JPH01295205A - Color filter - Google Patents

Abstract

PURPOSE:To obtain an inexpensive color filter provided with a black pattern by forming the black pattern in a same stage of forming a color pattern comprising three primary colors (red, green, and blue). CONSTITUTION:When a color pattern comprising primary colors (red, green, and blue) is formed in a filter substrate, a part of the pattern, where >=2 kinds of the color pattern superposed, becomes black because there is almost no fraction of the light having the wavelength capable of transmitting said superposed part. If a black area is intended to form in a boundary area of a red area, green area of blue area of a color filter element, or in an adjacent area thereto, each coloring stage for red, green, and blue, is performed in a manner that >=2 kinds of the color area superpose on the area to be the black area. Thus, a black pattern is formed at the same time when a color pattern of primary colors is formed. By this method, no additional stage for forming a black pattern is necessary. Thus, preparation cost is reduced, and generation of defective product is prevented because of the simplification of the production stage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color filter for a liquid crystal color display panel.

[Conventional technology]

Conventionally, color filters for LCD color display panels have coloring patterns of the three primary colors of red, green, and blue, and
and a black pattern that fills the outer periphery.

The black pattern filling between the colored patterns not only has the effect of improving the contrast and saturation of the displayed image, but also serves as a light-shielding layer for elements on the opposing substrate, such as TPT made of amorphous silicon. . Furthermore, the black pattern on the outer periphery functions as a light shielding mask for the outer periphery of the screen.

Methods for forming such a black pattern include forming a pattern using a suitable method such as vapor deposition of a metal thin film, printing with black ink, forming resist 1~patterns by a foliolithography method, etc., and then dyeing the pattern. Methods are known.

[Problem that the invention is trying to solve]

The formation of the black pattern described above is performed using red, green,
In addition to the pattern formation of the three primary colors of blue, one additional manufacturing process is required to form the black pattern, which is disadvantageous in terms of manufacturing costs compared to the case where only the three primary color patterns are created. An object of the present invention is to provide a low-cost color filter with a black pattern by simultaneously forming the black pattern during the process of forming red, green, and blue colored patterns.

[Means to solve the problem]

The color filter of the present invention will be explained below.

When forming a colored pattern of the three primary colors of red, green, and blue on a filter substrate, the portion where two or more of the red, green, and blue colors overlap will have a wavelength that can be transmitted, depending on the frequency transmission characteristics of the dye. Since there is almost no light, that area becomes black. By setting the red, green, and blue coloring processes so that two or more colors overlap in the area where you want to black the border or adjacent part of the red, green, and blue color filter elements,
When the colored patterns of the three primary colors of red, green, and blue are formed, a black pattern can also be formed at the same time. If a black pattern is formed using this method, there is no need to provide one special process for the black pattern.

In the above-mentioned color filter of the present invention, since the black pattern is formed by overlapping two or more of red, green, and blue, the film thickness of the black pattern portion is larger than that of the other color portions. If this difference in thickness becomes too large, it may become difficult to obtain an appropriate cell gap when assembling a liquid crystal cell.

For example, when the thickness of the red, green, and blue colored layers is 1 to 1.5 μm, the black portion where the three colors overlap is 2 to 3 μm, and the black portion where the two colors overlap is 1 to 2 μm. In order to smooth out the protrusion of the black part, there is a method of providing a buffer layer on the filter after the formation of the colored layer is completed, in which a transparent resin is coated to a thickness of 1 to 5 .mu.m. This buffer layer made of transparent resin reduces the level difference between the black part and other colors by 1. -aμm to 0.2 to 1 μm, which can be reduced by more than one-third.

The black pattern at the outer periphery of the display screen usually has a width of about 1 rMl, and the line width is thicker than the black pattern inside the display screen, which is about several tens of μm, so even if transparent resin is applied, it cannot be smoothed sufficiently, and the outer periphery Only the black part of the film becomes thicker.

Therefore, the black pattern part in the display screen is formed by overlapping three colors of red, green, and blue, and the black pattern part at the outer periphery of the screen is formed by overlapping two colors among red, green, and blue. There is a method of reducing the thickness of the black pattern on the outer periphery.

In addition, the black pattern part within the display screen is formed by overlapping two colors of red, green, and blue, and the black pattern part at the outer periphery of the screen is formed by one color of red, green, and blue to create a pseudo black color. There is also a method of reducing the film thickness of the pattern at the outer periphery by forming a pattern.

〔Example〕

Hereinafter, a color filter according to an embodiment of the present invention will be described based on the drawings.

Gelatin photo-sensitized by dichromate was coated on a Corning 7059 GSLJ plate 2' by a spin coating method, exposed through a mask having a predetermined pattern, and developed, as shown in FIG. A patterned layer having the following cross-sectional structure was obtained.This patterned layer was dyed with a green acid dye to obtain a green colored layer 3'.

The thickness of this green layer was measured and found to be 1 μm. Thereafter, a thermosetting acrylic resin was formed thereon as an intermediate layer to a thickness of 0.1 μm by spin coating.

For the second color, a layer with a predetermined pattern was formed using the same process as the first color, and the layer was dyed red to obtain a red colored layer. A cross-sectional view of the filter after staining with the second color is shown in FIG. The thickness of the colored layer B' dyed red was 1 μm, and an intermediate layer of 0.1 μm was further formed thereon in the same manner as in the case of the first color.

A predetermined pattern was formed for the third color using the same process as for the first and second colors, and dyed blue.

FIG. 3 shows a cross-sectional view of the filter after staining with the third color. The film thickness of the blue-dyed part (a) was 1 μm, and the film thickness of the black part formed by overlapping the two colors (red and blue) was 2 μm. As a result, the difference in level between the black part and the colored pattern parts of red, green, and blue was 1 μm.

Finally, a thermosetting acrylic resin (b) was applied to a thickness of 3 μm by spin coating. The results are shown in FIG.

With this method, the inside of the display screen is made up of a colored area of the three primary colors of red, green, and blue, and a black area formed by overlapping red and blue, and a color filter formed of blue is formed around the outer periphery of the screen. It's done. In this example, the surface unevenness could be suppressed to about 0.2 μm.

〔Effect of the invention〕

The color filter of the present invention reduces the number of manufacturing steps by one, thereby reducing costs, and simplifies the process, thereby reducing the number of defective products.

[Brief explanation of the drawing]

1.2,3. FIG. 4 is an explanatory diagram showing the manufacturing process of a color filter according to an embodiment of the present invention. 1...Glass substrate, 2...Green colored layer 23...Red colored layer.

Claims (4)

[Claims] (1) A color filter consisting of colored patterns of three primary colors and a black pattern, characterized in that the black pattern is formed by overlapping two or more of the three primary colors. (2) The color filter according to claim 1, further comprising a thickness difference buffer layer provided on the colored layer of the color filter. (3) The black pattern within the display screen is formed by overlapping the three primary colors, and the black pattern on the outer periphery of the screen is formed using two of the three primary colors.
3. The color filter according to claim 1, wherein the color filter is formed by overlapping colors. (4) Claim 1 characterized in that the black pattern within the display screen is formed by overlapping two or more of the three primary colors, and the pattern at the outer periphery of the screen is formed as a pseudo black pattern using one of the three primary colors. Or the color filter described in 2.