JP2000193953A - Liquid crystal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent production of bubbles by constituting the inside of a liquid crystal device to enable pressurizing. SOLUTION: This liquid crystal device is produced by laminating an upper substrate 4 and a lower substrate 6 with a sealing agent, and the space (gap) between the upper substrate 4 and the lower substrate 6 is uniformly kept by a spacer 5. The gap between the upper substrate 4 and lower substrate 6 is filled with a liquid crystal compsn. 7 injected through a sealing inlet. Thus, the liquid crystal device is produced by forming a closed space between the upper substrate 4 and lower substrate 6 and filling the closed space with the liquid crystal compsn. 7. The inside of the liquid crystal device has a structure which can be pressurized. Namely, by pressurizing the inside of the liquid crystal device, bubbles are hardly produced, and even when bubbles are produced, such a state that bubbles disappear in a short time can be intentionally produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a liquid crystal device.

[0002]

2. Description of the Related Art Liquid crystal elements have been realized in various fields because they are thin, lightweight, and excellent in power saving. At present, its use as a display element is particularly conspicuous, and it is used as a display element of a portable electronic device that makes full use of its features. Other than the use as a display element or a display device, there is a use as a light control means or a large-diameter light modulation means.

A liquid crystal element generally has a structure in which a liquid crystal composition is sandwiched between two glass substrates. However, when the substrate is made of a polymer film, the weight and impact resistance are reduced. Is more suitable for portable use.

[0004]

When a polymer film is used as a substrate for a liquid crystal device, some external stimulus may trigger an air bubble in the liquid crystal device. This phenomenon may be seen in a liquid crystal element using a glass substrate, though infrequently. As described above, when bubbles are generated in the liquid crystal element, a portion where the bubbles are generated is not filled with the liquid crystal, so that the portion does not function as a liquid crystal element. there were.

It is an object of the present invention to provide a liquid crystal device capable of preventing bubbles from being generated in the liquid crystal device.

It is another object of the present invention to provide a liquid crystal element which can quickly eliminate bubbles even when bubbles are generated.

[0007]

In order to achieve the above object, according to the present invention, a closed space is formed between an upper substrate and a lower substrate, and the closed space is filled with a liquid crystal composition. The liquid crystal element formed by the above method is characterized in that the inside of the liquid crystal element can be pressurized.

According to a second aspect of the present invention, in the liquid crystal device according to the first aspect, at least a part of the upper substrate and the lower substrate is formed of a flexible material.

According to a third aspect of the present invention, in the liquid crystal device according to the first or second aspect, a spacer for maintaining a constant gap between the upper substrate and the lower substrate is provided between the upper substrate and the lower substrate. The spacer is bonded or adhered to at least the upper substrate and the lower substrate at least in the display portion so that the distance between the upper substrate and the lower substrate in the display portion does not increase even when pressure is applied. It is characterized by being.

According to a fourth aspect of the present invention, there is provided the liquid crystal device according to any one of the first to third aspects, wherein:
Further, a pressure adjusting means for adjusting the degree of pressure is provided.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 are views showing an example of the configuration of a general liquid crystal element. 1 is a schematic plan view and FIG.
Is a sectional view. Referring to FIGS. 1 and 2, in this liquid crystal element, an upper substrate 4 and a lower substrate 6 are bonded together by a sealant 1, and a gap (gap) between the upper substrate 4 and the lower substrate 6 is determined by a spacer 5. It is kept even. The space between the upper substrate 4 and the lower substrate 6 is filled with the liquid crystal composition 7 injected from the sealing opening 2. The liquid crystal composition 7 is conventionally sealed with a kind of adhesive called an encapsulant in order to prevent outside air from flowing in from the encapsulation port 2 and to prevent the liquid crystal composition 7 from flowing out. ing.

The inventor of the present application has found that in such a liquid crystal device, if the pressure inside the liquid crystal device is higher than the outside and the liquid crystal composition flows out naturally when the liquid crystal device is opened, bubbles Have been found to hardly occur and disappear even within a short period of time.

Focusing on this, the present invention relates to a liquid crystal device formed by forming a closed space between the upper substrate 4 and the lower substrate 6 and filling the closed space with a liquid crystal composition 7. It is characterized in that the inside of the liquid crystal element can be pressurized. As described above, since the inside of the liquid crystal element can be pressurized, that is, by pressurizing the inside of the liquid crystal element, bubbles are unlikely to be generated, and even if they are generated, they disappear in a short time. A state can be created intentionally.

FIG. 3 is a diagram showing a specific example of the liquid crystal element of the present invention. In the example of FIG.
A display unit 9 is provided. In this case, in the present invention,
The non-display section 8 of the liquid crystal element is pressurized by mechanical force from outside the liquid crystal element, and it is possible to create a state in which the pressure inside the liquid crystal element is higher than that outside. This makes it possible to intentionally create a state in which bubbles are unlikely to be generated and disappear even within a short period of time even if they are generated. Note that FIG.
In the example, the position of the non-display unit 8 is an example, and is not limited to the position in the drawing. That is, the non-display unit 8 can be provided at an arbitrary position.

When the upper substrate 4 or the lower substrate 6 is a substrate having high rigidity such as a glass substrate, the gap between the upper substrate 4 and the lower substrate 6 changes even in the peripheral portion where the pressure is applied. When the display reaches the display unit 9, the problem of display unevenness occurs separately. To avoid this problem, the non-display portion 8 of the substrate may be made of a flexible material. That is, a part of the members constituting the liquid crystal element, such as the upper substrate 4 and the lower substrate 6, may be formed of a flexible material, that is, a material having flexibility. At this time, the change in the gap between the upper substrate 4 and the lower substrate 6 of the display unit 9 can be suppressed, and the influence on the display performance can be reduced.

FIG. 4 is a view showing a configuration example of a liquid crystal element in which a part of members constituting the liquid crystal element is formed of a flexible material. In FIG. 4, an alignment film, a transparent electrode, and the like are omitted. In the liquid crystal element of FIG. 4, a part (indicated by reference numeral 22) of the upper substrate 4 is a thin film.

FIG. 5 is a view showing another configuration example of a liquid crystal element in which a part of members constituting the liquid crystal element is formed of a flexible material. In the liquid crystal element of FIG. 5, a thin film portion 22 is formed by attaching a thin film to an end of the upper substrate 4. In this case, a thin film portion 22 may be formed by forming a hole in a part of the upper substrate 4 and attaching a thin film in such a manner as to cover the hole.

In the configuration example shown in FIG. 4 or 5, the thickness of the thin film portion 22 is about 50 μm or less when a general polymer is used. Flexibility is obtained.

The above thin film portion is provided on the lower substrate 6.
Such a thin film portion 22 formed on the upper substrate 4 or the lower substrate 6 can be formed by etching the substrate or laminating the thin film as described above.

Further, a liquid crystal element manufactured by using a polymer film substrate for both the upper substrate 4 and the lower substrate 6 is excellent in portability and impact resistance, and is particularly preferable.

Specifically, flexible materials usable as substrates for liquid crystal devices include polyethylene terephthalate, polycarbonate, polyether sulfone, polyarylate, and the like.
Examples include polyolefin and polyethylene naphthalate.

Further, as shown in FIG. 6, by making the shape of the portion 10 to be pressurized such that the amount of liquid crystal entering therein is larger than that of the other portions, the range in which pressure can be applied can be widened. The pressurized state can be maintained by holding means (not shown) such as a clamp.

When the range in which pressure can be applied is widened as shown in FIG. 6, the substrate is easily deformed in a liquid crystal element formed using a flexible substrate. The gap between the upper substrate 4 and the lower substrate 6 (for example, the distance between the upper substrate 4 and the lower substrate 6 in the display portion 8) is increased, and it is difficult to return the gap to the original uniform gap. To prevent this, it is necessary to hold the upper substrate 4 and the lower substrate 6 firmly. For example, the spacer 5 is coated with an adhesive or a pressure-sensitive adhesive, and the spacer 5 is bonded or adhered to the upper substrate 4 and the lower substrate 6 so that the distance between the upper substrate 4 and the lower substrate 6 does not become larger than a desired distance. can do.

Further, in this case, the shape of the spacer 5 is
It is preferable to use a rectangular parallelepiped or the like having a large contact area with the upper substrate 4 and the lower substrate 6 instead of a spherical shape.

As described above, by fixing the spacer 5 between the upper substrate 4 and the lower substrate 6, even when a flexible substrate is used, the thickness of the liquid crystal layer is kept constant, and the height of the liquid crystal layer is reduced. A quality liquid crystal element can be provided.

When the range in which the pressure can be applied is widened as described above, display unevenness due to excessive pressurization is prevented.
It may be necessary to adjust the degree of pressurization while checking the gap between the upper substrate 4 and the lower substrate 6. As the pressure adjusting means for adjusting the degree of the pressure, for example, a screw mechanism 11 as shown in FIG. 7 can be used. Alternatively, a cam mechanism 12 with a latch as shown in FIG. 8 or a wedge mechanism 13 as shown in FIG. 9 can be used. By providing such a pressure adjusting means, fine adjustment of the degree of pressure can be performed. That is, by providing an adjusting means so that the pressure in the liquid crystal element is not excessively increased,
The generation of bubbles can be prevented without causing display unevenness, and even when bubbles are generated, the bubbles can be quickly eliminated.

Further, as shown in FIG.
By making the spacer 5 larger and more elastic than the spacer 5 of the display unit 9 and by configuring the pressing unit 14 to be reversibly deformable, the degree of pressing can be more easily adjusted.

The inventor of the present application has compared a liquid crystal device manufactured using a polymer film substrate as the upper substrate 4 and the lower substrate 6 with a liquid crystal device using a glass substrate as the upper substrate 4 and the lower substrate 6. As a result, bubbles are generated more frequently in the liquid crystal element manufactured using the polymer film substrate. For this reason, the present invention is particularly preferable for a liquid crystal element manufactured using a polymer film substrate.

[0029]

As described above, according to the first aspect of the present invention, a closed space is formed between the upper substrate and the lower substrate, and the closed space is formed by filling the liquid crystal composition. In such a liquid crystal element, since the inside of the liquid crystal element can be pressurized, generation of bubbles can be prevented, and even when bubbles are generated, the bubbles can be quickly eliminated.

According to the second aspect of the present invention, in the first aspect,
In the liquid crystal device described above, since at least a part of the upper substrate and the lower substrate are formed of a flexible material, the generation of bubbles is prevented without causing display unevenness, and the case where bubbles are generated However, the bubbles can be eliminated quickly.

According to the third aspect of the present invention, by fixing the spacer between the upper substrate and the lower substrate, the thickness of the liquid crystal layer is kept constant even when a flexible substrate is used, and the generation of bubbles is achieved. It is possible to provide a high-quality liquid crystal element that is difficult to perform.

Further, in the invention according to the fourth aspect, by providing an adjusting means for preventing the pressure in the liquid crystal element from being excessively increased, the generation of bubbles without preventing display unevenness is prevented. Even when bubbles occur, the bubbles can be quickly eliminated.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration example of a general liquid crystal element.

FIG. 2 is a diagram illustrating a configuration example of a general liquid crystal element.

FIG. 3 is a view showing a specific example of the liquid crystal element of the present invention.

FIG. 4 is a diagram illustrating a configuration example of a liquid crystal element in which a part of members constituting the liquid crystal element is formed of a flexible material.

FIG. 5 is a diagram showing another configuration example of a liquid crystal element in which a part of members constituting the liquid crystal element is formed of a flexible material.

FIG. 6 is a diagram showing a configuration example of a liquid crystal element capable of expanding a pressure range.

FIG. 7 is a diagram illustrating an example of a pressure adjusting unit.

FIG. 8 is a diagram illustrating an example of a pressure adjusting unit.

FIG. 9 is a diagram illustrating an example of a pressure adjusting unit.

FIG. 10 is a diagram illustrating a configuration example of a liquid crystal element of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sealant 2 Enclosure port 4 Upper substrate 5 Spacer 6 Lower substrate 7 Liquid crystal composition 8 Non-display part 9 Display part 10 Pressurizing part 11 Screw mechanism 12 Cam mechanism 13 Wedge mechanism 14 Pressing part 22 Thin film part

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akihiko Kanemoto 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Tomoaki Sugawara 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Inventor Kazuhiko Umemura 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (reference) 2H089 HA07 HA17 LA03 LA07 LA09 NA58 2H090 JA04 JB02 JB03 LA02

Claims (4)

[Claims] 1. A liquid crystal device formed by forming a closed space between an upper substrate and a lower substrate and filling the closed space with a liquid crystal composition, wherein the inside of the liquid crystal device can be pressurized. A liquid crystal element, comprising: 2. The liquid crystal device according to claim 1, wherein at least a part of the upper substrate and the lower substrate are formed of a flexible material. 3. The liquid crystal device according to claim 1, wherein a spacer for keeping a constant gap between the upper substrate and the lower substrate is sandwiched between the upper substrate and the lower substrate. The spacer is bonded or adhered to both the upper substrate and the lower substrate at least in the display portion so that the distance between the upper substrate and the lower substrate in the display portion is not widened by pressurization. Liquid crystal element. 4. The liquid crystal device according to claim 1, further comprising a pressure adjusting means for adjusting a degree of pressure.