Liquid crystal display device

• US 7,683,996 B2
• Filed: 12/10/2008
• Issued: 03/23/2010
• Est. Priority Date: 09/07/1999
• Status: Expired due to Fees

• 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:
  US12/331,583
• Publication Number:
  US 20090096979A1
• Time in Patent Office: 468 Days
• Field of Search: 349/141, 349/139, 349/143, 349/147, 349/43, 349/129, 349/38
• US Class Current: 349/139
• 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 includes a pair of transparent substrates opposed to each other with liquid crystal therebetween, one of the pair of transparent substrates having a plurality of drain signal lines and a plurality of gate signal lines, and a plurality of pixel areas defined by the drain signal lines and the gate signal lines. The pixel areas includes a pixel electrode formed of a transparent electrode having a plurality of slits including a slit opened in a first direction and a slit opened in a second direction, and a counter electrode formed of a transparent electrode disposed between the transparent electrode of the pixel electrode having the plurality of slits and the one substrate.

Claims

1. A liquid crystal display comprising:

a pair of transparent substrates opposed to each other with liquid crystal therebetween, one of the pair of transparent substrates having a plurality of drain signal lines and a plurality of gate signal lines; and

a plurality of pixel areas defined by the drain signal lines and the gate signal lines;

wherein the pixel areas have;

a thin-film transistor connected to one of the drain signal lines and one of the gate signal lines;

a first electrode formed of a transparent conducting layer having at least a substantially rectangular outline in plan view and having a plurality of slits, the first electrode being connected to the thin-film transistor, and the plurality of slits of the first electrode extending in at least one direction which is non-parallel with respect to an extending direction of the drain signal lines and with respect to an extending direction of the gate signal lines; and

a second electrode formed of a transparent conducting layer arranged in a superposed position with respect to the first electrode;

wherein the first electrode and the second electrode are disposed in such a manner that at least a portion of a side of the second electrode facing the one of the drain signal lines and at least a portion of a side of the second electrode facing the one of the gate signal lines are closer to the respective drain and gate signal lines than corresponding portion of corresponding sides of the first electrode.

2. The liquid crystal display according to claim 1, wherein

the first electrode is one of a pixel electrode and a counter electrode and the second electrode is an other of the pixel electrode and the counter electrode;

and

the pixel areas each have a counter voltage signal line that feeds an electric signal to the counter electrode.

3. The liquid crystal display according to claim 2, wherein, of the drain signal line, the gate signal line, and the counter voltage signal line, the line in contact with the transparent conducting layer is made of a material containing aluminum, and the surface in contact with the transparent conducting layer has a high-melting metal layer.

4. The liquid crystal display according to claim 3, wherein the high-melting metal layer is made of any titanium, chromium, molybdenum, tantalum, and tungsten.

5. The liquid crystal display according to claim 1, wherein one portion of the slits of the first electrode extend in a first non-parallel direction and another portion of the slits extend in a second non-parallel direction.

6. The liquid crystal display according to claim 1, wherein the second electrode is formed without slits.