Liquid crystal display

• US 5,926,244 A
• Filed: 07/17/1997
• Issued: 07/20/1999
• Est. Priority Date: 12/26/1996
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Fujitsu Limited
• Inventors: Takeda, Arihiro, Koike, Yoshio
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): DUDEK, JAMES A
• Application Number:
  US08/895,948
• Time in Patent Office: 733 Days
• Field of Search: 349/139, 349/141, 349/142, 349/143, 349/144, 349/146, 349/147
• US Class Current: 349/139
• 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 1/134336 Matrix
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]

Abstract

Liquid crystal 20 is sealed between a first substrate 10 and a second substrate 16 opposed each other. A first electrode 12 is formed on the first substrate 10 at a prescribed position in a prescribed region. A second electrode 18 is formed on the second substrate 16 at a position offset with respect to the first electrode 12 in the prescribed region. When a voltage is applied between the first and second electrodes 12 and 18, the prescribed region is divided in at least two regions of a first region and a second region where application of the voltage to the liquid crystal 20 is different between the two regions. Orientations of the liquid crystal 20 in the first region and that in the second region are different from each other. As a result, a view angle which is equal or larger than that obtained by in-plane switching can be obtained. The first electrode 12 and the second electrode 18 are formed on the substrates 10, 16, which are different from each other, whereby it is not necessary to consider short-circuit between the adjacent electrodes 12, 18. The liquid crystal display device having a large view angle can be fabricated with high yields.

Claims

1. A liquid crystal display device including a first substrate and a second substrate which are opposed to each other, and liquid crystal sealed between the first and the second substrates, wherein light transmission of the liquid crystal is controlled by electrically controlling double refraction of the liquid crystal, the liquid crystal display device comprising:

a first electrode formed on the first substrate and having an effective portion formed on a part of a picture element region such that another part of the picture element region lacks the effective portion of the first electrode; and

a second electrode formed on the second substrate and having an effective portion formed on a part of the picture element region such that another part of the picture element region lacks the effective portion of the second electrode, the effective portion of the second electrode being offset with respect to the effective portion of the first electrode in the picture element region;

wherein when a voltage is applied between the first and the second electrodes, the picture element region is divided into at least two regions, a first region and a second region, whereby an electric field distribution in the liquid crystal of the first region and an electric field distribution in the liquid crystal of the second region are different from each other, and an orientation of the liquid crystal in the first region and an orientation of the liquid crystal in the second region are also different from each other.

2. A liquid crystal display device according to claim 1, wherein

the first electrode is formed on the first substrate within the picture element region;

and

the second electrode is formed on the second substrate along an outer edge of the picture element region.

3. A liquid crystal display device according to claim 1, wherein

the first electrode is formed on the first substrate within the picture element region;

and

the second electrode is formed on the second substrate along outer edges of the picture element region that are opposed to each other.

4. A liquid crystal display device according to claim 1, wherein

the picture element region is substantially rectangular;

the first electrode is formed on the first substrate along a line traversing the picture element region; and

the second electrode is formed on the second substrate along an outer edge of the picture element region.

5. A liquid crystal display device according to claim 1, wherein

the picture element region is substantially rectangular;

the first electrode is formed on the first substrate along a line traversing the picture element region; and

the second electrode is formed on the second substrate along outer edges of the picture element region that are opposed to each other.

6. A liquid crystal display device according to claim 1, wherein

the first electrode is formed on the first substrate along a first line;

and

the second electrode is formed on the second substrate along a second line intersecting the first line.

7. A liquid crystal display device according to claim 6, wherein

the prescribed region is substantially rectangular;

the first electrode is formed on the first substrate along one outer edge of the prescribed region; and

the second electrode is formed on the second substrate along a line substantially traversing the approximate center of the prescribed region and intersecting one outer edge thereof.

8. A liquid crystal display device according to claim 6, wherein

orientation of the liquid crystal is homogeneous;

and

the orientation of the liquid crystal is substantially parallel with or normal to a direction of the first electrode and/or the second electrode.

9. A liquid crystal display device according to claim 6, wherein

without a voltage applied between the first and the second electrodes, an orientation of the liquid crystal is substantially vertical to the first substrate and/or the second substrate.

10. A liquid crystal display device according to claim 6, wherein

the prescribed region includes an opposed region where the first and the second electrodes are opposed to each other with the liquid crystal therebetween, and a non-opposed region where the first and the second electrodes are not opposed to each other;

and

the opposed region is smaller than the non-opposed region.

11. A liquid crystal display device according to claim 6, wherein

when a refractive index anisotropy of the liquid crystal is represented by Δ

n, and a thickness of the liquid crystal is represented by d, Δ

nxd is substantially below 0.5 and above 0.25.

12. A liquid crystal display device according to claim 6, wherein

the first electrode and/or the second electrode is formed of a black matrix layer sealing transmitted light.

13. A liquid crystal device according to claim 1, wherein

orientation of the liquid crystal is homogeneous;

and

the orientation of the liquid crystal is substantially parallel with or normal to a direction of the first electrode and/or the second electrode.

14. A liquid crystal display device according to claim 1, wherein

without a voltage applied between the first and the second electrodes, an orientation of the liquid crystal is substantially vertical to the first substrate and/or the second substrate.

15. A liquid crystal display device according to claim 1, wherein

the prescribed region includes an opposed region where the first and the second electrodes are opposed to each other with the liquid crystal therebetween, and a non-opposed region where the first and the second electrodes are not opposed to each other;

and

the opposed region is smaller than the non-opposed region.

16. A liquid crystal display device according to claim 1, wherein

when a refractive index anisotropy of the liquid crystal is represented by Δ

n, and a thickness of the liquid crystal is represented by d, Δ

nxd is substantially below 0.5 and above 0.25.

17. A liquid crystal display device according to claim 1, wherein

the first electrode and/or the second electrode is formed of a black matrix layer sealing transmitted light.

18. A liquid crystal display device according to claim 17, wherein

a filter layer is formed on the black matrix layer on the first electrode and/or the second substrate;

and

the first electrode and/or the second electrode is the black matrix layer exposed in an opening in the filter layer.

19. A liquid crystal display device including a first substrate and a second substrate which are opposed to each other, and liquid crystal sealed between the first and the second substrates, the liquid crystal display device comprising:

a first electrode formed on the first substrate at a prescribed position in a prescribed region; and

a second electrode formed on the second substrate at a position which is offset with respect to the first electrode in the prescribed region;

wherein when a voltage is applied between the first and the second electrodes, the prescribed region is divided into at least two regions, a first region and a second region, whereby an electric field distribution in the liquid crystal at the first region and an electric field distribution in the liquid crystal at the second region are different from each other, and an orientation of the liquid crystal in the first region and an orientation of the liquid crystal in the second region are also different from each other;

wherein the first electrode is formed on the first substrate within the prescribed region;

the second electrode is formed on the second substrate along outer edges of the prescribed region that are opposed to each other;

a third electrode is formed on the second substrate between the second electrodes that are opposed to each other; and

the first electrode and the third electrode have substantially the same potential, and wherein a voltage is applied between the first and the third electrodes, and the second electrode.

20. A liquid crystal display device including a first substrate and a second substrate which are opposed to each other, and liquid crystal sealed between the first and the second substrates, the liquid crystal display device comprising:

a first electrode formed on the first substrate at a prescribed position in a prescribed region; and

a second electrode formed on the second substrate at a position which is offset with respect to the first electrode in the prescribed region;

wherein when a voltage is applied between the first and the second electrodes, the prescribed region is divided into at least two regions, a first region and a second region, whereby an electric field distribution in the liquid crystal at the first region and an electric field distribution in the liquid crystal at the second region are different from each other, and an orientation of the liquid crystal in the first region and an orientation of the liquid crystal in the second region are also different from each other;

wherein the prescribed region is substantially rectangular;

the first electrode is formed on the first substrate along a line traversing the prescribed region;

the second electrode is formed on the second substrate along outer edges of the prescribed region that are opposed to each other;

a third electrode is formed on the second substrate between the second electrodes that are opposed to each other; and

the first electrode and the third electrode have substantially the same potential, and wherein a voltage is applied between the first and the third electrodes, and the second electrode.

21. A liquid crystal display device including a first substrate and a second substrate which are opposed to each other, and liquid crystal sealed between the first and the second substrates, the liquid crystal display device comprising:

a first electrode formed on the first substrate at a prescribed position in a prescribed region; and

a second electrode formed on the second substrate at a position which is offset with respect to the first electrode in the prescribed region;

wherein when a voltage is applied between the first and the second electrodes, the prescribed region is divided into at least two regions, a first region and a second region, whereby an electric field distribution in the liquid crystal at the first region and an electric field distribution in the liquid crystal at the second region are different from each other, and an orientation of the liquid crystal in the first region and an orientation of the liquid crystal in the second region are also different from each other;

wherein the first electrode is formed on the first substrate within the prescribed region;

the second electrode is formed on the second substrate along an outer edge of the prescribed region; and

a third electrode is formed on the second substrate at a position enclosed by the second electrode; and

the first and the third electrodes have substantially the same potential, and wherein a voltage is applied between the first and the third electrodes, and the second electrode.

22. A liquid crystal display device including a first substrate and a second substrate which are opposed to each other, and liquid crystal sealed between the first and the second substrates, the liquid crystal display device comprising:

a first electrode formed on the first substrate at a prescribed position in a prescribed region; and

a second electrode formed on the second substrate at a position which is offset with respect to the first electrode in the prescribed region;

wherein when a voltage is applied between the first and the second electrodes, the prescribed region is divided into at least two regions, a first region and a second region, whereby an electric field distribution in the liquid crystal at the first region and an electric field distribution in the liquid crystal at the second region are different from each other, and an orientation of the liquid crystal in the first region and an orientation of the liquid crystal in the second region are also different from each other;

wherein the prescribed region is substantially rectangular;

the first electrode is formed on the first substrate along a line traversing the prescribed region;

the second electrode is formed on the second substrate along an outer edge of the prescribed region; and

a third electrode is formed on the second substrate at a position enclosed by the second electrode; and

the first and the third electrodes have substantially the same potential, and wherein a voltage is applied between the first and the third electrodes, and the second electrode.

23. A liquid crystal display device including a first substrate and a second substrate which are opposed to each other, and liquid crystal sealed between the first and the second substrates, the liquid crystal display device comprising:

a first electrode formed on the first substrate at a prescribed position in a prescribed region; and

a second electrode formed on the second substrate at a position which is offset with respect to the first electrode in the prescribed region;

wherein when a voltage is applied between the first and the second electrodes, the prescribed region is divided into at least two regions, a first region and a second region, whereby an electric field distribution in the liquid crystal at the first region and an electric field distribution in the liquid crystal at the second region are different from each other, and an orientation of the liquid crystal in the first region and an orientation of the liquid crystal in the second region are also different from each other;

wherein the prescribed region is substantially rectangular;

the first electrode is formed on the first substrate along a first line slantly traversing the prescribed region; and

the second electrode is formed on the second substrate along a second line slantly traversing the prescribed region and intersecting the first line.

24. A liquid crystal display device including a first substrate and a second substrate which are opposed to each other, and liquid crystal sealed between the first and the second substrates, the liquid crystal display device comprising:

a first electrode formed on the first substrate at a prescribed position in a prescribed region; and

a second electrode formed on the second substrate at a position which is offset with respect to the first electrode in the prescribed region;

wherein when a voltage is applied between the first and the second electrodes, the prescribed region is divided into at least two regions, a first region and a second region, whereby an electric field distribution in the liquid crystal at the first region and an electric field distribution in the liquid crystal at the second region are different from each other, and an orientation of the liquid crystal in the first region and an orientation of the liquid crystal in the second region are also different from each other;

wherein the prescribed region is substantially rectangular;

the first electrode is formed on the first substrate along a first line traversing the prescribed region and extending substantially in parallelism with one outer edge; and

the second electrode is formed on the second substrate along the second line traversing the prescribed region and extending substantially perpendicular to the first line.

25. A liquid crystal display device including a first substrate and a second substrate which are opposed to each other, and liquid crystal sealed between the first and the second substrates, the liquid crystal display device comprising:

a first electrode formed on the first substrate at a prescribed position in a prescribed region; and

a second electrode formed on the second substrate at a position which is offset with respect to the first electrode in the prescribed region;

wherein when a voltage is applied between the first and the second electrodes, the prescribed region is divided into at least two regions, a first region and a second region, whereby an electric field distribution in the liquid crystal at the first region and an electric field distribution in the liquid crystal at the second region are different from each other, and an orientation of the liquid crystal in the first region and an orientation of the liquid crystal in the second region are also different from each other;

wherein on one side of a parting line dividing the first and the second regions, the first substrate is treated for orientation at a first pre-tilt angle while the second substrate is treated for orientation at a second pre-tilt angle larger than the first pre-tilt angle;

on the other side of the parting line dividing the first and the second regions, the first substrate is treated for orientation at a third pre-tilt angle while the second substrate is treated for orientation at a fourth pre-tilt angle smaller than the third pre-tilt angle;

when a voltage is applied between the first and the second electrodes, an orientation of the liquid crystal in the first region is different between the two regions divided by the parting line, and an orientation of the liquid crystal in the second region is different between the two regions divided by the parting line.

26. A liquid crystal display device according to claim 25, wherein

the first and the fourth pre-tilt angles are substantially the same;

and

the second and the third pre-tilt angles are substantially the same.

27. A liquid crystal display device according to claim 26, wherein

the prescribed region is substantially rectangular;

the prescribed region is quartered by a boundary line between the first and the second regions and the parting line dividing the first and the second regions; and

when a voltage is applied between the first and the second electrodes, an orientation of liquid crystal in the respective divided regions is radial with respect to the intersection of the boundary line and the parting line.

28. A liquid crystal display device according to claim 25, wherein

the prescribed region is substantially rectangular;

the prescribed region is quartered by a boundary line between the first and the second regions and the parting line dividing the first and the second regions; and

when a voltage is applied between the first and the second electrodes, an orientation of liquid crystal in the respective divided regions is radial with respect to the intersection of the boundary line and the parting line.

29. A liquid crystal display device according to claim 25, wherein

orientation of the liquid crystal is homogeneous;

and

the orientation of the liquid crystal is substantially parallel with or normal to a direction of the first electrode and/or the second electrode.

30. A liquid crystal display device according to claim 25, wherein

without a voltage applied between the first and the second electrodes, an orientation of the liquid crystal is substantially vertical to the first substrate and/or the second substrate.

31. A liquid crystal display device according to claim 25, wherein

the prescribed region includes an opposed region where the first and the second electrodes are opposed to each other with the liquid crystal therebetween, and a non-opposed region where the first and the second electrodes are not opposed to each other;

and

the opposed region is smaller than the non-opposed region.

32. A liquid crystal display device according to claim 25, wherein

when a refractive index anisotropy of the liquid crystal is represented by Δ

n, and a thickness of the liquid crystal is represented by d, Δ

nxd is substantially below 0.5 and above 0.25.

33. A liquid crystal display device according to claim 25, wherein

the prescribed region is a picture element region.

34. A liquid crystal display device according to claim 25, wherein

the first electrode and/or the second electrode is formed of a black matrix layer sealing transmitted light.

35. A liquid crystal display device including a first substrate and a second substrate which are opposed to each other, and liquid crystal sealed between the first and the second substrates, the liquid crystal display device comprising:

a first electrode formed on the first substrate at a prescribed position in a prescribed region; and

a second electrode formed on the second substrate at a position which is offset with respect to the first electrode in the prescribed region;

wherein when a voltage is applied between the first and the second electrodes, the prescribed region is divided into at least two regions, a first region and a second region, whereby an electric field distribution in the liquid crystal at the first region and an electric field distribution in the liquid crystal at the second region are different from each other, and an orientation of the liquid crystal in the first region and an orientation of the liquid crystal in the second region are also different from each other;

wherein the first electrode is formed on the first substrate along the first line;

the second electrode is formed on the second substrate along a second line intersecting the first line;

wherein on one side of a parting line dividing the first and the second regions, the first substrate is treated for orientation at a first pre-tilt angle while the second substrate is treated for orientation at a second pre-tilt angle larger than the first pre-tilt angle;

on the other side of the parting line dividing the first and the second region, the first substrate is treated for orientation at a third pre-tilt angle while the second substrate is treated for orientation at a fourth pre-tilt angle smaller than the third pre-tilt angle;

when a voltage is applied between the first and the second electrodes, an orientation of the liquid crystal in the first region is different between the two regions divided by the parting line, and an orientation of the liquid crystal in the second region is different between the two regions divided by the parting line.

36. A liquid crystal display device according to claim 35, wherein

the first and the fourth pre-tilt angles are substantially the same;

and

the second and the third pre-tilt angles are substantially the same.