Liquid crystal display device

• US 8,274,628 B2
• Filed: 06/11/2009
• Issued: 09/25/2012
• Est. Priority Date: 12/06/2004
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Nishi, Takeshi, Ishitani, Tetsuji, Kubota, Daisuke
• Primary Examiner(s): Glick, Edward
• Assistant Examiner(s): NGUYEN, SANG V
• Application Number:
  US12/482,680
• Publication Number:
  US 20090244458A1
• Time in Patent Office: 1,202 Days
• Field of Search: 349/123, 349/156, 349/122, 349/182
• US Class Current: 349/122
• CPC Class Codes: C09K 2323/00 Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
• CPC Class Codes: C09K 2323/02 Alignment layer characterised by chemical composition
• CPC Class Codes: C09K 2323/03 Viewing layer characterised by chemical composition
• CPC Class Codes: G02F 1/0045 Liquid crystals characterised by their physical properties
• CPC Class Codes: G02F 1/133377 Cells with plural compartments or having plurality of liquid crystal microcells partitioned by walls, e.g. one microcell per pixel

Abstract

In the present invention, it is an object to improve display quality by improving response speed of a liquid crystal element in a liquid crystal display device, in particular, response speed in the case of falling. In the present invention, it is characterized that a liquid crystal layer is divided into plural regions (domains) substantially by mixing a chemical compound including a liquid crystal skeleton in a liquid crystal layer having existing liquid crystal molecules as a technique to improve response speed of a liquid crystal element in a liquid crystal display device for solving the above problem.

Claims

1. A liquid crystal display device comprising:

a first substrate and a second substrate, which are opposed to each other;

a first electrode and a second electrode, which are over the first substrate;

a projection and a spacer between the first substrate and the second substrate; and

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

wherein a distance between a first end of the projection and the second substrate is smaller than a distance between the first end of the projection and the first substrate,

wherein a distance between a second end of the projection and the first substrate is smaller than a distance between the second end of the projection and the second substrate,

wherein the liquid crystal layer includes a liquid crystal molecule and a compound having a liquid crystal skeleton, and

wherein the liquid crystal layer includes a plurality of domain regions.

4. A liquid crystal display device according to claim 1, wherein the compound having the liquid crystal skeleton has a weight ratio at 5 wt % to 15 wt % with respect to the liquid crystal molecule.

7. A liquid crystal display device according to claim 1, wherein the compound having the liquid crystal skeleton is a liquid crystal monomer or a liquid crystal polymer.

10. A liquid crystal display device according to claim 7, wherein the liquid crystal monomer is obtained by bonding the liquid crystal skeleton to an acrlyloyl oxy group.

13. A liquid crystal display device according to claim 7, wherein the liquid crystal polymer is obtained by polymerizing the liquid crystal monomer.

16. A liquid crystal display device according to claim 1, wherein the liquid crystal skeleton is one of a biphenyls skeleton, a tolans skeleton, an esters skeleton, an alkenyls skeleton, a cyclohexenes skeleton, azines skeleton, fluorine-containing condensed rings skeleton, and a naphthalenes skeleton.

19. A liquid crystal display device according to claim 1, further comprising a first orientation film between the first electrode and the liquid crystal layer;

and

a second orientation film between the second electrode and the liquid crystal layer.

22. A liquid crystal display device according to claim 1, wherein the liquid crystal display device is one selected from the group consisting of a television set, a digital camera, a digital video camera, a mobile phone set, a portable information terminal, a portable game machine, a monitor for a computer, a computer, an audio reproducing device, and an image reproducing device with a recording medium.

25. A liquid crystal display device according to claim 1, wherein dielectric anisotropy of the liquid crystal molecule is negative.

28. A liquid crystal display device according to claim 1, wherein a dimension of at least one of the plurality of domain regions is 100 μ

m or less.

31. A liquid crystal display device according to claim 1, wherein the liquid crystal layer is provided between the first electrode and the second electrode.

2. A liquid crystal display device comprising:

a first substrate and a second substrate, which are opposed to each other;

a first electrode and a second electrode, which are over the first substrate;

a projection and a spacer between the first substrate and the second substrate; and

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

wherein a distance between a first end of the projection and the second substrate is smaller than a distance between the first end of the projection and the first substrate,

wherein a distance between a second end of the projection and the first substrate is smaller than a distance between the second end of the projection and the second substrate,

wherein the liquid crystal layer includes a liquid crystal molecule and a compound having a liquid crystal skeleton,

wherein the liquid crystal layer includes a plurality of domain regions, and

wherein a part of the liquid crystal layer is provided between the projection and the second substrate.

5. A liquid crystal display device according to claim 2, wherein the compound having the liquid crystal skeleton has a weight ratio at 5 wt % to 15 wt % with respect to the liquid crystal molecule.

8. A liquid crystal display device according to claim 2, wherein the compound having the liquid crystal skeleton is a liquid crystal monomer or a liquid crystal polymer.

11. A liquid crystal display device according to claim 8, wherein the liquid crystal monomer is obtained by bonding the liquid crystal skeleton to an acrlyloyl oxy group.

14. A liquid crystal display device according to claim 8, wherein the liquid crystal polymer is obtained by polymerizing the liquid crystal monomer.

17. A liquid crystal display device according to claim 2, wherein the liquid crystal skeleton is one of a biphenyls skeleton, a tolans skeleton, an esters skeleton, an alkenyls skeleton, a cyclohexenes skeleton, azines skeleton, fluorine-containing condensed rings skeleton, and a naphthalenes skeleton.

20. A liquid crystal display device according to claim 2, further comprising a first orientation film between the first electrode and the liquid crystal layer;

and

a second orientation film between the second electrode and the liquid crystal layer.

23. A liquid crystal display device according to claim 2, wherein the liquid crystal display device is one selected from the group consisting of a television set, a digital camera, a digital video camera, a mobile phone set, a portable information terminal, a portable game machine, a monitor for a computer, a computer, an audio reproducing device, and an image reproducing device with a recording medium.

26. A liquid crystal display device according to claim 2, wherein dielectric anisotropy of the liquid crystal molecule is negative.

29. A liquid crystal display device according to claim 2, wherein a dimension of at least one of the plurality of domain regions is 100 μ

m or less.

32. A liquid crystal display device according to claim 2, wherein the liquid crystal layer is provided between the first electrode and the second electrode.

3. A liquid crystal display device comprising:

a first substrate and a second substrate, which are opposed to each other;

a first electrode and a second electrode, which are over the first substrate;

a projection and a spacer between the first substrate and the second substrate;

a liquid crystal layer between the first electrode and the second substrate; and

an active element electrically connected to the first electrode, substrate,

wherein a distance between a first end of the projection and the second substrate is smaller than a distance between the first end of the projection and the first substrate,

wherein a distance between a second end of the projection and the first substrate is smaller than a distance between the second end of the projection and the second substrate,

wherein the liquid crystal layer includes a liquid crystal molecule and a compound having a liquid crystal skeleton, and

wherein the liquid crystal layer includes a plurality of domain regions.

6. A liquid crystal display device according to claim 3, wherein the compound having the liquid crystal skeleton has a weight ratio at 5 wt % to 15 wt % with respect to the liquid crystal molecule.

9. A liquid crystal display device according to claim 3, wherein the compound having the liquid crystal skeleton is a liquid crystal monomer or a liquid crystal polymer.

12. A liquid crystal display device according to claim 9, wherein the liquid crystal monomer is obtained by bonding the liquid crystal skeleton to an acrlyloyl oxy group.

15. A liquid crystal display device according to claim 9, wherein the liquid crystal polymer is obtained by polymerizing the liquid crystal monomer.

18. A liquid crystal display device according to claim 3, wherein the liquid crystal skeleton is one of a biphenyls skeleton, a tolans skeleton, an esters skeleton, an alkenyls skeleton, a cyclohexenes skeleton, azines skeleton, fluorine-containing condensed rings skeleton, and a naphthalenes skeleton.

21. A liquid crystal display device according to claim 3, further comprising a first orientation film between the first electrode and the liquid crystal layer;

and

a second orientation film between the second electrode and the liquid crystal layer.

24. A liquid crystal display device according to claim 3, wherein the liquid crystal display device is one selected from the group consisting of a television set, a digital camera, a digital video camera, a mobile phone set, a portable information terminal, a portable game machine, a monitor for a computer, a computer, an audio reproducing device, and an image reproducing device with a recording medium.

27. A liquid crystal display device according to claim 3, wherein dielectric anisotropy of the liquid crystal molecule is negative.

30. A liquid crystal display device according to claim 3, wherein a dimension of at least one of the plurality of domain regions is 100 μ

m or less.

33. A liquid crystal display device according to claim 3, wherein the liquid crystal layer is provided between the first electrode and the second electrode.