Liquid crystal display device

• US 20030030761A1
• Filed: 10/10/2002
• Published: 02/13/2003
• Est. Priority Date: 06/22/1996
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: Komatsu Hiroshi
• Inventors: Hiroshi, Komatsu
• Granted Patent: US 6,778,245 B2
• Time in Patent Office: Days
• US Class Current: 349/43
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]

Abstract

A liquid crystal display device includes first and second substrates, a plurality of gate bus lines and data bus lines on the first substrate, the gate bus lines being perpendicular to the data bus lines, a plurality of pixels defined by the gate bus lines and the data bus lines, the pixels having a plularity of regions, at least a pair of electrodes in each region having a common direction, and a plurality of liquid crystal molecules between the substrates.

Claims

1. A liquid crystal display device, comprising:

first and second substrates;

a plurality of gate bus lines and data bus lines on the first substrate, the gate bus lines being perpendicular to the data bus lines;

a plurality of pixels defined by the gate bus lines and the data bus lines, the pixels having a plularity of regions;

at least a pair of electrodes in each region having a common direction; and

a plurality of liquid crystal molecules between the substrates.

2. The device according to claim 1, wherein the electrodes include a data electrode and a common electrode.

3. The device according to claim 1, wherein an electric field having an intensity changing gradually from the first substrate to the second substrate is applied to the liquid crystal molecules.

4. The device according to claim 3, wherein the liquid crystal molecules are rotated gradually from the first substrate to the second substrate when the electric field is applied to the electrodes.

5. A liquid crystal display device, comprising:

first and second substrates;

a plurality of gate bus lines and data bus lines on the first substrate in a matrix form;

a plurality of pixels defined by the gate bus lines and the data bus lines, the pixels having first and second regions;

at least one common bus line at each pixel, the common bus line being parallel to the gate bus line;

at least a pair of first and second electrodes in the first and second regions, respectively, the first and second electrodes having first and second electrode elongation directions (θ

_EL1 and θ

_EL2) with respect to a longitudinal direction of the common bus line;

a color filter layer over the second substrate;

first and second alignment layers over the first and second substrates, the first and second alignment layers having first and second alignment directions (θ

_R1 and θ

_R2), respectively;

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

a polarizer and a analyzer attached to the first substrate and the second substrate, respectively.

6. The device according to claim 5, wherein the electrodes are separated by a distance smaller than a thickness of the liquid crystal layer.

7. The device according to claim 5, wherein the liquid crystal layer has a retardation value (And) of λ

/2<

Δ

nd<

λ

(where Δ

n is an anisotropy of a refractive index, d is a thickness of the liquid crystal layer, and λ

is a wavelength of an incident light).

8. The device according to claim 7, wherein the retardation value is approximately 0.74λ

.

9. The device according to claim 5, wherein the first alignment layer has an anchoring energy lower than that of the second alignment layer.

10. The device according to claim 9, wherein the second alignment layer includes a polygamic acid base material.

11. The device according to claim 5, wherein the first and second alignment layers have rubbing directions parallel to a polarized direction of the analyzer.

12. The device accordance to claim 11, wherein the polarizer has a polarized direction perpendicular to the polarized direction of the analyzer.

13. The device according to claim 5, wherein the first electrode elongation direction has an absolute value the same as that of the second electrode elongation direction.

14. The device according to claim 5, wherein the first and second electrode elongation directions are between 0°

and 90° and

between −

90° and

0°

, respectively.

15. The device according to claim 14, wherein the first and second electrode elongation directions are −

90° and

90°

with respect to a longitudinal direction of the gate bus lines, respectively.

16. The device according to claim 5, wherein the first and second electrode elongation directions are 90°

and between 90° and

180°

, respectively.

17. The device according to claim 16, wherein the θ

_EL1<

θ

_R1<

θ

_EL2 and the θ

_R2=180°

−

θ

EL1.

18. The device according to claim 5, wherein the first and second electrode elongation directions have complementary angles with respect to the longitudinal direction of the common bus line.

19. The device according to claim 18, wherein the first and second alignment directions have ranges of 0°

<

θ

_R1<

90° and

−

90°

<

θ

_R2<

0°

with respect to the common bus line, respectively.

20. The device in accordance with claim 19, wherein the first and second alignment directions have a relationship of θ

_R1−

θ

_R2.

21. The device according to claim 5, further comprising a first optical compensator between the polarizer and the first substrate.

22. The device according to claim 5, further comprising a second optical compensator between the second substrate and the analyzer.

23. A liquid crystal display device having a plurality of pixels each including a plurality of regions, the device comprising:

first and second substrates;

a liquid crystal molecular layer having liquid crystal molecules between the first and second substrates;

a plurality of electrodes in each region of the pixels, an electric field parallel to the substrates being applied to the electrodes; and

first and second alignment layers over the first and second substrates, respectively, the first and second alignment layers having first and second alignment directions of θ

1 and θ

2 relative to an electrode elongating direction.

24. The device according to claim 23, wherein the liquid crystal molecules in each region and a neighboring region are rotated in directions opposite with each other when an electric field is applied in the device.

25. The device according to claim 23, wherein the electrodes include at least a pair of electrodes.

26. The device according to claim 25, wherein the pair of electrodes include a data electrode and a common electrode.

27. The device according to claim 25, wherein a gap between the pair of electrodes is smaller than a thickness of the liquid crystal molecular layer.

28. The device according to claim 23, wherein the first alignment direction is 0°

<

θ

₁<

90°

.

29. The device according to claim 23, wherein the second alignment direction is −

90°

<

θ

₂<

0°

.

30. The device according to claim 23, wherein the first and second alignment directions have a relationship of θ

₁=−

θ

₂.

31. The device according to claim 23, wherein the liquid crystal layer has a retardation value And of λ

/2<

Δ

nd≦

λ

(where Δ

n is an anisotropy of a refractive index, d is thickness of the liquid crystal molecular layer, and λ

is a wavelength of an incident light).

32. The device according to claim 31, wherein the retardation value is about 0.74λ

.

33. A liquid crystal display device having a plurality of pixels each including a plurality of regions, the device comprising:

first and second substrates;

a liquid crystal molecular layer having liquid crystal molecules between the first and second substrates;

a plurality of electrodes on the first substrate in each region of the pixels, an electric field parallel to the substrates being applied to the electrodes, which is different from the electric field of a neighboring region to rotate the liquid crystal molecules in opposite directions in each neighboring region applying to the electrodes in each region; and

first and second alignment layers over the first and second substrates, the first and second alignment layers providing for is first and second alignment directions of θ

₁ and θ

₂ with respect to a longitudinal direction of a common bus line.

34. The device according to claim 33, wherein the electrodes includes at least a pair of electrodes.

35. The device according to claim 34, wherein the pair of electrodes includes a data electrode and a common electrode.

36. The device according to claim 34, wherein the pair of electrodes have a space therebetween smaller than a thickness of the liquid crystal molecular layer.

37. The device according to claim 33, wherein the first alignment direction has an angle of 0°

<

θ

₁<

90°

.

38. The device according to claim 33, wherein the second alignment direction has an angle of −

90°

<

θ

₂<

0°

.

39. The device according to claim 33, wherein an angle between the first alignment direction and the second alignment direction is a supplementary angle.

40. The device according to claim 33, wherein the liquid crystal molecular layer has a retardation value (Δ

nd) of λ

/2<

Δ

nd≦

λ

(where Δ

n is an anisotropy of a refractive index, d is a thickness of the liquid crystal layer, and λ

is a wavelength of an incident light).

41. The device according to claim 39, wherein the retardation value 0.74λ

.