JPH03231702A - Color filter - Google Patents

Abstract

PURPOSE:To eliminate ununiformity due to whitening and overlapping without forming a light shielding part by forming a partition wall of a photosensitive transparent resin at each boundary region between picture elements and making the cross-sectional shape of the wall triangular. CONSTITUTION:A transparent partition wall 3 is formed at each boundary region between picture elements of a color filter and a colored resin 5 is filled into each opening 4 enclosed with such partition walls 3. The cross-sectional shape of the walls 3 is a triangle whose height is equal to the thickness of the films of the picture elements and the colored resin 5 is filled up to the vertex of the triangle. The shape of the picture element is stabilized in a printing stage or a smoothening stage after printing because of the partition walls 3, ununiformity in print and density is reduced and productivity is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a color filter used in TN type and STN type bay crystal color display devices.

<Prior art> Color display devices using TN type and STN type liquid crystals: In this case, a color filter is used in which red (R), green (G), and blue (B) color pixels are arranged in stripes. has been done. In the manufacturing process of color filters, color unevenness due to thickness unevenness of the colored resin layer itself, overlapping of pixels in gaps between pixels, white spots, etc. has conventionally been a problem. In particular, color filters formed by printing methods have problems with flickering and deformation around pixels. When the ink is transferred from the printing plate to the glass substrate via the blanket cylinder, etc., smearing occurs around each pixel due to the physical properties of the ink, the circumstances and wettability of the blanket cylinder, and the physical conditions of the printing press operation. As a result, white areas or overlapping areas would occur in the pixels, causing unevenness on the display screen. Figure 5 shows a cross-sectional view of such a pixel.
) is the formed pixel, (11) is the contacting part, (12)
The white part is the part, and (13) is the overlapping part.

To solve this problem, a matrix-like light-shielding part is formed with a predetermined thickness using black colored resin between pixels, and the pixel ink is embedded into the opening surrounded by the light-shielding part using this as a partition wall. Another method is being considered. Figure 6 shows a cross-sectional view of such a color filter.
5) is a formed pixel, and (6) is a light shielding portion. Since each pixel is partitioned by a light-shielding portion, white spots, overlapping, etc. are eliminated by completely filling the space between the light-shielding portions.

<Problems to be Solved by the Invention> However, in display devices using TN-type and STN-type liquid crystals, unlike TFT-type liquid crystal display devices, it is not necessary in principle to provide a light-shielding part to provide a transistor between pixels. However, by providing the light shielding part, the pixel formation area becomes narrower, and the aperture becomes narrower, resulting in a darker screen as a whole.

<Means for Solving the Problems> The present invention further improves the color filter using the light shielding part as a partition wall, thereby providing a color that eliminates unevenness due to white spots, overlaps, etc. without providing a light shielding part. It provides a filter.

The color filter is characterized in that a partition wall made of photosensitive transparent resin is provided at the pixel boundary in place of the light shielding part, and the partition wall has a triangular cross-sectional shape. The height of the triangle corresponds to the film thickness required for the colored resin layer to satisfy a predetermined optical density, and the length of the base is preferably as small as possible because it can increase the pixel area, but this is within the range of the current state of the art. Considering the cost and cost, 5 to 10 μm is appropriate.

FIG. 1 is a cross-sectional view of a pixel of a color filter according to the present invention. (1) is the substrate, (2'''A is the transparent resin layer, (3
) is the partition wall, (4) is a pixel forming portion, and (5) is each color pixel.

The shape of the transparent resin layer will be explained in more detail.

There are the following three shapes of the transparent resin layer.

(a) The partition wall is formed directly on the substrate using transparent resin, similar to the conventional light shielding part. FIG. 2 shows a transparent resin layer having such a shape, where (1) is the substrate and (3) is the partition wall.

(b) The resin layer is formed in the pixel forming area, and the surface thereof is provided with predetermined irregularities, and the convex parts form the shape of the partition wall. FIG. 3 shows a cross-sectional view of the boundary between the pixel area and the non-pixel area of such a color filter, where (1) shows the substrate;
(2) is a transparent resin layer, (3) is the partition wall, and (4) is a pixel forming portion.

(c) The resin layer is formed on the entire surface of the substrate, and the surface thereof is provided with predetermined unevenness, and the protrusions form the shape of the partition wall.

FIG. 4 shows a cross-sectional view of the boundary between the pixel area and the non-pixel area of such a color filter, where (1) is the substrate, (2) is the boundary between the pixel area and the non-pixel area.
) is a transparent resin layer, (3) is the partition wall, and (4) is a pixel forming portion.

Effect> Since the ink or colored resin of each color is filled up to the triangular apex of the transparent partition wall, the space between the pixels appears to be a tweezers. Therefore, a color filter capable of displaying evenly is obtained without providing a light shielding part.

<Example> A resin layer is formed on the entire surface of the substrate using a transparent ultraviolet curable acrylate resin or polyester resin, and its surface is patterned with concavities and convexities in which the part corresponding to the light-shielding part of the pixel formation area is a convex part and the pixel forming part is a concave part. Provided for. The convex portion was a partition wall, and its cross-sectional shape was a triangle with a base of 10 μm and a height of 2 μm from the bottom of the concave portion to the tip of the convex portion. Ink of each color was printed in the recess, that is, an opening surrounded by the partition wall, by an offset printing method, and then pressure was applied to the surface to fill the ink of each color.

<Effects of the Invention> Since there is no light-shielding part between pixels, pixels can be made by combing the tweezers together, resulting in a wider opening and a brighter display effect.

Since partition walls are created between pixels, the pixel shape is stabilized during the printing process and post-printing smoothing process, which reduces printing unevenness and density unevenness, greatly increasing productivity.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a color filter according to the present invention. FIG. 2 is a sectional view of a color filter according to claim (2). FIG. 3 is a sectional view of a color filter according to claim (3). FIG. 4 is a sectional view of a color filter according to claim (4). FIG. 5 is a cross-sectional view of a conventional color filter pixel. FIG. 6 is a cross-sectional view of a boundary between pixels in a conventional color filter with a light shielding portion. 1...Substrate, 2...Transparent resin layer, 3. Partition wall (
convex part), 4... pixel forming part (opening surrounded by partition wall), 5... colored resin layer, 6... light shielding part, 7...
Non-pixel forming area, 8... Pixel forming area, 11... Part where pixels are in contact with each other, 12... White area is part,

Claims (4)

[Claims] (1) In a color filter in which a transparent partition wall is provided at each pixel boundary area of the color filter on a transparent substrate, and a colored resin is filled in an opening surrounded by the partition wall, the transparent partition wall A color filter characterized in that the cross-sectional shape is a triangle with a height equal to the thickness of a pixel coating, and the color filter is filled with colored resins of each color up to the apex of the triangle. (2) The color filter according to claim (1), wherein the transparent partition wall is provided directly on the transparent substrate. (3) The color filter according to claim 1, wherein the transparent partition wall is formed on the surface of a transparent resin layer that covers the color filter forming area. (4) The color filter according to claim (1), wherein the transparent partition wall is formed on the surface of a transparent resin layer covering the entire surface of the substrate.