JPH0442130A - Liquid crystal injection method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a liquid crystal injection method for injecting liquid crystal into cells of a liquid crystal display element.

[Conventional technology]

The method of injecting liquid crystal into the cell of a liquid crystal display element is as follows:
Generally, a vacuum injection method is used. In this vacuum injection method, a liquid crystal injection port formed on the side of a cell is placed in a liquid crystal bath in a vacuum, and the surrounding pressure is returned to atmospheric pressure in this state, thereby creating a pressure difference within the vacuum cell. Injecting liquid crystal into a cell using this vacuum injection method has conventionally been carried out as follows.

That is, FIGS. 6 to 8 show the conventional liquid crystal injection method, and in the figures, 1 is a liquid crystal dish placed in an airtight container (not shown), and a liquid crystal bath 2 is inside this liquid crystal dish 1. be. 3
is a cell of a liquid crystal display element. As is well known, this cell 3 is made up of a pair of transparent substrates on which transparent electrodes for display and an alignment film are formed on opposing surfaces, which are bonded together via a frame-shaped sealing material. The gap is a liquid crystal sealed space, and a liquid crystal injection port 4 is provided on one side of the cell 3 by cutting out a portion of the sealing material. Moreover, this cell 3 is manufactured in a state in which a plurality of cells are connected, and each cell 3 is made by injecting liquid crystal into the liquid crystal filling space inside the cell 3, then sealing the liquid crystal injection port 4, and then forming the cell 3 at the dividing line a. The cells 3 are separated into individual cells 3 along these lines.

In order to inject the liquid crystal into the cell 3, first, a cell holding member (not shown) provided in the airtight container is filled with the liquid crystal.
A predetermined number of cells 3 are held with their liquid crystal injection ports 4 facing downward, and then the airtight container is sealed to create a vacuum inside. Next, the cell holding member is lowered and the liquid crystal inlet forming side of each cell 3 held by the cell holding member is exposed to the liquid crystal reservoir in the liquid crystal pan 1 as shown in FIGS. 6(a) and 7. In this state, the pressure inside the airtight container is returned to atmospheric pressure, and the liquid crystal LC in the liquid crystal reservoir 2 is injected into the vacuum cell 3 using the pressure difference. After this,
The cell holding member is raised to its original position and each cell 3 is pulled up from the liquid crystal reservoir 2 as shown in FIG. 6(b) and FIG. The liquid crystal injection port 4 is sealed with a sealing resin.

[Problem to be solved by the invention]

However, in the conventional liquid crystal injection method described above, since the side surface of the cell 3 where the liquid crystal injection port is formed is immersed in the liquid crystal reservoir 2 to inject the liquid crystal LC, when the cell 3 is immersed in the liquid crystal reservoir 2, this The liquid crystal LC adheres to the entire side surface of the cell 3 where the liquid crystal injection port is formed, and the liquid crystal LC is removed together with the cell 3 as shown in FIG. As a result, a large amount of the liquid crystal LC adhered to the entire side surface of the cell 3 where the liquid crystal injection port is formed is wasted, and expensive liquid crystal is wasted.

The present invention was made in view of the above-mentioned circumstances, and its purpose is to reduce the amount of liquid crystal that adheres to the side surface of the cell where the liquid crystal injection port is formed and is carried away together with the cell. Therefore, it is an object of the present invention to provide a liquid crystal injection method that can efficiently use expensive liquid crystals.

[Means to solve the problem]

In order to achieve the above object, the liquid crystal injection method of the present invention has the following features:
A liquid crystal adhesion member slightly wider than the liquid crystal injection port opened on the side of the cell is immersed in the liquid crystal reservoir, and after pulling this liquid crystal adhesion member from the liquid crystal reservoir, the liquid crystal adhering to the liquid crystal adhesion member is The liquid crystal on the liquid crystal adhesion member is injected into the cell by a vacuum injection method by touching the liquid crystal injection port of the cell, which is arranged with the length direction of the liquid crystal injection port forming side facing the width direction of the liquid crystal adhesion member. It is designed to be injected inside the body.

[Effect]

That is, in the liquid crystal injection method of the present invention, the liquid crystal adhering member is immersed in a liquid crystal reservoir and the liquid crystal adhering member is pulled up from the liquid crystal reservoir to deposit a small amount of liquid crystal on the liquid crystal adhering member. The liquid crystal on the adhesion member is injected into the cell by vacuum injection method, and the width of the liquid crystal adhered on the liquid crystal adhesion member is the width of the liquid crystal adhesion member, that is, the width of the liquid crystal injected into the cell. Since the cell is slightly wide, the cell is arranged with the length direction of the side surface forming the liquid crystal injection port facing the width direction of the liquid crystal attachment member,
If you touch the liquid crystal injection port of this cell to the liquid crystal above the liquid crystal attachment member and inject the liquid crystal into the cell, the liquid crystal above the liquid crystal attachment member will only slightly adhere to the periphery of the liquid crystal injection port of the cell. It is.

Therefore, according to this liquid crystal injection method, the amount of liquid crystal that adheres to the side surface of the cell where the liquid crystal injection port is formed and is carried away together with the cell can be reduced, and expensive liquid crystal can be used efficiently.

C Embodiment] Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 5.

First, the structure of the liquid crystal injection device will be described. In FIG. 1, reference numeral 1 denotes a liquid crystal dish placed in an airtight container (not shown), and within this liquid crystal dish 1 is a liquid crystal reservoir 2. The liquid crystal LC in the liquid crystal reservoir 2 in the liquid crystal pan 1 is replenished as the amount of liquid crystal LC is reduced by injecting the liquid crystal into the cell. Reference numeral 5 denotes a liquid crystal adhering member which is located above the liquid crystal dish 1 in the airtight container and is movable up and down. This liquid crystal adhesion member 5 is made of a horizontal long material with a rectangular cross section, and the width of the upper surface of this liquid crystal adhesion member 5 is slightly wider than the liquid crystal injection port 4 opened on the side surface of the cell 3. It is said that Further, on the upper surface of this liquid crystal adhesion member 5, a plurality of narrow protrusions 6 are integrally provided along the width direction thereof at intervals slightly larger than the thickness of the cell 3, and each of the protrusions 6 is , liquid crystal adhesion member 5
It is formed over the entire width of the upper surface. The portions between adjacent protrusions 6 on the upper surface of the liquid crystal adhesion member 5 are respectively designated as liquid crystal adhesion parts 7, and the area of the liquid crystal adhesion parts 7 and the height of the protrusions 6 are determined by the following: The amount of liquid crystal placed on the cell 7 in an upwardly bulging state due to surface tension is set to be an amount commensurate with the amount of liquid crystal injected into the cell 3. A plurality of the liquid crystal adhesion members 5 (same number as the number of cells 3 connected to each other) are arranged in parallel, and each liquid crystal adhesion member 5 is raised and lowered simultaneously by a lifting mechanism (not shown).

In this liquid crystal injection method, the liquid crystal LC is injected into the cell 3 using the injection device described above, and the liquid crystal LC is injected into the cell 3 as follows.

First, as shown in FIGS. 1 and 2(a), a plurality of cells 3 manufactured in a connected state are attached to the liquid crystal adhesion member 5.
The same number of cells 3 as the number of liquid crystal adhesion parts 7 of the liquid crystal adhesion member 5 are carried into the airtight container.
The upper ends of the cells 3 are held by a cell holding member (not shown) provided in the airtight container. In this case, each cell 3 has the side surface on which the liquid crystal injection port 4 is formed facing downward, the length direction of the side surface forming the liquid crystal injection port facing the width direction of the liquid crystal adhesion member 5, and the liquid crystal injection port 4 facing downward. Liquid crystal attachment part 7 of liquid crystal attachment member 5
is positioned directly above the cell holding member and held by the cell holding member.

Next, the airtight container is sealed to create a vacuum inside the container, and then the liquid crystal adhering member 5 is lowered so that the liquid crystal adhering member 5 is deposited in the amount of liquid crystal 2 in the liquid crystal pan 1 as shown in FIG. 2(b). After that, the liquid crystal adhesion member 5 is raised to its original position as shown in FIG. 2(c). In this way, once the liquid crystal adhesion member 5 is immersed in the liquid crystal bath 2 and then pulled up, as shown in FIG.
C) and as shown in FIG. 3, a small amount of liquid crystal LC is deposited on the liquid crystal adhesion member 5 and taken out from the liquid crystal amount 2. The liquid crystal LC is adhered to each liquid crystal adhesion portion 7 defined by each protrusion 6 on the liquid crystal adhesion member 5 in an upwardly swollen state due to surface tension.

After this, as shown in FIG. 2(d), each cell 3 is lowered by lowering the cell holding member until the side surface forming the liquid crystal injection port comes into contact with the upper surface of each liquid crystal adhesion part 7 of the liquid crystal adhesion member 5. and connect the liquid crystal injection port 4 of each cell 3 to the liquid crystal adhesion member 5.
touch the liquid crystal LC on top of the screen. Although the liquid crystal injection port 4 is inserted into the liquid crystal LC in the figure, the liquid crystal injection port 4 may be brought into contact with the surface of the liquid crystal LC.

In this case, each cell 3 is held by the cell holding member with the length direction of the side surface forming the liquid crystal injection port facing the width direction of the liquid crystal adhesion member 5 as described above. The forming side surface contacts the liquid crystal LC on the liquid crystal adhering member 5 only at the part where it intersects with the liquid crystal adhering member 5, and the width of the liquid crystal LC adhering on the liquid crystal adhering member 5 is the width of this liquid crystal adhering member 5, that is, Since the width is slightly wider than the liquid crystal injection port 4 of each cell 3, the liquid crystal injection port forming side surface of each cell 3 enters into the liquid crystal LC on the liquid crystal adhesion member 5 only at the liquid crystal injection port 4 portion, and the other portions are slightly wider than the liquid crystal injection port 4 of the cell 3. is in the space on the side of the liquid crystal attachment member 5.

Next, the air pressure inside the airtight container is returned to atmospheric pressure, and the liquid crystal LC on each liquid crystal adhesion part 7 of the liquid crystal adhesion member 5 is placed inside the vacuum cell 3 using the pressure difference as shown in FIG. 2(e). and injection as shown in FIG. Note that when the liquid crystal injection port 4 is inserted into the liquid crystal LC, even if the side surface of the cell 3 where the liquid crystal injection port is formed comes into contact with the top surface of the liquid crystal attachment member 5, the side surface of the cell 3 where the liquid crystal injection port is formed is completely flat. Since the liquid crystal attachment member 5 is not a surface, the liquid crystal LC on the liquid crystal attachment member 5 is sucked into the cell 3 through the gap between the side surface of the cell 3 where the liquid crystal injection port is formed and the upper surface of the liquid crystal attachment member 5. Further, when the liquid crystal injection port 4 is brought into contact with the surface of the liquid crystal LC, the liquid crystal LC on the liquid crystal adhesion member 5 is sucked into the cell 3 from the surface layer side. The liquid crystal LC on top of the cell 3 is drawn into the cell 3 by the surface tension of the liquid crystal LC.

After this, the cell holding member is raised to its original position to separate each cell 3 from the liquid crystal attachment member 5 as shown in FIG. 2(f) and FIG. 5, and then the airtight container is opened. Each cell 3 is taken out and its liquid crystal injection port 4 is sealed with sealing resin. Note that each cell 3 is then separated and separated along the dividing line a.

That is, the liquid crystal injection method described above involves soaking the liquid crystal adhesion member 5 in the amount of liquid crystal 2 in the liquid crystal dish 1 and pulling up the liquid crystal adhesion member 5 from the amount of liquid crystal 2, thereby removing each liquid crystal adhering to the liquid crystal adhesion member 5. Only a small amount of liquid crystal LC adhering on part 7 is taken out from liquid crystal quantity 2, and this liquid crystal LC on liquid crystal adhesion member 5 is injected into each cell 3 by a vacuum injection method. The width of the liquid crystal LC attached to the attachment member 5 is the width of the liquid crystal attachment member 5, that is, the width of the cell 3.
Since the width is slightly wider than the liquid crystal injection port 4 of the cell 3, the cell 3 is arranged with the length direction of the liquid crystal injection port forming side facing the width direction of the liquid crystal adhesion member 5, and the liquid crystal of this cell 3 is If the injection port 4 is brought into contact with the liquid crystal LC on the liquid crystal adhesion member 5 and the liquid crystal is injected into the cell 3, the liquid crystal LC on the liquid crystal adhesion member 5 will be applied only to the periphery of the liquid crystal injection port 5 of the cell 3. It just attaches to the house. Therefore, according to this liquid crystal injection method, the amount of liquid crystal that adheres to the side surface of the cell 3 where the liquid crystal injection port is formed and is carried away together with the cell can be reduced.
Expensive liquid crystals can be used efficiently. Note that among the liquid crystal LC that has adhered to the liquid crystal adhesion member 5 and taken out from the liquid crystal amount 2, the liquid crystal LC that has been placed on the portion other than the liquid crystal adhesion portion 7, that is, on both ends of the liquid crystal adhesion member 5, is cell 3
If the liquid crystal is not injected into the cell and remains on the liquid crystal adhesion member 5 as shown in FIG. This liquid crystal LC remains on the adhesion part 7, but this liquid crystal LC is then attached to the liquid crystal adhesion member 5.
When the liquid crystal is immersed in liquid crystal amount 2, it is returned to the liquid crystal amount, so this liquid crystal is not wasted. This also applies to the liquid crystal adhered to the side and bottom surfaces of the liquid crystal adhering member 5, and this liquid crystal is also returned to the liquid crystal amount when the liquid crystal adhering member 5 is next penetrated into the liquid crystal amount 2.

In the above embodiment, the liquid crystal adhering member 5 has a rectangular cross section, but the liquid crystal adhering member 5 may have an inverted square or semicircular cross section as long as its upper surface is substantially flat. In addition, the convex strip 6 on the top surface of the liquid crystal adhesion member 5 is eliminated, the entire length of the top surface of the liquid crystal adhesion member 5 is used as a liquid crystal adhesion part, and the liquid crystal placed on the entire length of the top surface of the liquid crystal adhesion member 5 is distributed and injected into each cell. You can also do this. Furthermore, in the above embodiment,
The liquid crystal LC is injected by bringing the side surface of the cell 3 where the liquid crystal injection port is formed into contact with the top surface of the liquid crystal adhesion member 5. The cell 3 may be placed facing the upper surface of the member 5 with a slight gap, or the cell 3 may be placed opposite the upper surface of the member 5 with a slight gap.
As long as the length direction of the side surface forming the liquid crystal injection port is along the width direction of the liquid crystal adhesion member 5, the orientation may be perpendicular or diagonally intersecting. Furthermore, in the above embodiment, the case where the liquid crystal LC is injected into a plurality of cells 3 at the same time has been explained.
It can also be applied to the case where liquid crystal is injected into each cell.

〔Effect of the invention〕

In the liquid crystal injection method of the present invention, a wide liquid crystal adhesion member is individually immersed in an amount of liquid crystal through a liquid crystal injection port opened on the side surface of a cell, and after this liquid crystal adhesion member is pulled up from the liquid crystal amount, this liquid crystal adhesion member is immersed into an amount of liquid crystal. Touch the liquid crystal adhered on the member with the liquid crystal inlet of the cell arranged with the length direction of the side surface forming the liquid crystal inlet facing the width direction of the liquid crystal attaching member, and The liquid crystal is injected into the cell using a vacuum injection method, which reduces the amount of liquid crystal that adheres to the side surface of the cell where the liquid crystal injection port is formed and is carried away with the cell, thereby reducing the cost of expensive liquid crystal. Liquid crystals can be used efficiently.

[Brief explanation of the drawing]

Figures 1 to 5 show an embodiment of the present invention. Figure 1 is a perspective view of a liquid crystal injection device, Figure 2 is a liquid crystal injection process diagram, and Figure 3 is a diagram of the liquid crystal injection process shown in Figure 2. ■A cross-sectional view along the line, Figure 4 is a cross-sectional view along line IV-IV in Figure 2, Figure 5 is a cross-sectional view along line IV-IV in Figure 2.
It is a sectional view along the -v line. Figure 6 is an injection process diagram showing the conventional liquid crystal injection method, and Figures 7 and 8 are
FIG. 3 is a cross-sectional view along lines -■ and -■. 1...Liquid crystal dish, 2...Liquid crystal bath, LC...Liquid crystal, 3
...Cell, a...Dividing line, 4...Liquid crystal injection port, 5
...Liquid crystal adhesion member, 6...Convex strip, 7...Liquid crystal adhesion part. Applicant's representative Patent attorney Takehiko Suzue

Claims (1)

[Claims] In a method of injecting liquid crystal into a cell of a liquid crystal display element,
A liquid crystal adhesion member that is slightly wider than the liquid crystal injection port opened on the side surface of the cell and longer than the thickness of the cell is immersed in the liquid crystal bath, and after being pulled up from the liquid crystal bath, the liquid crystal adhesion member is removed. The liquid crystal inlet of the cell, which is arranged with the length direction of the side surface forming the liquid crystal inlet facing the width direction of the liquid crystal attaching member, is brought into contact with the liquid crystal attached on the liquid crystal attaching member. A liquid crystal injection method characterized in that liquid crystal is injected into the cell by a vacuum injection method.