Liquid crystal display having wide viewing angle

• US 6,285,431 B2
• Filed: 05/29/1998
• Issued: 09/04/2001
• Est. Priority Date: 05/29/1997
• Status: Expired due to Term

• Current Assignee: TCL China Star Optoelectronics Technology Co. Ltd. (TCL Technology Group Corp.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Kycong-Hyeon, Lyu, Jae-Jin, Lee, Hea-Ri, Chen, Jian-Min
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): CHOWDHURY, TARIFUR RASHID
• Application Number:
  US09/087,408
• Publication Number:
  US 20010001567A1
• Time in Patent Office: 1,194 Days
• Field of Search: 349/38, 349/42, 349/129, 349/143, 349/144
• US Class Current: 349/143
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: G02F 1/1337 Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
• 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 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/134336 Matrix
• CPC Class Codes: G02F 1/134372 for fringe field switching [FFS] where the common electrode is not patterned
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/137 characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering
• CPC Class Codes: G02F 1/13712 the liquid crystal having negative dielectric anisotropy
• 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
• CPC Class Codes: G02F 2201/121 common or background
• CPC Class Codes: G02F 2201/128 field shaping

Abstract

Apertures are formed in the common electrode or in the pixel electrode of a liquid crystal display to form a fringe field. Storage capacitor electrodes are formed at the position corresponding to the apertures to prevent the light leakage due to the disclination caused by the fringe field. The apertures extend horizontally, vertically or obliquely. The apertures in adjacent pixel regions may have different directions to widen the viewing angle.

Claims

1. A liquid crystal display comprising:

a first substrate including a common electrode; and

a second substrate opposite the first substrate, the second substrate including a pixel electrode located at a position corresponding to the common electrode and a storage capacitor electrode overlapping the pixel electrode,

wherein one of the pixel electrode and the common electrode has an elongated linear aperture, the storage capacitor electrode is located at a position corresponding to the elongated aperture, and wherein each of the elongated apertures in adjacent pixel regions extend in different directions than the elongated linear aperture.

2. A liquid crystal display of claim 1, further comprising a liquid crystal layer having negative dielectric anisotropy and interposed between the first and the second substrates.

3. A liquid crystal display of claim 2, wherein the liquid crystal layer comprises a chiral nematic liquid crystal.

4. A liquid crystal display of claim 2, wherein the liquid crystal layer comprises a nematic liquid crystal including chiral dopant of 0.01 to 3.0 wt %.

5. A liquid crystal display of claim 2, further comprising two alignment layers formed on the first and the second substrates respectively and aligning the molecular axes of liquid crystal molecules in the liquid crystal layer in the direction perpendicular to the substrates.

6. A liquid crystal display of claim 5, wherein the alignment layers are not rubbed.

7. A liquid crystal display of claim 2, further comprising a spacer made of a metal or an organic material.

8. A liquid crystal display of claim 1, wherein the number of the apertures is equal to or more than two, and the apertures are linear.

9. A liquid crystal display of claim 8, wherein the width of the aperture is in the range of 3-15 μ

m.

10. A liquid crystal display of claim 9, wherein the distance between the apertures is 8-50 μ

m.

11. A liquid crystal display comprising:

a first substrate including a plurality of gate lines, a plurality of data lines, a plurality of pixel electrodes formed in pixel regions defined by the gate lines and the data lines and a plurality of storage capacitor electrodes overlapping the pixel electrodes to form storage capacitors; and

a second substrate opposite the first substrate, the second substrate including a common electrode having a plurality of elongated linear aperatures located at positions corresponding to the storage capacitor electrodes, and wherein each of the elongated apertures in adjacent pixel regions extend in different directions than the plurality of elongated linear apertures.

12. A liquid crystal display of claim 11, further comprising a liquid crystal layer having negative dielectric anisotropy and interposed between the first and the second substrates.

13. A liquid crystal display of claim 12, wherein the liquid crystal layer comprises a chiral nematic liquid crystal.

14. A liquid crystal display of claim 12, wherein the liquid crystal layer comprises a nematic liquid crystal including 0.01-3.0 wt % of chiral dopant.

15. A liquid crystal display of claim 12, further comprising two alignment layers formed on the first and the second substrates respectively and aligning the molecular axes of liquid crystal molecules in the liquid crystal layer in the direction perpendicular to the substrates.

16. A liquid crystal display of claim 15, wherein the alignment layers are not rubbed.

17. A liquid crystal display of claim 11, wherein the number of the apertures in each pixel is equal to or more than two.

18. A liquid crystal display of claim 17, wherein the apertures are formed linearly and extend parallel to the data line.

19. A liquid crystal display of claim 17, wherein the apertures are formed linearly and extend parallel to the gate line.

20. A liquid crystal display of claim 17, wherein the apertures are formed linearly and make an angle of 0°

-90°

about the data line and the gate line.

21. A liquid crystal display of claim 20, wherein the apertures are parallel to each other.

22. A liquid crystal display of claim 21, further comprising two alignment layers formed on the first and the second substrates respectively and aligning the molecular axes of liquid crystal molecules in the liquid crystal layer in the direction perpendicular to the substrates.

23. A liquid crystal display of claim 22, wherein the alignment layers are rubbed.

24. A liquid crystal display of claim 23, wherein the rubbing direction of the alignment layers makes an angle of 0°

-135°

about the direction of the aperture.

25. A liquid crystal display of claim 24, wherein the width of the aperture is in the range of 3-15 μ

m.

26. A liquid crystal display of claim 25, wherein the distance between the apertures in a pixel region is in the range of 8-50 μ

m.

27. A liquid crystal display of claim 11, wherein the gate line and the storage capacitor electrode are connected to each other.

28. A liquid crystal display comprising:

a first substrate including a plurality of gate lines, a plurality of data lines, a plurality of pixel electrodes formed in the pixel regions defined by the gate lines and the data lines, a plurality of storage capacitor electrodes overlapping the pixel electrodes to form storage capacitors, wherein the pixel electrodes have an elongated linear aperture located at a position corresponding to the storage capacitor electrode, and wherein each of the elongated linear apertures of adjacent pixel regions extend in different directions than the elongated linear aperture; and

a second substrate opposite the first substrate, the second substrate including a common electrode.

29. A liquid crystal display of claim 28, further comprising a liquid crystal layer having negative dielectric anisotropy and interposed between the first and the second substrates.

30. A liquid crystal display of claim 29, wherein the liquid crystal layer comprises a chiral nematic liquid crystal.

31. A liquid crystal display of claim 29, wherein the liquid crystal layer comprises a nematic liquid crystal including chiral dopant of 0.01-3.0 wt %.

32. A liquid crystal display of claim 28, further comprising two alignment layers formed on the first and the second substrates respectively and aligning the molecular axes of liquid crystal molecules in the liquid crystal layer in the direction perpendicular to the substrates.

33. A liquid crystal display of claim 32, wherein the alignment layers are not rubbed.

34. A liquid crystal display of claim 28, wherein the number of the apertures in each is at least two.

35. A liquid crystal display of claim 34, wherein the apertures are formed linearly and extend parallel to the data line.

36. A liquid crystal display of claim 34, wherein the apertures are formed linearly and extend parallel to the gate line.

37. A liquid crystal display of claim 34, wherein the apertures are formed linearly and make an angle of 0°

-90°

about the data line and the gate line.

38. A liquid crystal display of claim 37, wherein the apertures are parallel to each other.

39. A liquid crystal display of claim 38, further comprising two alignment layers formed on the first and the second substrates respectively and aligning the molecular axes of liquid crystal molecules in the liquid crystal layer in the direction perpendicular to the substrates.

40. A liquid crystal display of claim 39, wherein the alignment layers are rubbed.

41. A liquid crystal display of claim 40, wherein the rubbing direction of the alignment layers makes an angle of 0°

-135°

about the direction of the aperture.

42. A liquid crystal display of claim 34, wherein the width of the aperture is in the range of 3-15 μ

m.

43. A liquid crystal display of claim 42, wherein the distance between the apertures in a pixel region is in the range of 8-50 μ

m.

44. A liquid crystal display of claim 28, further comprising an organic insulating layer disposed between the gate line, the data line and the storage capacitor electrode and the pixel electrode.

45. A liquid crystal display of claim 44, wherein the thickness of the organic insulating layer is equal to or more than 3 μ

m.

46. A liquid crystal display of claim 45, further comprising a spacer made of metal or an organic material.