Transflective liquid crystal display device

• US 20040252262A1
• Filed: 03/30/2004
• Published: 12/16/2004
• Est. Priority Date: 06/10/2003
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Park, Jae-Deok
• Granted Patent: US 7,248,316 B2
• Time in Patent Office: Days
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133371 Cells with varying thickness of the liquid crystal layer
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer

Abstract

A transflective liquid crystal display device includes a first substrate including transmissive and reflective pixels. Gate and data lines on the first substrate cross each other to define a pixel region, with a thin film transistor at each crossing. The transmissive and reflective pixels correspond to respective pixel regions. A first passivation layer covers the thin film transistor and has a transmissive hole in the transmissive pixel. A first reflector is disposed on the first passivation layer in the reflective pixel. A second passivation layer is disposed on the first reflector and in the transmissive hole. A pixel electrode on the second passivation layer is connected to the thin film transistor. A second substrate opposing the first substrate has a color filter layer on an inner surface thereof. The color filter layer contains R, G and B sub color filters, which each correspond to a pixel region.

Claims

24. A transflective liquid crystal display device, comprising:

a first substrate including a transmissive pixel and a reflective pixel;

a plurality of gate lines and a plurality of data lines on the first substrate, the gate and data lines crossing each other to define a pixel region, the transmissive pixel and the reflective pixel corresponding to respective pixel regions;

a thin film transistor at each crossing of the gate and data lines;

a first passivation layer covering the thin film transistor, the first passivation layer having a transmissive hole in the transmissive pixel;

a reflective electrode on the first passivation layer in the reflective pixel, the reflective electrode connected to the thin film transistor;

a pixel electrode disposed in the transmissive pixel and connected to the thin film transistor;

a second substrate spaced apart from and facing the first substrate;

a color filter layer on an inner surface of the second substrate, the color filter layer containing red (R), green (G) and blue (B) sub color filters, each sub color filter corresponding to one of the pixel regions; and

a liquid crystal layer between the first and second substrates.

1. A transflective liquid crystal display device, comprising:

a first substrate including a transmissive pixel and a reflective pixel;

a plurality of gate lines and a plurality of data lines on the first substrate, the gate and data lines crossing each other to define a pixel region, the transmissive and reflective pixels correspond to respective pixel regions;

a thin film transistor at each crossing of the gate and data lines;

a first passivation layer covering the thin film transistor, the first passivation layer having a transmissive hole in the transmissive pixel;

a first reflector on the first passivation layer in the reflective pixel;

a second passivation layer in the transmissive pixel;

a pixel electrode on the second passivation layer;

a second substrate spaced apart from and facing the first substrate;

a color filter layer on an inner surface of the second substrate, the color filter layer containing red (R), green (G) and blue (B) sub color filters, each sub color filter corresponding to one of the pixel regions; and

a liquid crystal layer between the first and second substrates.

2. The device according to claim 1, further comprising a second reflector between the first and second passivation layers in the transmissive pixel, the second reflector covering sides of the first passivation layer corresponding to the transmissive hole.

3. The device according to claim 2, wherein the second reflector overlaps the data lines.

4. The device according to claim 1, wherein the thin film transistor has a bottom gate structure, which includes a gate electrode, a gate insulating layer on the gate electrode, an active layer of amorphous silicon on the gate insulating layer, an ohmic contact layer of doped amorphous silicon on the active layer, source and drain electrodes on the ohmic contact layer.

5. The device according to claim 1, wherein the thin film transistor has a top gate structure, which includes a semiconductor layer of polycrystalline silicon having an active area and source and drain areas, a gate insulating layer on the semiconductor layer, a gate electrode on the gate insulating layer over the active area, an inter insulating layer on the gate electrode, and source and drain electrodes on the inter insulating layer, the source and drain electrodes are connected to the source and drain areas, respectively.

6. The device according to claim 1, wherein three pixel regions of R, G and B extending in a first direction parallel with the gate lines constitute one dot.

7. The device according to claim 6, wherein the transmissive pixel and the reflective pixel are alternately arranged in the first direction.

8. The device according to claim 7, wherein the dot includes one transmissive pixel and two reflective pixels.

9. The device according to claim 7, wherein the dot includes two transmissive pixels and one reflective pixel.

10. The device according to claim 6, wherein the dots include a transmissive dot having three transmissive pixels and a reflective dot having three reflective pixels.

11. The device according to claim 10, wherein the transmissive and reflective dots are alternately arranged in the first direction.

12. The device according to claim 11, wherein the transmissive and reflective dots are alternately arranged in a second direction orthogonal to the first direction.

13. The device according to claim 7, wherein the transmissive and reflective pixels are alternately arranged in a second direction orthogonal to the first direction.

14. The device according to claim 1, wherein the second passivation layer is disposed on the first reflector.

15. The device according to claim 2, wherein the first passivation layer has an uneven surface and the first reflector formed on the uneven surface of the first passivation layer is uneven.

16. The device according to claim 15, wherein the first passivation layer has an even surface between the first reflector and the second reflector and on which the first reflector is not formed.

17. The device according to claim 16, wherein the even surface of the first passivation layer essentially corresponds to an area above which the data lines are formed.

18. The device according to claim 17, wherein the second passivation layer covers at least a portion of the even surface.

19. The device according to claim 15, wherein the second passivation layer separates the second reflector from the first reflector.

20. The device according to claim 15, wherein no portion of the first passivation over which the second reflector is formed has an uneven surface.

21. The device according to claim 1, wherein the transmissive hole is formed in an area adjacent to the transistor in a direction parallel with the gate lines.

22. The device according to claim 1, wherein the pixel electrode is formed in the reflective pixel.

23. The device according to claim 22, wherein the pixel electrode is connected to the thin film transistor.

25. The device according to claim 24, further comprising a second passivation layer disposed in the transmissive pixel on which the pixel electrode is disposed and a reflector between the first and second passivation layers in the transmissive pixel, the reflector covering sides of the first passivation layer corresponding to the transmissive hole.

26. The device according to claim 25, wherein the reflector overlaps the data lines.

27. The device according to claim 25, wherein the second passivation layer does not cover the reflective electrode.

28. The device according to claim 27, wherein the second passivation layer terminates before extending into the reflective pixel.

29. The device according to claim 25, wherein the first passivation layer has an uneven surface and the reflective electrode formed on the uneven surface of the first passivation layer is uneven.

30. The device according to claim 29, wherein the first passivation layer has an even surface between the reflective electrode and the reflector on which the reflective electrode is not formed.

31. The device according to claim 30, wherein the even surface of the first passivation layer essentially corresponds to an area above which the data lines are formed.

32. The device according to claim 31, wherein the second passivation layer covers at least a portion of the even surface.

33. The device according to claim 31, wherein the pixel electrode terminates before extending substantially into an area over the portion of the even surface.

34. The device according to claim 25, wherein the second passivation layer covers the reflector and separates the reflector from the reflective electrode.

35. The device according to claim 25, wherein no portion of the first passivation over which the reflector is formed has an uneven surface.

36. The device according to claim 24, wherein the thin film transistor has a bottom gate structure, which includes a gate electrode, a gate insulating layer on the gate electrode, an active layer of amorphous silicon on the gate insulating layer, an ohmic contact layer of doped amorphous silicon on the active layer, source and drain electrodes on the ohmic contact layer.

37. The device according to claim 24, wherein the thin film transistor has a top gate structure, which includes a semiconductor layer of polycrystalline silicon having an active area and source and drain areas, a gate insulating layer on the semiconductor layer, a gate electrode on the gate insulating layer over the active area, an inter insulating layer on the gate electrode, and source and drain electrodes on the inter insulating layer, the source and drain electrodes are connected to the source and drain areas, respectively.

38. The device according to claim 24, wherein three pixel regions of R, G and B extending in a first direction parallel with the gate lines constitute one dot.

39. The device according to claim 38, wherein the transmissive pixel and the reflective pixel are alternately arranged in the first direction.

40. The device according to claim 39, wherein the dot includes one transmissive pixel and two reflective pixels.

41. The device according to claim 39, wherein the dot includes two transmissive pixels and one reflective pixel.

42. The device according to claim 38, wherein the dots include a transmissive dot having three transmissive pixels and a reflective dot having three reflective pixels.

43. The device according to claim 42, wherein the transmissive dot and the reflective dot are alternately arranged in the first direction.

44. The device according to claim 43, wherein the transmissive and reflective dots are alternately arranged in a second direction orthogonal to the first direction.

44-1. The device according to claim 24, wherein the transmissive hole is formed in an area adjacent to the transistor in a direction parallel with the gate lines.

45. A transflective liquid crystal display device, comprising:

opposing first and second substrates;

a liquid crystal layer between the first and second substrates;

transmissive and reflective pixels formed on the first substrate, the transmissive and reflective pixels separated by intersecting gate and data lines and alternating along at least one direction parallel with the gate or data lines;

a color filter layer containing red (R), green (G) and blue (B) sub color filters, each of which corresponds to one of the transmissive and reflective pixels; and

each of the transmissive and reflective pixels containing a thin film transistor covered by a first passivation layer and a first reflector disposed on the first passivation layer over the thin film transistor;

wherein the transmissive pixel contains a second passivation layer on which a pixel electrode is disposed, the first passivation layer contains a hole, and a second reflector that covers sides of the hole is disposed between the first and second passivation layers, and

in each of the transmissive and reflective pixels, the pixel electrode or first reflector is connected to the transistor.

46. The device according to claim 45, wherein, in each of the transmissive and reflective pixels, the second passivation layer is disposed on the first reflector and the pixel electrode, which is disposed over the first reflector, is connected to the transistor.

47. The device according to claim 45, wherein the first passivation layer has an uneven surface and the first reflector formed on the uneven surface of the first passivation layer is uneven.

48. The device according to claim 47, wherein the first passivation layer has an even surface between the first reflector and the second reflector and on which the first reflector is not formed and the second passivation layer covers at least a portion of the even surface.

49. The device according to claim 48, wherein the second passivation layer separates the second reflector from the first reflector.

50. The device according to claim 49, wherein no portion of the first passivation over which the first reflector is formed has an uneven surface.

51. The device according to claim 45, wherein the transmissive hole is formed in an area adjacent to the transistor in a direction parallel with the gate lines.

52. The device according to claim 45, wherein the first reflector is connected to the thin film transistor.