Liquid crystal display device

• US 7,248,324 B2
• Filed: 09/14/2004
• Issued: 07/24/2007
• 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): Nguyen; Dung T.
• Assistant Examiner(s): Duong; Thoi V.
• Application Number:
  US10/939,941
• Publication Number:
  US 20050030461A1
• Time in Patent Office: 1,043 Days
• Field of Search: 349/141, 349/139, 349/143, 349/144, 349/146
• US Class Current: 349/141
• 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 counter voltage 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 being formed on the first substrate in each pixel region and enabling forming of an electric field therebetween. The counter electrode is of planar shape and, the pixel electrode is of planar shape with plurality of slits and is overlapped with the counter electrode with an insulating layer provided therebetween. Both the counter electrode and pixel electrode are made of a transparent conductor. The counter voltage signal line is made of metal and extends in center region in each pixel region and is directly connected to the counter electrode.

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 counter voltage 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 being formed on the first substrate in each pixel region and enabling an electric field to be formed therebetween;

wherein the counter electrode is of planar shape, the pixel electrode is of planar shape with a plurality of slits and being overlapped with the counter electrode and an insulating layer being provided therebetween, both the counter electrode and the pixel electrode being made of a transparent conductor, and the counter voltage signal line being made of metal extends in a center region in each pixel region and is directly connected to the counter electrode; and

wherein the plurality of slits of the pixel electrode have portions which do not extend in parallel to an extending direction of the drain signal lines and an extending direction of the gate signal lines.

2. A liquid crystal display device according to claim 1, wherein the counter voltage signal line crosses the gate signal lines.

3. A liquid crystal display device according to claim 1, wherein the counter voltage signal line crosses the drain signal lines.

4. A liquid crystal display device according to claim 1, wherein the extending directions of the plurality of slits of the pixel electrode on one side of the counter voltage signal line are different from the extending directions of the slits of the pixel electrode on another side of the counter voltage signal line.

5. A liquid crystal display device comprising:

first and second substrate with a liquid crystal layer therebetween;

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

a plurality of counter voltage 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 being formed on the first substrate in each pixel region and enabling an electric field to be formed therebetween;

wherein the counter electrode is of planar shape, the pixel electrode is of planar shape with a plurality of slits and being overlapped with the counter electrode and an insulating layer being provided therebetween, both the counter electrode and the pixel electrode are made of a transparent conductor, and the counter voltage signal line being made of metal extends in each pixel region and is directly connected to the counter electrode, and the counter electrode exists at opposite sides of the counter voltage signal line in the pixel region when viewed in plane view; and

wherein the plurality of slits of the pixel electrode have portions which do not extend in parallel to an extending direction of the drain signal lines and an extending direction of the gate signal lines.