Liquid crystal display device and the method thereof

• US 20070200989A1
• Filed: 12/21/2006
• Published: 08/30/2007
• Est. Priority Date: 12/28/2005
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Kazuyoshi, Nagayama, Yuichi, Momoi, Hidefumi, Yoshida, Hidefumi, Yamashita, Kaoru, Furuta, Shinichi, Kimura
• Granted Patent: US 7,821,608 B2
• Time in Patent Office: Days
• US Class Current: 349/129
• CPC Class Codes: G02F 1/133707 Structures for producing distorted electric fields, e.g. bumps, protrusions, recesses, slits in pixel electrodes
• CPC Class Codes: G02F 1/133753 with different alignment orientations or pretilt angles on a same surface, e.g. for grey scale or improved viewing angle
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• 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

Abstract

Disclosed herein is a liquid crystal display device which can control a viewing angle in up/down and left/right directions without need of forming white subpixels. In the liquid crystal display device which includes a first region having liquid crystal molecules aligned in a slanted direction, and a second region having the liquid crystal molecules aligned in up and down directions or in left and right directions. Voltage is independently applied to the second region from the first region.

Claims

1. A liquid crystal display having a plurality of pixels, each pixel comprising:

a first region having liquid crystal molecules aligned in a slanted direction; and

a second region having the liquid crystal molecules aligned in up and down directions or in left and right directions, and the liquid crystal molecules in the first region being independent controllable from the liquid crystal molecules of the second region.

2. The device according to claim 1, wherein each of the pixels has red, green and blue (RGB) subpixels, and the second region includes at least one of an up and down control region and a left and right control region.

3. The device according to claim 2, wherein the up and down region controls the liquid crystal molecules in the up and down directions and the left and right control region controls the liquid crystal molecules in the left and right directions.

4. The device according to claim 2, wherein the second region includes at least one of the up and down control region and the left and right control region.

5. The device according to claim 2, wherein the first region at least one of has a slit and a protrusion in a pixel electrode in a slanted direction, and the up and down control region of the second region has one of a wide slit and a protrusion in a pixel electrode in the left and right directions.

6. The device according to claim 4, wherein the first region has one of a slit and a protrusion in a pixel electrode in a slanted direction, and the up and down control region of the second region has a wide slit or a protrusion in a pixel electrode in the left and right directions.

7. The device according to claim 5, wherein the up and down control region of the second region further includes a small slit in the pixel electrode in the up and down directions.

8. The device according to claim 6, wherein the up and down control region of the second region further includes a small slit in the pixel electrode in the up and down directions.

9. The device according to claim 2, wherein the first region has one of a slit and a protrusion in a pixel electrode in a slanted direction, and the left and right control region of the second region has one of a wide slit and a protrusion in a pixel electrode in the up and down directions.

10. The device according to claim 4, wherein the first region has one of a slit and a protrusion in a pixel electrode in a slanted direction, and the left and right control region of the second region has one of a wide slit and a protrusion in a pixel electrode in the up and down directions.

11. The device according to claim 9, wherein the left and right control region of the second region further includes a small slit in the pixel electrode in the left and right directions.

12. The device according to claim 10, wherein the left and right control region of the second region further includes a small slit in the pixel electrode in the left and right directions.

13. The device according to claim 2, wherein the first region has one of a slit and a protrusion in a pixel electrode in a slanted direction, the up and down control region of the second region has one of a wide slit and a protrusion in a pixel electrode in the left and right directions, and the left and right control region of the second region one of has a wide slit and a protrusion in a pixel electrode in the up and down directions.

14. The device according to claim 4, wherein the first region has one of a slit and a protrusion in a pixel electrode in a slanted direction, the up and down control region of the second region has one of a wide slit and a protrusion in a pixel electrode in the left and right directions, and the left and right control region of the second region has one of a wide slit and a protrusion in a pixel electrode in the up and down directions.

15. The device according to claim 13, wherein the up and down control region of the second region further includes a small slit in the pixel electrode in the up and down directions, and the left and right control region of the second region further includes a small slit in the pixel electrode in the left and right directions.

16. The device according to claim 14, wherein the up and down control region of the second region further includes a small slit in the pixel electrode in the up and down directions, and the left and right control region of the second region further includes a small slit in the pixel electrode in the left and right directions.

17. The device according to claims 2, wherein the up and down control region and the left and right control region are arranged in the display screen to form a predetermined pattern.

18. The device according to claim 4, wherein the up and down control region and the left and right control region are arranged in the display screen to form a predetermined pattern.

19. The device according to claim 1, wherein each of the pixels further includes a metal line which is formed substantially in parallel with a gate electrode by using a gate layer in the second region and connected to a pixel electrode formed at the second region through a contact hole.

20. The device according to claim 19, wherein the metal line extends across a middle portion of the second region in each of the pixels.

21. The device according to claim 19, wherein the contact hole is formed by a process of forming a hole to contact a pixel electrode of the first region and a source electrode.

22. The device according to claim 19, wherein the metal line is provided at a position opposite to a mounting position of a gate driver to apply voltage.

23. The device according to claim 1, wherein voltage which is controlled to have a desired value is applied to the second region.

24. The device according to claim 1, wherein alternating current voltage of a variable period is applied to the second region.

25. The device according to claim 1, wherein alternating current voltage whose frequency is 60 Hz and less is applied to the second region.

26. The device according to claim 1, wherein alternating current voltage which varies a center voltage is applied to the second region.

27. The device according to claim 1, wherein voltage which varies periodically is applied to the second region.

28. The device according to claim 1, wherein voltage which is turned ON and OFF periodically is applied to the second region.

29. The device according to claim 1, wherein the second region includes small slits having a width of about 5 microns and less and a gap of about 5 microns and less at a surface.

30. The device according to claim 29, wherein the small slits are formed at a portion of the first region.

31. The device according to claim 1, wherein alternating current voltage whose frequency is about 30 Hz and less is applied to the second region.

32. The device according to claim 1, further comprising a liquid crystal layer in a cross-nicol arrangement of a polarizer and an analyzer.

33. The device according to claim 32, wherein the polarizer and the analyzer have absorption axes in the up and down directions and the left and right directions.

34. A method for fabricating of a liquid crystal display having a plurality of pixels, comprising:

forming a first region having liquid crystal molecules aligned in a slanted direction; and

forming a second region having the liquid crystal molecules aligned in up and down directions or in left and right directions, and the liquid crystal molecules in the first region being independent controllable from the liquid crystal molecules of the second region.

35. The method according to claim 34, wherein each of the pixels has red, green and blue (RGB) subpixels, and the second region includes at least one of an up and down control region and a left and right control region.

36. The method according to claim 35, wherein the up and down region controls the liquid crystal molecules in the up and down directions and the left and right control region controls the liquid crystal molecules in the left and right directions.

37. The method according to claim 34, wherein the second region includes at least one of the up and down control region and the left and right control region.