Transflective liquid crystal display device

• US 20110025961A1
• Filed: 10/07/2010
• Published: 02/03/2011
• Est. Priority Date: 07/14/2006
• Status: Active Grant

• Current Assignee: Hitachi Displays Limited (Japan Display Incorporated), Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Hitachi Displays Limited (Japan Display Incorporated)
• Inventors: Morimoto, Masateru, Sasaki, Tohru, Ochiai, Takahiro, Miyazawa, Toshio, Maki, Masahiro
• Granted Patent: US 7,944,529 B2
• Time in Patent Office: Days
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/1337 Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
• 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

A transflective liquid crystal display device with improved display quality in which the liquid initial alignment direction of the liquid crystal layer is in a direction perpendicular to the extending direction of a clearance between the counter electrode of a transmission portion and a counter electrode of a reflection portion or in a direction within a range of ±2° in the clockwise direction perpendicular to the extending direction of the clearance in a case where the liquid crystal layer comprises positive type liquid crystals, or the liquid crystal initial alignment direction of the liquid crystal layer is in a direction parallel with the extending direction of a clearance, or a direction within a range of ±2° in the clockwise direction relative to the extending direction of the clearance in a case where the liquid crystal layer comprises negative type liquid crystals.

Claims

1. A transflective liquid crystal display device including a liquid crystal display panel having a pair of substrates and a liquid crystal layer put between the pair of substrates, in which the liquid crystal display panel has a plurality of sub-pixels each having a transmission portion and a reflection portion, and each of the plurality of sub-pixels has a pixel electrode and a counter electrode, wherein:

an active element formed below the reflection portion and a video signal line extending while bending in each of the sub-pixels overriding the transmission portion and the reflection portion are provided; and

for adjacent two display lines defined as one display line and the other display line, the bending direction and the bending angle of the video signal line in the reflection portion of one display line is identical with the bending direction and the bending angle of the video signal line in the reflection portion of the other display line.

2. A transflective liquid crystal display device according to claim 1, wherein:

in each of the sub-pixels, the pixel electrode is in common with the transmission portion and the reflection portion, and the counter electrode is independent between the transmission portion and the reflection portion respectively;

the potential applied to the counter electrode is different between the transmission portion and the reflection portion;

the counter electrode and the pixel electrode are formed on one of the pair of the substrates;

the transmission portion has a normally black characteristic providing black display in a state of not applying voltage; and

the reflection portion has a normally white characteristic providing white display in a state of not applying voltage.

3. A transflective liquid crystal display device including a liquid crystal display panel having a pair of substrates and a liquid crystal layer put between the pair of substrates, in which the liquid crystal display panel has a plurality of sub-pixels each having a transmission portion and a reflection portion, and each of the plurality of sub-pixels has a pixel electrode and a counter electrode, wherein:

in each of the sub pixels, the pixel electrode is in common with the transmission portion and the reflection portion, and the counter electrodes is independent respectively between the transmission portion and the reflection portion; and

at least a central portion along the extending direction of the clearance between the counter electrode of the transmission portion and the counter electrode of the reflection portion is shielded by a light shielding film.

4. A transflective liquid crystal display device according to claim 3, wherein:

the potential applied to the counter electrodes is different between the transmission portion and the reflection portion;

the counter electrode and the pixel electrode are formed on one of the pair of substrates;

the transmission portion has a normally black characteristic providing black display in a state of not applying a voltage; and

the reflection portion has a normally white characteristic providing white display in a state of not applying a voltage.