Liquid crystal display having a modified electrode array

• US 7,733,454 B2
• Filed: 02/01/2007
• Issued: 06/08/2010
• Est. Priority Date: 11/03/1997
• Status: Expired due to Term

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Na, Byoung-Sun, Kim, Dong-Gyu, Song, Jang-Kun, Chang, Jong-Woong, Lee, Kye-Hun, Lee, Hyun-Sik, Shim, Jung-Uk, Yuh, Jin-Tae
• Primary Examiner(s): Dudek; James A
• Application Number:
  US11/669,991
• Publication Number:
  US 20070146602A1
• Time in Patent Office: 1,223 Days
• Field of Search: 349/106, 349/110, 349/141
• US Class Current: 349/141
• 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 having electrodes on a single substrate. A transparent planar electrode elongated in the transverse direction is formed on the inner surface of a substrate, and an insulating film is deposited thereon. A plurality of linear electrodes, which are elongated in the longitudinal direction and either transparent or opaque, are formed on the insulating film. Potential difference between the planar and the linear electrodes generated by applying voltages to the electrodes yields an electric field. The electric field is symmetrical with respect to the longitudinal central line of the linear electrodes, and has parabolic or semi-elliptical lines of force having a center on a boundary line between the planar and the linear electrodes. The line of force on the planar and the linear electrodes and on the boundary line between the planar and the linear electrodes has the vertical and the horizontal components, and the liquid crystal molecules are re-arranged to have a twist angle and a tilt angle. The polarization of the incident light varies due to the rearrangement of the liquid crystal molecules.

Claims

1. A liquid crystal display (LCD), comprising:

a first substrate comprising a gate line and a data line;

a thin film transistor connected to the gate line and the data line;

a second substrate facing the first substrate;

a liquid crystal layer interposed between the first substrate and the second substrate;

at least two linear type electrodes on the first substrate;

a planar electrode disposed on the first substrate; and

an insulating layer between the linear type electrodes and the planar electrode;

wherein at least one of the linear type electrodes and the planar electrode is connected to the thin film transistor, the linear type electrodes overlaps with the planar electrode, and the planar electrode forms a continuous plane between the linear type electrodes.

2. The liquid crystal display of claim 1, wherein a width of linear type electrode is equal to or less than a space between the linear type electrodes.

3. The liquid crystal display of claim 2, wherein a long axis of a liquid crystal molecule in the liquid crystal layer is aligned in a horizontal direction when an electric field is not applied.

4. The liquid crystal display of claim 3, wherein the linear type electrodes are formed on the planar electrode and the insulating layer.

5. The liquid crystal display of claim 4, wherein one of the linear type electrode and the planar electrode is pixel electrode and the other of the linear type electrode and the planar electrode is a common electrode.

6. The liquid crystal display of claim 3, wherein the liquid crystal layer comprises a nematic liquid crystal having negative dielectric anisotropy.

7. The liquid crystal display of claim 6, wherein the linear type electrodes are formed on the planar electrode and the insulating layer.

8. The liquid crystal display of claim 7, wherein one of the linear type electrode and the planar electrode is pixel electrode and the other of the linear type electrode and the planar electrode is a common electrode.

9. The liquid crystal display of claim 3, wherein the liquid crystal layer comprises a nematic liquid crystal having positive dielectric anisotropy.

10. The liquid crystal display of claim 9, wherein the linear type electrodes are formed on the planar electrode and the insulating layer.

11. The liquid crystal display of claim 10, wherein one of the linear type electrode and the planar electrode is pixel electrode and the other of the linear type electrode and the planar electrode is a common electrode.

12. The liquid crystal display of claim 2, wherein the liquid crystal layer is aligned perpendicular to the substrates when an electric field is not applied and has positive dielectric anisotropy.

13. The liquid crystal display of claim 12, wherein the linear type electrodes are formed on the planar electrode and the insulating layer.

14. The liquid crystal display of claim 13, wherein one of the linear type electrode and the planar electrode is pixel electrode and the other of the linear type electrode and the planar electrode is a common electrode.

15. The liquid crystal display of claim 12, wherein the liquid crystal layer comprises a nematic liquid crystal having negative dielectric anisotropy.

16. The liquid crystal display of claim 15, wherein the liquid crystal layer comprises a nematic liquid crystal and a chiral dopant of 0.001 to 3.0 wt %.

17. The liquid crystal display of claim 15, wherein the linear type electrodes are formed on the planar electrode and the insulating layer.

18. The liquid crystal display of claim 16, wherein one of the linear type electrode and the planar electrode is pixel electrode and the other of the linear type electrode and the planar electrode is a common electrode.

19. The liquid crystal display of claim 12, wherein the liquid crystal layer comprises a nematic liquid crystal having positive dielectric anisotropy.

20. The liquid crystal display of claim 19, wherein the liquid crystal layer comprises a nematic liquid crystal and a chiral dopant of 0.001 to 3.0 wt %.

21. The liquid crystal display of claim 19, wherein the linear type electrodes are formed on the planar electrode and the insulating layer.

22. The liquid crystal display of claim 21, wherein one of the linear type electrode and the planar electrode is pixel electrode and the other of the linear type electrode and the planar electrode is a common electrode.

23. The liquid crystal display of claim 2, wherein the linear type electrodes are formed on the planar electrode and the insulating layer.

24. The liquid crystal display of claim 23, wherein one of the linear type electrode and the planar electrode is pixel electrode and the other of the linear type electrode and the planar electrode is a common electrode.

25. The liquid crystal display of claim 1, wherein a long axis of a liquid crystal molecule in the liquid crystal layer is aligned in a horizontal direction when an electric field is not applied.

26. The liquid crystal display of claim 25, wherein the linear type electrodes are formed on the planar electrode and the insulating layer.

27. The liquid crystal display of claim 25, wherein one of the linear type electrode and the planar electrode is pixel electrode and the other of the linear type electrode and the planar electrode is a common electrode.

28. The liquid crystal display of claim 25, wherein the liquid crystal layer comprises a nematic liquid crystal having negative dielectric anisotropy.

29. The liquid crystal display of claim 28, wherein the linear type electrodes are formed on the planar electrode and the insulating layer.

30. The liquid crystal display of claim 29, wherein one of the linear type electrode and the planar electrode is pixel electrode and the other of the linear type electrode and the planar electrode is a common electrode.

31. The liquid crystal display of claim 25, wherein the liquid crystal layer comprises a nematic liquid crystal having positive dielectric anisotropy.

32. The liquid crystal display of claim 31, wherein the linear type electrodes are formed on the planar electrode and the insulating layer.

33. The liquid crystal display of claim 32, wherein one of the linear type electrode and the planar electrode is pixel electrode and the other of the linear type electrode and the planar electrode is a common electrode.

34. The liquid crystal display of claim 2, wherein the liquid crystal layer is aligned perpendicular to the substrates when an electric field is not applied and has positive dielectric anisotropy.

35. The liquid crystal display of claim 34, wherein the linear type electrodes are formed on the planar electrode and the insulating layer.

36. The liquid crystal display of claim 35, wherein one of the linear type electrode and the planar electrode is pixel electrode and the other of the linear type electrode and the planar electrode is a common electrode.

37. The liquid crystal display of claim 35, wherein the liquid crystal layer comprises a nematic liquid crystal having negative dielectric anisotropy.

38. The liquid crystal display of claim 37, wherein the linear type electrodes are formed on the planar electrode and the insulating layer.

39. The liquid crystal display of claim 38, wherein one of the linear type electrode and the planar electrode is pixel electrode and the other of the linear type electrode and the planar electrode is a common electrode.

40. The liquid crystal display of claim 34, wherein the liquid crystal layer comprises a nematic liquid crystal having positive dielectric anisotropy.

41. The liquid crystal display of claim 40, wherein the linear type electrodes are formed on the planar electrode and the insulating layer.

42. The liquid crystal display of claim 41, wherein one of the linear type electrode and the planar electrode is pixel electrode and the other of the linear type electrode and the planar electrode is a common electrode.

43. The liquid crystal display of claim 1, wherein the linear type electrodes are formed on the planar electrode and the insulating layer.

44. The liquid crystal display of claim 43, wherein one of the linear type electrode and the planar electrode is pixel electrode and the other of the linear type electrode and the planar electrode is a common electrode.

45. The liquid crystal display of claim 1, wherein the width of the linear electrodes is about 5 um and the space beween the linear electrodes is from 5 μ

m to 17 μ

m.

46. The liquid crystal display of claim 45, wherein a long axis of a liquid crystal molecule in the liquid crystal layer is aligned in a horizontal direction when an electric field is not applied.

47. The liquid crystal display of claim 45, wherein the liquid crystal layer is aligned perpendicular to the substrates when an electric field is not applied and has positive dielectric anisotropy.

48. The liquid crystal display of claim 45, wherein the linear type electrodes are formed on the planar electrode and the insulating layer.

49. The liquid crystal display of claim 48, wherein one of the linear type electrode and the planar electrode is pixel electrode and the other of the linear type electrode and the planar electrode is a common electrode.