Liquid crystal display device

• US 8,711,312 B2
• Filed: 04/08/2011
• Issued: 04/29/2014
• Est. Priority Date: 04/12/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kubota, Daisuke, Yamashita, Akio, Ishitani, Tetsuji, Tamura, Tomohiro
• Primary Examiner(s): Nguyen, Dung
• Assistant Examiner(s): DUONG, TAI V
• Application Number:
  US13/083,114
• Publication Number:
  US 20110249229A1
• Time in Patent Office: 1,117 Days
• Field of Search: 349/43, 349/139, 349/141, 349/143, 349/167, 349/171, 349/175, 257/43, 257/59, 257/72, 345/92
• US Class Current: 349/141
• CPC Class Codes: G02F 1/133622 Colour sequential illumination
• 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 1/134318 having a patterned common electrode
• 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 1/13793 Blue phases
• CPC Class Codes: G02F 1/1395 Optically compensated birefringence [OCB]- cells or PI- cells

Abstract

A liquid crystal display device using a liquid crystal material exhibiting a blue phase is provided to achieve higher contrast. Further, the power consumption of the liquid crystal display device using a liquid crystal exhibiting a blue phase is reduced. In a liquid crystal display device including: a first substrate provided with a pixel electrode layer (also referred to as a first electrode layer); and a second substrate provided with a common electrode layer (also referred to as a second electrode layer), between which a liquid crystal layer exhibiting a blue phase is interposed, the pixel electrode layer and the common electrode layer project into the liquid crystal layer and are arranged so that the adjacent pixel electrode layer and common electrode layer engage with each other at a distance with the liquid crystal layer interposed therebetween.

Claims

1. A liquid crystal display device comprising:

a first substrate provided with a first electrode layer;

a second substrate provided with a second electrode layer; and

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

wherein the first electrode layer and the second electrode layer project into the liquid crystal layer with the liquid crystal layer interposed therebetween, and

wherein sum of a maximum film thickness of the first electrode layer and a maximum film thickness of the second electrode layer is greater than a maximum thickness of the liquid crystal layer.

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

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

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

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

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

wherein a transistor is provided between the first substrate and the first electrode layer;

and

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

7. The liquid crystal display device according to claim 6, wherein the transistor comprises an oxide semiconductor layer.

8. The liquid crystal display device according to claim 1, wherein the first electrode layer and the second electrode layer are configured to form an electric field substantially parallel to the first substrate and the second substrate in the liquid crystal layer.

9. A liquid crystal display device comprising:

a first substrate provided with a first electrode layer;

a second substrate provided with a second electrode layer; and

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

wherein the first electrode layer and the second electrode layer project into the liquid crystal layer with the liquid crystal layer interposed therebetween,

wherein a distance between the first electrode layer and the second electrode layer is a distance at which a liquid crystal in the liquid crystal layer between the first electrode layer and the second electrode layer responds to a voltage applied to the first electrode layer and the second electrode layer, and

wherein sum of a maximum film thickness of the first electrode layer and a maximum film thickness of the second electrode layer is greater than a maximum thickness of the liquid crystal layer.

10. The liquid crystal display device according to claim 9, wherein the first electrode layer and the second electrode layer each have a comb-like shape.

11. The liquid crystal display device according to claim 9, wherein the first electrode layer and the second electrode layer are in contact with the liquid crystal layer.

12. The liquid crystal display device according to claim 9, wherein the liquid crystal layer comprises a chiral agent.

13. The liquid crystal display device according to claim 9, wherein the liquid crystal layer comprises a photocurable resin and a photopolymerization initiator.

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

wherein a transistor is provided between the first substrate and the first electrode layer;

and

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

15. The liquid crystal display device according to claim 14, wherein the transistor comprises an oxide semiconductor layer.

16. The liquid crystal display device according to claim 9, wherein the first electrode layer and the second electrode layer are configured to form an electric field substantially parallel to the first substrate and the second substrate in the liquid crystal layer.

17. A liquid crystal display device comprising:

a first substrate and a second substrate between which a liquid crystal layer including a liquid crystal material exhibiting a blue phase is interposed;

a rib-shaped first structure body which projects into the liquid crystal layer from a surface of the first substrate on the liquid crystal layer side;

a rib-shaped second structure body which projects into the liquid crystal layer from a surface of the second substrate on the liquid crystal layer side;

a first electrode layer which covers top and side surfaces of the rib-shaped first structure body; and

a second electrode layer which covers top and side surfaces of the rib-shaped second structure body,

wherein the first electrode layer and the second electrode layer are arranged with the liquid crystal layer interposed therebetween, and

wherein sum of a maximum film thickness of the rib-shaped first structure body and a maximum film thickness of the rib-shaped second structure body is greater than a maximum thickness of the liquid crystal layer.

18. The liquid crystal display device according to claim 17, wherein the rib-shaped first structure body and the rib-shaped second structure body each have a comb-like shape.

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

20. The liquid crystal display device according to claim 17, wherein the first electrode layer and the second electrode layer are in contact with the liquid crystal layer.

21. The liquid crystal display device according to claim 17, wherein the liquid crystal layer comprises a chiral agent.

22. The liquid crystal display device according to claim 17, wherein the liquid crystal layer comprises a photocurable resin and a photopolymerization initiator.

23. The liquid crystal display device according to claim 17,

wherein a transistor is provided between the first substrate and the first electrode layer;

and

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

24. The liquid crystal display device according to claim 23, wherein the transistor comprises an oxide semiconductor layer.

25. The liquid crystal display device according to claim 17, wherein the first electrode layer and the second electrode layer are configured to form an electric field substantially parallel to the first substrate and the second substrate in the liquid crystal layer.

26. A liquid crystal display device comprising:

a first substrate and a second substrate between which a liquid crystal layer including a liquid crystal material exhibiting a blue phase is interposed;

a rib-shaped first structure body which projects into the liquid crystal layer from a surface of the first substrate on the liquid crystal layer side;

a rib-shaped second structure body which projects into the liquid crystal layer from a surface of the second substrate on the liquid crystal layer side;

a first electrode layer which covers top and side surfaces of the rib-shaped first structure body; and

a second electrode layer which covers top and side surfaces of the rib-shaped second structure body,

wherein the first electrode layer and the second electrode layer are arranged with the liquid crystal layer interposed therebetween; and

wherein a distance between the first electrode layer and the second electrode layer is a distance at which a liquid crystal in the liquid crystal layer between the first electrode layer and the second electrode layer responds to a voltage applied to the first electrode layer and the second electrode layer, and

wherein sum of a maximum film thickness of the rib-shaped first structure body and a maximum film thickness of the rib-shaped second structure body is greater than a maximum thickness of the liquid crystal layer.

27. The liquid crystal display device according to claim 26, wherein the rib-shaped first structure body and the rib-shaped second structure body each have a comb-like shape.

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

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

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

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

32. The liquid crystal display device according to claim 26,

wherein a transistor is provided between the first substrate and the first electrode layer;

and

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

33. The liquid crystal display device according to claim 32, wherein the transistor comprises an oxide semiconductor layer.

34. The liquid crystal display device according to claim 26, wherein the first electrode layer and the second electrode layer are configured to form an electric field substantially parallel to the first substrate and the second substrate in the liquid crystal layer.