Liquid crystal display device comprising a liquid crystal material exhibiting a blue phase and a structure body projecting into the liquid crystal layer

• US 8,355,109 B2
• Filed: 11/11/2010
• Issued: 01/15/2013
• Est. Priority Date: 11/24/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kubota, Daisuke, Ishitani, Tetsuji, Yamashita, Akio
• Primary Examiner(s): Robinson, Mark
• Assistant Examiner(s): LEE, PAUL CHANG
• Application Number:
  US12/944,097
• Publication Number:
  US 20110122332A1
• Time in Patent Office: 796 Days
• Field of Search: 349/110, 349/111, 349/147, 349155-157
• US Class Current: 349/155
• 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 1/134336 Matrix
• CPC Class Codes: G02F 1/134381 Hybrid switching mode, i.e. for applying an electric field with components parallel and orthogonal to the substrates
• CPC Class Codes: G02F 1/13793 Blue phases

Abstract

An object is to provide a liquid crystal display device which includes a liquid crystal material exhibiting a blue phase and enables higher contrast. In the liquid crystal display device including a liquid crystal layer exhibiting a blue phase, the liquid crystal layer exhibiting a blue phase is interposed between a pixel electrode layer having an opening pattern (slit) and first and second common electrode layers which face each other and have opening patterns. The pixel electrode layer is formed over a structure body which projects into the liquid crystal layer from a surface of a first substrate on the liquid crystal layer side, and the pixel electrode layer is positioned between the first common electrode layer and the second common electrode layer in the liquid crystal layer. The cell gap of the liquid crystal display device is less than 5 μm (preferably 1 μm or more).

Claims

1. A liquid crystal display device comprising:

a first substrate and a second substrate;

a liquid crystal layer including a liquid crystal material exhibiting a blue phase between the first substrate and the second substrate;

a transistor provided between the first substrate and the liquid crystal layer;

an insulating film between the liquid crystal layer and the transistor;

a light-blocking layer overlapped with the transistor;

a structure body provided between the insulating film and the liquid crystal layer, the structure body projecting into the liquid crystal layer;

a first electrode layer having a first opening pattern, the first electrode layer being provided on the structure body and electrically connected to the transistor;

a second electrode layer having a second opening pattern, the second electrode layer being provided between the second substrate and the liquid crystal layer; and

a third electrode layer having a third opening pattern, the third electrode layer being provided between the first substrate and the liquid crystal layer and overlapped with the second electrode layer,

wherein the structure body is provided at least partly in the third opening pattern,

wherein a distance between the first electrode layer and the third electrode layer is smaller than a distance between the second electrode layer and the third electrode layer in a thickness direction of the liquid crystal layer, and

wherein a cell gap is less than 5 μ

m.

2. The liquid crystal display device according to claim 1, wherein the cell gap is 1 μ

m or more.

3. The liquid crystal display device according to claim 1, wherein a distance between the first electrode layer and the second electrode layer is substantially equal to a distance between the first electrode layer and the third electrode layer.

4. The liquid crystal display device according to claim 1, wherein the first electrode layer, the second electrode layer, and the third electrode layer are in contact with the liquid crystal layer.

5. The liquid crystal display device according to claim 1, wherein the first electrode layer, the second electrode layer, and the third electrode layer each have a comb-like shape.

6. The liquid crystal display device according to claim 1, wherein the liquid crystal layer comprises a chiral agent.

7. The liquid crystal display device according to claim 1, wherein the liquid crystal layer comprises a photocurable resin and a photopolymerization initiator.

8. The liquid crystal display device according to claim 1, wherein the transistor comprises an oxide semiconductor layer.

9. The liquid crystal display device according to claim 1, wherein the insulating film includes the light-blocking layer.

10. The liquid crystal display device according to claim 9,

wherein the light-blocking layer is provided between the transistor and the liquid crystal layer.

11. The liquid crystal display device according to claim 1,

wherein the light-blocking layer is provided between the second substrate and the second electrode layer.

12. The liquid crystal display device according to claim 1, further comprising a chromatic-color light-transmitting resin layer between the first substrate and the liquid crystal layer.

13. A liquid crystal display device comprising:

a first substrate and a second substrate;

a liquid crystal layer including a liquid crystal material exhibiting a blue phase between the first substrate and the second substrate;

a first structure body provided between the first substrate and the liquid crystal layer, the first structure body projecting into the liquid crystal layer;

a first electrode layer having a first opening pattern, the first electrode layer being provided on the first structure body;

a second structure body provided between the second substrate and the liquid crystal layer, the second structure body projecting into the liquid crystal layer;

a second electrode layer having a second opening pattern, the second electrode layer being provided between the second structure body and the liquid crystal layer; and

a third electrode layer having a third opening pattern, the third electrode layer being provided between the first substrate and the liquid crystal layer and overlapped with the second electrode layer,

wherein the first structure body is provided at least partly in the third opening pattern,

wherein a distance between the first electrode layer and the third electrode layer is smaller than a distance between the second electrode layer and the third electrode layer in a thickness direction of the liquid crystal layer, and

wherein a cell gap is less than 5 μ

m.

14. The liquid crystal display device according to claim 13, wherein the cell gap is 1 μ

m or more.

15. The liquid crystal display device according to claim 13, wherein a distance between the first electrode layer and the second electrode layer is substantially equal to a distance between the first electrode layer and the third electrode layer.

16. The liquid crystal display device according to claim 13, wherein the first electrode layer, the second electrode layer, and the third electrode layer are in contact with the liquid crystal layer.

17. The liquid crystal display device according to claim 13, wherein the first electrode layer, the second electrode layer, and the third electrode layer each have a comb-like shape.

18. The liquid crystal display device according to claim 13, wherein the liquid crystal layer comprises a chiral agent.

19. The liquid crystal display device according to claim 13, wherein the liquid crystal layer comprises a photocurable resin and a photopolymerization initiator.

20. The liquid crystal display device according to claim 13, further comprising a transistor between the first substrate and the liquid crystal layer,

wherein the first electrode layer is electrically connected to the transistor.

21. The liquid crystal display device according to claim 20, wherein the transistor comprises an oxide semiconductor layer.

22. The liquid crystal display device according to claim 13, further comprising a light-blocking layer.

23. The liquid crystal display device according to claim 20, further comprising a light-blocking layer,

wherein the light-blocking layer is provided between the transistor and the liquid crystal layer.

24. The liquid crystal display device according to claim 22,

wherein the light-blocking layer is provided between the second substrate and the second electrode layer.

25. The liquid crystal display device according to claim 13, further comprising a chromatic-color light-transmitting resin layer between the first substrate and the liquid crystal layer.

26. A liquid crystal display device comprising:

a first substrate and a second substrate;

a liquid crystal layer including a liquid crystal material exhibiting a blue phase between the first substrate and the second substrate;

a first structure body provided between the first substrate and the liquid crystal layer, the first structure body projecting into the liquid crystal layer;

a first electrode layer having a first opening pattern, the first electrode layer being provided on the first structure body;

a second structure body provided between the second substrate and the liquid crystal layer, the second structure body projecting into the liquid crystal layer;

a second electrode layer having a second opening pattern, the second electrode layer being provided between the second structure body and the liquid crystal layer;

a third structure body provided between the first substrate and the liquid crystal layer, the third structure body projecting into the liquid crystal layer; and

a third electrode layer having a third opening pattern, the third electrode layer being provided between the liquid crystal layer and the third structure body and overlapped with the second electrode layer,

wherein the first structure body is provided at least partly in the third opening pattern;

wherein a distance between the first electrode layer and the third electrode layer is smaller than a distance between the second electrode layer and the third electrode layer in a thickness direction of the liquid crystal layer, and

wherein a cell gap is less than 5 μ

m.

27. The liquid crystal display device according to claim 26, wherein the cell gap is 1 μ

m or more.

28. The liquid crystal display device according to claim 26, wherein a distance between the first electrode layer and the second electrode layer is substantially equal to a distance between the first electrode layer and the third electrode layer.

29. The liquid crystal display device according to claim 26, wherein the first electrode layer, the second electrode layer, and the third electrode layer are in contact with the liquid crystal layer.

30. The liquid crystal display device according to claim 26, wherein the first electrode layer, the second electrode layer, and the third electrode layer each have a comb-like shape.

31. The liquid crystal display device according to claim 26, wherein the liquid crystal layer comprises a chiral agent.

32. The liquid crystal display device according to claim 26, wherein the liquid crystal layer comprises a photocurable resin and a photopolymerization initiator.

33. The liquid crystal display device according to claim 26, further comprising a transistor between the first substrate and the liquid crystal layer,

wherein the first electrode layer is electrically connected to the transistor.

34. The liquid crystal display device according to claim 33, wherein the transistor comprises an oxide semiconductor layer.

35. The liquid crystal display device according to claim 26, further comprising a light-blocking layer.

36. The liquid crystal display device according to claim 33, further comprising a light-blocking layer,

wherein the light-blocking layer is provided between the transistor and the liquid crystal layer.

37. The liquid crystal display device according to claim 35,

wherein the light-blocking layer is provided between the second substrate and the second electrode layer.

38. The liquid crystal display device according to claim 26, further comprising a chromatic-color light-transmitting resin layer between the first substrate and the liquid crystal layer.