JPS63253301A - Production of color filter for liquid crystal display body - Google Patents

Abstract

PURPOSE:To permit printing with high accuracy without scumming by providing a stage for forming a black matrix by printing ink contg. carbon powder and magnesium carbonate powder and a stage for forming a picture element part. CONSTITUTION:This process for production has the stage for printing the ink contg. at least the carbon powder and magnesium carbonate powder on a transparent substrate and the stage for forming the picture element part. The amt. of the carbon powder is preferably set larger than the amt. of the magnesium carbonate powder in order to obtain a good black color. The result is better as the thickness in the picture element part of the color filter is smaller and, therefore, the carbon powder and the magnesium carbonate powder are preferably formed to the grain sizes smaller than 1mum. Printing without scumming is thereby permitted and the black matrix having an excellent degree of light shielding and high contrast is formed. There is no malfunction of the thin amorphous film field effect transistors of the picture element electrodes disposed under the black matrix by light and the good image is obtainable.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing a color filter for a liquid crystal display used in a color liquid crystal display device.

Conventional technology The conventional manufacturing method for color filters is to impart photosensitivity to denatured proteins such as gelatin, casein, or synthetic dyeing resin to create a pixel pattern, and then dye it, or to dye the dyed resin coated in advance. A common method is to use a resist on top and dye each pixel.

Furthermore, methods of forming pixels by printing have also been attempted.

In order to obtain an image with good contrast, it is necessary to form a black matrix around each RoG and B pixel. The black matrix can be obtained by mixing dyes of various colors or dyeing with black dye, by printing with black ink containing carbon powder, or by vapor depositing metals such as chromium. has been done.

Problems to be Solved by the Invention In the method using dyeing, it is difficult to obtain a sufficient black color and only a poor contrast ratio can be obtained.

Chromium vapor deposition has the disadvantage of being very costly. Ink based on carbon powder used in the printing method has the problem of severe background smearing, which has a large effect on pixel areas.

Means for Solving the Problems The present invention provides a step of printing an ink containing at least carbon powder and magnesium carbonate powder on a transparent substrate;
A color filter for a liquid crystal display is manufactured through a process of forming a pixel portion.

In order to obtain a good black color, the amount of carbon powder is preferably greater than the amount of magnesium carbonate powder. Furthermore, the thinner the thickness of the pixel portion of the color filter, the more desirable it is, so it is preferable that the particle size of the carbon powder and magnesium carbonate powder be as small as 1 μm.

Effects According to the present invention, it is possible to print without background smear, and a black matrix with excellent light shielding and high contrast is formed. The image quality is also good due to the high contrast. Further, a good image can be obtained without any malfunction caused by light in the amorphous TPT (thin film field effect transistor) of the pixel electrode arranged under the black matrix.

Example: 18 parts by weight of carbon black powder (Diben 1255: manufactured by Nippon Columbia Carbon ■), 1 part by weight of magnesium carbonate powder (manufactured by Kanto Kagaku ■), and titanium oxide powder (P-25).
: manufactured by Nippon Aerosil ■) were mixed and kneaded together with 69 parts by weight of fess consisting of soybean oil, phenol resin, alkyd resin, and petroleum resin using a triple roll. Further, a total of 17 parts by weight of gel varnish, polyethylene compound, and dryer were added to obtain black ink.

An original plate was prepared using this ink using a waterless lithographic plate manufactured by Toshi ■, and a black matrix was printed on a transparent substrate using a flatbed offset printing machine.

After forming the black matrix portion, R, G, and B color inks were printed to form pixel portions, completing a color filter for a liquid crystal display.

The light transmittance of the obtained black matrix is 1.6 in thickness.
O in the visible range from 400 nm to 700 nm in μm
, s 1 L, had sufficient blackness, and had no effect on the operation of the amorphous TPT provided below the black matrix.

Furthermore, the black ink used in the present invention was free from scumming and had no adverse effect on the pixel area.

In ink with a similar formulation that does not contain magnesium carbonate, background smearing occurred in high humidity, which had an adverse effect on the pixel area.

The figure shows a schematic cross-sectional view of a liquid crystal panel of a color liquid crystal device using the color filter of the present invention.

A liquid crystal 3 is sandwiched between transparent substrates 1 and 11. On the upper transparent substrate 1, a black matrix 2a, a color filter 2 consisting of a pixel portion, and a common electrode 4 formed of a transparent electrode film are laminated in this order. A pixel electrode 6 formed of a TFT and a transparent conductive film driven by the TFT is supported on the lower transparent substrate 1/. Polarizing plates 6 and 6' are arranged so that their polarization axes are parallel to each other. The alignment of liquid crystal molecules is controlled by the alignment films 7 and 7.

With the liquid crystal panel configured as described above, when white light is irradiated from below and at the same time the TPT is driven according to the pixel signal and the voltage applied to the liquid crystal layer is changed, the amount of light passing through the liquid crystal layer changes accordingly. and a color image is reproduced.

Effects of the Invention According to the present invention, it is possible to print with high precision without background smearing, easily achieve a high contrast ratio, and print with amorphous TP.
It is possible to obtain an excellent color filter for a liquid crystal display that does not cause T malfunction.

[Brief explanation of drawings]

The figure is a schematic cross-sectional view of a liquid crystal panel of a color liquid crystal display device using the color filter of the present invention. 1...Transparent substrate, 2...Color filter, 2a...Black matrix.

Claims (4)

[Claims] (1) A color for a liquid crystal display comprising the steps of printing an ink containing at least carbon powder and magnesium carbonate powder on a transparent substrate to form a black matrix, and forming a pixel portion. Filter manufacturing method. (2) The method for manufacturing a color filter for a liquid crystal display according to claim 1, wherein the ink contains more carbon powder than the magnesium carbonate powder. (3) The method for manufacturing a color filter for a liquid crystal display according to claim 1, wherein the particle size of the carbon powder and the magnesium carbonate powder is smaller than 1 μm. (4) The method for manufacturing a color filter for a liquid crystal display according to claim 1, wherein the ink contains titanium oxide powder.