JPS62127716A - Color liquid crystal display - Google Patents

Abstract

PURPOSE:To make uniform contrast of each color of red, green and blue color filters and to improve the color balance by arranging the film thickness of a red, green, and blue color filter to larger thickness in the order of blue, green and red color filter, thus varying the voltage drop caused by each color filter. CONSTITUTION:A lengthwise linear electrode 3 is formed on a transparent substrate 1, and a transverse linear electrode 4 is formed on a transparent substrate 2. Further, each red, green, and blue color filter 5, 6, 7 is formed along the lengthwise line on the electrode 3 arranging the film thickness successively larger in the order from blue, green, then red, where the film thickness for the red color filter is the smallest. Relation of the film thickness of each color filter is adjusted to such manner that DELTAVR-deltaV1, and DELTAVG-DELTAVB=DELTAV2, where DELTAVR, DELTAVG, DELTAVB are voltage drop due to the red, green, and blue color filter. By this adjustment, the voltage impressed to the liquid crystal layer 10 for red color filter is smaller by DELTAV1 then that for the blue color filter, and that for the green color filter is smaller by DELTAV2 than that for the blue color filter. Thus, each color has almost equal transmittance.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a color liquid crystal display device that performs color display using red, m, and blue color filters.

<Summary of the Invention> In a liquid crystal cell in which red, green, and blue color filters are formed on electrodes, by increasing the film thickness of the color filters in the order of blue, green, and red, the voltage drop of each color filter can be made different. This also equalizes the contrast of each color and improves color balance.

<Prior Art> Conventionally, color display was performed by forming red, green, and blue color filters with the same film thickness on corresponding electrodes.

<Problems to be Solved by the Invention> However, current TN-FEM type liquid crystal display elements have large differences in voltage-transmittance characteristics depending on the wavelength of light, that is, the color. Figure 2 is red (650 nm).

It shows voltage-transmittance characteristics in three colors: green (550 nm) and blue (450 nm). As can be seen from this figure, red light generally changes at a lower voltage than blue light.

This means that when displaying in color using a TN-FEM type liquid crystal display element, red light has a higher transmittance than green or blue light at the same voltage, so the entire display has a reddish tinge. Furthermore, there will be a difference in contrast between each color.

SUMMARY OF THE INVENTION An object of the present invention is to provide a color liquid crystal display device in which the difference in voltage-transmittance characteristics of each color is reduced by varying the voltage drop, the contrast of each color is made uniform, and the color balance is improved.

<Means for solving the problem> In a liquid crystal cell in which color filters that transmit red, green, and blue light are formed on electrodes, the film thickness of each color filter is changed to blue, green, and blue.
Form thickly in the order of green and red. The relationship between the film thickness of each color filter at this time is red.

Eliminates voltage drop due to green and blue color filters
, ΔVG, ΔvB, ΔvR-muVB is Δv1
．． It is formed by adjusting ΔV6-ΔvB to become Δv2.

<Function> With the above structure, the voltage applied to the liquid crystal layer is Δv1 lower for red than blue, and Δv2 lower for green than blue, and each color has approximately the same transmittance.

<Example> FIG. 1 shows an embodiment of the present invention.

In FIG. 1, 1 and 2 are transparent substrates, 3 and 4 are electrodes, and vertical lines (line width 200 μm, line spacing 2
An electrode 3 with a thickness of 0 μm) is formed on the transparent substrate 2, and a structure line (
Electrodes 4 with a line width of 640 μm and a line spacing of 2 (bw) were formed.

Further, on the electrode 3, red, green, and blue filters of 5° and 6.7 mm were formed along vertical lines by patterning natural gelatin for each color by a photo process and dyeing the filter. An alignment film 8 is formed on these transparent substrates 1 and 2.
Sealing material 9I formed with ゜8 and using epoxy resin
I pasted it together. The cell cap at this time was 9 μm, and the liquid crystal 10 was injected and sealed. Polarizing plates 11 are arranged parallel to each other on both sides of this liquid crystal cell so as to be used as a negative display.

This voltage drop for each color due to the color filter 5.6.7 varies depending on the liquid crystal used, but in the case of the liquid crystal used in this example, it is 0.6 for a selection voltage of 2M.
(V/μm). Also red.

The voltage difference according to the V-T curve at the same transmittance for green and blue colors was V = 0.11 (Vl) between red and blue, and V2 = 0.05 (Vl) between green and blue.Liquid crystal In order to display sufficient color in the cell, the color filter needs to have a thickness close to Ipm.This allows the film thickness of each color to be reduced to 1.5mm for red.
A color filter was formed with a thickness of 1 μm, green of 1.0 μm, and blue of 0.9 μm. The color balance of each color at this time was adjusted at the time of dyeing.

Due to the above structure, the red, green, and blue V-T curves almost match (
It was about ±0.1 V. When this liquid crystal cell was used to display a display using a white type fluorescent lamp as a lighting device,
Compared to conventional color liquid crystal display devices, a display with excellent color balance was obtained.

<Effects of the Invention> As described above, according to the present invention, it is possible to provide a color liquid crystal display device that can make the contrast of each color of red, green, and blue uniform and can provide a display with good color balance.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, and FIG. 2 is a TN
- It is a characteristic diagram showing the voltage-transmittance curve of the FEM type liquid crystal display element. 1.2...Transparent substrate, 3.4...Electrode, 5...Red film 8/lateral J-direction film, 9...Sealing material, 10...Liquid crystal, 11...Polarizing plate .

Claims (1)

[Claims] 1. In a color liquid crystal display device that displays color using a liquid crystal cell in which color filters that transmit red, green, and blue light are formed on electrodes, the film thicknesses of the red, green, and blue color filters are set to blue, A color liquid crystal display device characterized by increasing the thickness in the order of green and red.