JPH06337412A - Color liquid crystal display device - Google Patents

Abstract

PURPOSE:To provide a color liquid crystal display device having high transmissivity by specifying a line width of a light shielding film. CONSTITUTION:One member in which a light shielding film 2 of a grid shape pattern having a rectangular opening whose line width in one direction becomes larger than a line width in the other direction is formed on a transparent substrate and a color filter 10 having a line width larger than a dimension in the other direction of the opening is arranged in a stripe shape in one direction on the opening and a transparent electrode is arranged in a stripe shape in the other direction on a stripe shape color filter 10 through an insulating layer so as to be situated above the opening and the other member in which a transparent electrode 11 is arranged in a stripe shape in one direction on a transparent substrate, are stuck together through liquid crystal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a color liquid crystal display device using a color filter.

[0002]

2. Description of the Related Art A color liquid crystal display device using a color filter has been proposed. In this color liquid crystal display device, a photosensitive coloring resin containing pigments such as red, green and blue is applied on a transparent substrate. It is manufactured by a technique of forming fine color filters in a grid pattern by a photolithography technique, and this technique is usually called a "pigment dispersion method".
(See JP-A-58-102976). A stripe arrangement as shown in FIGS. 2 and 3 has been proposed for the pixel arrangement using this color filter (see Japanese Patent Laid-Open No. 60-207118), but the stripe shown in FIG. 2 from the viewpoint of manufacturing yield and the like. Arrangement is advantageous.

A method of manufacturing a color filter for this color liquid crystal display device will be described with reference to FIGS. In FIG. 4, reference numeral 1 denotes a transparent substrate such as glass, and a light shielding film 2 made of metallic chromium or the like is formed on the transparent substrate 1 by vacuum deposition or sputtering. The light-shielding film 2 is formed in a grid shape, and each grid corresponds to an individual pixel.

Next, as shown in FIG. 5, for example, a photosensitive resin 3 in which a red pigment is dispersed is applied to the entire surface by printing or spin coating, and is exposed through a mask 4. Then, as shown in FIG. Is formed.

Further, by repeating this process for other pixels of green and blue, respectively, a green pixel 6 and a blue pixel 7 are formed as shown in FIG.

Further, as shown in FIG. 8, each pixel 5, 6, 7
In order to flatten the unevenness caused by, the acrylic resin 8 or the like is applied, and the transparent electrode 9 is formed on the resin layer 8 to form one liquid crystal display substrate.

In the color liquid crystal display device having the above structure, the aperture ratio of the display area is determined by the aperture ratio of the light-shielding film 2, and this aperture ratio is further increased with the demand for a high transmittance panel.

FIG. 9 is a schematic diagram showing the positional relationship among the color filter 10, the light-shielding film 2 and the transparent electrode 11 of the pixels 5, 6 and 7 in such a color liquid crystal display device.

In FIG. 1, the shaded area is the light-shielding film 2, and when forming the light-shielding film 2, the lattice-shaped pattern having the same line width and the rectangular openings 12 is formed. It should be noted that along the rectangular side of the opening 12, one direction X and another direction Y are defined.

Red, green and blue color filters R, G and B are arranged in a stripe shape along the one direction X with respect to the opening 12. In this arrangement, each color filter R, G, B is formed with a width slightly larger than the width of the opening 12.

Further, with respect to the opening 12, the transparent electrode 1
1s are arranged in stripes along the other direction Y. This array is formed so as to have almost the same width as the opening 12.

[0012]

However, in the case of the color liquid crystal display device having the above structure, when the aperture ratio is gradually increased in accordance with the demand of the high transmittance panel, the line width of the light shielding film 2 is accordingly increased. There was a problem as shown in FIG.

That is, according to the figure, since the pattern width of the transparent electrode 11 is almost the same size as the X dimension in one direction of the opening 12 or about several microns larger, the pattern is formed when the transparent electrode 11 is formed. In the negative type liquid crystal display device, when light is displaced, the region where the light-shielding film 2 and the transparent electrode 11 overlap prevents the transmission of light even when the liquid crystal is driven, and vice versa. Although the light is not shielded by the light shielding film 2, the liquid crystal is not driven because the voltage is not applied. As a result, the voltage application area of the opening 12 is reduced, and the aperture ratio during driving is lowered, and as a result, the image quality is lowered due to the reduction of the transmittance. Further, there is a problem in that the transmittance varies between products when the deviation width varies depending on the individual products.

On the other hand, when the line width of the light-shielding film 2 is made thinner in order to further increase the aperture ratio and the line width is made thinner than the accuracy of the exposure device, white spots in the pixels occur due to the pattern shift when the color filter is formed. There was also the problem of doing.

[0015]

A color liquid crystal display device according to the present invention has a grid pattern having a rectangular opening on a transparent substrate such that the line width in one direction is larger than the line width in the other direction. A light-shielding film is formed, and color filters with a line width larger than the other dimension of the opening are arranged in a stripe shape in one direction on the opening, and the color filter is located above the opening via an insulating layer on the stripe color filter. As described above, one member formed by arranging transparent electrodes in a stripe shape in the other direction and the other member formed by arranging transparent electrodes in a stripe shape in one direction on a transparent substrate are bonded together through a liquid crystal. Characterize.

[0016]

As described above, in order to increase the aperture ratio, the line width of the light shielding film may be made small. However, if the line width is made too small, white spots may occur due to misalignment during exposure of color pixels. The line width of the film depends on the alignment accuracy of the exposure machine.

Further, in the case of the color filter arrangement as shown in FIG. 3, the line widths in one direction and the other direction of the light shielding film need to be the same line width to the extent that white spots do not occur due to the accuracy of the exposure machine. However, with the arrangement of color filters as shown in FIG. 2, there is no concern that white spots will occur even if the line width in the other direction is reduced. Even if there is no light-shielding film in the other direction, white spots do not occur, but in that case, the absence of the light-shielding film causes a decrease in contrast.

Therefore, in the color liquid crystal display device of the present invention, the light-shielding film in one direction ensures a line width that does not cause white spots in the accuracy of the exposure device, and the line-width of the light-shielding film in the other direction. By making the size smaller than one direction, the deterioration of contrast is suppressed as much as possible, and even if the alignment deviation occurs when forming the transparent electrode, the light shielding film and the transparent electrode do not overlap, or the overlap becomes as small as possible, and the liquid crystal drive There is almost no change in the aperture ratio when
As a result, the transmittance corresponding to the aperture ratio, which has been lowered due to the overlap with the light shielding film, is improved.

[0019]

Embodiments of the present invention will be described in detail below with reference to FIG. The same parts as those in FIG. 9 are designated by the same reference numerals. A thin metal film of Cr is sputtered on a previously cleaned transparent substrate by sputtering.
The light-shielding film 2 was formed with a thickness of 0 A, and a grid pattern was formed by photolithography. At that time, the width b in one direction X of the light shielding film 2 was 30 μm, while the width d in the other direction Y of the light shielding film 2 was 15 μm. After forming the light-shielding film, a color filter pattern 10 (red, green, blue) having a film thickness of about 1.8 μm is formed by a photolithography process, and a protective film layer of a photosensitive acrylic resin is formed on the color filter pattern 10 by about 2 μm.
Laminated to a thickness of μm. Next, a transparent conductive film was formed on this substrate by a sputtering method with a thickness of 2000A. The transparent conductive film on the color filter thus obtained was patterned into stripes by a photolithography process to form the transparent electrode 11. The pixel pitch of this color filter was 0.3 mm, and the line width of the transparent electrode was 275 μm. As a substrate on the opposite side, after forming a transparent conductive film with a thickness of 2000 A on a transparent substrate,
Similarly, a stripe pattern was formed by a photolithography process. These two substrates were made to face each other, the peripheral portion was sealed, and liquid crystal was injected to obtain a color liquid crystal display device.

According to the color liquid crystal display device thus obtained, the reduction in contrast is suppressed as much as possible and the transparent electrode 1 is used.
Even if alignment deviation occurs during formation of No. 1, the light-shielding film 2 and the transparent electrode 11 do not overlap, or the overlap becomes as small as possible, and there is almost no change in the aperture ratio when liquid crystal is driven. As a result, the transmittance corresponding to the aperture ratio, which had been lowered due to the overlap with the light shielding film 2, was remarkably improved.

According to the results of the above experiments conducted by the present inventors, a substantially stable transmittance was obtained with an accuracy of ± 5 μm of the exposure machine used for forming the transparent electrode 11. The present invention is not limited to the above embodiments, and various modifications and improvements may be made without departing from the scope of the present invention.

[0022]

As described above, according to the color liquid crystal display device of the present invention, the problem of the reduction of the voltage application area of the pixel opening due to the pattern shift of the transparent electrode does not occur, and the reduction of the transmittance is prevented. It was possible to obtain a color liquid crystal display device having high transmittance.

Further, according to the present invention, the variation in the transmittance between the products due to the pattern shift of the transparent electrode is reduced depending on the individual products, thereby improving the manufacturing yield and, as a result, the low cost. In addition, a high quality and highly reliable color liquid crystal display device could be provided.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a positional relationship among a color filter, a light shielding film, and a transparent electrode in an example.

FIG. 2 is an array diagram of color filters.

FIG. 3 is an array diagram of color filters.

FIG. 4 is a process drawing of a color liquid crystal display device.

FIG. 5 is a process drawing of a color liquid crystal display device.

FIG. 6 is a process drawing of a color liquid crystal display device.

FIG. 7 is a process drawing of a color liquid crystal display device.

FIG. 8 is a process drawing of a color liquid crystal display device.

FIG. 9 is a schematic diagram showing a positional relationship among a color filter, a light shielding film, and a transparent electrode.

FIG. 10 is a schematic diagram showing a positional relationship among a color filter, a light shielding film, and a transparent electrode.

[Explanation of symbols]

 2 Light-shielding film 5, 6, 7 pixels 10 Color filter 11 Transparent electrode 12 Opening

Claims (1)

[Claims] 1. A light-shielding film of a grid pattern having a rectangular opening in which a line width in one direction is larger than a line width in the other direction is formed on a transparent substrate, and the light shielding film is formed in comparison with the size in the other direction of the opening. Color filters with a large line width are arranged in a stripe shape in one direction on the opening, and transparent electrodes are arranged in a stripe shape in the other direction so as to be located above the opening via an insulating layer on the stripe color filter. A color liquid crystal display device in which one member made up of the above and the other member formed by arranging transparent electrodes in a one-direction stripe pattern on a transparent substrate are bonded together via a liquid crystal.