Liquid crystal display device

• US 7,253,863 B2
• Filed: 12/03/2004
• Issued: 08/07/2007
• 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:
  US11/002,518
• Publication Number:
  US 20050078260A1
• Time in Patent Office: 977 Days
• Field of Search: 349/141, 349/143, 349145-147, 349/43, 349/139
• 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
• CPC Class Codes: H05K 999/00 dummy group
• CPC Class Codes: H05K 999/99 dummy group

Abstract

A liquid crystal display device having first and second substrates with a liquid crystal layer therebetween, a plurality of gate signal lines made of metal and a plurality of drain signal lines made of metal, a plurality of counter voltage signal lines, a plurality of pixel regions defined by neighboring gate signal lines and drain signal lines and a pixel electrode formed on first substrate in each pixel region. The pixel electrode and the counter voltage signal lines have an overlapping region, and an edge of the pixel electrode which extends in parallel to the drain signal line shifts to inside of the pixel region at the overlapping region as compared to the edge of the pixel electrode at a non-overlapping region.

Claims

1. A liquid crystal display device comprising:

first and second substrates with a liquid crystal layer therebetween;

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

a plurality of counter voltage signal lines;

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

a pixel electrode formed on the first substrate in each pixel region; and

a counter electrode formed on the first substrate in each pixel region, the counter electrode having a substantially rectangular shape;

wherein the pixel electrode and the counter voltage signal lines have an overlapping region, the pixel electrode has an edge with portions which extend in parallel to the drain signal line at each of the overlapping region and a non overlapping region, and the edge portion of the pixel electrode at the overlapping region shifts to inside of the pixel region as compared to the edge portion of the pixel electrode at the non-overlapping region; and

wherein the counter electrode has side portions which extend substantially in parallel to the gate signal line and other side portions which extend substantially in parallel to the drain signal line.

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

3. A liquid crystal display device according to claim 1, wherein the counter electrode is of planar shape and has overlapping relation with the pixel electrode, and an insulating layer is provided therebetween.

4. A liquid crystal display device according to claim 3, wherein the counter electrode and the counter voltage signal line have an overlapping region, and at least one of the other side portions of the counter electrode at the overlapping region shifts to inside of the pixel region.

5. A liquid crystal display device according to claim 4, wherein the counter voltage signal line crosses the drain signal line at a central part of the pixel region.

6. A liquid crystal display device according to claim 4, wherein both of the other side portions of the counter electrode at the overlapping region shift to inside of the pixel region.

7. A liquid crystal display device according to claim 1, wherein the pixel electrode and the counter electrode are made of a transparent conductor.

8. A liquid crystal display device according to claim 1, wherein the pixel electrode in the overlapping region has two portions which extend in parallel to the drain line and are adjacent thereto, each of the two portions at the overlapping region have parts which shift in a direction toward a center of the pixel region in comparison with adjoining parts of the two portions of the pixel electrode at a non-overlapping region.