside of the vacuum container is evacuated, the opening of the liquid crystal panel is soaked in liquid crystal inside the vacuum container, the inside of the vacuum container is filled with a gas to restore the internal pressure of the vacuum container, and the liquid crystal panel In a liquid crystal injection method for injecting the liquid crystal into the liquid crystal panel by a pressure difference between the inside and the outside, the inside and the outside of the liquid crystal panel depending on a difference between an exhaust speed for exhausting the inside of the vacuum container to a vacuum and an exhaust speed from the inside of the liquid crystal panel. The expansion of the liquid crystal panel due to the difference in atmospheric pressure is measured using a displacement measuring means, and based on the measurement data, the exhaust rate from the vacuum container and the filling of a very small amount of gas into the vacuum container A liquid crystal injection method for controlling at least the exhaust speed so that expansion of the liquid crystal panel does not exceed a predetermined limit. 3. After the inside of the vacuum container has been evacuated, the opening of the liquid crystal panel is immersed in the liquid crystal inside the vacuum container, and the gas inside the vacuum container is filled to restore the internal pressure of the vacuum container. In a liquid crystal injection method for injecting the liquid crystal into the liquid crystal panel by a pressure difference between the inside and the outside, the inside and the outside of the liquid crystal panel depending on a difference between an exhaust speed for exhausting the inside of the vacuum container to a vacuum and an exhaust speed from the inside of the liquid crystal panel. Based on the measurement data of the expansion of the liquid crystal panel due to the atmospheric pressure difference measured in advance by using displacement measuring means, at least the exhaust speed in the vacuum container and the filling of a very small amount of gas into the vacuum container are exhausted. A method for injecting liquid crystal, wherein the speed is controlled so that the expansion of the liquid crystal panel does not exceed a predetermined limit. 4. The control of the exhaust speed in the pressure control in the vacuum container controls at least one of the rotation speed of the exhaust pump and the opening / closing amount of the exhaust valve. The liquid crystal injection method according to any one of claims. 5. A vacuum container is provided with at least a liquid crystal and a liquid crystal panel, the interior of the vacuum container is evacuated, the opening of the liquid crystal panel is immersed in the liquid crystal, and the vacuum container is filled with gas. In the liquid crystal injecting device for injecting the liquid crystal into the liquid crystal panel by the pressure difference between the inside and the outside of the liquid crystal panel in the vacuum container, the pressure inside the vacuum container is restored, and the inside of the vacuum container is evacuated to make a vacuum. And a liquid crystal injection device having a control unit for controlling the pressure in the vacuum container so that the expansion of the liquid crystal panel due to the pressure difference between the inside and outside of the liquid crystal panel does not exceed a predetermined limit. 6. At least a liquid crystal and a liquid crystal panel are installed in a vacuum container, the inside of the vacuum container is evacuated, the opening of the liquid crystal panel is immersed in the liquid crystal, and the vacuum container is filled with gas. In the liquid crystal injecting device for injecting the liquid crystal into the liquid crystal panel by the pressure difference between the inside and the outside of the liquid crystal panel in the vacuum container, the gas is exhausted to make the inside of the vacuum container a vacuum. Based on the measurement data from the panel displacement measuring unit that measures the expansion of the liquid crystal panel due to the difference in air pressure inside and outside the liquid crystal panel due to the difference between the speed and the exhaust speed from the inside of the liquid crystal panel, based on the measurement data from the panel displacement measuring means, A liquid crystal having a control means for controlling at least the exhaust speed of the exhaust gas from the vacuum container and the filling of a very small amount of gas into the vacuum container so that the expansion of the liquid crystal panel does not exceed a predetermined limit. Input devices. 7. A vacuum container is provided with at least a liquid crystal and a liquid crystal panel, the inside of the vacuum container is evacuated, the opening of the liquid crystal panel is immersed in the liquid crystal, and the vacuum container is filled with gas. In the liquid crystal injecting device for injecting the liquid crystal into the liquid crystal panel by the pressure difference between the inside and the outside of the liquid crystal panel in the vacuum container, the panel expansion and displacement measurement provided in the vacuum container is performed. Panel member, a displacement measuring means for measuring a panel expansion displacement of the panel member, and an exhaust speed in the vacuum container and a minute amount into the vacuum container based on displacement data from the displacement measuring means. At least the pumping speed of the gas filling of
A liquid crystal injection device having control means for controlling expansion of the liquid crystal panel so as not to exceed a predetermined limit. 8. A vacuum container is provided with at least a liquid crystal and a liquid crystal panel, the interior of the vacuum container is evacuated, the opening of the liquid crystal panel is immersed in the liquid crystal, and the vacuum container is filled with gas. In the liquid crystal injecting device for injecting the liquid crystal into the liquid crystal panel by the pressure difference between the inside and the outside of the liquid crystal panel in the vacuum container, the gas is exhausted to make the inside of the vacuum container a vacuum. The evacuation speed in the vacuum container is based on the measurement data obtained by measuring the expansion of the liquid crystal panel due to the difference in pressure between the inside and the outside of the liquid crystal panel due to the difference between the speed and the evacuation speed from the inside of the liquid crystal panel using a panel displacement measuring unit. And a liquid crystal injection device having control means for controlling at least the evacuation speed of filling a small amount of gas into the vacuum container so that the expansion of the liquid crystal panel does not exceed a predetermined limit.