JPH095761A - Method for injecting liquid crystal - Google Patents

Abstract

PURPOSE: To shorten the time required for injection by forming intermediate injection ports between the discharge ports and injection ports of a liquid crystal cell and injecting liquid crystals from these intermediate injection ports after the front ends of the liquid crystals injected from the injection ports pass the intermediate injection ports. CONSTITUTION: The liquid crystal cell 1 is formed by adhering the peripheral edge of two sheets of plate glass 2 by an adhesive layer 3, forming the non-adhered parts at one end as the injection ports 4 and providing the other end with discharge ports 5. Further, the intermediate injection ports 6 are formed in the central parts in both side parts of the liquid crystal cell 1. Injection nozzles are previously connected to the injection ports 4 and the intermediate injection ports 6 and discharge nozzles are previously connected to the discharge ports in the case where the liquid crystals are injected into the liquid crystal cell 1. The liquid crystals 7 are then injected in a pressurized state into the cells from the injection ports 4 and on the other hand, the cell is evacuated from the discharge ports. The injection nozzles connected to the intermediate injection ports 6 are opened and the liquid crystals 7 in the pressurized state are injected from the intermediate injection ports 6 as well after the front ends of the liquid crystals 7 injected from the injection ports 4 pass the intermediate injection ports 6.

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 for injecting liquid crystal into a liquid crystal cell, and more particularly to a liquid crystal injection method suitable for injecting liquid crystal into a large liquid crystal cell.

[0002]

2. Description of the Related Art Conventionally, in the case of injecting liquid crystal into a liquid crystal cell of a liquid crystal display device, as shown in FIG. Adhesive portions are respectively formed, one non-adhesive portion serves as an injection port E _N , and the other non-adhesive portion serves as an exhaust port E _X. Then, the injection port E _N is immersed in the Y liquid crystal L in the liquid crystal reservoir, and the liquid crystal L is injected into the liquid crystal cell C by vacuum suction from the exhaust port E _X (JP-A-3-138615). ,
(See Japanese Patent Laid-Open No. 5-11260).

[0003]

The distance between the two plate glasses G, G (only one plate glass G is shown in FIG. 7) constituting the liquid crystal cell C is usually several μm or less, which is very narrow. Therefore, when the liquid crystal L is injected into the liquid crystal cell C, a large pressure loss occurs. As a result, there is a problem that the injection speed decreases as the injection amount of the liquid crystal increases, and it takes a lot of time to inject the liquid crystal into the entire liquid crystal cell C. In particular, since the liquid crystal cell C has recently become large, such a problem has become remarkable.

[0004]

The present invention has been made to solve the above problems, and the invention according to claim 1 injects liquid crystal from an injection port formed at one end of a liquid crystal cell. On the other hand, in the liquid crystal injecting method in which the air is exhausted from the exhaust port formed at the other end of the liquid crystal cell, an intermediate injection port is formed at an intermediate portion between the exhaust port and the injection port of the liquid crystal cell,
After the liquid crystal injected from the injection port at one end of the liquid crystal cell passes through the intermediate injection port, the liquid crystal is injected into the liquid crystal cell from the intermediate injection port. In this case, a plurality of the intermediate injection ports are formed from one end side of the liquid crystal cell toward the other end side, and the liquid crystal injected from the injection port at one end of the liquid crystal cell passes through each intermediate injection port and then each intermediate injection port is formed. It is desirable to inject liquid crystal from each of the inlets. Further, it is desirable to form the above-mentioned intermediate injection port on one side and the other side of the liquid crystal cell, respectively. Furthermore, an end injection port is formed at the other end where the exhaust port of the liquid crystal cell is formed, and the liquid crystal injected from the end injection port and the liquid crystal injected from the injection port and the intermediate injection port are separated from each other. It is desirable to inject the liquid crystal from the end injection port so that the uninjected space of the liquid crystal partitioned by the liquid crystal into the liquid crystal cell faces the exhaust port when contacting. Particularly, in this case, it is preferable that the exhaust port is formed at each of both side corners of the other end of the liquid crystal cell, and the end injection port is formed at the center of the other end. Further, in any case, it is desirable to perform forced exhaust from the exhaust port.

[0005]

In the invention according to claim 1, when the liquid crystal is injected from the intermediate injection port after the front end of the liquid crystal injected from the injection port has passed through the intermediate injection port, the front end of the liquid crystal is injected from the intermediate injection port. Pressurized by the liquid crystal. Therefore,
The liquid crystal can be injected into the liquid crystal cell in a short time. In this case, a plurality of intermediate inlets may be arranged from one end of the liquid crystal cell toward the other end, or may be arranged on both sides of the liquid crystal cell,
When the liquid crystal cell is arranged at the end portion (the other end portion) on the exhaust port side or is forcedly exhausted from the exhaust port, the injection efficiency is improved and the injection time can be further shortened.

[0006]

EXAMPLES Examples of the liquid crystal injection method according to the present invention will be described below with reference to FIGS. FIG. 1 (A) ~
(C) shows an embodiment of the liquid crystal injection method according to the present invention, in which the liquid crystal is injected into the rectangular liquid crystal cell 1. Of course, it is also possible to inject liquid crystal into liquid crystal cells of other shapes.

First, the liquid crystal cell 1 will be described. As shown in FIG. 1A, in the liquid crystal cell 1, the peripheral portions of two plate glasses (only one plate glass is shown) 2 are bonded by an adhesive layer 3. At one end of the liquid crystal cell 1 (the right end in FIG. 1), non-adhesive portions without an adhesive layer are formed at three locations, a central portion and both side portions thereof. Then, each non-adhesive portion serves as a liquid crystal injection port 4. Similarly, three exhaust ports 5 are formed at the other end of the liquid crystal cell 1. In addition, in the center of both sides of the liquid crystal cell 1,
Each of the intermediate injection ports 6, which is a feature of the present invention, is formed.

When injecting liquid crystal into the liquid crystal cell 1, an injection nozzle (not shown) is previously connected to the injection port 4 and the intermediate injection port 6, and an exhaust nozzle (not shown) is connected to the exhaust port 5. ) Is connected in advance. And FIG.
As shown in (B), the liquid crystal 7 is injected under pressure from the injection port 4, while vacuum suction is performed from the exhaust port 5. At this time, the injection nozzle connected to the intermediate injection port 5 is closed.

As shown in FIG. 1C, when the tip of the liquid crystal 7 injected from the injection port 4 passes through the intermediate injection port 6,
The injection nozzle connected to the intermediate injection port 6 is opened, and the pressurized liquid crystal L is also injected from the intermediate injection port 6. in this way,
The tip of the liquid crystal 7 injected from the inlet 4 is the intermediate inlet 6
The reason why the intermediate inlet 6 is opened after passing through is because of the following reason.

That is, when the liquid crystal is injected from the intermediate injection port 6 before the tip of the liquid crystal injected from the injection port 4 passes through the intermediate injection port 6, as shown by the imaginary line in FIG. The liquid crystal 7, 7 injected from the inlet 4 and the intermediate injection port 6 respectively, or the liquid crystal 7, 7 and the adhesive layer 3 form a closed space a, and air may remain in the closed space a. In this respect, if the liquid crystal 7 injected from the injection port 4 passes through the intermediate injection port 6 and then the liquid crystal 7 is injected from the intermediate injection port 6, the liquid crystal 7 is injected into the liquid crystal 7, so that the liquid crystal 7 is hermetically sealed. Space a is never formed. Therefore, it is possible to prevent air from remaining in the liquid crystal cell 1.

The opening operation of the injection nozzle connected to the intermediate injection port 6 is carried out based on the detection signal of the sensor by installing a sensor for detecting the liquid crystal 7 at a position slightly closer to the other end side than the intermediate injection port 6. be able to. Alternatively, after starting the injection of the liquid crystal 7 from the injection port 4, it is possible to measure the time until the tip of the liquid crystal 7 passes through the intermediate injection port 6 and perform the measurement based on the measured time.

Liquid crystal 7 injected from the intermediate injection port 6
The pressure of 1 may be higher than the pressure of the liquid crystal 7 injected from the injection port 4 or may be lower than the pressure of the liquid crystal 7, but normally the same pressure is preferable. After the injection from the intermediate injection port 6 is started, the injection nozzle connected to the injection port 4 may be closed to end the injection of the liquid crystal 7 from the injection nozzle.

When the injection of the liquid crystal 7 from the intermediate injection port 6 is started, the injection amount from both sides of the liquid crystal cell 1 is increased.
As shown by an imaginary line in FIG. 1C, both side portions of the liquid crystal 7 precede the central portion and head toward the other end portion side. Then, at the other end of the liquid crystal cell 1, the liquid crystal 7 goes from both sides to the exhaust port 5 at the center. Therefore, no bubbles remain in the liquid crystal cell 1. When the liquid crystal 7 is injected into the entire liquid crystal cell 1, the injection nozzle and the exhaust nozzle are closed. This completes the liquid crystal injection. After the liquid crystal injection is complete,
Remove the injection nozzle and exhaust nozzle,
And the exhaust port 5 is closed.

When the liquid crystal 7 is injected into the liquid crystal cell 1 as described above, the tip of the liquid crystal 7 injected from the injection port 4 decreases in pressure as it advances to the other end, and the advancing speed (injection) However, when the pressure of the liquid crystal 7 drops, the liquid crystal 7 without pressure drop is injected from the intermediate injection port 6, so that the injection speed of the liquid crystal 7 increases again. Therefore, the liquid crystal 7 can be injected into the liquid crystal cell 1 in a short time.

Next, another embodiment of the present invention will be described. In the embodiment shown in FIG.
2 are formed on both sides of the liquid crystal cell 1. When the tip of the liquid crystal 7 injected from the injection port 4 passes through the intermediate injection port 6 on one end side (right end side) of the liquid crystal cell 1, the intermediate injection port 6 The liquid crystal 7 is injected through the liquid crystal 7, and when the tip of the liquid crystal 7 passes through the intermediate injection port 6 on the other end side, the liquid crystal 7 is also injected through the intermediate port 6.

In the embodiment shown in FIGS. 3 and 4, the liquid crystal cell 1 has an inlet 4 formed at the center of one end and exhaust ports 5 formed at both corners of the other end. An intermediate inlet 6 is formed in the center of the part. Further, an exhaust port 8 is formed at one end-side corner of both side parts, and an end injection port 9 is formed at the center part of the other end.

When injecting the liquid crystal 7 into the liquid crystal cell 1, the liquid crystal 7 is first injected through the injection port 4. At this time,
Keep the inlets 6 and 9 closed. In addition, the exhaust port 5,
Evacuate from 8. The liquid crystal 7 injected from the inlet 4 is shown in FIG.
As shown in (A), the liquid crystal cell 1 spreads in a substantially concentric shape. Therefore, normally, bubbles do not remain in both corners on one end side of the liquid crystal cell 1.

However, as shown in FIG. 5, when the frictional resistance between the liquid crystal 7 and the adhesive layer 3 is large, the speed of the portion b of the liquid crystal 7 in the vicinity of the contact portion with the adhesive layer 3 is changed from that. It may be slightly slower than the part c near the other end. In such a case, since the partial c near the other end comes into contact with both side portions of the adhesive layer 3 earlier than the adjacent partial b, a space indicated by reference numeral 2 is formed at the corner of the liquid crystal cell 1. Bubbles (air) may remain in. Provisionally, the exhaust port 8 is formed to exhaust such air. Of course, FIG.
As shown in (A), if the liquid crystal 7 is injected concentrically and there is no risk of bubbles remaining in the corners of the liquid crystal cell 1, the exhaust port 8 may not be formed. When the liquid crystal 7 reaches the exhaust port 9 and fills it, the exhaust port 9 is closed.

When the tip of the liquid crystal 7 injected from the injection port 4 passes through the intermediate injection port 6, injection of the liquid crystal 7 from the intermediate injection port 6 is started. Then the inlet 4 and the intermediate inlet 6
When the tip of the liquid crystal 7 injected from the above reaches a proper position, the liquid crystal is also injected from the end injection port 9. That is, FIG.
As shown by an imaginary line in (C), the liquid crystal 7 injected from the end injection port 9 and the liquid crystal 7 injected from the injection ports 4 and 6.
The injection timing from the end injection port 9 is determined so that the uninjected spaces (e) and (e) partitioned by the liquid crystals 7 face the exhaust port 5 when and are in contact with each other. If the injection from the end injection port 9 is too early, as shown in FIG. 6, the liquid crystal 7 injected from the injection ports 4 and 6 and the liquid crystal 7 injected from the end injection port 9 are injected.
This is because, when and are in contact with each other, the uninjected space defined by them does not face the exhaust port 5, so that air remains there. After that, when the liquid crystal 7 is injected into the entire liquid crystal cell 1, the injection ports 4, 6, 9 and the exhaust port 5 are closed,
Complete the injection.

The present invention is not limited to the above embodiment, but can be modified as appropriate. For example, in the above embodiment, the liquid crystal 7 is injected under pressure from the injection port 4, the intermediate injection port 6 and the end injection port 9, but is forced by vacuum suction from the exhaust ports 5 and 9. When exhausting, the liquid crystal 7 may be injected by the atmospheric pressure as in the conventional injection method. Conversely, the inlets 4, 6,
When the liquid crystal 7 pressurized from 9 is injected, natural exhaust (exhaustion by the injected liquid crystal 7) may be performed from the exhaust ports 5 and 9.

[0021]

As described above, according to the first aspect of the invention, the injection speed of the liquid crystal into the liquid crystal cell can be increased and the time required for the injection can be shortened.
Therefore, even in a large liquid crystal cell, the injection can be completed in a short time. Moreover, it is possible to prevent bubbles from remaining in the liquid crystal cell. Further, according to the inventions of claims 2 to 6, the injection time of the liquid crystal can be further shortened.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.
FIG. 1A is a sectional view of the liquid crystal cell cut by an adhesive layer, FIG.
FIG. 1B shows a state in which liquid crystal is injected into the liquid crystal cell shown in FIG. 1A only from an injection port, and FIG. 1C shows a state in which liquid crystal is injected also from an intermediate injection port. .

2 is a diagram showing another embodiment of the present invention, FIG.
FIG. 2A shows a state where liquid crystal is being injected from the inlet and an intermediate inlet on one end side of the liquid crystal cell, and FIG. 2B shows a state where liquid crystal is being injected from all the inlets. .

3A and 3B are views showing still another embodiment of the present invention, in which FIG. 3A shows a state where liquid crystal is injected only from an injection port, and FIG. 3B shows an intermediate injection port. FIG. 3C shows a situation where liquid crystal is being injected, and FIG. 3C shows a situation when liquid crystal is also being injected from the end injection port.

FIG. 4 is a view showing the injection situation of the embodiment shown in FIG. 3 following FIG. 3, and FIG. 4 (A) shows the liquid crystal injected from the injection port and the intermediate injection port and the liquid crystal injected from the end injection port. 4B shows the situation after the contact with the liquid crystal, and FIG. 4B shows the situation immediately before the completion of the injection.

5 is a diagram for explaining the reason why an exhaust port is formed on one end side of the liquid crystal cell in the embodiment shown in FIGS. 3 and 4. FIG.

FIG. 6 is a diagram for explaining the time when the liquid crystal starts to be injected from the end injection port.

FIG. 7 is a diagram showing an example of a conventional injection method.

[Explanation of symbols]

 1 Liquid crystal cell 3 Adhesive layer 4 Injection port 5 Exhaust port 6 Intermediate injection port 7 Liquid crystal 8 Exhaust port 9 End injection port

Claims (6)

[Claims] 1. A liquid crystal injection method in which liquid crystal is injected from an injection port formed at one end of the liquid crystal cell while being exhausted from an exhaust port formed at the other end of the liquid crystal cell. An intermediate injection port is formed at an intermediate portion between the exhaust port and the injection port, and the liquid crystal is injected from the intermediate injection port after the tip of the liquid crystal injected from the injection port at one end of the liquid crystal cell passes through the intermediate injection port. A liquid crystal injecting method, which comprises injecting into a liquid crystal cell. 2. A plurality of the intermediate injection ports are formed from one end side of the liquid crystal cell toward the other end side, and the tip of the liquid crystal injected from the injection port of the one end part of the liquid crystal cell forms each intermediate injection port. The liquid crystal injection method according to claim 1, wherein the liquid crystal is injected from each intermediate injection port after the liquid crystal has passed through. 3. The liquid crystal injection method according to claim 1, wherein the intermediate injection port is formed in one side portion and the other side portion of the liquid crystal cell, respectively. 4. An end injection port is formed at the other end where the exhaust port of the liquid crystal cell is formed, and liquid crystal injected from the end injection port and the liquid crystal injected from the injection port and the intermediate injection port are formed. The liquid crystal is injected from the end injection port so that a non-injection space of the liquid crystal partitioned by the liquid crystal into the liquid crystal cell faces the exhaust port when the liquid crystal comes into contact with the liquid crystal. 4. The liquid crystal injection method according to any one of 3 to 3. 5. The exhaust port is formed at each of both side corners of the other end of the liquid crystal cell, and the end injection port is formed at the center of the other end. Liquid crystal injection method described. 6. The liquid crystal injection method according to claim 1, wherein forced exhaust is performed from the exhaust port.