Liquid crystal display device

• US 7,271,869 B2
• Filed: 12/06/2004
• Issued: 09/18/2007
• Est. Priority Date: 09/07/1999
• Status: Expired due to Term

• Current Assignee: Japan Display Incorporated
• Original Assignee: Hitachi, Ltd.
• Inventors: Ono, Kikuo, Yamamoto, Tsunenori, Yoneya, Makoto, Nakayoshi, Yoshiaki, Hirakata, Junichi
• Primary Examiner(s): Duong; Thoi V.
• Application Number:
  US11/003,533
• Publication Number:
  US 20050083471A1
• Time in Patent Office: 1,016 Days
• Field of Search: 349/141, 349/43, 349/139, 349/143, 349/147
• US Class Current: 349/143
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/13394 spacers regularly patterned on the cell subtrate, e.g. walls, pillars G02F1/133377 takes precedence
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: G02F 1/13458 Terminal pads
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/1393 the birefringence of the liquid crystal being electrically controlled, e.g. ECB-, DAP-, HAN-, PI-LC cells G02F1/1396, G02F1/141 take precedence
• CPC Class Codes: G02F 2201/40 Arrangements for improving the aperture ratio

Abstract

A liquid crystal display device having first and second substrates with a liquid crystal layer therebetween, a plurality of gate signal lines and a plurality of drain signal lines, a plurality of pixel regions defined by neighboring gate signal lines and drain signal lines, and a pixel electrode in each pixel region. The drain signal line has a metal layer and another layer formed by a transparent conductor, and the another layer is electrically connected to the metal layer. The pixel electrode is made of a transparent conductor, and a transparent conductor of the pixel electrode and the transparent conductor of the drain signal line are of the same material.

Claims

1. A liquid crystal display device comprising:

first and second substrates with a liquid crystal layer therebetween;

a plurality of gate signal lines and a plurality of drain signal lines;

a plurality of pixel regions defined by neighboring gate signal lines and drain signal lines; and

a pixel electrode in each pixel region;

a counter electrode formed on a same substrate as a substrate on which the pixel electrode is formed, the counter electrode being overlapped with the pixel electrode and an insulating layer being provided therebetween;

wherein the drain signal line has a metal layer and another layer formed by a transparent conductor, the another layer being electrically connected to the metal layer;

wherein the pixel electrode is made of a transparent conductor, and the counter electrode is made of a transparent conductor, and the transparent conductor of the pixel electrode, the transparent conductor of the drain signal line and the transparent conductor of the counter electrode are of the same material; and

wherein the transparent conductor of the drain signal line and the transparent conductor of the counter electrode are formed on a same layer.

2. A liquid crystal display device according to claim 1, wherein the same material is ITO.

3. A liquid crystal display device according to claim 1, wherein a width of the metal layer of the drain signal line is wider than a width of the transparent conductor of the drain signal line.

4. A liquid crystal display device comprising:

first and second substrates with a liquid crystal layer therebetween;

a plurality of gate signal lines and a plurality of drain signal lines;

a plurality of pixel regions defined by neighboring gate signal lines and drain signal lines; and

a counter electrode and a pixel electrode in each pixel region and being formed on a same substrate;

wherein the drain signal line has a metal layer and another layer formed by a transparent conductor, the another layer being electrically connected to the metal layer, and the counter electrode is made of a transparent conductor, and the transparent conductor of the counter electrode and the transparent conductor of the drain signal line are of the same material; and

wherein the transparent conductor of the drain signal line and the transparent conductor of the counter electrode are formed on a same layer.

5. A liquid crystal display device according to claim 4, wherein the pixel electrode is made of a transparent conductor, and wherein the transparent conductor of the pixel electrode, a transparent conductor of the drain signal line and the transparent conductor of the counter electrode are of the same material.

6. A liquid crystal display device according to claim 5, wherein the same material is ITO.

7. A liquid crystal display device according to claim 4, wherein the same material is ITO.

8. A liquid crystal display according to claim 4, wherein a width of the metal layer of the drain signal line is wider than a width of the transparent conductor of the drain signal line.

9. A liquid crystal display device comprising:

first and second substrates with a liquid crystal layer therebetween;

a plurality of gate signal lines and a plurality of drain signal lines;

a plurality of pixel regions defined by neighboring gate signal lines and drain signal lines; and

a pixel electrode in each pixel region;

a counter electrode formed on a same substrate as a substrate on which the pixel electrode is formed, the counter electrode being overlapped with the pixel electrode and an insulating layer being provided therebetween;

wherein the drain signal line has a metal layer and another layer formed by a transparent conductor, the drain signal line having a portion where the metal layer and the transparent conductor are directly connected; and

wherein the pixel electrode is made of a transparent conductor, and the counter electrode is made of a transparent conductor;

wherein the transparent conductor of the pixel electrode, the transparent conductor of the drain signal line and the transparent conductor of the counter electrode are of the same material; and

wherein the transparent conductor of the drain signal line and the transparent conductor of the counter electrode are formed on a same layer.

10. A liquid crystal display device according to claim 9, wherein the same material is ITO.

11. A liquid crystal display device according to claim 9, wherein a width of the metal layer of the drain signal line is wider than a width of the transparent conductor of the drain signal line.