Liquid crystal display device

• US 20070153215A1
• Filed: 06/29/2006
• Published: 07/05/2007
• Est. Priority Date: 12/30/2005
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Lee, Tae-Rim
• Granted Patent: US 7,738,068 B2
• Time in Patent Office: Days
• US Class Current: 349/156
• CPC Class Codes: G02F 1/13394 spacers regularly patterned on the cell subtrate, e.g. walls, pillars G02F1/133377 takes precedence
• CPC Class Codes: G02F 1/13396 Spacers having different sizes

Abstract

A liquid crystal display device minimizing touch inferiority and a press inferiority defects is provided. The device includes first and second substrates, a liquid crystal layer interposed therebetween, gap spacers between the first and second substrates for maintaining a cell gap, and pressure spacers between the first and second substrates configured to contact the first and second substrates when pressure is applied to the first or second substrate, wherein a spatial density of the gap spacers or a spatial density of the pressure spacers varies at different positions across the first and second substrates.

Claims

1. A liquid crystal display device comprising;

first and second substrates;

a liquid crystal layer between the first and second substrates;

column spacers between the first and second substrates to maintain a cell gap; and

protrusions contacting corresponding column spacers,

wherein a spatial density of the protrusions varies at different positions across the first or second substrates.

2. The device of claim 1 further comprising:

gate lines and data lines on the second substrate defining a plurality of pixels; and

a thin film transistor in each pixel.

3. The device of claim 2, wherein the thin film transistor includes:

a gate electrode on the second substrate;

a gate insulating layer on the gate electrode;

a semiconductor layer on the insulating layer;

a source electrode and a drain electrode on the semiconductor layer; and

a passivation layer over the second substrate.

4. The device of claim 2, wherein at least one column spacer is over the gate line.

5. The device of claim 2, wherein at least one column spacer is over on a the data line.

6. The device of claim 1, wherein at least one of the column spacers comprises an organic material.

7. The device of claim 1, wherein at least one of the protrusions comprises an end portion configured to contact the corresponding column spacer disposed on the opposing substrate.

8. The device of claim 1, wherein the at least one protrusion is disposed on the second substrate and the column spacer is disposed on the first substrate.

9. The device of claim 7, wherein the area of the end portion of the protrusions is smaller than the area of the corresponding column spacer contacting the opposing substrate.

10. The device of claim 9, wherein the area of the corresponding column spacer is 1.5 to 2.5 times larger than the end portion of the protrusions.

11. The device of claim 3, wherein the protrusions comprise:

a semiconductor layer on the gate insulating layer; and

a metal layer on the semiconductor layer.

12. The device of claim 10, wherein the protrusion includes a metal layer on the passivation layer.

13. The device of claim 1, wherein at least one of the column spacers resides on the first substrate and is spaced from the second substrate by a predetermined distance.

14. The device of claim 1, wherein the spatial density of protrusions in a center portion of the substrates is lower than in an outer periphery portion of the substrates.

15. The device of claim 1, wherein the spatial density of the protrusions linearly decreases in a direction from a peripheral portion toward a center portion of the first and second substrates.

16. The device of claim 1, wherein the liquid crystal display device comprises one of an In Plane Switching (IPS) mode device, Twisted Nematic (TN) mode device, or a Vertical Alignment (VA) mode device.

17. A liquid crystal display device comprising

first column spacers contacting first and second substrates;

and

second column spacers on one of the first and second substrates and spaced apart from the other of the first and second substrates,

wherein a spatial density of the first column spacers varies across the first and second substrates, such that the spatial density in a center portion is less than an outer periphery portion.

18. The device of claim 17, wherein the first column spacers comprise a protrusion in contact with a gap spacer.

19. The device of claim 18, wherein the protrusion comprises another gap spacer.

20. The device of claim 18, wherein the protrusion comprises an end portion configured to contact the gap spacer.

21. The device of claim 18, wherein the area of an end portion of the protrusion is smaller than the area of the gap spacer in contact with the protrusion.

22. The device of claim 21, wherein the area of the gap spacer in contact with the protrusion is 1.5 to 2.5 times larger than the end portion of the protrusion.

23. The device of claim 21, wherein the area of the gap spacer in contact with the protrusion is equal to the area of the end portion of the protrusion.

24. The device of claim 18, wherein the gap spacer comprises a structure having a flat surface.

25. The device of claim 24, wherein the area of an end portion of the protrusion is smaller than the area of the flat surface of the gap spacer.

26. The device of claim 18, wherein the gap spacer comprises a structure having a round surface.

27. A liquid crystal display device comprising

a plurality of pixels;

first column spacers contacting first and second substrates; and

second column spacers on one of the first and second substrates and spaced apart from the other of the first and second substrates,

wherein the number of the first column spacers in the plurality of pixels varies across the first and second substrates, such that the number of first column spacers in the pixels in a center portion of the display is less than the number of first column spacers in the pixels in a periphery portion.

28. The device of claim 27, wherein the first column spacers comprise protrusions on one of the first and second substrates having an end portion configured to contact a corresponding column spacer disposed on the opposing substrate.

29. The device of claim 27, wherein the number of the first column spacers in the plurality of pixels linearly varies across the first and second substrates.

30. The device of claim 27, wherein the number of the first column spacers in the plurality of pixels exponentially varies across the first and second substrates.

31. The device of claim 27, wherein the number of the first column spacers in the plurality of pixels logarithmically varies across the first and second substrates.

32. A liquid crystal display device comprising:

first column spacers contacting first and second substrates;

a plurality of pixels having gate lines and data lines;

second column spacers on one of the first and second substrates and spaced apart from the other of the first and second substrates,

wherein the number of second column spacers between the first column spacers increases along the data and gate lines from a peripheral portion of the display toward a center portion of the display.

33. The device of claim 32, wherein the first column spacers comprise protrusions on one of the first and second substrates having an end portion configured to contact a corresponding column spacer disposed on the opposing substrate.

34. The device of claim 32, wherein the number of second column spacers between the first column spacers increases linearly across the first and second substrates.

35. The device of claim 32, wherein the number of second column spacers between the first column spacers exponentially increases across the first and second substrates.

36. The device of claim 32, wherein the number of second column spacers between the first column spacers logarithmically increases across the first and second substrates

37. A liquid crystal display device comprising;

first and second substrates;

a liquid crystal layer between the first and second substrates;

column spacers between the first and second substrates to maintain a cell gap; and

protrusions contacting corresponding column spacers,

wherein the distance between the protrusions increases in a direction from a periphery of the display toward a center of the first or second substrates.

38. The device of claim 37, wherein the distance between the protrusions linearly increases in a direction from a periphery of the display toward a center of the first or second substrates.

39. The device of claim 37, wherein the distance between the protrusions exponentially increases in a direction from a periphery of the display toward a center of the first or second substrates.

40. The device of claim 37, wherein the distance between the protrusions logarithmically increases in a direction from a periphery of the display toward a center of the first or second substrates.

41. A method for making a liquid crystal display device comprising:

forming first and second substrates;

forming column spacers between the first and second substrates to maintain a cell gap;

forming protrusions contacting corresponding column spacers,

wherein a spatial density of the protrusions varies at different positions across the first or second substrates; and

disposing a liquid crystal layer between the first and second substrates.

42. The method of claim 41 further comprising:

forming gate lines, data lines and pixels on the second substrate; and

forming thin film transistors in the pixels,

wherein a plurality of the thin film transistors are formed by a process comprising;

forming a gate electrode on the second substrate;

forming a gate insulating electrode on the gate electrode;

forming a semiconductor layer on the insulating layer;

forming a source electrode and a drain electrode on the semiconductor layer; and

forming a passivation layer over the second substrate.

44. The method of claim 42 forming protrusions comprises forming at least one protrusion on the second substrate, wherein the area of the end portion of the protrusions is smaller than the area of the corresponding column spacer contacting the opposing substrate.

45. The method of claim 42, wherein at least on of the column spacers on the first or second substrate are formed to be spaced at a predetermined distance from the opposing substrate.

47. The method of claim 42, wherein forming protrusions comprises forming a semiconductor layer on the gate insulating layer and disposing a metal layer on the semiconductor layer.

48. The method of claim 47, wherein forming protrusions comprises forming a metal layer on the passivation layer.

43. The method of clam 42 further comprising forming at least one protrusion on at least one of a gate line or a data line.

46. The method of clam 42 wherein the protrusions are formed so that the spatial density of protrusions in a center portion of the substrates is lower than in an outer periphery portion of the substrates.