Liquid Crystal Display Device

• US 20100231842A1
• Filed: 03/04/2010
• Published: 09/16/2010
• Est. Priority Date: 03/11/2009
• Status: Abandoned Application

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Ishitani, Tetsuji, Yamashita, Akio, Kubota, Daisuke, Fukai, Shuji
• Application Number:
  US12/717,580
• Publication Number:
  US 20100231842A1
• 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
• CPC Class Codes: G02F 1/13718 based on a change of the texture state of a cholesteric liquid crystal

Abstract

To provide a liquid crystal display device in which a cell thickness (the thickness of a liquid crystal layer) having a certain value or more is secured, or to increase productivity of the liquid crystal display device. The liquid crystal display device includes a first substrate, a second substrate, a first spacer layer provided for the first substrate, a second spacer layer provided for the second substrate, and a liquid crystal layer including a liquid crystal between the first substrate and the second substrate, in which the thickness of the liquid crystal layer is controlled to be 6 μm or more and the birefringence Δn of the liquid crystal layer under a white display condition is 0.05 or less.

Claims

1. A liquid crystal display device comprising:

a first substrate;

a second substrate;

a first spacer layer formed on the first substrate;

a second spacer layer formed on the second substrate; and

a liquid crystal layer including a liquid crystal between the first substrate and the second substrate,

wherein the first spacer layer and the second spacer layer are provided between the first substrate and the second substrate,

wherein at least a part of the second spacer layer overlaps with at least a part of the first spacer layer,

wherein a thickness of the liquid crystal layer is more than or equal to 6 μ

m, and

wherein a birefringence Δ

n of the liquid crystal layer under a white display condition is less than or equal to 0.05.

2. The liquid crystal display device according to claim 1, wherein a surface area of the first spacer layer including a region on the second spacer layer is larger than a surface area of the second spacer layer including a region on the first spacer layer.

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

wherein the first spacer layer has a long side and a short side in a surface parallel to a main surface of the first substrate,

wherein the second spacer layer has a long side and a short side in a surface parallel to a main surface of the second substrate, and

wherein the long side of the first spacer layer crosses the long side of the second spacer layer.

4. The liquid crystal display device according to claim 3, wherein each length in long-side directions of the first spacer layer and the second spacer layer is shorter than a length in a short-side direction of a pixel.

5. The liquid crystal display device according to claim 1, wherein a blue phase is used as a liquid crystal phase of the liquid crystal layer.

6. The liquid crystal display device according to claim 1, wherein a pixel electrode and a common electrode are provided over the first substrate.

7. The liquid crystal display device according to claim 1 further comprising a scan line and a signal line between the first substrate and the first spacer layer.

8. The liquid crystal display device according to claim 1 further comprising a common electrode between the second substrate and the second spacer layer.

9. A liquid crystal display device comprising:

a first substrate;

a second substrate;

a first spacer layer formed on the first substrate;

a second spacer layer formed on the second substrate; and

a liquid crystal layer including a liquid crystal between the first substrate and the second substrate,

wherein the first spacer layer and the second spacer layer are provided between the first substrate and the second substrate,

wherein at least a part of the second spacer layer overlaps with at least a part of the first spacer layer,

wherein a thickness of the liquid crystal layer is more than or equal to 6 μ

m, and

wherein a Kerr coefficient of the liquid crystal layer is more than or equal to 1×

10<sup>−

9</sup> mV<sup>−

2</sup>.

10. The liquid crystal display device according to claim 9, wherein a surface area of the first spacer layer including a region on the second spacer layer is larger than a surface area of the second spacer layer including a region on the first spacer layer.

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

wherein the first spacer layer has a long side and a short side in a surface parallel to a main surface of the first substrate,

wherein the second spacer layer has a long side and a short side in a surface parallel to a main surface of the second substrate, and

wherein the long side of the first spacer layer crosses the long side of the second spacer layer.

12. The liquid crystal display device according to claim 11, wherein each length in long-side directions of the first spacer layer and the second spacer layer is shorter than a length in a short-side direction of a pixel.

13. The liquid crystal display device according to claim 9, wherein a blue phase is used as a liquid crystal phase of the liquid crystal layer.

14. The liquid crystal display device according to claim 9, wherein a pixel electrode and a common electrode are provided over the first substrate.

15. The liquid crystal display device according to claim 9 further comprising a scan line and a signal line between the first substrate and the first spacer layer.

16. The liquid crystal display device according to claim 9 further comprising a common electrode between the second substrate and the second spacer layer.

17. A liquid crystal display device comprising:

a first substrate;

a second substrate;

a first spacer layer formed on the first substrate;

a second spacer layer formed on the second substrate; and

a liquid crystal layer including a liquid crystal between the first substrate and the second substrate,

wherein the first spacer layer and the second spacer layer are provided between the first substrate and the second substrate,

wherein at least a part of the second spacer layer overlaps with at least a part of the first spacer layer,

wherein a thickness of the liquid crystal layer is more than or equal to 6 μ

m, and

wherein driving is performed by an electric field more than or equal to 3.0×

10⁶ V/m under a white display condition.

18. The liquid crystal display device according to claim 17, wherein a surface area of the first spacer layer including a region on the second spacer layer is larger than a surface area of the second spacer layer including a region on the first spacer layer.

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

wherein the first spacer layer has a long side and a short side in a surface parallel to a main surface of the first substrate,

wherein the second spacer layer has a long side and a short side in a surface parallel to a main surface of the second substrate, and

wherein the long side of the first spacer layer crosses the long side of the second spacer layer.

20. The liquid crystal display device according to claim 19, wherein each length in long-side directions of the first spacer layer and the second spacer layer is shorter than a length in a short-side direction of a pixel.

21. The liquid crystal display device according to claim 17, wherein a blue phase is used as a liquid crystal phase of the liquid crystal layer.

22. The liquid crystal display device according to claim 17, wherein a pixel electrode and a common electrode are provided over the first substrate.

23. The liquid crystal display device according to claim 17 further comprising a scan line and a signal line between the first substrate and the first spacer layer.

24. The liquid crystal display device according to claim 17 further comprising a common electrode between the second substrate and the second spacer layer.

25. A liquid crystal display device comprising:

a first substrate;

a second substrate;

a first spacer layer formed on the first substrate;

a second spacer layer formed on the second substrate; and

a liquid crystal layer including a liquid crystal between the first substrate and the second substrate,

wherein the first spacer layer and the second spacer layer are provided between the first substrate and the second substrate,

wherein at least a part of the second spacer layer overlaps with at least a part of the first spacer layer,

wherein a thickness of the liquid crystal layer is more than or equal to 6 μ

m,

wherein a birefringence Δ

n of the liquid crystal layer under a white display condition is less than or equal to 0.05,

wherein a Kerr coefficient of the liquid crystal layer is more than or equal to 1×

10<sup>−

9</sup> mV<sup>−

2</sup>, and

wherein driving is performed by an electric field more than or equal to 3.0×

10⁶ V/m under a white display condition.

26. The liquid crystal display device according to claim 25, wherein a surface area of the first spacer layer including a region on the second spacer layer is larger than a surface area of the second spacer layer including a region on the first spacer layer.

27. The liquid crystal display device according to claim 25,

wherein the first spacer layer has a long side and a short side in a surface parallel to a main surface of the first substrate,

wherein the second spacer layer has a long side and a short side in a surface parallel to a main surface of the second substrate, and

wherein the long side of the first spacer layer crosses the long side of the second spacer layer.

28. The liquid crystal display device according to claim 27, wherein each length in long-side directions of the first spacer layer and the second spacer layer is shorter than a length in a short-side direction of a pixel.

29. The liquid crystal display device according to claim 25, wherein a blue phase is used as a liquid crystal phase of the liquid crystal layer.

30. The liquid crystal display device according to claim 25, wherein a pixel electrode and a common electrode are provided over the first substrate.

31. The liquid crystal display device according to claim 25 further comprising a scan line and a signal line between the first substrate and the first spacer layer.

32. The liquid crystal display device according to claim 25 further comprising a common electrode between the second substrate and the second spacer layer.