Liquid crystal display apparatus

• US 20060278873A1
• Filed: 06/07/2006
• Published: 12/14/2006
• Est. Priority Date: 06/10/2005
• Status: Active Grant

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: Casio Computer Company Limited
• Inventors: Ishii, Hiromitsu
• Granted Patent: US 7,361,934 B2
• Time in Patent Office: Days
• US Class Current: 257/59
• CPC Class Codes: G02F 1/136209 Light shielding layers, e.g. black matrix, incorporated in the active matrix substrate, e.g. structurally associated with the switching element
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/13629 Multilayer wirings
• CPC Class Codes: G02F 2201/40 Arrangements for improving the aperture ratio
• CPC Class Codes: G02F 2203/01 transmissive

Abstract

A thin film transistor is provided in a vicinity of a crossing region of scanning and the data lines on a first substrate. A pixel electrode is connected with the thin film transistor. A transparent electroconductive layer which is applied with a common potential is provided between the pixel electrodes and the scanning lines and data lines to cover the scanning and date lines, is superimposed on peripheral portions of the pixel electrodes on both sides. An insulating film is formed between the pixel electrodes and the electroconductive layer. An opposed electrode is formed on a second substrate to correspond to the pixel electrodes. A liquid crystal is provided between the pixel electrodes and opposed electrode.

Claims

1. A liquid crystal display apparatus comprising:

one and the other substrates;

a plurality of scanning lines which are formed on one surface side of the one substrate and extended in one direction;

a plurality of data lines which are formed on the one surface side of the one substrate and extended in a direction crossing the scanning lines;

a plurality of thin film transistors each of which is provided in the vicinity of each crossing region of the scanning lines and the data lines on the one surface side of the one substrate, the transistor including a semiconductor thin film, a gate electrode arranged on one surface side of the semiconductor thin film and source and drain electrodes respectively connected with source and drain regions of the semiconductor thin film;

a plurality of pixel electrodes each of which is connected with each of the thin film transistors;

a transparent electroconductive layer which is provided between the pixel electrodes and the scanning lines and data lines to cover the data lines, the electroconductive layer being disposed in a region including an interspace between the adjoined pixel electrodes and superimposed on at least parts of peripheral portions of the adjoined pixel electrodes, and applied with a common potential;

an insulating film formed between the pixel electrodes and the electroconductive layer;

at least one opposed electrode formed on a side of the other substrate to correspond to the pixel electrodes; and

a liquid crystal provided between the pixel electrodes and opposed electrode.

2. The liquid crystal display apparatus according to claim 1, wherein a potential with which a black display is observed is applied between the electroconductive layer and the opposed electrode.

3. The liquid crystal display apparatus according to claim 2, wherein the liquid crystal is a TN liquid crystal having a twist angle of 90°

.

4. The liquid crystal display apparatus according to claim 1, wherein the electroconductive layer has a lattice-like shape and is provided to cover the scanning lines and the data lines.

5. The liquid crystal display apparatus according to claim 1, wherein each of the thin film transistors is configured to transmit light therethrough, and each of the pixel electrodes is provided to cover the thin film transistor.

6. The liquid crystal display apparatus according to claim 5, wherein the semiconductor thin film of the thin film transistor is formed of a metal oxide, and the drain and source electrodes and the gate electrode are formed of a metal oxide containing impurities.

7. The liquid crystal display apparatus according to claim 6, wherein the drain and source electrodes are provided on the semiconductor thin film.

8. The liquid crystal display apparatus according to claim 5, wherein the semiconductor thin film of the thin film transistor is formed of a metal oxide, the gate electrode is formed of a metal oxide containing impurities, and the drain and source electrodes are formed of a transparent electroconductive material.

9. The liquid crystal display apparatus according to claim 8, wherein the drain and source electrodes are provided under the semiconductor thin film.

10. The liquid crystal display apparatus according to claim 6, wherein the gate electrode of the thin film transistor is formed of a metal oxide containing p-type impurities.

11. The liquid crystal display apparatus according to claim 6, wherein the scanning line is electrically connected with the gate electrode, the scanning line is formed of the same material as that of the gate electrode, the data line is electrically connected with one of the drain and source electrodes, and the data line is formed of the same material as that of said one of the drain and source electrodes.

12. The liquid crystal display apparatus according to claim 1, wherein a light-shielding type electroconductive film is formed of on one of upper and lower surfaces of the transparent electroconductive layer which is wider than the light-shielding type electroconductive film to cover the light-shielding type electroconductive film.

13. The liquid crystal display apparatus according to claim 1, wherein the electroconductive layer has a part which substantially covers an entire region of the thin film transistor.