JPS6364764B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid crystal display device having a fixed display of numbers, characters, symbols, etc. within the liquid crystal display. In particular, it relates to a liquid crystal display device having a twisted oriented nematic liquid crystal layer.

Twisted nematic liquid crystal display devices, which use nematic liquid crystals with positive dielectric anisotropy, have been widely used in recent years, especially in fields such as watches and calculators, because their display performance is superior to other types. There is.

A twisted nematic type liquid crystal display device has a structure in which a nematic liquid crystal having positive dielectric anisotropy is sandwiched between two opposing electrode plates. In this case, the molecules of the liquid crystal have their molecular axes parallel to the electrode plates, are aligned in almost the same direction on the same plane parallel to the electrode plates, and are arranged in adjacent planes in a direction perpendicular to the electrode plates. In between, they have a so-called "twisted orientation" in which they are arranged in a mutually continuous twisted direction. Such orientation of the molecular axes can be achieved by polishing the electrode surface in one direction with cloth, paper, etc., and injecting liquid crystal between the two sheets stacked so that the polishing directions cross each other. Near the electrode surface, the molecular axes are aligned in the polishing direction, and within the liquid crystal layer, the molecular axes are continuously twisted. However, when a voltage is applied between the two electrodes, the twisted orientation of the liquid crystal molecules It is known that only the applied portion is converted to vertical orientation.
As a result, by placing polarizing plates on both sides of two electrode plates that sandwich the liquid crystal layer, and making the polarization axes of the polarizing plates perpendicular or parallel to each other,
A positive display or a negative display is performed.

Until now, it has often been necessary to form fixed displays such as numbers, characters, symbols, etc. in the display of the liquid crystal display device as described above. As a method of forming a fixed display of numbers, letters, symbols, etc., for example, as described in JP-A-49-113651, an adhesive that also serves as a spacer is screen printed in the form of numbers or letters within the liquid crystal display. A method is known in which the formation is made by, for example, However, with this method, it is difficult to print the spacer adhesive in the form of numbers or letters with high precision, and furthermore, the spacer adhesive printed in the form of numbers or letters is pressed against the two electrode plates. When clamped, the adhesive layer spreads in the plane direction, making it difficult to clearly distinguish even small numbers or letters.

As another method, a method is known in which a fixed display is created by placing a transparent film on which characters or figures are printed in advance on the outside of the substrate of the display device. However, since this method uses film, the display surface becomes darker, and the fixed display surface and the operating display surface are separated by the thickness of the transparent electrode substrate, so the fixed display appears to be floating. There are drawbacks to this.

The inventors of the present invention have made extensive studies in view of the various drawbacks mentioned above, and have discovered a liquid crystal display device that has a fixed display of numbers, letters, symbols, etc., with the same accuracy as the operational display of a liquid crystal.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a liquid crystal display device having a fixed display with a dynamic display and the same accuracy within the liquid crystal display.

Another object of the present invention is to provide a liquid crystal display device that has fixed displays such as clear numbers, characters, and symbols within the liquid crystal display.

Furthermore, another object of the present invention is to provide a liquid crystal display device having a fixed display that eliminates floating appearance.

This object of the present invention is achieved by applying an irradiation pattern of electron beams or ultraviolet rays to a liquid crystal layer sandwiched between two substrates, at least one of which has a transparent conductive coating.

Quite unexpectedly, the inventors have developed a layer of nematic liquid crystal with positive dielectric anisotropy oriented along wall-oriented planes and twisted between two substrates. It has been discovered that by applying an irradiation pattern of electron beams or light beams containing ultraviolet rays, it is possible to display images independently of the applied voltage at that location.

The present invention was made based on this unexpected alignment state of liquid crystals.

A method of forming a fixed display pattern in a liquid crystal display according to the present invention involves forming a positive dielectric anisotropy that is oriented along a wall-oriented surface and twisted between two substrates. After arranging a nematic liquid crystal layer in a display device by a predetermined method, a patterned irradiation light is applied to the liquid crystal layer using an irradiation device that emits a suitable electron beam or a light beam containing ultraviolet light. You can do it by leaning. FIG. 1 shows a cross-sectional view of a liquid crystal display device having a fixed display pattern according to the present invention.

In FIG. 1, 11 and 16 are substrates, 15
12 is a conductive film that becomes a common electrode, 12 is a conductive film that becomes a display electrode, 13 and 14 are alignment agents or alignment films, and 17 is a layer of nematic liquid crystal having positive dielectric anisotropy. Reference numeral 18a indicates a liquid crystal layer in which a fixed display pattern is formed regardless of the applied voltage by irradiation with electron beams or ultraviolet light, and reference numeral 18b indicates a twisted liquid crystal layer before voltage application.

The conductive film 12 is used to form a liquid crystal motion display. When a driving voltage is applied to this and the conductive film 15, the twisted orientation of the liquid crystal molecules 18b is converted to vertical alignment to form a motion display pattern. is formed. When this driving voltage is removed, the vertically aligned liquid crystal molecules are returned to the twisted alignment and the motion display pattern disappears. Although the driving voltage cannot be specified depending on the type of liquid crystal used, it is generally at or below the saturation voltage, and is approximately 1V to 15V. In particular, in order to increase display contrast, it is preferable to drive at a saturation voltage.

FIG. 2 is a plan view of a liquid crystal display device having a fixed display according to the invention within the liquid crystal display. 21a,
21b, . . . , 21h are fixed display portions each having a liquid crystal layer 18a having an arrangement formed by irradiation with an electron beam or a light beam containing ultraviolet rays.

Reference numerals 22a, 22b, and 22e are operational display portions formed by vertically aligning the twistedly aligned liquid crystal molecules 18b of FIG. 1 by applying a driving voltage. The operational display is driven by an external circuit (not shown) through electrode terminal 23. In the figure, 24 indicates a sealing material formed by a method such as screen printing, and 25 indicates a sealing material. As the sealing material 24 and the sealing material 25, epoxy resin adhesive or the like can be used.

Liquid crystals with positive dielectric anisotropy that can be used in the present invention include Schiff-type liquid crystals, biphenyl-type liquid crystals, azoxy-type liquid crystals, ester-type liquid crystals, and cyclohexane-type nematic liquid crystals, such as those shown below. can.

These liquid crystals can contain small amounts of cholesteric liquid crystals.

The electrode plate used in the liquid crystal display device of the present invention is a substrate on which at least one side is provided with a transparent conductive film (for example, indium oxide, tin oxide, indium oxide-tin oxide (tin oxide: 0.1 to 40% by weight), etc.) (glass, plastic, etc.) is preferably used. Furthermore, examples of the opaque conductive film used in the present invention include aluminum, gold, silver, copper, and lead.

Further, in the liquid crystal display device of the present invention, an alignment film made of a suitable insulating film can be used.
The alignment film is a film that has been oriented by a method such as rubbing to have a surface whose walls are oriented in one direction. Nylene diamine, m-xylene diamine, P-xylene diamine, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane,
4,4'-diaminodiphenyl sulfide, 4,
4'-diaminodiphenylsulfone, 1,5-diaminonaphthalene, 3,3'-dimethylbenzidine,
Diamines such as bis(4-β-amino-t-butylphenyl) ether and pyromellitic anhydride,
2,3,6,7-naphthalenetetracarboxylic anhydride, 3,3,4',4'-diphenyltetracarboxylic anhydride, 1,2,5,6-naphthalenetetracarboxylic anhydride, thiophene- 2, 3, 4, 5
-tetracarboxylic acid anhydride, 2,2'-bis(3,
It can be produced by a condensation reaction with a dicarboxylic acid anhydride such as 4-biscarboxyphenyl)propane anhydride. ), polybenzoxazole,
Insulating coatings such as polybenzimidazole, polybenzothiadiazole, polyparaxylylene, polyolefin (eg, polyethylene, polypropylene, etc.), fluoroethylene, polyester (eg, polyethylene terephthalate) can be used. It is also possible to provide a suitable silane coupling agent (eg, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, etc.) between the conductive film and the alignment film. Furthermore, the alignment film may contain a suitable alignment improver (eg, titanium oxide, zinc oxide, etc.).

Although not shown in FIG. 1, the liquid crystal display device of the present invention includes glass beads, granular aluminum oxide,
A spacer material such as glass fiber can be placed between the two electrode plates.

Cell assembly consists of two electrode plates oriented in one direction, each with an orientation direction of 90° or 90°±α° (α:
1 to 20) so as to intersect with each other. For example, Japanese Patent Application Laid-open Nos. 47-36998 and 47-22693 disclose cells assembled in this way.
No. 48-30397, No. 49-79543, No. 53-
No. 17751, No. 49-130756, No. 50-50055, No. 52
A liquid crystal display device is created by injecting liquid crystal according to the method described in Publications No. -27653, No. 49-79541, and No. 49-79542, etc., and then sealing the injection port with epoxy adhesive or the like. can do.

Polarizing films that can be used in the liquid crystal display device of the present invention include a polyhalogen polarizing film in which iodine molecules are arranged in a certain direction on a polyvinyl alcohol film, a dye polarizing film in which polyvinyl alcohol dichroic dyes are arranged in a certain direction, and a polyvinyl alcohol film in which dichroic dyes are arranged in a certain direction. Examples include a polyvinylene polarizing film having a polyene structure obtained by intramolecularly dehydrochlorinating vinyl chloride, and a metal polarizing film. The polarizing film can be arranged in a liquid crystal display device by making the direction of the polarization axis parallel to the alignment direction or perpendicular to the orientation direction.

According to the present invention, the floating appearance of the fixed display is eliminated, and the fixed display such as numbers, letters, symbols, etc. can be distinguished brightly and clearly. Furthermore, it has the advantage of being able to display fixed images with the same accuracy as the dynamic display of liquid crystals.

Hereinafter, the present invention will be explained according to examples.

Example 1 A display electrode was created by patterning a transparent conductive film of indium oxide on a glass substrate. The patterning is performed by the operation display sections 22a and 22 shown in FIG.
b, . . . 22e were formed. Then, on top of this, "Ethyl orthosilicate 60"
After applying the silane agent (manufactured by Nippon Colcoat Co., Ltd.),
A silicon dioxide film was formed by heat treatment. The orientation treatment was carried out by rubbing the silicon dioxide film in one direction with a cotton cloth.

On the other hand, a common electrode plate was created by patterning a transparent conductive film of indium oxide to serve as a common electrode on a glass substrate. Next, a silicon dioxide film was provided by a method similar to the method used to create the display electrode plate, and then an alignment treatment was performed.

To form the sealing material shown at 24 in Figure 2, glass frit is applied along the frame of the common electrode plate by screen printing, and then the rubbing directions of the common electrode plate and the display electrode plate are aligned with each other. After arranging the glass frits so as to face each other at right angles, a heat treatment was performed to melt the glass frits, and cells were assembled. Thereafter, liquid crystal "Nematic Phase 1565TNC Crystal" manufactured by Merck & Co., Ltd., West Germany, was injected through the injection port, and the injection port was sealed with a sealant. Then, a display device was created by arranging the polarizing film at a predetermined position.

21 in Fig. 2 on the display device created in this way.
In order to create the fixed displays shown in a and 21b to 21h, pattern irradiation was applied for 30 minutes using a 2KW high-pressure mercury lamp. As a result, a liquid crystal display image independent of the applied voltage was formed in the ultraviolet irradiation area.

Next, using this liquid crystal display device, when a driving voltage (3 V DC) was applied between the conductive film forming the operation display sections 22a to 22e and the common electrode, an operation display was formed.

Example 2 The same results as in Example 1 were obtained when 10MR electron beam irradiation was applied instead of the patterned ultraviolet irradiation using the 2KW high-pressure mercury lamp used in Example 1.

Example 3 A similar fixed display was formed by the same method as in Example 1, except that polyparaxylylene was used instead of the silicon dioxide alignment film used in Example 1, and the same results were obtained. The results were obtained.

Example 4 In place of the liquid crystal used in Example 1, the above-mentioned biphenyl-type liquid crystal (2), ester-type liquid crystal (4), Schiff-type liquid crystal (1), azoxy-type liquid crystal (3), and cyclohexane-type liquid crystal ( Example 1 except that 5) was used.
When a similar fixed display was formed using a method similar to that described above, similar results were obtained.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a liquid crystal display device of the present invention, and FIG. 2 is a plan view thereof. DESCRIPTION OF SYMBOLS 11, 16... Substrate, 12... Conductive film of fixed display part, 13, 14... Aligning agent or alignment film, 15
...A conductive film serving as a common electrode, 17...A layer of nematic liquid crystal with positive dielectric anisotropy, 18a...A fixed display pattern is formed by irradiation with an electron beam or a light beam containing ultraviolet light, regardless of the applied voltage. liquid crystal layer, 18b...Twisted oriented liquid crystal molecules, 21
a, 21b,...21h...Fixed display section, 22a, 2
2b,...22e...operation display section, 23...electrode terminal,
24... Sealing material, 25... Sealing material.

Claims (1)

[Claims] 1 A liquid crystal layer sandwiched between two substrates having a transparent conductive film and a rubbed alignment film,
1. A liquid crystal device characterized in that a fixed display pattern is formed by applying an irradiation pattern with an electron beam or a light beam containing ultraviolet light.