LIQUID CRYSTAL DISPLAY DEVICE

• US 20100128208A1
• Filed: 06/30/2009
• Published: 05/27/2010
• Est. Priority Date: 11/27/2008
• Status: Active Grant

• Current Assignee: Japan Display West Incorporated (Japan Display Incorporated)
• Original Assignee: Epson Imaging Devices Corporation (Seiko Group)
• Inventors: KURASAWA, Hayato
• Granted Patent: US 8,004,644 B2
• Time in Patent Office: Days
• US Class Current: 349/106
• CPC Class Codes: G02F 1/1323 Arrangements for providing a switchable viewing angle
• 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

Abstract

A liquid crystal display device includes a first substrate and a second substrate which face each other with a liquid crystal layer interposed therebetween, in which a display sub-pixel and a viewing angle control sub-pixel are placed adjacently to each other for each of pixels, wherein the first substrate is provided with a pixel electrode and a common electrode driven by a lateral electric field mode in the display sub-pixel and is provided with a viewing angle control electrode in the viewing angle control sub-pixel, and in which the second substrate is provided with a transparent conductive electrode formed to overlap with both of the display sub-pixel and the viewing angle control sub-pixel on a liquid crystal layer side.

Claims

1. A liquid crystal display device comprising:

a first substrate and a second substrate which face each other with a liquid crystal layer interposed therebetween,

a display sub-pixel and a viewing angle control sub-pixel are placed adjacent to each other for each of pixels, the first substrate is provided with a pixel electrode and a common electrode driven by a lateral electric field mode in the display sub-pixel, and is provided with a viewing angle control electrode in the viewing angle control sub-pixel, and wherein the second substrate on a liquid crystal layer side is provided with a transparent conductive electrode formed to overlap with both of the display sub-pixel and the viewing angle control sub-pixel.

2. The liquid crystal display device according to claim 1, wherein liquid crystals are homogeneously aligned and wherein a rubbing direction of an and an optical axis direction of the liquid crystals with respect to the rubbing direction in the viewing angle control sub-pixel are the same as those in the display sub-pixel.

3. The liquid crystal display device according to claim 1, wherein the transparent conductive electrode is formed in a lowermost layer of the second substrate.

4. The liquid crystal display device according to claim 1, wherein the pixel electrode and the common electrode driven by the lateral electric field mode are composed of a lower common electrode and an upper pixel electrode provided with a plurality of slits, with an insulating film interposed therebetween, and operate in an FFS mode.

5. The liquid crystal display device according to claim 1, wherein the pixel electrode and the common electrode driven by the lateral electric field mode are composed of a lower pixel electrode and an upper common electrode provided with a plurality of slits, with an insulating film interposed therebetween, and operate in an FFS mode.

6. The liquid crystal display device according to claim 5, wherein the viewing angle control electrode is formed in the same layer as the lower pixel electrode.

7. The liquid crystal display device according to claim 1, wherein the second substrate has a resinous light-shielding member and the transparent conductive electrode is formed to cover the resinous light-shielding member.

8. The liquid crystal display device according to claim 1, wherein the second substrate has a color filter layer and the transparent conductive electrode is formed to cover the color filter layer.

9. The liquid crystal display device according to claim 1, wherein a common voltage is applied to the transparent conductive electrode.