JPH10206841A - Color liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent liquid crystal from being colored and deteriorating in display quality by providing colored pixels which are different in thickness corresponding to display colors, and forming a columnar body with large strength by laminating another colored layer at or nearby a non-display part of a colored pixel of one color. SOLUTION: The columnar body is formed of the same material with a colored layer by using a photomask having the pattern of the columnar body 4 on a black matrix at or nearby the non-display part of the colored pixel of one color at the time of the formation of the colored pixel. When a colored pixel of R is formed, a colored layer of R is formed on the columnar body 4 at the same time and when a colored pixel of G is formed, a colored layer of G is formed. Further, when a colored pixel of B is formed, a colored layer of B is formed and the interval with an opposite plate 5 is held to specific size. Then, the thickness of the colored pixels is specified by adjusting the thickness of liquid crystal and when the colored pixels are formed, the thickness of the colored layers forming the columnar body is specified equally to the liquid crystal sandwiching interval.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color liquid crystal display device, and more particularly, to a liquid crystal display device characterized by maintaining a distance between substrates for holding liquid crystal.

[0002]

2. Description of the Related Art A liquid crystal display device is formed by opposing a transparent substrate such as glass provided with a transparent electrode with a liquid crystal layer interposed therebetween, and orienting the liquid crystal in a certain direction by a voltage applied between the electrodes. The image is displayed using transparent and opaque parts. A color liquid crystal display device generally includes three colored pixels of red (R), green (G), and blue (B) on any one of transparent electrode substrates, and three primary colors are formed by a shutter action of liquid crystal. A desired color is displayed by adding colors.

In a display using a twisted nematic (TN) liquid crystal generally used in a liquid crystal display device, ideally, when no voltage is applied, the liquid crystal is desired to completely block light and not transmit light. In fact, due to the optical rotation of the TN liquid crystal, the linearly polarized light incident on the liquid crystal cell becomes elliptically polarized light, and a part of the light passes through the liquid crystal cell. Therefore, even in the normally black state where no voltage is applied, some light is transmitted. Since the light transmittance depends on the thickness of the liquid crystal layer and the incident wavelength, in the dark state where no voltage is applied, the light is colored with light leakage and the color display quality is deteriorated. Therefore, in order to solve such a problem, the thickness of the liquid crystal layer is set to a predetermined thickness in the order of R, G, and B from the larger one for each of the R, G, and B colored pixels. For this reason, the thickness of the colored pixels formed on the color filter is increased in the order of R, G, and B.

In a liquid crystal display device, a spacer is mixed in a liquid crystal to maintain a liquid crystal sandwiching interval. However, in a liquid crystal display device having a different thickness according to the color of a colored pixel, a liquid crystal display device having a constant interval is used. In comparison, a large weight concentrates on the colored pixel portion having the smallest interval.

In order to solve such a problem, Japanese Patent Application Laid-Open No. 60-202423 discloses a technique in which the thickness of a liquid crystal layer is changed in accordance with a color pixel, the thickness of the liquid crystal layer is small, and the holding distance is small. It has been proposed that the area of the blue (B) colored pixel is made larger than other colored pixels to distribute the weight on the spacer. According to this method, it is possible to prevent coloring of the liquid crystal display device due to a difference in light wavelength and to prevent deformation of the spacer due to concentration of a load on the spacer.
A large amount of particles of about 00 particles / mm ² are dispersed in the liquid crystal. However, when the particles are dispersed in a highly viscous liquid crystal and injected into the holding space, the spacers are not uniformly dispersed, and the spacers are partially dispersed. There was a problem that a phenomenon of stagnation occurred and display quality deteriorated.

[0006]

SUMMARY OF THE INVENTION The present invention prevents the liquid crystal display from being colored when no voltage is applied due to the difference in the wavelength of light in the liquid crystal display device, and reduces the display quality of the liquid crystal display device due to the dispersion of spacers. It is an object to prevent it.

[0007]

According to the present invention, there is provided a color liquid crystal display device in which a liquid crystal layer is sandwiched between a color filter and a counter substrate. A color liquid crystal display device having a color filter in which another colored layer is laminated on a non-display portion of a colored pixel or in the vicinity thereof to form a columnar body having high strength.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS That is, in the liquid crystal display device of the present invention, the thickness of the coloring layer is changed according to the color, and the distance between the color filter of the liquid crystal display device and a substrate such as a TFT opposed thereto is maintained. In order to achieve this, a columnar member having a high strength is formed in a non-display portion of any one of the colored pixels or in the vicinity of the non-display portion, and a laminated body in which another colored layer is laminated.

The color filter of the liquid crystal display device of the present invention will be described with reference to the drawings.

FIG. 1 is a view for explaining an embodiment of the present invention. FIG. 1 (A) shows a partial plan view of a color filter, and FIG. 1 (B) shows FIG. 1 (A). 2 is a cross-sectional view of the liquid crystal display device taken along the line AA in FIG. A black matrix 2 having a desired pattern is formed on a transparent substrate 1 such as a glass substrate by depositing metal chromium or the like by sputtering or the like. After the formation of the black matrix, the colored pixels 3 are formed. The order of forming colored pixels is
R (red), G
(Green) and B (blue) are preferably formed in this order.

The colored pixels can be formed by applying a synthetic resin composition containing a pigment or the like and eluting unnecessary portions using a predetermined pattern. If you use a conductive material,
A colored pixel can be formed only by development processing after exposure using a predetermined photomask. In forming a colored pixel, a columnar body is formed using the same material as the colored layer using a photomask having a pattern of the columnar body 4 on a non-display portion of a colored pixel of any one color or on a black matrix in the vicinity thereof. ing.

As shown in the cross-sectional view of FIG. 1B, when the R colored pixel is formed, the R colored layer is also formed on the columnar body 4 at the same time, and then when the G colored pixel is formed. Is formed with a G colored layer. In addition, when forming a B colored pixel, a B colored layer is formed, and the distance from the opposing plate 5 can be maintained at a predetermined size.

In the present invention, the thickness of the colored pixel is adjusted to a predetermined thickness in order to prevent light leakage or the like by adjusting the thickness of the liquid crystal, and a columnar body is formed when the colored pixel is formed. It is also necessary that the thickness of the colored layer to be formed has a predetermined value equal to the liquid crystal sandwiching interval.

In the present invention, it has been found that such two kinds of thickness requirements are formed by a single operation. In other words, when the thickness of the coloring layer to be formed is large in the area of the coloring layer for the columnar body formed earlier, the amount of the synthetic resin composition flowing out due to the difference in height from the surroundings is small,
In the case where the thickness of the formed colored layer is large, and conversely, if the area of the previously formed colored layer is small, the applied colored layer flows out to the surroundings, the height is leveled, and the formed colored layer is formed. It has been found that the height of the layer is reduced. By utilizing such a phenomenon, the thickness of the colored pixel of the display unit can be set to a predetermined thickness, and the height of the columnar body on which the colored layers are stacked can be adjusted to the liquid crystal sandwiching interval.

Further, the columnar body formed in the present invention is formed in or near a colored pixel of any one color. For example, three columns of red (R), green (G), and blue (B) are used. In the case of a color filter having colored pixels of a color, the color filter is formed in only one of the three colors, and the area of the columnar body is set to a predetermined size, and a specific substance is used as a composition for forming a colored layer. By using the liquid crystal, it is possible to sufficiently maintain the liquid crystal sandwiching interval with a small number of columnar bodies. For example, in a color filter provided with three colored pixels having a size of 288 μm in length and 96 μm in width, the uppermost 200 μm
μm by forming a ² ～1600Myuemu columnar body made of colored layers ^2, can hold the liquid crystal sandwiched intervals by pillars of small number. Although the size of the columnar body is preferably as large as possible, it is preferable that the size be within 40 μm □ in consideration of the formation in the black matrix portion.

The composition for forming the colored layer includes:
Polyfunctional acrylate monomer and polyfunctional methacrylate monomer, one of the polymerizable compounds having an ethylenically unsaturated bond, and chemical properties such as heat resistance and chemical resistance, and mechanical properties such as surface hardness and volume shrinkage. For example, a basic composition including an organic polymer binder for imparting the same and a photopolymerization initiator composed of a halomethyloxadiazole-based compound, a halomethyl-s-triazine-based compound alone or a composite can be used. Examples of the polyfunctional acrylate monomer and polyfunctional methacrylate monomer include ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butadiol diacrylate, tetramethylene glycol diacrylate, propylene glycol diacrylate, trimethylolpropane triacrylate, trimethyl Methylol triacrylate, 1,4-cyclohexanediol diacrylate, pentaerythritol triacrylate, tetraethylene glycol diacrylate, pentaerythritol diacrylate,
Pentaerythritol tetraacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorivitol pentaacrylate, sorbitol hexaacrylate, tetramethylene glycol dimethacrylate, triethylene glycol di Methacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, dipentaerythritol dimethacrylate, sorbitol trime Acrylate, sorbitol tetramethacrylate, bis - [p-(3- methacryloxy -
2-hydroxypropoxy) phenyl] dimethylmethane, bis- [p- (methacryloxyethoxy) phenyl] dimethylmethane, and the like. In addition to monomers, prepolymers, that is, dimers and trimers are also effective. Also useful are other unsaturated carboxylic acids such as itaconic acid, crotonic acid, isocrotonic acid, and ester compounds of maleic acid and aliphatic polyhydric alcohols. As the organic polymer binder,
Copolymers containing an unsaturated organic acid compound such as acrylic acid and methacrylic acid compatible with an acrylate monomer and an unsaturated organic acid ester such as methyl acrylate, ethyl methacrylate and benzyl methacrylate as monomers are exemplified. Having an acidic group such as a carboxyl group enables water-soluble development and is more economical and safer than organic solvent development.

On the color filter on which the colored layer is formed,
A transparent protective film made of a synthetic resin or an inorganic substance may be formed. Further, a transparent electrode film for driving a liquid crystal made of ITO or the like is formed on the coloring layer directly or after forming a protective film. Further, if there is an electrical problem between the ITO and the opposing substrate, the columnar portion may be masked during the ITO film formation. When a black matrix is formed on the TFT substrate side, a column is also formed on the TFT substrate side with a non-conductive black matrix, and the gap can be maintained by combining the column with the column on the color filter side. it can.

[0018]

Embodiments of the present invention will be described below in more detail. Example 1 7 having a short side of 370 mm, a long side of 470 mm, and a plate thickness of 1.1 mm
A 0.2 μm-thick chromium oxide / chromium laminated structure film was formed on 059 glass (manufactured by Corning Incorporated) by sputtering. Observation from the glass surface side gave a low reflection optical density of 4.0. Next, a photoresist (OFPR-800 manufactured by Tokyo Ohka) is applied to a thickness of 0.5 μm, prebaked, exposed using a mask having a predetermined pattern formed thereon, and after developing the resist, chromium oxide / chrome The film was subjected to etching, resist stripping, washing and drying steps to form a black matrix.

Next, an anthraquinone red pigment (CI: a mixture of Pigment Red 177 and Pigment Yellow 139) having a submicron particle size is dispersed in a solvent and a radical polymerization type photopolymer (acrylic), and benzyl methacrylate-methacrylic acid copolymer is dispersed. Ethyl 3-ethoxypropionate as a solvent was added to the union, pentaerythritol tetraacrylate, and 4- [PN, N-di (ethoxycarbonylmethyl)]-2-6-di (trichloromethyl) -S-triazine as a solvent. Then, a composition of a photosensitive material adjusted to a solid content of 30% and a viscosity of 15 cP (25 ° C.) was applied so as to have a thickness of 3 μm after the final heat treatment. After pre-baking at 100 ° C., exposure is performed using a red pattern forming mask, development, washing, and drying, and post-baking at 200 ° C. to form red colored pixels and blue stripes. A red colored layer for forming a columnar portion having a size of 18 μm × 28 μm was formed on the black matrix portion.

Next, a photosensitive material in which a phthalocyanine-based green pigment is dispersed (CI: a mixture of Pigment Green 7 and Pigment Yellow 83) is dispersed in a composition similar to that used for the red photosensitive material. The active material was applied to a thickness of 3.6 μm after the final heat treatment. After pre-baking at 100 ° C., it is exposed to light using a green pattern forming mask, developed, washed, and dried.
Post-baking is performed at 00 ° C. to form a green colored pixel, and a 15 μm × 25 μm is formed on the previously formed columnar body in a black matrix portion where a blue stripe is formed.
A green colored layer having a size of μm was formed.

Next, a phthalocyanine blue pigment (C
3. A photosensitive material in which a photosensitive material in which I: Pigment Blue 15: 3 and Pigment Violet 23 are dispersed is dispersed in a composition similar to that used for the red photosensitive material. It was applied to a thickness of 7 μm. After pre-baking at 100 ° C., exposure was performed using a blue pattern forming mask, development, washing, and drying, followed by post-baking at 200 ° C. to form a blue colored layer.

After an alignment film made of polyimide was formed on the color filter thus obtained, a glass substrate on which a TFT was formed using an epoxy resin as a sealant was bonded, and TN liquid crystal was sealed as a liquid crystal.

[0023]

According to the present invention, in a liquid crystal display device in which a liquid crystal is sandwiched between two substrates, the thickness of a colored pixel of a color filter constituting the liquid crystal display device is changed according to the color, and the thickness of the color filter is changed. In the display area, a colored layer is laminated to form a columnar body for maintaining a distance between the liquid crystal display devices, so that even when a display using a twisted nematic (TN) liquid crystal is applied with no voltage applied, light is completely blocked and light is transmitted. The liquid crystal display surface can be prevented from being colored undesirably, there is no need to disperse particulate or rod-shaped spacer members in the liquid crystal, and spacers are evenly arranged on the entire display surface. The columnar body having the function of (1) can be formed at the same time in the process of forming the colored pixels, so that there is no problem such as display unevenness due to uneven distribution of the spacer member, etc. It can be obtained shows apparatus.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating one embodiment of a liquid crystal display device of the present invention.

[Explanation of symbols]

1 ... substrate, 2 ... black matrix, 3 ... colored pixel,
4 ... columnar body 5 ... counter substrate

Claims (1)

[Claims] In a color liquid crystal display device in which a liquid crystal layer is sandwiched between a color filter and a counter substrate, the color liquid crystal display device has colored pixels having different thicknesses according to display colors, and a non-display portion of one of the colored pixels or A color liquid crystal display device having a color filter in the vicinity of which another colored layer is laminated to form a columnar body having high strength.