LIQUID CRYSTAL DISPLAY DEVICE

• US 20070146591A1
• Filed: 12/01/2006
• Published: 06/28/2007
• Est. Priority Date: 12/05/2005
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: KIMURA, Hajime, UOCHI, Hideki
• Granted Patent: US 7,889,295 B2
• Time in Patent Office: Days
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/133371 Cells with varying thickness of the liquid crystal layer
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605
• CPC Class Codes: G02F 1/133555 Transflectors
• 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 1/134372 for fringe field switching [FFS] where the common electrode is not patterned
• CPC Class Codes: G02F 1/134381 Hybrid switching mode, i.e. for applying an electric field with components parallel and orthogonal to the substrates
• 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 2201/121 common or background
• CPC Class Codes: G02F 2201/123 pixel
• CPC Class Codes: G02F 2203/01 transmissive
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body

Abstract

It is an object of the present invention to provide a liquid crystal display device which has a wide viewing angle and less color-shift depending on an angle at which a display screen is seen and can display an image favorably recognized both outdoors in sunlight and dark indoors (or outdoors at night). The liquid crystal display device includes a first portion where display is performed by transmission of light and a second portion where display is performed by reflection of light. Further, a liquid crystal layer includes a liquid crystal molecule which rotates parallel to an electrode plane when a potential difference is generated between two electrodes of a liquid crystal element provided below the liquid crystal layer.

Claims

1. A liquid crystal display device including a first portion and a second portion, the device comprising:

a liquid crystal element including a pixel electrode and a first common electrode each having a light-transmitting property, a second common electrode having reflectiveness, and a liquid crystal layer provided over the pixel electrode and the first common electrode,

wherein the pixel electrode is provided over the second common electrode with an insulating layer interposed therebetween in the first portion; and

wherein the pixel electrode and the first common electrode are provided over the insulating layer in the second portion.

2. A liquid crystal display device according to claim 1, wherein the second common electrode is electrically connected to the first common electrode.

3. A liquid crystal display device according to claim 1, wherein the liquid crystal layer includes a liquid crystal molecule rotating parallel to a substrate plane.

4. A liquid crystal display device according to claim 1, wherein the pixel electrode is comb-shaped.

5. A liquid crystal display device according to claim 1, wherein the first common electrode is comb-shaped.

6. A liquid crystal display device including a first portion and a second portion, the device comprising:

a liquid crystal element including a pixel electrode and a first common electrode each having a light-transmitting property, a second common electrode having reflectiveness, and a liquid crystal layer provided over the pixel electrode,

wherein the pixel electrode is provided over the second common electrode with an insulating layer interposed therebetween in the first portion; and

wherein the pixel electrode is provided over the first common electrode with the insulating layer interposed therebetween in the second portion.

7. A liquid crystal display device according to claim 6, wherein the second common electrode is electrically connected to the first common electrode.

8. A liquid crystal display device according to claim 6, wherein the liquid crystal layer includes a liquid crystal molecule rotating parallel to a substrate plane.

9. A liquid crystal display device according to claim 6, wherein the pixel electrode is comb-shaped.

10. A liquid crystal display device including a first portion and a second portion, the device comprising:

a liquid crystal element including a pixel electrode having a light-transmitting property, a common electrode including a first conductive layer having reflectiveness and a second conductive layer having a light transmitting property, and a liquid crystal layer provided over the pixel electrode,

wherein the pixel electrode is provided over the first conductive layer with an insulating layer interposed therebetween in the first portion; and

wherein the pixel electrode is provided over the second conductive layer with the insulating layer interposed therebetween in the second portion.

11. A liquid crystal display device according to claim 10, wherein the liquid crystal layer includes a liquid crystal molecule rotating parallel to a substrate plane.

12. A liquid crystal display device according to claim 10, wherein the pixel electrode is comb-shaped.

13. A liquid crystal display device comprising:

a liquid crystal element between a first substrate and a second substrate, which includes a pixel electrode having a light-transmitting property, a first common electrode having a light-transmitting property, a second common electrode having reflectiveness, and a liquid crystal layer provided between the pixel electrode and the second substrate;

wherein the first common electrode and the second common electrode are provided over the first substrate; and

wherein the pixel electrode is provided over the first common electrode and the second common electrode with an insulating layer interposed therebetween.

14. A liquid crystal display device according to claim 13, wherein the liquid crystal layer includes a liquid crystal molecule rotating parallel to a substrate plane.

15. A liquid crystal display device according to claim 13, wherein the pixel electrode is comb-shaped.