JPH0980487A - Liquid crystal display device and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device having a high display grade and a process for efficiently producing this liquid crystal display device. SOLUTION: The liquid crystal material of the liquid crystal display device formed by holding the liquid crystal material between a pair of substrates 1 and 1 contains multichromatic dyestuff molecules 4 and the density of the multichromatic dyestuff molecules 4 near the substrates 1, 1 is set smaller than the density of the multichromatic dyestuff molecules 4 in the central part between the substrates. A cell is produced by forming patterned electrode layers and oriented films subjected to orientation treatments on two sheets of the substrates 1, 1, supplying the liquid crystal material onto these oriented films to adsorb the liquid crystal molecules 3 in the liquid crystal material on the oriented films and arranging two sheets of the substrates 1, 1 apart a prescribed spacing in such a manner that the oriented films face each other. The liquid crystal material contg. the liquid crystal molecules 3 and the multichromatic dyestuff molecules 4 is injected into this cell.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a liquid crystal display device and a method for manufacturing the same.

[0002]

2. Description of the Related Art CRTs have been widely used for display devices conventionally used as displays. However, the CRT requires a large display depth in order to scan all the pixels with one electron gun, and further consumes a large amount of power and is heavy, which is unsuitable as a portable panel. Further, as other displays, a plasma display, an EL display, and the like are conceivable, but any of them has a problem in practical use as a portable panel.

The only portable display device currently in practical use is a liquid crystal display device. Since this liquid crystal display device is thin and can be driven at a low voltage, it is widely used as a display device for wrist watches, calculators and the like. In particular, since the TN type liquid crystal display device can exhibit display characteristics similar to that of a CRT by incorporating an active switch element such as a TFT,
It is also used in televisions and the like. However, since the TN type liquid crystal display device uses the polarizing plate, the light utilization efficiency is low. For this reason, the backlight must be used to replenish the amount of light, resulting in increased power consumption.

On the other hand, as a liquid crystal display device, there is a guest-host (GH) type liquid crystal display device using a dichroic dye which does not require a polarizing plate. When performing full-color display using this GH type liquid crystal display device, it is necessary to arrange liquid crystal materials of different colors in each sub-pixel or to stack three or more liquid crystal cells of different colors. However, the GH type liquid crystal display device has a display problem of low contrast.

The present invention has been made in view of the above points, and an object thereof is to provide a liquid crystal display device having a high display quality and a manufacturing method capable of efficiently obtaining the liquid crystal display device.

[0006]

The present invention is a liquid crystal display device comprising a liquid crystal material sandwiched between a pair of substrates, wherein the liquid crystal material contains polychromatic dye molecules. There is provided a liquid crystal display device characterized in that the concentration of the pleochroic dye molecule in the vicinity is lower than the concentration of the pleochroic dye molecule in the central portion between the substrates.

Further, according to the present invention, a step of sequentially forming a patterned electrode layer and an alignment-treated alignment film on two substrates, and supplying a liquid crystal material onto the alignment film to supply the liquid crystal to the alignment film. A step of adsorbing liquid crystal molecules in the material,
A step of making a cell by arranging the two substrates so that the alignment films face each other and at a predetermined interval; and a liquid crystal containing the liquid crystal molecule and the polychromatic dye molecule in the cell. A method for manufacturing a liquid crystal display device, comprising the step of injecting a material.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The pleochroic dye molecule contained in the liquid crystal material of a GH type liquid crystal display device changes its direction following the operation of the liquid crystal molecule by applying a voltage. In this case, light absorption occurs when the light absorption axis of the polychromatic dye molecule is parallel to the substrate, and light transmission occurs when the light absorption axis is perpendicular to the substrate, thereby performing the optical shutter operation. You can However, as shown in FIG. 3, when the substrate 1 is arranged so that the liquid crystal molecules 3 are horizontally aligned,
The liquid crystal molecules 3 and the pleochroic dye molecules 4 between the substrates 1 do not operate even when a voltage is applied (light transmission mode), which causes a decrease in contrast of the liquid crystal display device. It should be noted that a phase transition GH type liquid crystal display device in which a glass substrate is arranged so that liquid crystal molecules are vertically aligned can be expected to have high contrast, but the phase transition GH type liquid crystal display device cannot display full gradation and thus has a display problem. There are many.

As a means for solving this problem of contrast reduction, as a result of intensive investigations by the present inventors, the concentration of polychromatic dye molecules contained in the liquid crystal material sandwiched between the substrates was changed between the substrates. Has been found to be effective.

The alignment of the liquid crystal molecules is controlled by the alignment film, and the liquid crystal molecules near the alignment film are strongly adsorbed on the alignment film, and once they are adsorbed, they hardly move. Therefore, a thin liquid crystal material that does not contain polychromatic dye molecules (dichroic dye molecules) is supplied to the interface of the alignment film by thin coating or vapor deposition so that the vicinity of the alignment film where the liquid crystal molecules have an adsorptive effect is not colored. By supplying the liquid crystal material containing the pleochroic dye molecule to the region where the adsorption action on the liquid crystal molecule does not work so much, the regions having different concentrations of the pleochroic dye molecule are provided between the substrates.

In particular, as shown in FIG. 1, the concentration of the pleochroic dye molecule 4 in the vicinity of the substrate 1 is set to be lower than the concentration of the pleochroic dye molecule 4 in the central portion between the substrates 1, that is, In the vicinity of the substrate 1, the concentration of the liquid crystal molecules 3 is higher than that of the pleochroic dye molecules 4, and in the central portion between the substrates 1, the concentrations of the liquid crystal molecules 3 and the pleochroic dye molecules 4 are almost the same. Set to.

For example, when a display is performed using a p-type liquid crystal and a dichroic dye molecule whose molecular long axis is the light absorption axis, light is absorbed without applying a voltage, and the dichroic dye molecule is generated by applying a voltage. Stands up and becomes transparent. However, as shown in FIG. 3, the liquid crystal molecules 3 and the dichroic dye molecules 4 are adsorbed to the alignment film, and there is a region that does not rise due to the application of a voltage, so that a perfect transmission state cannot be created. As a result, the dichroic dye molecule 4 that does not rise when a voltage is applied
The contrast is reduced due to the coloring due to.

According to the present invention, as shown in FIG. 1, the concentration of the pleochroic dye molecule 4 in the region where it hardly operates by applying a voltage, that is, in the region near the substrate 1, is lowered. Coloring by the non-dichroic dye molecule 4 is suppressed, and the adverse effect on the display characteristics in the region where the molecule operates can be reduced.

In the liquid crystal display device of the present invention, as shown in FIG. 2, a patterned electrode layer and an alignment film subjected to alignment treatment are formed on two substrates 1, and a liquid crystal material is supplied onto the alignment film. The liquid crystal molecules 3 in the liquid crystal material are adsorbed on the alignment film, and 2
A cell is prepared by arranging a plurality of substrates 1 so that the alignment films face each other and at a predetermined interval, and liquid crystal molecules 3 are placed in the cell.
It is manufactured by injecting a liquid crystal material containing the polychromatic dye molecule 4 and sealing the cell with the sealing material 2. Here, an epoxy resin or the like can be used as the sealing material 2. As the alignment treatment applied to the alignment film, a rubbing treatment, a SiO oblique vapor deposition treatment, or the like can be used.

In the present invention, a method for specifically supplying a liquid crystal material onto the alignment film to adsorb liquid crystal molecules in the liquid crystal material to the alignment film is a liquid crystal material containing no polychromatic dye molecule on the alignment film. By a spin coating method, an offset printing method, a liquid crystal material containing no pleochroic dye molecules is heated in a vacuum bell jar, and is supplied by vapor deposition on the alignment film. Examples thereof include a method of transferring a molecular film onto an alignment film.

Among the above methods, when the liquid crystal material is supplied onto the alignment film by a printing method or the like, it can be applied thinly by making the liquid crystal material into an isotropic liquid state. Further, in this case, by washing away the excess liquid crystal material with the solvent, it is possible to supply the liquid crystal material in a thinner film form.

The constitution of the present invention can be realized by using, as the material of the alignment film, a material having an adsorbing power of the polychromatic dye molecules smaller than that of the liquid crystal molecules.
As a material for the alignment film, a material that does not easily adsorb polychromatic dye molecules may be used. For example, by using a polymer liquid crystal material having a structure similar to that of the liquid crystal molecules as the material of the alignment film, the liquid crystal molecules can be adsorbed onto the alignment film more preferentially than the polychromatic dye molecules. Further, it is also effective to reduce the polarity of the material of the alignment film in order to inhibit the adsorption of the polychromatic dye molecule having a strong polarity. Further, it is also effective to selectively bond liquid crystal molecules to the alignment film by a chemical reaction. For example, the liquid crystal molecules and the alignment film material may be provided with unsaturated bond sites for heating reaction or condensation reaction, respectively, and heating reaction or condensation reaction may be performed.

The present invention is most preferably applied to a guest-host liquid crystal display system. Any guest-host liquid crystal display method may be used. However, it is desirable that the light use efficiency is high without using a polarizing plate.
In the case of a liquid crystal display device that does not have a memory function,
Matrix driving becomes possible by making the threshold characteristics steeper. Furthermore, by providing a hold element such as a TFT, it is possible to perform better display with high contrast.

In the present invention, as the host liquid crystal material, nematic liquid crystal typified by cyanobiphenyl can be used. As the guest dye, dichroic dyes having different absorption spectra, for example, cyan, magenta,
A dichroic dye such as yellow can be used. However, the degree of alignment order of the dye in the liquid crystal is preferably 0.8 or more. This is because the contrast decreases when the orientation order is less than 0.8.

Further, in the present invention, the liquid crystal molecules adsorbed on the surface of the alignment film and the liquid crystal molecules in the liquid crystal material containing the polychromatic dye molecule may be the same material or different materials. . However, it is more preferable that the dye solubility of the liquid crystal material supplied for adsorption on the surface of the alignment film is smaller than the dye solubility of the liquid crystal material containing the polychromatic dye molecule. This is because the rate of migration of the polychromatic dye molecules to the alignment film surface is small. For example, it is preferable to use a PCH (phenylcyclohexane) liquid crystal material having a relatively small polarity in which fluorine is substituted.

The liquid crystal display device of the present invention can be used as both a transmissive type and a reflective type. In the case of the reflective type, a scattering surface or a directional reflecting surface is provided on the back surface of the laminated liquid crystal cells. is necessary. Further, it is desirable to provide an antireflection film on the front substrate.

Examples of the present invention will be specifically described below. (Example 1) 2 μm thick on a 1.1 mm thick glass substrate
Was formed, and the surface of the polyimide film was embossed by embossing, and then an aluminum film having a thickness of 1000 angstrom was formed on the polyimide film by vapor deposition. Then, the thickness of 2μ on the aluminum film
m resist film was formed, and the resist film was exposed and developed to be patterned into stripes, and the aluminum film was etched using the resist film as a mask to form stripe pixel electrodes.

An ITO film having a thickness of 200 angstrom was formed on another glass substrate having a thickness of 1.1 mm by vapor deposition and patterned in the same manner as above. Polyimide AL-1051 (manufactured by Japan Synthetic Rubber Co., Ltd., trade name) having a thickness of 6 was formed on the surfaces of the two glass substrates manufactured as described above.
Apply at 00 angstrom and 1 in oven
The alignment film was formed by baking at 80 ° C. for 60 minutes. After rubbing the alignment film, the liquid crystal ZLI-18 is formed on the alignment film.
40 (made by Merck & Co., Inc., product name) in an isotropic liquid state with a thickness of 1
00 angstrom was applied.

Next, a parallel alignment liquid crystal cell was produced by combining two glass substrates so that their alignment films face each other and at a predetermined interval. For this liquid crystal cell, a black dichroic dye S-344 (manufactured by Mitsui Toatsu Co., Ltd.,
A liquid crystal material obtained by dissolving (trade name) in liquid crystal ZLI-1840 was injected.

TAB (Tape Automated B
The driver IC is mounted by onding), the transmission easy axis of the polarizing plate is set parallel to the alignment direction of the liquid crystal molecules, and a voltage of 5 V is applied between the electrodes, resulting in a good display with a contrast of 5: 1. did it. It is considered that this is because the concentration of dye molecules in the region near the alignment film is low, so that coloring due to dye molecules that do not rise when a voltage is applied is suppressed, and the adverse effect on display characteristics in the region where the molecules operate is small. To be (Example 2) 2 μm thick on a 1.1 mm thick glass substrate
Was formed, and the surface of the polyimide film was embossed by embossing, and then an aluminum film having a thickness of 1000 angstrom was formed on the polyimide film by vapor deposition. Then, the thickness of 2μ on the aluminum film
m resist film was formed, and the resist film was exposed and developed to be patterned into stripes, and the aluminum film was etched using the resist film as a mask to form stripe pixel electrodes.

On another glass substrate having a thickness of 1.1 mm, an ITO film having a thickness of 200 angstrom was formed by vapor deposition and patterned in the same manner as above. In addition, ITO is applied to each of four glass substrates having a thickness of 0.3 mm to have a thickness of 2
It was vapor-deposited at 00 Å and patterned in the same manner as above.

Polyimide AL-1051 having a thickness of 600 is formed on the surfaces of all glass substrates manufactured as described above.
Apply angstrom and 180 in oven
The alignment film was formed by baking at 60 ° C. for 60 minutes. After rubbing the alignment film, liquid crystal ZLI-1840 is formed on the alignment film.
Was applied in an isotropic liquid state to a thickness of 100 angstrom.

Next, glass substrates having a thickness of 1.1 mm were used as the uppermost layer and the lowermost layer, and glass substrates having a thickness of 0.3 mm were combined so as to be positioned in the middle, and each was scribed and then superposed, as shown in FIG. Each cell thickness as shown 10
A liquid crystal cell having a three-layer structure of μm was produced.

For this liquid crystal cell, yellow SI-486 (manufactured by Mitsui Toatsu Co., Ltd.) and magenta M-
618 (Mitsui Toatsu Co., Ltd., trade name), Cyan M-403
Liquid crystal ZLI-1840 in which a dichroic dye (manufactured by Mitsui Toatsu Co., Ltd.) was dissolved was continuously injected.

A driver I is attached to this liquid crystal cell by TAB.
When C was mounted and a voltage of 5 V was applied between the electrodes facing each other in the three layers, good color display with a contrast of 2: 1 was achieved. (Example 3) A titanium oxide film having a thickness of 1000 angstrom was formed on a glass substrate having a thickness of 1.1 mm by vapor deposition, and an ITO film having a thickness of 1000 angstrom was formed thereon by vapor deposition. A resist film having a thickness of 2 μm was formed on the ITO film, and the resist film was exposed and developed to be patterned into stripes. The ITO film was etched using the resist film as a mask to form stripe-shaped pixel electrodes.

On another glass substrate having a thickness of 1.1 mm, an ITO film having a thickness of 200 angstrom was formed by vapor deposition and patterned in the same manner as above. Further, ITO was vapor-deposited at a thickness of 200 angstroms on both surfaces of two glass substrates having a thickness of 0.3 mm and patterned in the same manner as above.

Alignment films were formed by vapor-depositing SiO at an inclination angle of 98 ° on the surfaces of all the glass substrates manufactured as described above. Liquid crystal ZLI-4792 (manufactured by Merck & Co., Inc., trade name) was applied on the alignment film in an isotropic liquid state to a thickness of 100 angstrom.

Next, glass substrates having a thickness of 1.1 mm were used as the uppermost layer and the lowermost layer, and glass substrates having a thickness of 0.3 mm were combined so as to be positioned in the middle, and each was scribed and then overlapped with each other. Each cell thickness as shown 10
A liquid crystal cell having a three-layer structure of μm was produced.

For this liquid crystal cell, yellow LSY-115 (trade name, manufactured by Mitsubishi Chemical Corporation) and magenta L are used.
SR-401 (trade name, manufactured by Mitsubishi Chemical Corporation), Cyan LSB
Liquid crystal ZLI-2806 (manufactured by Merck, Inc.) in which a dichroic dye of -335 (manufactured by Mitsubishi Chemical Co., Ltd.) was dissolved was continuously injected.

COG (Chip On Glass) is added to this liquid crystal cell.
When a driver IC was mounted by applying a voltage of 5 V between the electrodes facing each other in three layers, normally white and bright and favorable color display with a contrast of 2.5: 1 was achieved. Example 4 A glass substrate having a thickness of 1.1 mm has a thickness of 2 μm.
Was formed, and the surface of the polyimide film was embossed by embossing, and then an aluminum film having a thickness of 1000 angstrom was formed on the polyimide film by vapor deposition. Then, the thickness of 2μ on the aluminum film
m resist film was formed, and the resist film was exposed and developed to be patterned into stripes, and the aluminum film was etched using the resist film as a mask to form stripe pixel electrodes.

On another glass substrate having a thickness of 1.1 mm, an ITO film having a thickness of 200 angstrom was formed by vapor deposition and patterned in the same manner as above. Further, ITO was vapor-deposited at a thickness of 200 angstroms on both surfaces of two glass substrates having a thickness of 0.1 mm, and patterned in the same manner as above.

Polyimide SE-4140 (manufactured by Nissan Kagaku Co., Ltd., trade name) was applied on all glass substrate surfaces produced as described above at a thickness of 600 Å,
Baking was performed in an oven at 280 ° C. for 60 minutes. Then, on a glass substrate having a thickness of 0.1 mm, a PET film was attached as a protective film on one surface thereof. Then, after rubbing the polyimide surface of each glass substrate, liquid crystal ZLI-4792 was applied on the alignment film in an isotropic liquid state at a thickness of 500 angstrom, and washed with ethanol. At this time, the thickness of the liquid crystal thin film was 50 Å.

Next, a 1.1 mm-thick glass substrate is used as the uppermost layer and the lowermost layer, the protective film on the 0.1 mm-thick glass substrate is peeled off, and then the polyimide surface is rubbed so that it is positioned in the middle. As shown in FIG. 2, a liquid crystal cell having a three-layer structure with a cell thickness of 6 μm was produced as shown in FIG. The rubbing direction in each cell was set to 240 ° twist.

For this liquid crystal cell, dichroic dyes of yellow SI-486, magenta G-202 (manufactured by Japan Photosensitive Dyes Co., Ltd.) and cyan SI-497 (manufactured by Mitsui Toatsu Co., Ltd.) Liquid Crystal ZLI-2293
(Manufactured by Merck, trade name, d / P = 0.9) was continuously injected.

A driver I is attached to this liquid crystal cell by TAB.
C was implemented. In addition, the scanning line pad portions provided in a staircase pattern were all common. When a voltage of 3 V was applied between the opposing electrodes of the three layers of this liquid crystal cell, a good color display with a contrast of 3: 1 was achieved. (Example 5) A titanium oxide film having a thickness of 1000 angstrom was formed on a glass substrate having a thickness of 1.1 mm by vapor deposition, and an ITO film having a thickness of 1000 angstrom was formed thereon by vapor deposition. A resist film having a thickness of 2 μm was formed on the ITO film, and the resist film was exposed and developed to be patterned into stripes. The ITO film was etched using the resist film as a mask to form stripe-shaped pixel electrodes.

On another glass substrate having a thickness of 1.1 mm, an ITO film having a thickness of 200 angstrom was formed by vapor deposition and patterned in the same manner as above. Further, ITO was vapor-deposited at a thickness of 200 angstroms on both surfaces of one glass substrate having a thickness of 0.3 mm, and patterned in the same manner as above.

On all the glass substrate surfaces produced as described above, SiO was vapor-deposited at an inclination angle of 98 ° to form an alignment film. Then, liquid crystal ZLI-4792 was vapor-deposited on the alignment film in a vacuum bell jar.

Then, 1.1 mm-thick glass substrates were used as the uppermost layer and the lowermost layer, and the 0.3 mm-thick glass substrates were combined so as to be positioned in the middle, and after scribing each other, they were superposed, as shown in FIG. Each cell thickness as shown 10
A liquid crystal cell having a three-layer structure of μm was produced. In this case, the alignment directions of the liquid crystal molecules were set to be parallel alignment in the liquid crystal cells and set to be shifted by 90 ° between the cells.

For this liquid crystal cell, yellow LSY-115, magenta LSR-401, and cyan LS, respectively.
Liquid crystal ZLI-28 in which dichroic dye of B-335 is dissolved
06 was continuously injected.

A driver I is applied to this liquid crystal cell by COG.
When C was mounted and a voltage of 5 V was applied between the electrodes facing each other in the three layers, normally white and bright and favorable color display with a contrast of 5: 1 was achieved. Example 6 A glass substrate having a thickness of 1.1 mm has a thickness of 2 μm.
Was formed, and the surface of the polyimide film was embossed by embossing, and then an aluminum film having a thickness of 1000 angstrom was formed on the polyimide film by vapor deposition. Then, the thickness of 2μ on the aluminum film
m resist film was formed, and the resist film was exposed and developed to be patterned into stripes, and the aluminum film was etched using the resist film as a mask to form stripe pixel electrodes.

Another glass substrate having a thickness of 1.1 mm was sputtered on the glass substrate to a thickness of 200 .ANG.
A TO film was formed and patterned in the same manner as above.
Further, ITO was sputtered on both surfaces of two glass substrates each having a thickness of 0.1 mm to a thickness of 200 Å and patterned in the same manner as above.

The main chain type polymer liquid crystal is applied to the surfaces of all the glass substrates prepared as described above in a thickness of 600 angstroms, and isotropically cooled by applying a magnetic field in the alignment direction. An alignment film was formed from the liquid state. Then, on a glass substrate having a thickness of 0.1 mm, a PET film was attached as a protective film on one surface thereof.

Next, a glass substrate having a thickness of 1.1 mm was used as the uppermost layer and the lowermost layer, the protective film on the glass substrate having a thickness of 0.1 mm was peeled off, and then the polyimide surface was rubbed so that it was positioned in the middle. As shown in FIG. 2, a liquid crystal cell having a three-layer structure with a cell thickness of 6 μm was produced as shown in FIG. The rubbing direction in each cell was set to 240 ° twist.

For this liquid crystal cell, yellow SI-486, magenta G-202, and cyan SI-49, respectively.
Liquid crystal ZLI-2293 (d) in which the dichroic dye of 7 is dissolved
/P=0.9) was continuously infused.

A driver I is attached to this liquid crystal cell by TAB.
C was implemented. In addition, the scanning line pad portions provided in a staircase pattern were all common. When a voltage of 3 V was applied between the opposing electrodes of the three layers of this liquid crystal cell, a good color display with a contrast of 3: 1 was achieved. (Example 7) A titanium oxide film having a thickness of 1000 angstrom was formed on a glass substrate having a thickness of 1.1 mm by vapor deposition, and an ITO film having a thickness of 1000 angstrom was formed thereon by vapor deposition. A resist film having a thickness of 2 μm was formed on the ITO film, and the resist film was exposed and developed to be patterned into stripes. The ITO film was etched using the resist film as a mask to form stripe-shaped pixel electrodes.

Another glass substrate having a thickness of 1.1 mm was sputtered on the glass substrate to a thickness of 200 .ANG.
A TO film was formed and patterned in the same manner as above.
Further, ITO was sputtered on both surfaces of two glass substrates each having a thickness of 0.1 mm to a thickness of 200 Å and patterned in the same manner as above.

Polydimethylsiloxane having an active hydrogen group was applied on the surfaces of all the glass substrates manufactured as described above to a thickness of 600 angstroms. Furthermore, a low-molecular liquid crystal having a double bond at the alkyl end is applied together with a platinum catalyst, and this is heated to form a high-molecular liquid crystal, which is then cooled slowly while applying a magnetic field in the alignment direction. An alignment film was formed from the liquid state. Then
On a glass substrate having a thickness of 0.1 mm, a PET film was attached as a protective film on one surface thereof.

Next, a glass substrate having a thickness of 1.1 mm was used as the uppermost layer and a lowermost layer, the protective film on the glass substrate having a thickness of 0.1 mm was peeled off, and then the polyimide surface was rubbed so that it was positioned in the middle. As shown in FIG. 2, a liquid crystal cell having a three-layer structure with a cell thickness of 6 μm was produced as shown in FIG. The rubbing direction in each cell was set to 240 ° twist.

For this liquid crystal cell, yellow SI-486, magenta G-202, and cyan SI-49, respectively.
Liquid crystal ZLI-2293 (d) in which the dichroic dye of 7 is dissolved
/P=0.9) was continuously infused.

A driver I is attached to this liquid crystal cell by TAB.
C was implemented. In addition, the scanning line pad portions provided in a staircase pattern were all common. When a voltage of 3 V was applied between the opposing electrodes of the three layers of this liquid crystal cell, a good color display with a contrast of 3: 1 was achieved. (Example 8) A titanium oxide film having a thickness of 1000 angstrom was formed on a glass substrate having a thickness of 1.1 mm by vapor deposition, and an ITO film having a thickness of 1000 angstrom was formed thereon by vapor deposition. A resist film having a thickness of 2 μm was formed on the ITO film, and the resist film was exposed and developed to be patterned into stripes. The ITO film was etched using the resist film as a mask to form stripe-shaped pixel electrodes.

On another glass substrate having a thickness of 1.1 mm, an ITO film having a thickness of 200 angstrom was formed by vapor deposition and patterned in the same manner as above. Further, ITO was vapor-deposited at a thickness of 200 angstroms on both surfaces of one glass substrate having a thickness of 0.3 mm, and patterned in the same manner as above.

Teflon was vapor-deposited at an inclination angle of 98 ° to form an alignment film on the surfaces of all the glass substrates manufactured as described above. Then, liquid crystal ZLI-4792 was vapor-deposited on the alignment film in a vacuum bell jar.

Next, glass substrates having a thickness of 1.1 mm were used as the uppermost layer and the lowermost layer, and glass substrates having a thickness of 0.3 mm were combined so as to be positioned in the middle, and after scribing each, they were superposed on each other. Each cell thickness as shown 10
A liquid crystal cell having a three-layer structure of μm was produced. In this case, the alignment directions of the liquid crystal molecules were set to be parallel alignment in the liquid crystal cells and set to be shifted by 90 ° between the cells.

For this liquid crystal cell, yellow LSY-115, magenta LSR-401, and cyan LS, respectively.
Liquid crystal ZLI-28 in which dichroic dye of B-335 is dissolved
06 was continuously injected.

A driver I is applied to this liquid crystal cell by COG.
When C was mounted and a voltage of 5 V was applied between the electrodes facing each other in the three layers, normally white and bright and favorable color display with a contrast of 5: 1 was achieved. (Conventional example) A polyimide film having a thickness of 2 μm is formed on a glass substrate having a thickness of 1.1 mm, a dimple process is performed on the surface of the polyimide film by embossing, and then an aluminum film having a thickness of 1000 angstrom is vapor-deposited on the polyimide film. Was formed. Then, 2 μm thick on the aluminum film
The resist film was formed, and the resist film was exposed and developed to be patterned into stripes. The aluminum film was etched using the resist film as a mask to form stripe-shaped pixel electrodes.

On another glass substrate having a thickness of 1.1 mm, an ITO film having a thickness of 200 angstrom was formed by vapor deposition and patterned in the same manner as above. Polyimide AL-1051 was applied on the surfaces of the two glass substrates manufactured as described above in a thickness of 600 Å, and baked in an oven at 180 ° C. for 60 minutes to form an alignment film. The rubbing treatment was applied to the alignment film.

Then, two glass substrates were combined so that their alignment films face each other and at a predetermined interval, to produce a parallel alignment liquid crystal cell. For this liquid crystal cell, a black dichroic dye S-344 was added to the liquid crystal ZLI-1.
The liquid crystal material dissolved in 840 was injected.

A driver I is attached to this liquid crystal cell by TAB.
When C was mounted, the easy axis of transmission of the polarizing plate was set parallel to the alignment direction of the liquid crystal molecules, and a voltage of 5 V was applied between the electrodes, the contrast was 4: 1. Compared with this, the contrast was lowered. It is considered that this is because the dye molecules in the dichroic dye are adsorbed on the alignment film and the coloring by the dye molecules is caused.

[0064]

As described above, the liquid crystal display device of the present invention is a liquid crystal display device in which a liquid crystal material is sandwiched between a pair of substrates, and the liquid crystal material contains polychromatic dye molecules. Since the concentration of the pleochroic dye molecule in the vicinity of the substrate is lower than the concentration of the pleochroic dye molecule in the central portion between the substrates, the display quality is high.

According to the method of manufacturing a liquid crystal display device of the present invention, a patterned electrode layer and an alignment film subjected to alignment treatment are formed on two substrates, and a liquid crystal material is supplied onto the alignment film to form a liquid crystal material on the alignment film. A liquid crystal containing a liquid crystal molecule and a polychromatic dye molecule in a cell by adsorbing liquid crystal molecules therein and arranging two substrates so that the alignment films face each other and arranged at a predetermined interval. Since the material is injected, a liquid crystal display device with high display quality can be efficiently obtained.

[Brief description of drawings]

FIG. 1 is a schematic view showing a liquid crystal display device of the present invention.

FIG. 2 is a schematic diagram showing a three-layer liquid crystal display device according to the present invention.

FIG. 3 is a schematic view showing a conventional liquid crystal display device.

[Explanation of symbols]

1 ... Substrate, 2 ... Sealing material, 3 ... Liquid crystal molecule, 4 ... Polychromatic dye molecule (dichroic dye molecule).

Claims (2)

[Claims] 1. A liquid crystal display device in which a liquid crystal material is sandwiched between a pair of substrates, wherein the liquid crystal material contains a polychromatic dye molecule, and the polychromatic dye molecule near the substrate. Is smaller than the concentration of the pleochroic dye molecule in the central portion between the substrates. 2. A step of forming a patterned electrode layer and an alignment film subjected to an alignment treatment on two substrates, and supplying a liquid crystal material onto the alignment film to supply liquid crystal molecules in the liquid crystal material to the alignment film. And a step of producing a cell by arranging the two substrates so that the alignment films face each other and at a predetermined interval, and in the cell, the liquid crystal molecule and the polychromatic A step of injecting a liquid crystal material containing a dye molecule, and a method for manufacturing a liquid crystal display device.