JPS5987491A - Matrix color liquid crystal display - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a matrix color liquid crystal display device that combines a liquid crystal, a thin film transistor array, and a filter.

In recent years, active address type matrix display devices, in which each pixel is provided with a switching element made of a thin film transistor to drive a liquid crystal, have been actively developed, and are expected to be applied to flat TV image display values. Furthermore,
Attempts have also been made to display color TV images by using color filters consisting of the three primary colors of red, green, and blue in active address type matrix display devices. FIG. 1 shows an example of an active address type color liquid crystal display device manufactured by Junmei, which uses a color filter and a thin film transistor array.

On the glass substrate 1 are a source electrode 2 and a drain electrode 4.
, a gate electrode 3 , a gate insulating film 6 , and a semiconductor film 5 . The drain electrode 4 is connected to a liquid crystal drive electrode 8 . The liquid crystal drive electrode 8 is
A capacitance is formed between the electrode 7 and the insulating film 9 .

On the other hand, the substrate 1 of the glass substrate 12 facing the glass substrate 1
A transparent electrode 11 is provided on the surface facing the transparent electrode 11, and a color filter 10 is provided thereon.

The color filter 10 is composed of a filter of one of three different colors, red, green, and blue, for each pixel. When an electrode is added to the gate electrode 3 to turn on the thin film transistor, a display signal is transmitted to the electrode 8 via the source 2 and drain 4.
, 7. It can be stored in the capacitance formed by the insulating film 9, and the liquid crystal layer 1 can be stored even after the gate voltage is turned off.
A voltage can be applied to 5 and the display state can be continued.

In FIG. 1, reference numerals 13 and 14 are polarizing plates, which are necessary when display is performed using twisted nematic liquid crystal. By arranging thin film transistors in a vertical and horizontal array as shown in FIG. 1 and providing a color filter for each pixel, a matrix liquid crystal display device 111 capable of color display at low voltage can be realized.

However, a matrix color liquid crystal display device using a conventional color filter and providing a thin film transistor for each pixel has the following drawbacks.

(1) When the color filter and the thin film transistor are not provided on the same substrate, it is difficult to align the two substrates. (Especially when displaying a high-density screen such as a TV image) (2) When a color filter is provided on the electrode 8 of the thin film transistor, the voltage applied to the liquid crystal is divided by the capacitance of the filter layer, and the liquid crystal Requires high voltage to drive.

SUMMARY OF THE INVENTION An object of the present invention is to provide a matrix color liquid crystal display device that eliminates the conventional drawbacks, facilitates alignment of a thin film transistor array and a color filter, and avoids a drop in liquid crystal drive voltage.

The present invention will be explained below with reference to the drawings.

FIG. 2 is a cross-sectional view of a unit pixel portion of a matrix liquid display device in which thin film transistors are arranged in an array according to an embodiment of the present invention. Transparent insulator substrate 1 such as glass
A color filter layer 22 made of the three primary colors of red, green, and blue is provided on the filter layer 22, and a first transparent insulating film 2 made of silicon dioxide or the like that serves as a protective layer for the filter is provided on the filter layer 22.
3, and a transparent conductive film 2 is provided on the first transparent insulating film 26.
4 is provided, and a second transparent insulating film 25 is provided on the transparent conductive film 24. A source electrode 17 is provided on the transparent insulating film 25.
, drain electrode 18, gate electrode 19, gate insulating film 2
1. A thin film transistor made of a semiconductor film 20 is provided. A transparent conductive film 26 is connected to the drain electrode 18 . On the transparent conductive films 26 and 24 and the transparent insulating film 25,
It constitutes capacitance. The filter film 22, the insulating films 23 and 25, and the transparent conductive film 24 can be formed continuously, and no process such as photolithography is required between them. On the other hand, a transparent conductive film 2 is provided on the surface of the glass substrate 28 facing the base 16, which faces the glass substrate 16.
7 is formed.

Polarizing plates 29 and 30 are provided on the substrates 16 and 28, respectively. Further, a liquid crystal layer 30 is sandwiched between the bases 16 and 28.

The liquid crystal display device according to the present invention described above can perform display in the same manner as described in the conventional example. Furthermore, (1) since the thin film transistor and the color filter are formed on the same substrate, the filter and the thin film transistor can be easily aligned. (Because the thin film transistor is formed by photolithography) (2) Since there is no need to form a color filter on the liquid crystal drive electrode, the liquid crystal can be driven with a low voltage.

As a semiconductor film that constitutes a thin film transistor, polycrystalline silicon, amorphous silicon, or the like can be used.

As the transparent conductive film, I. T. O (indium, tin oxide film) or the like is used.

As explained above, a matrix color liquid crystal display device that allows easy filter alignment and can be driven at low voltage was realized.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional matrix color liquid crystal display device, and FIG. 2 is a sectional view of an embodiment of the matrix liquid crystal display device of the present invention. 1... Glass plate 2, 3, 4... Electrode 5... Semiconductor film 6... Insulating film 7, 8
......Transparent conductive film 9...Insulating film 10.
...Color filter film 11...Transparent conductive film 12...Glass plates 13, 14...
...Polarizing plate 15...Liquid crystal layer 16...
Glass plates 17, 18, 19... Electrode 20... Semiconductor film 21... Insulating film 2
2...Color filter film 23...Insulating film 24...Transparent conductive film 25...Insulating film 26, 27...Transparent conductive film 28...Glass plate 29, 30...Polarizing plate 31...Liquid crystal layer

Claims (2)

[Claims] (1) A single layer of filter made of three primary colors provided on a transparent insulating substrate, a transparent insulating film provided on the filter layer, one plate made of a thin film transistor array provided on the transparent insulating film, and a transparent insulating layer. A matrix color liquid crystal display characterized in that a transparent conductive film is provided on a transparent substrate, and the surface with the filter layer and the surface with the transparent conductive film face each other, and a liquid crystal layer is sandwiched between them. Device. (2) A filter layer made of three primary colors provided on a transparent insulating substrate, a first transparent insulating film provided on the filter layer, a transparent conductive film provided on the first transparent insulating film, and a transparent conductive film provided on the first transparent insulating film. A second transparent insulating film provided on the film, one plate consisting of a thin film transistor array provided on the second transparent insulating film, and the other plate having a transparent conductive film provided on a transparent insulating substrate,
A matrix color liquid crystal display device characterized in that a surface with a filter layer and a surface with a transparent conductive film face each other, and a liquid crystal layer is sandwiched between them.