Display device

• US 7,952,673 B2
• Filed: 04/22/2009
• Issued: 05/31/2011
• Est. Priority Date: 07/14/2003
• Status: Expired due to Fees

• Current Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Hitachi Displays Limited (Japan Display Incorporated)
• Inventors: Yanagawa, Kazuhiko, Ochiai, Takahiro, Nakayoshi, Yoshiaki, Imayama, Hirotaka
• Primary Examiner(s): Chien; Lucy P
• Application Number:
  US12/427,859
• Publication Number:
  US 20090207351A1
• Time in Patent Office: 769 Days
• Field of Search: None
• US Class Current: 349/141
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/134318 having a patterned common electrode
• CPC Class Codes: G02F 1/134345 Subdivided pixels, e.g. for grey scale or redundancy
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]

Abstract

The present invention provides a liquid crystal display device which exhibits the excellent wide viewing angle characteristic and the high-speed responsiveness. A pixel region includes a switching element which is operated in response to a scanning signal from a gate signal line, a pixel electrode to which a video signal from a drain signal line is supplied through a switching element, and a counter electrode which generates an electric field between the counter electrode and the pixel electrode. The pixel region is constituted of divided respective regions. In one region, the counter electrode made of a light-transmitting material which is formed on the center except for a slight periphery of the region below an insulation film and the pixel electrode which is constituted of a group of electrodes which extend in one direction and are arranged in parallel to each other in the direction which intersects one direction above the insulation film in a state that the group of electrodes are overlapped to the counter electrode are formed. In another region, the counter electrode which is constituted of a group of electrodes which extend in one direction and are arranged in parallel to each other in the direction which intersects one direction below the insulation layer and the pixel electrode which is constituted of a group of electrodes which extend in one direction and are arranged in parallel in the direction which intersects one direction above the insulation film and is arranged alternately with the counter electrode are formed.

Claims

1. A display device comprising:

on one substrate out of a pair of substrates which are arranged to face each other with liquid crystal therebetween pixel electrodes and counter electrodes are formed;

wherein video signals are supplied to each of the pixel electrodes;

wherein the counter electrode generates an electric field between the counter electrode and the pixel electrode;

wherein the display device includes transmissive regions and reflective regions;

wherein an uppermost layer electrode is formed as an upper portion of one of the counter electrode and the pixel electrode;

wherein a distance from the substrate to the uppermost layer electrode formed of the one of the counter electrode and the pixel electrode is set larger in the reflective regions than in the transmissive regions; and

wherein a planar distance between adjacent parts of the one of the counter electrode and the pixel electrode forming the uppermost layer electrode is set larger in the transmissive regions than in the reflective regions.

2. A display device according to claim 1, wherein the display device includes a counter electrode made of a transparent conductor which extends between the transmissive region and the reflective region, the display device includes a counter electrode made of metal which is formed in the reflective region, and the display device includes a pixel electrode formed of a transparent electrode which is formed on an uppermost layer and is spaced apart from the counter electrode by way of an insulation film.

3. A display device according to claim 1, wherein the display device includes a pixel electrode made of a transparent conductor which extends between the transmissive region and the reflective region, the display device includes a pixel electrode made of metal which is formed in the reflective region, and the display device includes a counter electrode formed of a transparent electrode which is formed on an uppermost layer and is spaced apart from the pixel electrode by way of an insulation film.

4. A display device according to claim 1, wherein a boundary between the transmissive region and the reflective region exists in the inside of the display region.

5. A display device according to claim 4, wherein an initial orientation direction of the liquid crystal is substantially parallel to the extending direction of the boundary between the transmissive region and the reflective region.

6. A display device according to claim 4, wherein the boundary between the transmissive region and the reflective region is covered with the uppermost layer electrode formed of the one of the counter electrode and the pixel electrode.

7. A display device according to claim 6, wherein the uppermost layer electrode formed of the one of the counter electrode and the pixel electrode which covers the boundary between the transmissive region and the reflective region sets a transmissive-region-side width thereof larger than a reflective-region-side width thereof.

8. A display device according to claim 7, wherein the uppermost layer electrode which covers the boundary between the transmissive region and the reflective region sets the width thereof larger than a sum of a distance between the adjacent parts of the uppermost layer electrode in the transmissive region and a distance between the adjacent parts of the uppermost electrode in the reflective region.

9. A display device according to claim 7, wherein the uppermost layer electrode formed of the one of the counter electrode and the pixel electrode which covers the boundary between the transmissive region and the reflective region sets the transmissive-region-side width thereof larger than a distance between the adjacent parts of the uppermost layer electrode in the transmissive region and sets the reflective-region-side width thereof larger than a distance between the adjacent parts of the uppermost layer electrode in the reflective region.

10. A display device according to claim 1, wherein the uppermost layer electrode is formed as the upper portion of only one of the counter electrode and the pixel electrode.

11. A display device according to claim 10, wherein the adjacent parts of the uppermost layer electrode is formed in one of a strip shape and a linear shape.