JP2002182223A - Liquid crystal display element, method for manufacturing the same and manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease alignment defects even when barrier walls 5 are not completely adhered in a liquid crystal display element 1 having a smectic liquid crystal injected into the liquid crystal injection part having a plurality of linear spaces formed by the barrier walls 5. SOLUTION: The barrier walls 5 and a substrate 2 are tightly adhered by generating pressure difference between in and out of the liquid crystal injection part to pressurize the substrate 2 by the pressure difference 15. The liquid crystal is injected while the above state is kept, and then the liquid crystal is cooled while producing temperature gradient with substantially monotonous temperature change in the longitudinal direction of the linear spaces by a planar temperature controlling device 4. Thereby, the volume contraction force produced when the liquid crystal is cooled is effectively acted on the liquid crystal molecules in a specified direction so as to align the bending direction of the layers of the smectic liquid crystal and to decrease alignment defects.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device using a smectic liquid crystal.
In the process of heating and injecting into the isolated liquid crystal injection part having a plurality of linear spaces arranged in parallel and cooling the liquid crystal,
A liquid crystal display element having reduced alignment defects by causing a temperature gradient in which the temperature changes monotonically from one side to the other side in the longitudinal direction of the linear space, and a method of manufacturing the same,
It relates to a manufacturing device.

[0002]

2. Description of the Related Art In recent years, it has been possible to make small, thin, lightweight
A display element using a liquid crystal is regarded as important because of its advantages such as low power consumption. Currently, liquid crystal display elements mainly used are those using a nematic liquid crystal. The response time of a liquid crystal display element using a nematic liquid crystal is about 30 ms at the earliest.
With this response speed, it is impossible to display a moving image completely smoothly.

In recent years, a time-division display system capable of performing full-color display without using a color filter has been developed.
Attention has been paid to a method capable of performing color display with low cost and low power consumption. In order to perform the time-division display without deteriorating the display performance, the response time of the liquid crystal needs to be about several hundred μs, and it is difficult to realize the liquid crystal display element using the nematic liquid crystal. Therefore, it has been studied to manufacture a liquid crystal display element using a ferroelectric liquid crystal or an antiferroelectric liquid crystal that can respond in 1 ms or less.

However, these liquid crystals are smectic liquid crystals used in a state where the liquid crystal phase is a smectic phase. In a liquid crystal display device using the same, a contrast ratio is low due to a defect peculiar to the smectic phase.
Another problem is that the orientation is easily disturbed by an external impact. As described in, for example, “Structure and Physical Properties of Ferroelectric Liquid Crystal” by Atsuo Fukuda (Corona), nematic liquid crystal has a structure in which the major axis directions of liquid crystal molecules match, whereas smectic It is considered that the liquid crystal has a layer structure in which not only the major axis direction but also the position of the center of gravity of the molecule is aligned.

[0005] In a liquid crystal display element, an alignment film subjected to an alignment treatment is generally provided on a wall surface of a liquid crystal injection portion in order to align a liquid crystal. This alignment film can regulate the major axis direction of the liquid crystal molecules in a desired direction, but cannot control the layer structure. Therefore, merely providing the alignment film does not prevent the generation of a plurality of domains having different bending directions in the middle of the layer and the generation of alignment defects at the boundaries between the domains. For this,
It is believed that many alignment defects are observed in smectic liquid crystals.

On the other hand, Japanese Patent Application Laid-Open Nos. 9-304756 and 7-318912 disclose that in a liquid crystal display device using a smectic liquid crystal, a bending direction in the middle of a layer is aligned to generate an alignment defect. There is disclosed a liquid crystal display element in which the above is suppressed. About this liquid crystal display element,
This will be described with reference to FIG.

In the liquid crystal display element 21, an injection portion of the liquid crystal 23 is formed by two substrates 22 arranged opposite to each other and a sealant 27 formed so as to surround the periphery. In the liquid crystal injection part, isolated from each other,
A plurality of partition walls 25 made of a photosensitive material mainly composed of an acrylic resin or the like are formed so as to form a plurality of linear spaces arranged in parallel. The partition 25 is made of two substrates 22
Adhered to.

In the manufacturing process of the liquid crystal display element 21, the liquid crystal 23 is injected from an injection port formed at one end in the longitudinal direction of the linear space formed by the partition wall 25 so as to be along the linear space. Flowed and filled. Then, the liquid crystal 23 is once heated until the liquid crystal 23 changes to an isotropic phase. Thereafter, the cooling of the liquid crystal 23 is substantially performed from one side to the other side by arranging one side in the longitudinal direction of the linear space in the thermostatic layer and drawing the other side into the atmosphere. It is performed such that a temperature gradient in which the temperature decreases monotonously occurs (inclined cooling).

According to the above-mentioned publication, by cooling the liquid crystal 23 in this way, it is possible to align the bending direction of the layer formed at the time of transition to the smectic phase to the side to be cooled faster, and to obtain alignment defects. Can be reduced. It is considered that this is because the liquid crystal 23 is pulled to the side that is cooled faster in the cooling step due to the volume contraction force of the liquid crystal 23.

According to this manufacturing method, it is possible to reduce defects peculiar to the smectic phase, to improve the alignment state, and to manufacture a liquid crystal display element capable of displaying a liquid crystal with a high contrast ratio. In addition, the partition wall 25 forming the linear space is bonded to the two substrates 22 so that the liquid crystal display element 21 is resistant to impact. Therefore, by providing such a partition 25, disturbance of liquid crystal alignment due to external impact can be prevented. In recent years, studies on liquid crystal display elements using partition spacers have been actively conducted.

[0011]

As described above, the liquid crystal injection portion has a structure including a plurality of linear spaces by providing partitions therein, and the liquid crystal layer is tilted and cooled so that the liquid crystal layer is oriented in a certain direction. Aligning is very effective for reducing the alignment defects of the liquid crystal display element and improving the impact resistance. However, in such a structure in which the partition is provided, the partition needs to be bonded to the substrate, and if the adhesive strength is not sufficient, poor adhesion occurs, and only a weak impact is applied to the partition and the substrate. May be peeled off.

When a part where the partition wall and the substrate are separated occurs in the manufacturing process, the liquid crystal can flow around the separated part. For this reason, when the liquid crystal is cooled after the separation occurs, the liquid crystal flows through the separation part even when a temperature gradient is given, so that the volume contraction force can be effectively exerted on the liquid crystal molecules in a certain direction. Therefore, there arises a problem that alignment defects cannot be sufficiently reduced.

In the peeled portion, the liquid crystal is injected more than necessary at the time of injection of the liquid crystal, the liquid crystal panel tends to be pushed up, the partition wall portion is lifted from at least one of the substrates, and the liquid crystal is present in the lifted portion. There is a risk of becoming. In such a state, when an external shock is applied to the completed liquid crystal display element, the liquid crystal easily flows and the alignment state is disturbed, that is, the shock resistance is reduced. Further, there is a problem that the alignment defect generated in this manner easily spreads to the periphery because the liquid crystal is not blocked between the partition walls.

In a structure in which a partition is provided in a liquid crystal injection portion, a portion where the partition is provided cannot be used as a display area. For this reason, the partition is provided in a non-display area. In recent years, the definition of the display element has been advanced, and accordingly, the non-display area has been narrowed. For this reason, the installation area of the partition is limited to a narrow area, and as a result,
There is a need to reduce the partition wall width. When the partition wall width is narrowed and the line is made thinner, the bonding area is reduced, which causes a serious situation that problems such as poor bonding and peeling occur more frequently.

In providing a partition at the liquid crystal injection portion,
A partition is placed on the alignment film of one substrate and bonded to the other substrate coated with an alignment film. An "alignment film-partition-alignment film" structure, and a partition is placed on one substrate and then the alignment film is applied Then, a "partition-alignment film-alignment film" structure in which the alignment film is bonded to the alignment film of the other substrate is considered.

Among them, in the former "alignment film-partition-alignment film" structure, the bonding can be performed by the adhesive force of the partition, so that the alignment film has an adhesive function other than the function of determining the alignment direction of the liquid crystal molecules. Strong bonding can be performed relatively easily without having a function to perform the bonding. However, there is a drawback that the alignment film is contaminated such as a state in which a residue of the partition wall material is adhered on the alignment film due to the arrangement of the partition wall on the alignment film, which adversely affects the function of aligning the liquid crystal molecules. .

On the other hand, in the latter “partition-alignment film-alignment film” structure, there is no need to provide a partition on the alignment film, so that the problem of alignment film contamination does not occur. Therefore, it is necessary to give the alignment film an adhesive force. Generally, an alignment film does not have a strong adhesive force, and a step of heating the alignment film to a temperature equal to or higher than the glass transition point and softening the alignment film once is required to bond the alignment films relatively strongly. However, the heat softening step causes a problem that the alignment regulating force applied to the alignment film by the alignment treatment such as rubbing is reduced, and the function of aligning the liquid crystal is impaired.

As described above, in particular, as the partition wall width becomes finer, it has become more difficult to firmly bond the substrate and the partition wall without peeling.

In view of the above-mentioned problems of the prior art, an object of the present invention is to provide a liquid crystal injection portion having a partition structure and having a plurality of linear spaces formed by the partition walls. In a liquid crystal display device, even when the partition walls are not completely bonded and a gap is formed between the partition walls and the substrate, the liquid crystal molecules are effectively aligned by the volume shrinkage force of the liquid crystal due to the inclined cooling. An object of the present invention is to provide a liquid crystal display element which can reduce defects and is resistant to external impact, and a method and apparatus for manufacturing the same.

[0020]

In order to achieve the above object, a liquid display device according to the present invention comprises two substrates disposed opposite to each other and a liquid crystal injection portion formed between the two substrates. So as to surround the liquid crystal injection part, an outer wall fixing the substrate, and a partition wall provided between the two substrates and forming a plurality of linear spaces in the liquid crystal injection part; A liquid crystal display element having a liquid crystal injected into a liquid crystal injection part, wherein at least a part between the partition and at least one substrate is not coupled, and by applying a predetermined force on the substrate, It is characterized in that the partition and the substrate come into close contact with each other.

According to this structure, a predetermined force is applied to the substrate, and the liquid crystal is injected and the inclined cooling is performed in a state where the partition and the substrate are in close contact with each other. To the liquid crystal to be cooled in the linear space.

By performing tilt cooling in a linear space, the smectic liquid crystal can align the direction of bending in the middle of a layer formed at the time of phase transition to a smectic phase due to cooling, whereby alignment defects can be reduced. Can be greatly reduced. Therefore, by applying the present invention to a liquid crystal display device using a smectic liquid crystal as a liquid crystal, it is possible to greatly reduce alignment defects.

The method for manufacturing a liquid crystal display device according to the present invention comprises:
A partition is provided on the substrate so that a plurality of linear spaces are formed, an outer wall is provided so as to form a liquid crystal injection portion surrounding a portion where the partition is formed on the substrate, and another is provided on the outer wall. Bonding the substrate, applying a force from the outside of the liquid crystal injection section to the inside of the liquid crystal injecting section, and bringing the substrate into close contact with the partition, heating the liquid crystal, and bringing the substrate into contact with the partition. Injecting the liquid crystal into the liquid crystal injection part from the liquid crystal injection part to the outside while maintaining the liquid crystal injection part. Cooling while generating a temperature gradient in which the temperature changes substantially monotonously from one side to the other side in the longitudinal direction of the space.

In particular, the method for manufacturing a liquid crystal display element according to the present invention is suitable as a method for manufacturing a liquid crystal display element using a smectic liquid crystal as a liquid crystal. In this case, the liquid crystal is once subjected to a phase transition from a smectic phase in a liquid crystal heating step. Let
It is characterized in that the liquid crystal undergoes a phase transition to a smectic phase in the liquid crystal cooling step. By doing so, the bending direction in the middle of the layer formed at the time of the phase transition to the smectic phase due to cooling, the volume contraction force of the liquid crystal due to the tilt cooling effectively acts on the liquid crystal molecules in a certain direction. Can be aligned.

As described above, when the liquid crystal is injected and the inclined cooling is performed, a force is applied to the substrate to keep the substrate and the partition wall in close contact with each other. Then, there is a method of applying a force on the substrate. More specifically, the substrate is heated under reduced pressure, liquid crystal is dropped into the injection port, and the liquid crystal is heated and injected into the liquid crystal injection section. By bringing the pressure closer to the atmospheric pressure, a pressure difference is generated between the inside and the outside of the liquid crystal injection portion, and a force can be applied on the substrate by the pressure difference. In addition, a plurality of injection ports are provided, suction is performed from at least one of the plurality of injection ports, and liquid crystal is injected from the remaining injection ports to generate a pressure difference inside and outside the liquid crystal injection section. May exert a force on the substrate.

When performing liquid crystal injection and tilt cooling,
As another method of applying a force on the substrate to keep the substrate and the partition wall in close contact with each other, there is a method of mechanically applying a force on the substrate. More specifically, a force can be applied by bringing the flat-plate-shaped pressing device into contact with the substrate. In this case, as a flat pressing device, a temperature gradient in which the temperature changes substantially monotonously from one side to the other in the longitudinal direction of the linear space in a state of being in contact with the substrate is obtained. It is desirable to cool the liquid crystal while generating a temperature gradient by using a temperature-controllable liquid crystal and generating a temperature gradient in the flat-plate pressing device.

Further, the caterpillar pressure device may be brought into contact with the substrate to apply a force. In this case, the liquid crystal display element can be moved by circulating the caterpillar-shaped pressurizing device.
The liquid crystal display element can be moved from the heating section of the liquid crystal to the inclined cooling section as appropriate, and can be efficiently heated and cooled. Further, as a caterpillar-shaped pressurizing device, a temperature gradient is generated in which the temperature changes substantially monotonously from one side to the other in the longitudinal direction of the linear space in a state of being in contact with the substrate. After the liquid crystal injection is completed, the liquid crystal display element is moved to a position in contact with the caterpillar-shaped pressurizing device, and the caterpillar-shaped pressurizing device has a temperature gradient. By letting
Slant cooling may be performed.

Further, a roller-type pressing device having a plurality of rollers arranged side by side may be brought into contact with the substrate to apply a force. Pressing with a roller cannot be performed as uniformly as pressing with a caterpillar pressing device because the contact surface with the substrate is small and intermittent. Pressurization and movement of the liquid crystal display element can be performed with a device simpler than the pressure device. Also in this case, a roller-shaped pressing device capable of adjusting the temperature of each roller is used, and the roller is pressed against the substrate so that the rollers are arranged in the longitudinal direction of the linear space, and the roller is pressed against the substrate. Slant cooling can be performed by adjusting the temperature of each roller so that the temperature changes monotonically from one side to the other side.

The above-described pressurization based on the pressure difference and mechanical pressurization can be used together as necessary.

In the method of manufacturing a liquid crystal display device according to the present invention, if liquid crystal is excessively injected, the substrate may be pushed up from above the partition walls. Has an adverse effect such that it becomes impossible to act on the liquid crystal molecules in a certain direction. Therefore, in order to prevent the liquid crystal from being excessively injected, it is desirable to have a step of sealing the injection port immediately after the completion of the liquid crystal injection step.

In the method of manufacturing a liquid crystal display device according to the present invention, it is also preferable that the pressure outside the liquid crystal injection part is increased to a pressure higher than the atmospheric pressure in the liquid crystal injection step and the liquid crystal cooling step. By doing so, a force for bringing the partition wall and the substrate into close contact with each other can be more effectively applied to the substrate by the pressure difference between the inside and the outside of the liquid crystal injection portion.

An apparatus for manufacturing a liquid crystal display device according to the present invention comprises:
Two substrates opposing each other, an outer wall surrounding the liquid crystal injection part and fixing the substrate so as to form a liquid crystal injection part between the two substrates, and two substrates A liquid crystal display element is provided by injecting liquid crystal into a frame having a partition wall that forms a plurality of linear spaces in the liquid crystal injection section, and an injection port communicating from the inside of the liquid crystal injection section to the outside. A pressurizing means for applying a force on the substrate to bring the partition and the substrate into close contact with each other, and injecting the liquid crystal into the liquid crystal injection portion from the injection port while keeping the partition and the substrate in close contact with each other. Liquid crystal injecting means, liquid crystal heating means for heating the liquid crystal, and the liquid crystal is substantially moved from one side to the other side in the longitudinal direction of the linear space while keeping the partition and the substrate in close contact with each other. Liquid crystal that cools while generating a temperature gradient where the temperature changes monotonically And having a retirement unit.

In particular, the apparatus for manufacturing a liquid crystal display element according to the present invention is suitable as an apparatus for manufacturing a liquid crystal display element using a smectic liquid crystal as a liquid crystal. In this case, the liquid crystal heating means causes the liquid crystal to temporarily undergo a phase transition from the smectic phase. The liquid crystal cooling means changes the phase of the liquid crystal into a smectic phase.

More specifically, as the pressurizing means, it is possible to use a vacuum chamber capable of housing the frame and reducing the pressure inside. That is, the pressure inside the vacuum chamber is reduced in a state in which the frame is housed in the vacuum chamber, and the pressure in the vacuum chamber is brought close to the atmospheric pressure immediately after the liquid crystal is injected by the liquid crystal injection means. A difference is created, and this pressure difference can apply a force on the substrate.

A frame having a plurality of inlets may be used as the frame, and a suction device for sucking from at least one of the plurality of inlets may be used as the pressurizing means. That is, when liquid crystal is injected by the liquid crystal injection means,
A pressure difference is generated between the inside and outside of the liquid crystal injection section by the suction device, and a force can be applied to the substrate by the pressure difference.

Further, as the pressurizing means, a flat pressurizing device which abuts on the substrate and mechanically applies a force can be used. In this case, the temperature gradient in which the temperature is substantially monotonically changed from one side to the other side in the longitudinal direction of the linear space in a state where the flat pressing device is abutted on the substrate has a temperature gradient. The temperature can be adjusted so as to generate the liquid crystal, and the liquid crystal can be used as a liquid crystal cooling unit.

Further, as the pressing means, a caterpillar-shaped pressing device capable of moving the liquid crystal display element by circulating and applying a mechanical force in contact with the substrate can be used. In this case, the heating and cooling can be efficiently performed by appropriately moving the liquid crystal display element from the heating part of the liquid crystal to the inclined cooling part by the caterpillar pressing device. Further, in a state where at least one of the caterpillar-shaped pressurizing devices is in contact with the substrate, the temperature changes substantially monotonously from one side to the other in the longitudinal direction of the linear space. The temperature can be adjusted so as to generate a temperature gradient, and it can be used as a liquid crystal cooling means.

Further, as a pressing means, a plurality of rollers arranged side by side are provided, and the rollers abut on the substrate to apply a mechanical force and to move the liquid crystal display element by rotating. A roller-type pressurizing device capable of performing the above can be used. Also in this case, the heating and cooling can be efficiently performed by appropriately moving the liquid crystal display element from the heating part of the liquid crystal to the inclined cooling part by the roller-shaped pressing device. Further, the roller-type pressurizing device is capable of adjusting the temperature of each roller, and is brought into contact with the substrate so that the rollers are arranged in the longitudinal direction of the linear space, and each roller that is in contact with the substrate is It can be used as a liquid crystal cooling means by adjusting the temperature so that the temperature changes monotonically from one side to the other side.

An apparatus for manufacturing a liquid crystal display device according to the present invention
It is preferable to further have a mechanism for sealing the inlet.
Further, it is preferable to further include a mechanism for pressurizing the outside of the liquid crystal injection unit to a pressure higher than the atmospheric pressure as the pressurizing unit.

[0040]

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

[First Embodiment] FIG. 1 is a schematic perspective view conceptually showing a method of manufacturing a liquid crystal display element 1 according to a first embodiment of the present invention. FIG. 2 is a sectional view of the liquid crystal display element 1.

In the liquid crystal display element 1, a partition 5 is provided on one substrate 2 and an alignment film 8 is formed thereon. On the other substrate 2, only the alignment film 8 is formed. The two substrates 2 are arranged to face each other, and a sealing agent 7 is provided so as to surround the periphery of the two substrates 2, so that they are bonded to each other. Liquid crystal is injected into a portion surrounded by the sealant 7, and a certain area of the liquid crystal injection portion becomes a liquid crystal display portion. In the liquid crystal injection part,
A plurality of linear spaces are formed by the partition walls 5. The liquid crystal display element 1 is provided with a liquid crystal injection port 3 in the vicinity of the center of one side of the plurality of linear spaces in the longitudinal direction.

Here, in the liquid crystal display element 1, the partition 5
The alignment films 8 are arranged facing each other at the portions. As described above, in order to completely separate the linear spaces from each other with the partition wall 5 interposed therebetween, in order to bond the alignment films 8 to each other, it is necessary to heat the alignment film 5 once in order to bond sufficiently firmly.
There is a problem that it is necessary to perform a treatment that adversely affects the alignment function of the alignment film 5. Therefore, as the liquid crystal display element 1 of the present embodiment, an element in which the partition wall 5 is not bonded to one of the substrates 2 is used. However, when a predetermined force is applied to the substrate 2 by the pressure difference pressurization 15, the sealant 7 and the substrate 2 are deformed without adversely affecting these members, and the unbonded partition 5 and the substrate 2 Are designed to adhere. At this time, when no force is applied, a certain gap may be formed between the partition wall 5 and the substrate 2 as shown in FIG. This gap can be easily changed by pressing with, for example, a finger.

Next, an apparatus for manufacturing the liquid crystal display element 1 of the present invention will be described with reference to the schematic diagram shown in FIG.
This manufacturing apparatus has a vacuum chamber 9. A flat temperature controller 4 is provided in the vacuum chamber 9, and a frame body as the liquid crystal display element 1 before liquid crystal is injected is held thereon. Also, the injection port 3 of the held frame body
Is provided with a liquid crystal dropping mechanism (liquid crystal injection means) 16 for dropping a smectic liquid crystal. Flat plate temperature controller 4
In order to have a predetermined temperature distribution along the longitudinal direction of the partition wall 5 in the arrangement surface of the liquid crystal display element 1,
A heating / cooling mechanism is provided, and has both functions of a liquid crystal heating unit and a liquid crystal cooling unit.

Next, a method for manufacturing the liquid crystal display element 1 of the present embodiment will be described.

First, a partition 5 is formed on one substrate 2,
An orientation film 8 is applied thereon and fired. The other substrate 2
Only the orientation film 8 is applied and fired thereon. Then, the two substrates 2 are bonded to each other with a sealant 7 applied therebetween.

The frame thus formed is placed on the flat plate temperature controller 4 of the manufacturing apparatus shown in FIG. 3, and the pressure in the vacuum chamber 9 is reduced. At this time, the frame is heated to a predetermined temperature after or before the vacuum chamber is evacuated. This is because the smectic liquid crystal dropped by the liquid crystal dropping mechanism 16 is in a creamy state at room temperature, and it is difficult to inject it as it is.
This is because the smectic liquid crystal is heated to a temperature at which the liquid crystal becomes a nematic phase or an isotropic phase having higher fluidity.

Next, the smectic liquid crystal is dropped on the injection port 3 by the liquid crystal dropping mechanism 16. Then, when the injection of the smectic liquid crystal into the frame starts, the inside of the vacuum chamber 9 is returned to the atmospheric pressure. At this time, since the injection port 3 is closed by the liquid crystal dropped, the frame remains in a vacuum state. Therefore, the frame 1 is pressurized by the pressure difference between the inside and the outside, and a force is applied to the substrate 2 inward, so that the partition walls 5 come into close contact with the substrates 2 on both sides. In this state, the injection of the liquid crystal is continued.

At this time, if a predetermined amount or more of liquid crystal is injected into the liquid crystal display element 1, the force of the liquid crystal overcomes the atmospheric pressure and the substrate 2 is pushed up. In this case, when the liquid crystal is cooled in a later step, the volume shrinkage force cannot be sufficiently exerted on the liquid crystal molecules, so that the alignment defect is not reduced. In addition, when the external force is applied to the liquid crystal display element 1, the liquid crystal is reduced. There is a concern that adverse effects such as easy flow and disturbed alignment may occur.

In order to prevent this from happening, it is necessary to take care that the injection amount of the liquid crystal does not exceed a predetermined amount. In addition, a mechanism for dropping the photocurable resin into the injection port 3 of the liquid crystal display element and a light irradiation mechanism are prepared so that the liquid crystal is not excessively injected, and the photocurable resin is dropped after a predetermined amount of liquid crystal is injected. It is also effective to adopt a method of performing injection and light irradiation to seal the injection port 3. In any case,
After the injection is completed, the injection port 3 is closed so that the inside of the liquid crystal display element 1 is maintained at a negative pressure.

Next, after the injection is completed, the plate-shaped temperature controller 4
Is operated to perform inclined cooling along the longitudinal direction of the partition wall 5.
That is, when the injected liquid crystal is cooled, the flat plate is formed such that a predetermined temperature gradient in which the temperature changes substantially monotonously from one side to the other side along the longitudinal direction of the partition wall 5 occurs. The temperature control device 4 is set.

As a result, in the linear space formed by the partition walls 5, a phase transition of the liquid crystal occurs sequentially from one side set so that the temperature becomes lower. At this time, since the liquid crystal display element 1 is maintained in a pressurized state by the pressure difference between the inside and the outside, the partition walls 5 are maintained in a state of being in close contact with the substrates 2 on both sides. Therefore, the volume contraction force generated due to the phase transition of the liquid crystal can be caused to act on one side of the linear space where the temperature is set to be low, and to act to pull the liquid crystal molecules in a certain direction. . Thereby, the bending direction of the layer formed when the liquid crystal undergoes a phase transition to the smectic phase can be aligned so as to be directed to the side where the liquid crystal molecules are pulled, and the alignment defects can be greatly reduced.

In this way, the liquid crystal is cooled to room temperature,
The manufacture of the liquid crystal display element 1 is completed.

As described above, according to the present embodiment, the inclination cooling is performed in a state where the partition wall 5 and the substrate 2 are in close contact with each other by the pressure difference between the inside and the outside of the liquid crystal display element 1, thereby using the smectic liquid crystal. The liquid crystal display element 1 with few alignment defects can be manufactured.

Further, in the liquid crystal display element 1 of the present embodiment,
Since the inside is kept at a negative pressure, the partition walls 5 are always in close contact with the substrates 2 on both sides, and the liquid crystal display element 1 having excellent impact resistance can be provided.

In the present embodiment, the liquid crystal display element 1 having the configuration in which the partition walls 5 are bonded only to one substrate 2 is shown. However, the partition walls 5 are formed on the alignment film 8 of one substrate 2. It is also effective to apply the manufacturing method of the present embodiment to the liquid crystal display element 1 in which the other substrate 2 having the alignment film 8 applied and baked on the partition 5 is adhered. That is, in this case,
Even if the partition wall 5 is partially peeled off by an impact in a later step such as a break process, the liquid crystal is injected into the liquid crystal display element 1 and cooled so that the liquid crystal is well aligned. The liquid crystal can be prevented from flowing due to external impact after completion.

In the present embodiment, the liquid crystal is injected and cooled in a state where the inside of the vacuum chamber 9 is set to the atmospheric pressure. However, a mechanism for pressurizing the inside of the vacuum chamber 9 to the atmospheric pressure or higher is provided. 9 may be performed in a pressurized state. By doing so, a force can be more effectively applied to the substrate 2.

[Second Embodiment] Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a schematic configuration diagram of a manufacturing apparatus of the liquid crystal display element 1b. In the figure, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

This embodiment is different from the first embodiment in that the liquid crystal is not injected in the vacuum chamber. As the liquid crystal display element 1b, basically the same one as in the first embodiment can be used, but it is necessary to use one having a plurality of injection ports 3. In the example shown in FIG. 4, the liquid crystal display element 1b
Each of the plurality of linear spaces is provided with one injection port 3 in the vicinity of the center of each side on both ends in the longitudinal direction. The inlet 3 is preferably provided on the side of the liquid crystal display element 1b on the side of the longitudinal end of the linear space so that the liquid crystal is injected along the longitudinal direction of the linear space.

In the method of manufacturing the liquid crystal display element 1b according to the present embodiment, at the time of injecting liquid crystal, liquid crystal is dropped into one injection port 3, and a suction device 17 is attached to the other injection port 3, so that a liquid crystal display is provided. The pressure inside the element 1b is reduced. Thereby, a pressure difference is generated between the inside and outside of the liquid crystal display element 1b, and the partition wall 5 can be brought into close contact with the substrate 2 by the pressure difference pressurization 15, and the liquid crystal is injected in this state. Then, even when the liquid crystal is tilted and cooled after the completion of the liquid crystal injection, the inside of the liquid crystal display element 1b is kept at a negative pressure, and the partition wall 5 and the substrate 2 are kept in close contact with each other.

As described above, similarly to the first embodiment, the orientation defect can be greatly reduced by the volume shrinkage force accompanying the phase transition of the liquid crystal when the liquid crystal is tilted and cooled. In addition, all the injection ports 3 can be closed while the inside of the liquid crystal display element 1b is maintained at a negative pressure. In this manner, the partition walls 5 are always kept in close contact with the substrates 2 on both sides. Thus, the liquid crystal display element 1b having excellent impact resistance can be manufactured.

In the present embodiment, the same effects as in the first embodiment can be obtained without using a large-scale vacuum chamber. Also, even if the liquid crystal is slightly over-injected,
Since the liquid crystal over-injected by the suction device 17 is eliminated, it is not necessary to pay attention to the liquid crystal over-injection as in the first embodiment, the yield can be improved, and the manufacturing cost can be reduced. it can.

In this embodiment, the outside of the liquid crystal injection section may be pressurized to the atmospheric pressure or higher, and the pressure difference pressurization 15 may be performed more effectively.

[Third Embodiment] Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 5 is a schematic configuration diagram of a manufacturing apparatus of the liquid crystal display element 1. In the figure, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The present embodiment differs from the first embodiment in that a flat press mechanism 11 for mechanically pressing, ie, pressing, the liquid crystal display element 1 installed on the flat temperature controller 4 is used. different. The flat pressing mechanism 11 preferably includes a heating / cooling mechanism capable of providing a desired temperature distribution in the plane, similarly to the flat temperature controller 4. The pressing mechanism 11 can also be used as a liquid crystal heating means and a liquid crystal cooling means. As the liquid crystal display element 1, one having the same configuration as that of the first embodiment can be used at the stage of the frame before the liquid crystal is injected.

In the manufacturing process of the liquid crystal cover element 1 of the present embodiment, a frame is set on the plate-shaped temperature control device 4 and the frame is pressed by the plate-shaped pressing mechanism 11 so that the upper substrate 2 As shown in the sectional view of FIG.
It is brought into close contact with the substrate 2. Thereafter, while maintaining the state in which the partition wall 5 and the substrate 2 are kept in close contact with each other, the inside of the vacuum chamber 9 is evacuated and the liquid crystal display element 1 is heated, and the smectic liquid crystal is dropped into the injection port 3 to inject the liquid crystal. At this time, in this embodiment, if the force of the mechanical pressing by the flat pressing device 11 is set to a certain level or more, even if a predetermined amount or more of the liquid crystal is dropped, the substrate 2 is pushed up by the liquid crystal and the partition wall is pressed. 5 and no liquid crystal is over-injected. Therefore, it is not necessary to pay attention to over-injection of the liquid crystal as in the first embodiment.

After completion of the injection, the plate-shaped temperature controller 4 is operated to perform inclined cooling along the longitudinal direction of the partition walls 5. At this time, mechanical pressurization of the liquid crystal display element 1 is maintained, and the partition 5 is kept in close contact with the substrates 2 on both sides. By doing so, as in the first embodiment, the volume contraction force accompanying the phase transition of the liquid crystal when tilting the liquid crystal is cooled,
Alignment defects can be significantly reduced.

In the present embodiment, the liquid crystal is injected and cooled in a state where the partition walls 5 are in close contact with the substrates 2 on both sides, so that no liquid crystal is injected between the partition walls 5 and the substrate 2. Therefore, even if a slight impact is applied to the liquid crystal display element 1 and the gap between the substrate 2 and the partition 5 changes due to the deformation of the substrate 2 and the like, no direct force is applied to the injected liquid crystal. Does not flow and the orientation is not disturbed. That is, the liquid crystal display element 1 having excellent impact resistance can be manufactured.

Further, according to the present embodiment, it is possible to prevent the liquid crystal from being excessively injected into the liquid crystal display element 1, so that the production yield can be improved.

In the present embodiment, in order to inject the liquid crystal into the liquid crystal display element 1 well, the liquid crystal display element 1 is put into the vacuum chamber 9 before the liquid crystal is injected, and A negative pressure is applied to the inside of the element 1. Therefore, similarly to the first embodiment, when the liquid crystal is started to be injected into the injection port 3, the inside of the vacuum chamber 9 is returned to the atmospheric pressure, and the pressurization is performed using both the mechanical pressurization and the pressure difference pressurization. You may.

[Fourth Embodiment] Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 7 is a schematic configuration diagram of a manufacturing apparatus of the liquid crystal display element 1. In the figure, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, similar to the third embodiment, a mechanical force is applied to bring the partition wall 5 and the substrate 2 into close contact with each other. Is different from the third embodiment. The caterpillar-shaped pressurizing device 12 is capable of circulating movement, and also functions as means for moving the liquid crystal display element 1 by circulating. Further, it is desirable that the caterpillar-shaped pressurizing device 12 is provided with a temperature control mechanism, and that the temperature can be controlled simultaneously with pressurization.

With such a configuration, the liquid crystal display element 1 can be efficiently heated and cooled by moving the liquid crystal display element 1 to regions of the flat plate temperature control device 4 where different temperatures are set. is there. That is, in the example shown in FIG.
The left side area is set to a cooling temperature, and the pressure in the vacuum chamber 9 is reduced while the liquid crystal display element 1 is located in the right side area (heating unit), and the liquid crystal display element 1 is heated to form a liquid crystal. Perform injection. Then, the liquid crystal display element 1 is moved to the left side region (inclined cooling unit) by the caterpillar-shaped pressurizing device 12.
To perform inclined cooling. In the steps of injecting and cooling the liquid crystal, the liquid crystal display element 1 is kept in a state in which the partition wall 5 and the substrate 2 are in close contact with each other by the force from the caterpillar pressurizing device 12.

Further, heating and cooling may be performed by providing a plurality of caterpillar-shaped pressurizing devices 12 having different temperature settings. In the example shown in FIG. 7, two caterpillar-shaped pressurizing devices 12 are provided, and the one on the right side is for heating,
The one on the left side can be configured so that the temperature can be set for inclined cooling.

Further, by using the caterpillar-shaped pressurizing device 12, it is possible to hold the liquid crystal display element 1 vertically and move it in the vertical direction to perform heating and cooling. In this case, it is possible to use a dip method in which the injection port 3 of the liquid crystal display element 1 is immersed in the liquid crystal and the liquid crystal is injected by a capillary phenomenon.

As shown in FIG. 8, the liquid crystal display element 1 is sandwiched and held by caterpillar-shaped pressurizing devices 12 provided on both sides so that the liquid crystal display element 1 can be moved more easily.
You may make it move.

Instead of the caterpillar pressing device 12, a roller pressing device 13 having a plurality of rollers arranged side by side as shown in FIG. 9 can be used. In this case, it is desirable that the plurality of rollers can be set to different temperatures. When the roller-shaped pressing device 13 is used, since the contact surface with the liquid crystal display element 1 is small and intermittent, the distribution of the applied pressure and the settable temperature is reduced when the caterpillar-shaped pressing device 12 is used. It becomes coarser than. However, compared to the caterpillar press device 12, the caterpillar press device 1 has a simpler mechanism with fewer moving parts, and is therefore less expensive.
2 can be performed.

As described above, according to the present embodiment, heating and cooling can be performed efficiently, and the manufacturing cost of the liquid crystal display element 1 can be reduced. Efficient heating and cooling is also advantageous for mass-producing the liquid crystal display element 1.

[0079]

As described above, according to the present invention,
In a liquid crystal display device in which a smectic liquid crystal is injected into a liquid crystal injection portion formed between two substrates and in which a plurality of linear spaces are formed by the partitions provided between the two substrates, the partitions are completely bonded. Even when there is a gap between the partition and the substrate, the liquid crystal is injected and tilt-cooled in a state in which the partition and the substrate are in close contact with each other by applying a force on the substrate, whereby the liquid crystal is tilt-cooled. It is possible to reduce the alignment defect by effectively applying the volume contraction force to the liquid crystal molecules in a certain direction.

Further, the liquid crystal display element of the present invention is resistant to external impact since liquid crystal does not enter between the partition and the substrate.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view conceptually showing a method of manufacturing a liquid crystal display element according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the liquid crystal display device of FIG.

FIG. 3 is a schematic configuration diagram of a manufacturing apparatus of the liquid crystal display element of FIG.

FIG. 4 is a schematic configuration diagram of an apparatus for manufacturing a liquid crystal display element according to a second embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of an apparatus for manufacturing a liquid crystal display element according to a third embodiment of the present invention.

6 is a cross-sectional view of the liquid crystal display device in a state where a force is applied in the manufacturing apparatus of FIG.

FIG. 7 is a schematic configuration diagram of an apparatus for manufacturing a liquid crystal display element according to a fourth embodiment of the present invention.

FIG. 8 is a schematic configuration diagram of a manufacturing apparatus according to a modification of FIG. 7;

FIG. 9 is a schematic configuration diagram of a manufacturing apparatus according to another modification of FIG. 7;

FIG. 10 is a schematic perspective view showing a conventional method for manufacturing a liquid crystal display element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1b, 21 Liquid crystal display element 2, 22 Substrate 3 Inlet 4 Flat plate temperature controller 5, 25 Partition 7, 27 Sealant 8 Alignment film 9 Vacuum chamber 11 Flat plate press device 12 Caterpillar press device 13 Roller Pressure device 15 Atmospheric pressure difference pressurization 16 Liquid crystal dropping mechanism 17 Suction device 23 Liquid crystal 24 Constant temperature layer

Continued on the front page F-term (reference) 2H088 GA04 HA03 JA17 JA20 MA02 MA17 2H089 LA09 LA19 LA31 NA19 NA22 NA24 NA31 NA39 QA14 QA15 RA13 RA14 TA04

Claims (26)

[Claims] 1. A method according to claim 1, wherein two substrates disposed opposite to each other and a liquid crystal injection portion are formed between the two substrates.
An outer wall fixed to the substrate and disposed around the liquid crystal injection portion, a partition wall provided between the two substrates, and forming a plurality of linear spaces in the liquid crystal injection portion;
A liquid crystal display element having liquid crystal injected into the liquid crystal injection section, wherein at least a part between the partition and at least one of the substrates is not coupled, and a predetermined force is applied to the substrate. A liquid crystal display element in which the partition walls and the substrate are brought into close contact with each other when added. 2. The liquid crystal display device according to claim 1, wherein a smectic liquid crystal is used as the liquid crystal. 3. A partition is provided on a substrate so that a plurality of linear spaces are formed, and an outer wall is provided so as to form a liquid crystal injection portion surrounding a portion of the substrate on which the partition is formed. Laminating another substrate on the outer wall; applying a force from the outside of the liquid crystal injection portion to the inside of the liquid crystal injecting portion on the substrate to bring the substrate and the partition wall into close contact with each other; Heating, and while maintaining the state in which the substrate and the partition wall are in close contact with each other,
A step of injecting the liquid crystal into the liquid crystal injection section from an injection port communicating from the inside of the liquid crystal injection section to the outside, while keeping the substrate and the partition wall in close contact with each other,
Cooling the liquid crystal while generating a temperature gradient in which the temperature changes substantially monotonously from one side to the other in the longitudinal direction of the linear space. . 4. The liquid crystal according to claim 3, wherein a smectic liquid crystal is used as the liquid crystal, and the liquid crystal is once subjected to a phase transition from a smectic phase in the liquid crystal heating step, and the liquid crystal is caused to undergo a phase transition to a smectic phase in the liquid crystal cooling step. The method for manufacturing a liquid crystal display element according to the present invention. 5. The substrate is heated under reduced pressure, the liquid crystal is dropped into the injection port, the liquid crystal is heated, and the liquid crystal is injected into the liquid crystal injection section. 5. The liquid crystal according to claim 3, wherein a pressure difference is generated between the inside and outside of the liquid crystal injection section by bringing a pressure outside the liquid crystal injection section close to the atmospheric pressure, and a force is applied on the substrate by the pressure difference. A method for manufacturing a display element. 6. A plurality of the inlets are provided, suction is performed from at least one of the plurality of the inlets, and the liquid crystal is injected from the remaining inlets, so that air pressure is generated inside and outside the liquid crystal inlet. The method according to claim 3, wherein a difference is generated, and a force is applied on the substrate by the pressure difference. 7. The method for manufacturing a liquid crystal display element according to claim 3, wherein a force is applied by bringing a flat plate pressing device that mechanically applies a force into contact with the substrate. 8. The flat pressurizing device according to claim 1, wherein the temperature is substantially monotonically increased from one side to the other in the longitudinal direction of the linear space in a state of being in contact with the substrate. 8. The liquid crystal according to claim 7, wherein the liquid crystal is cooled while generating a temperature gradient by using a temperature-adjustable device to generate a changing temperature gradient and by generating a temperature gradient in the flat plate pressing device. A method for manufacturing a liquid crystal display element. 9. The apparatus according to claim 3, wherein a caterpillar-shaped pressurizing device capable of moving the liquid crystal display element by circulating and mechanically applying a force is brought into contact with said substrate to apply the force. 7. The method for manufacturing a liquid crystal display element according to any one of the above items 6. 10. The apparatus according to claim 1, wherein the caterpillar-shaped pressurizing device has a substantially monotonous temperature in a longitudinal direction of the linear space from one side to the other side in a state of being in contact with the substrate. 10. The liquid crystal according to claim 9, wherein the liquid crystal is cooled while generating a temperature gradient by using at least one temperature-adjustable device to generate a changing temperature gradient and generating a temperature gradient in the caterpillar-shaped pressurizing device. The method for manufacturing a liquid crystal display element according to the above. 11. A roller-shaped pressing device having a plurality of rollers arranged side by side and capable of moving a liquid crystal display element by rotating mechanically while applying a mechanical force to the substrate. The method for manufacturing a liquid crystal display element according to any one of claims 3 to 6, wherein a force is applied by bringing the liquid crystal display element into contact with the upper part. 12. The roller-type pressurizing device is capable of adjusting the temperature of each of the rollers, and the roller-type pressurizing device is mounted on the substrate so that the rollers are arranged in a longitudinal direction of the linear space. The temperature gradient of the liquid crystal is reduced by adjusting the temperature of the rollers contacting the substrate with each other so that the temperature changes monotonically in order from one side to the other side. The method for manufacturing a liquid crystal display element according to claim 11, wherein the liquid crystal display element is cooled while being generated. 13. The method of manufacturing a liquid crystal display element according to claim 3, further comprising a step of sealing the injection port immediately after the step of injecting the liquid crystal is completed. 14. Applying a force on the substrate by applying a pressure outside the liquid crystal injection part to an atmospheric pressure or more in the liquid crystal injection step and the liquid crystal cooling step,
The method for manufacturing a liquid crystal display device according to claim 3. 15. Two substrates opposing each other,
A liquid crystal injection portion formed between the two substrates, the liquid crystal injection portion being disposed so as to surround the liquid crystal injection portion, provided between an outer wall fixing the substrate and the two substrates; A manufacturing apparatus for manufacturing a liquid crystal display element by injecting liquid crystal into a frame having a partition wall forming a plurality of linear spaces in the liquid crystal injection section and an injection port communicating from the inside of the liquid crystal injection section to the outside. Pressurizing means for applying force on the substrate to bring the partition and the substrate into close contact with each other; and Liquid crystal injecting means for injecting the liquid crystal, a liquid crystal heating means for heating the liquid crystal, and the liquid crystal from one side in the longitudinal direction of the linear space while keeping the partition and the substrate in close contact with each other. There is a substantially monotonic temperature gradient towards the other side. And a liquid crystal cooling means for cooling while cooling. 16. The liquid crystal display device according to claim 15, wherein a smectic liquid crystal is used as the liquid crystal, the liquid crystal heating means temporarily changes the phase of the liquid crystal from a smectic phase, and the liquid crystal cooling means changes the phase of the liquid crystal to a smectic phase. ,
Equipment for manufacturing liquid crystal display elements. 17. The liquid crystal injecting means, wherein a vacuum chamber accommodating the frame body and capable of decompressing the inside is used as the pressurizing means, and the inside is decompressed while the frame body is accommodated in the vacuum chamber. Immediately after the liquid crystal is started to be injected, a pressure difference is generated between the inside and the outside of the liquid crystal injection section by bringing the pressure in the vacuum chamber close to the atmospheric pressure, and a force is applied on the substrate by the pressure difference. Item 17. An apparatus for manufacturing a liquid crystal display element according to item 15 or 16. 18. The liquid crystal display device according to claim 18, wherein the frame has a plurality of the inlets, and a suction device that performs suction from at least one of the plurality of the inlets is used as the pressurizing unit. The liquid crystal display device manufacturing apparatus according to claim 15 or 16, wherein a pressure difference is generated between the inside and outside of the liquid crystal injection section by a suction device when the liquid crystal is injected, and a force is applied on the substrate by the pressure difference. . 19. The liquid crystal display device according to claim 15, wherein a flat plate-shaped pressing device that abuts on the substrate and mechanically applies a force is used as the pressing unit. manufacturing device. 20. In a state where the flat press device is in contact with the substrate, the temperature is substantially monotonically increased from one side to the other in the longitudinal direction of the linear space. 20. The apparatus for manufacturing a liquid crystal display device according to claim 19, wherein the temperature can be adjusted so as to generate a changing temperature gradient, and the temperature control is also used as the liquid crystal cooling means. 21. A caterpillar-shaped pressurizing device which is capable of moving a liquid crystal display element by circulating and applying a mechanical force while being in contact with the substrate, as the pressurizing means. Item 19. An apparatus for manufacturing a liquid crystal display element according to any one of items 15 to 18. 22. A state in which at least one of the caterpillar-shaped pressurizing devices is in contact with the substrate, and is substantially monotonous from one side to the other in the longitudinal direction of the linear space. 22. The apparatus for manufacturing a liquid crystal display device according to claim 21, wherein the temperature can be adjusted so as to generate a temperature gradient in which the temperature changes, and the temperature gradient is also used as the liquid crystal cooling means. 23. The liquid crystal display device according to claim 23, further comprising a plurality of rollers arranged side by side as the pressing means, the rollers abutting on the substrate to mechanically apply a force and rotate. The manufacturing apparatus of a liquid crystal display element according to any one of claims 15 to 18, wherein a roller-shaped pressing device that can be moved is used. 24. The roller-shaped pressurizing device is capable of adjusting the temperature of each of the rollers, is brought into contact with the substrate so that the rollers are arranged in the longitudinal direction of the linear space, and is placed on the substrate. 24. The roller according to claim 23, wherein the rollers in contact with each other are used by adjusting the temperature so that the temperature monotonously changes in order from one side to the other side, and are also used as the liquid crystal cooling unit. Of manufacturing liquid crystal display element. 25. The apparatus for manufacturing a liquid crystal display device according to claim 15, further comprising a mechanism for sealing the injection port. 26. The apparatus for manufacturing a liquid crystal display element according to claim 15, further comprising, as said pressurizing means, a mechanism for pressurizing the outside of said liquid crystal injection section to a pressure higher than the atmospheric pressure.