JPH01167821A - Liquid crystal display device and production thereof - Google Patents

Abstract

PURPOSE:To obtain a liquid crystal device of a fine display pattern by superposing a perpendicularly oriented film which has good affinity to an orienting agent and is not lost in perpendicular orientability by a rubbing treatment on a substrate and a horizontally oriented film which is given horizontal directivity by a rubbing treatment to a prescribed pattern shape on a part of said film. CONSTITUTION:Dichromatic dye molecules 6 are sealed between glass plates 2 and a polarizing plate 1 is attached to the outside of the glass plate on a light source side. A transparent electrode 3 is provided on the inside and the perpendicularly oriented film 7 and the horizontally oriented film 4 of the display shape pattern are formed. The light of the light source is polarized by the polarizing plate 1 and is projected through the horizontally oriented film 4 and the perpendicularly oriented film 7 to the dichromatic dye molecules 6. The dye molecules 6 and the liquid crystal molecules 6 are oriented in parallel with the glass plate 2 to form the prescribed color in the region between the horizontally oriented films 4 and are perpendicularly oriented between the perpendicularly oriented films 7 to form the light source color when the voltage between the electrodes 3 is zero. The molecules are oriented perpendicularly to the glass plate 2 in the region between the horizontally oriented films 4 and the orientation perpendicular to the glass plate is maintained between the perpendicularly oriented films 7 when the voltage is impressed between the electrodes 3. The fine pattern display is enabled according to this constitution.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a liquid crystal display device and a method for manufacturing the same, and in particular, the present invention relates to a liquid crystal display device and a method for manufacturing the same.
The present invention relates to a liquid crystal display device comprising a (hereinafter referred to as horizontal alignment) film and a homeotropic alignment (hereinafter referred to as vertical alignment) film, and a method for manufacturing the same.

[Prior Art] Liquid crystal display devices are thin, low power consumption, and can be driven at low voltages, and black and white display devices are already used in a wide range of applications such as wristwatches and calculators. Displayable devices are also being put into practical use.

One of these color display liquid crystal display devices is the guest/host (
There is a type of liquid crystal display device (hereinafter referred to as G11).

3(A) and 3(B) are schematic explanatory diagrams showing the basic configuration of the G[1 type liquid crystal display device, FIG. 3(A) is the configuration when no voltage is applied, and FIG. 3(n ) indicates the configuration when voltage is applied.

As shown in FIGS. 3(A) and 3(B), liquid crystal molecules 5 and dichroic dye molecules 6 are located between two opposing glass substrates 2.
is included. A polarizing plate 1 is placed on the outer surface side of the glass substrate 2 on the back side (light source side).

A patterned transparent electrode 3 made of ITO or the like is formed on the inner surface of the glass substrate 2, and a horizontal alignment film 4 is formed on the transparent electrode 3 and the glass substrate 2.

Light emitted from a light source (not shown) passes through a polarizing plate 1, is polarized in a predetermined direction, passes through a transparent electrode 3 and a horizontal alignment film 4, or passes through a horizontal alignment film 4, and then passes through a dichroic dye molecule. 6 is irradiated.

As shown in FIG. 3(A), when no voltage is applied between the transparent electrodes 3, the dichroic dye molecules 6 and the liquid crystal molecules 5 are aligned approximately parallel to the glass substrate 2 by the horizontal alignment film 4, and are irradiated. A predetermined wavelength range of the emitted light is absorbed by the dichroic dye molecules 6 and passes through the display-side transparent electrode 3 and the horizontal alignment film 4 or the horizontal alignment film 4 . At this time, the display becomes a surface display colored in a uniform predetermined color, and there is no display.

On the other hand, as shown in FIG. 3(B), when a voltage is applied between the transparent electrodes 3, the dichroic dye molecules 6 are aligned with the liquid crystal molecules 5 in the region sandwiched between the transparent electrodes 3. Accordingly, they are arranged substantially at right angles to the glass substrate 2, and the emitted light passes through the transparent electrode 3 and the horizontal alignment film 4 on the display side without being almost absorbed.

The area not sandwiched between the transparent electrodes is shown in FIG. 3 (A) described above.
It is in a similar state.

At this time, the display is such that the pattern area sandwiched between the transparent electrodes 3 is the light source color, and the other areas are a uniform predetermined color.
The screen enters the display state, and the display is performed based on the contrast.

When attempting to display characters, numbers, etc. using a white light source in a GH-type liquid crystal display device with such a configuration, the display results in a so-called negative display in which the displayed characters are white and the other areas are colored. Become.

Generally, when displaying 6 characters or numbers, a so-called positive display is used, in which the displayed characters are colored (including black) and the other parts are white, as seen in newspapers, books, etc. This requirement is also strong in liquid crystal display devices.

In response to this demand, research and development of positive display type liquid crystal display elements is progressing.

4(A) and 4(B) are schematic explanatory diagrams showing the configuration of a positive display type GHH type crystal display device, and FIG. 4(A) shows the configuration when no voltage is applied, and FIG. B) shows the configuration when voltage is applied.

Note that the same components as those of the GH type liquid crystal display device shown in FIG. 3 are given the same reference numerals.

As shown in FIG. 4, the GH type liquid crystal display device with this configuration has a horizontal alignment film 4 and a vertical alignment film 7 adjacent to each other on a glass substrate 2, and uses the underwater alignment film portion as a display portion. It is something.

As shown in FIG. 4 IA), when no voltage is applied between the transparent electrodes 3, the dichroic dye molecules 6 and the liquid crystal molecules 5 are approximately connected to the glass substrate 2 in the region sandwiched between the horizontal alignment films 4. In a region that is oriented in parallel and sandwiched between one vertical alignment film 7, it is oriented substantially at right angles to the glass substrate 2.

At this time, the pattern area sandwiched between the horizontal alignment films 4 becomes a predetermined color, and the other area sandwiched between the vertical alignment films becomes a light source color, resulting in a two-display state, and the display is performed based on the contrast.

On the other hand, as shown in FIG. 4 (11), when a voltage is applied between the transparent electrodes 3, the dichroic dye molecules 6 are generated even in the region sandwiched between the horizontal alignment films 4 on the transparent electrodes 3. Along with the arrangement of the liquid crystal molecules 5, they are arranged substantially at right angles to the glass substrate 2.

In the area sandwiched between the vertical alignment films 7 other than the horizontal alignment film 4,
The dichroic dye molecules 6 are maintained in a state of being oriented substantially perpendicular to the glass substrate 2.

At this time, 1 display is a surface display with a uniform light source color, resulting in a state of no display.

[Problems to be solved by the invention] In the above positive display type GH type liquid crystal display device,
It is necessary to provide the horizontal alignment film 4 and the vertical alignment film 7 adjacent to each other. This manufacturing method includes a mask evaporation method in which layers are sequentially formed using mask plates having openings of the same shape as each pattern, and a patterned horizontal alignment film is formed and then adsorbed with this horizontal alignment film. A method of forming a vertical alignment layer by applying a difficult vertical alignment agent to an area other than the horizontal alignment film by utilizing the difference in adsorption between the horizontal alignment film and the substrate (disclosed in Japanese Patent Publication No. 60-48739) ).

However, the former method requires complicated steps such as mask alignment and is difficult to improve efficiency, and the latter method may result in vertical alignment agent remaining on the horizontal alignment film when the area becomes large. Also, there was a problem in that it was difficult to form fine pitch patterns adjacent to each other.

Means for Solving Problem E] The liquid crystal display device of the invention of the present invention is characterized in that the liquid crystal alignment film formed on the substrate has good compatibility with the alignment agent for forming the horizontal alignment film, and the rubbing treatment It is characterized by comprising a vertical alignment film whose vertical alignment property is not lost by the process, and a horizontal alignment film which is provided in a predetermined pattern shape on a part of the vertical alignment film and which is given horizontal alignment property by rubbing treatment. .

The method for manufacturing a liquid crystal display device according to the invention of Part 2 of the present application forms a vertical alignment film that is compatible with an alignment agent for forming a horizontal alignment film on a substrate and whose vertical alignment properties are not lost by rubbing treatment, A horizontal alignment film is formed by applying a horizontal alignment agent to a part of the vertical alignment film in a predetermined pattern shape, and then subjecting at least the predetermined pattern portion to a rubbing treatment.

[Function] In the case where a horizontal alignment film and a vertical alignment film are formed on the same substrate, the liquid crystal display device of the invention in Part 1 of the present application is compatible with the alignment agent for forming the horizontal alignment film as the vertical alignment film. By using a material with good adhesion, it is possible to form a horizontal alignment film relatively easily and accurately on a vertical alignment film. By using a material that does not lose its vertical alignment during the rubbing process to obtain it, it is possible to perform the rubbing process without considering deterioration of the vertical alignment of the vertical alignment film.

The method for manufacturing a liquid crystal display device according to the invention in Section 2 is used for the liquid crystal display device according to the invention in Section 1 above,
First, a vertical alignment film that is compatible with the alignment agent for forming a horizontal alignment film on a substrate and whose vertical alignment properties are not lost by mouth rubbing treatment is formed, and then a predetermined film is formed on this vertical alignment film. In order to form a horizontal alignment film with a pattern shape of , it is possible to perform the rubbing treatment in a step after forming both the horizontal alignment film and the vertical alignment film, without considering deterioration of the vertical alignment property.

[Example] Embodiments of the present invention will be described in detail below with reference to the drawings.

Although a GH type liquid crystal display device will be described as an example of the liquid crystal display device of the present invention, the present invention is not limited to this type, and a liquid crystal display device in which a horizontal alignment film and a vertical alignment film are formed adjacent to each other. If so, the present invention can be used.

FIG. 1(^)(n) is a schematic explanatory diagram showing an example of the configuration of a liquid crystal display device according to the present invention, and FIG. 1(A) is the configuration when no voltage is applied. ) indicates the configuration when voltage is applied.

Note that the same components as those of the GH type liquid crystal display element shown in FIG. 4 are given the same reference numerals.

As shown in FIGS. 1A and 1B, liquid crystal molecules 5 and dichroic dye molecules 6 are located between two opposing glass substrates 2.
is included. A polarizing plate 1 is mounted on the outer surface side of the glass substrate 2 on the back side (light source side).

A patterned transparent electrode 3 made of ITO or the like is formed on the inner surface of the glass substrate 2. A vertical alignment film 7 is formed on the transparent electrode 3 and the glass substrate 2, and is further patterned into a display shape. A horizontal alignment film 4 is formed. This horizontal alignment film 4 is provided at a required portion on the vertical alignment film at least in the area sandwiched between the upper and lower transparent electrodes 3.

Light emitted from a light source (not shown) passes through a polarizing plate 1, is polarized in a predetermined direction, passes through a horizontal alignment film 4, or passes through a horizontal alignment film 4 and a vertical alignment film 7, and is dichroic. The dye molecules 6 are irradiated.

As shown in FIG. 1(A), when no voltage is applied between the transparent electrodes 3, the dichroic dye molecules 6 and the liquid crystal molecules 5 are in contact with the glass substrate 2 in the area sandwiched between the horizontal alignment films 4. The regions are oriented substantially parallel to each other, and are oriented substantially perpendicular to the glass substrate 2 in the region sandwiched between the vertical alignment films 7 . At this time, in one display, the pattern area sandwiched between the horizontal alignment films 4 takes on a predetermined color, and the other areas sandwiched between the vertical alignment films take on the light source color, resulting in a display state, and display is performed based on the contrast.

On the other hand, when a voltage is applied between the transparent electrodes 3 as shown in FIG. As the molecules 5 are arranged, they are arranged substantially perpendicularly to the glass substrate 2, and the state of being oriented substantially perpendicularly to the glass substrate 2 is maintained in the region sandwiched between the vertical alignment films.

At this time, the 5 display becomes a surface display with a uniform light source color, and is in a state of no display.

A feature of the present invention is that a positive display type liquid crystal display element is constructed by forming a horizontal alignment film on a part of the vertical alignment film. In order to form a horizontal alignment film, it is necessary for the vertical alignment film to be compatible with the alignment agent used to form the horizontal alignment film.
Further, it is necessary that the vertical alignment is not lost due to the rubbing treatment for imparting the alignment of the horizontal alignment film. The rubbing process is a process in which the film surface (the film formed by drying the alignment agent) is rubbed with absorbent cotton, cloth, etc. to provide orientation in order to form fine grooves.

Vertical alignment agents that form such vertical alignment films include:
Cationic surfactants are preferably used. As the cationic interface and surfactant, for example, cetyltrimethylammonium bromide and cetylviridinium bromide are preferably used, and dialkyl (hexadecyl, heptadecyl and/or octadecyl) dimethylammonium chloride is more preferably used.

That is, among the cationic surfactants, those containing a long-chain alkyl group having 16 or more carbon atoms are preferable because they tend to have less deterioration in vertical alignment due to rubbing.

As the horizontal alignment agent for forming the horizontal alignment film, polyimide precursor alignment agents, photosensitive polyimide precursor compositions, and the like are preferably used. This photosensitive polyimide precursor composition can be formed into a desired shape by photoprinting and is suitable for forming precise display patterns.

Silane coupling agents 1, which are known as vertical alignment agents and have a similar structure to the above-mentioned vertical alignment agents, but are unsuitable for the present invention, include silane coupling agents 1, for example, NN-dimethyl-N-tadecyl-3; -Aminopropyltrimethoxysilyl chloride, decyltrimethoxysilane, octadecyltriethoxysilane, etc. have poor compatibility when applying a polyimide precursor solution as a horizontal alignment agent on top of a vertical alignment film made of these materials. Therefore, repellency occurs and a horizontally aligned film cannot be formed.

Another silane coupling agent, 3-phenylaminopropyltrimethoxysilane, does not cause the problem described in 1. However, when rubbing treatment is applied to impart horizontal alignment to a polyimide film, it becomes a vertically aligned film. However, the silane coupling agent film also causes horizontal alignment, which is unsuitable.

Hereinafter, embodiments of the manufacturing process of a liquid crystal display device according to the present invention will be described.

FIGS. 2(A) to 2(D) are manufacturing process diagrams of one embodiment of the manufacturing process of a liquid crystal display device according to the present invention.

First, as shown in FIG. 2(A), on the glass substrate 2,
An ITO (Indium-Tin Oxide) film is formed, a resist is applied, and then etched to pattern the desired shape (display area and lead line area) to form transparent electrodes 3.

Next, as shown in FIG. 2 (Is), dialkyl (hexadecyl, heptadecyl and/or octadecyl) dimethyl ammonium chloride, which is a cationic surfactant as described above, is mixed with ethanol and IPA (for example, the ratio of ethanol and iPA is adjusted to 1:1). 0.1% to 1
% diluted solution is applied by spinner coating, dip coating, etc., and is heated and dried under conditions of 80° C. to 150° C. and 1 l-1 r to form the vertical alignment film 7.

Next, as shown in FIG. 2(C), apply the above-mentioned polyimide alignment agent (for example, Semicofine 5P-910, Toshi Co., Ltd., Sunever 1309) only to the predetermined area to be displayed.
manufactured by Yasan Kagaku Kogyo) or a photosensitive polyimide precursor composition (PL-tooo).

(manufactured by Hitachi Chemical) by a resin letterpress printing method or a mask spinning method at 200°C to 300°C.

Dry by heat drying or ultraviolet irradiation under the conditions of 111r. Thereafter, a rubbing treatment is performed with absorbent cotton to form a horizontal alignment film 4.

Next, as shown in FIG. 2(0), they are pasted together with a sealant 8 so that a constant interval is maintained. In the cell thus formed, a G H p-type color liquid crystal (e.g.
LHB-045C (blue), LIIR-03IC (red), manufactured by Mitsubishi Chemical Industries, Ltd.) are enclosed. After that, it is sealed with a sealing material 9 such as epoxy resin.

I like this! A liquid crystal display device as illustrated in FIG. 1 can be manufactured using the i2 step.

[Effects of the Invention] As explained in detail above, according to the liquid crystal display device of the first invention of the present application, one horizontal alignment film can be formed relatively easily and accurately on a vertical alignment film, so that A liquid crystal display device with a fine display pattern can be manufactured relatively easily. In addition, since uniform rubbing treatment can be performed on the horizontal alignment film without considering deterioration of the vertical alignment properties of the vertical alignment film, stable operation of the liquid crystal display can be achieved even with relatively large area display patterns. A display device n can be manufactured.

Further, according to the method for manufacturing a liquid crystal display device of the second invention of the present application, the horizontal alignment film can be formed regardless of the positional accuracy of the arrangement of the vertical alignment film, so the manufacturing process is simplified,
Liquid crystal display devices can be manufactured with high viscosity.

[Brief explanation of the drawing]

FIG. 1(A) (formerly is a schematic explanatory diagram showing an example of the configuration of a liquid crystal display device according to the present invention. FIG. 2(A) to (0) are diagrams showing the manufacture of a liquid crystal display device according to the present invention. FIG. 4 is a manufacturing process diagram of an example of the process. FIGS. ) is a schematic explanatory diagram showing the configuration of a positive display type Gll type liquid crystal display element. 1: polarizing plate, 2 glass substrates, 3: transparent electrode, 4: horizontal alignment film, 5: liquid crystal molecules, 6: Dichroic dye molecule, 7; Vertical alignment film, 8: Sealing material,
9: Sealing material. Agent Patent Attorney Jo Yamashita Figure 1 (1st day) Figure 3 (A) Figure 4 (A) 1st day)

Claims (1)

[Scope of Claims] (1) The liquid crystal alignment film formed on the substrate has good compatibility with the alignment agent for forming a homogeneous alignment film, and the homeotropic alignment is not lost by rubbing treatment. A liquid crystal display device comprising a Bic alignment film and a homogeneous alignment film provided in a predetermined pattern shape on a portion of the homeotropic alignment film and imparted homogeneous alignment by rubbing treatment. (2) The liquid crystal display device according to claim 1, wherein the liquid crystal composition in contact with the liquid crystal alignment film has positive dielectric anisotropy and contains a dichroic dye. (3) Claim 1, wherein the homogeneous alignment film is a polyimide-based alignment film, and the homeotropic alignment film is a cationic surfactant-based alignment film containing a long-chain alkyl group with 16 or more carbon atoms. The liquid crystal display device described in Section 1. (4) To form a homogeneous alignment film on a substrate, form a homeotropic alignment film that is compatible with the alignment agent and whose homeotropic alignment properties are not lost by rubbing treatment, and on this homeotropic alignment film. A method for manufacturing a liquid crystal display device, comprising: depositing a homogeneous alignment agent in a predetermined pattern shape on a portion of the liquid crystal display device, and then subjecting at least the predetermined pattern portion to a rubbing treatment to form a homogeneous alignment film. (5) The alignment agent forming the homogeneous alignment film is made of a polyimide precursor, and the alignment agent forming the homeotropic alignment film is a cationic surfactant containing a long chain alkyl group having 16 or more carbon atoms. Claim No. 4
A method for manufacturing a liquid crystal display device as described in Section 1.