LIQUID CRYSTAL DISPLAY

• US 20180004049A1
• Filed: 08/30/2017
• Published: 01/04/2018
• Est. Priority Date: 03/28/2008
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: JUNG, Mee-Hye, SOHN, Ji-Won, LYU, Jae-Jin, CHAI, Chong-Chul
• Granted Patent: US 10,877,324 B2
• Time in Patent Office: Days
• CPC Class Codes: G02F 1/1337 Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
• CPC Class Codes: G02F 1/133715 by first depositing a monomer
• CPC Class Codes: G02F 1/133742 for homeotropic alignment
• CPC Class Codes: G02F 1/133753 with different alignment orientations or pretilt angles on a same surface, e.g. for grey scale or improved viewing angle
• CPC Class Codes: G02F 1/133788 by light irradiation, e.g. linearly polarised light photo-polymerisation
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/134336 Matrix
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/13624 having more than one switching element per pixel
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence

Abstract

A liquid crystal display includes a pixel electrode including a first subpixel electrode and a second subpixel electrode spaced apart with a gap therebetween, a common electrode facing the pixel electrode, and a liquid crystal layer formed between the pixel electrode and the common electrode and including a plurality of liquid crystal molecules. The first and second subpixel electrodes include a plurality of branches, and each of the first and second subpixel electrodes includes a plurality of subregions. The branches extend in different directions in different subregions.

Claims

1. A display device, comprising:

a first pixel electrode;

a data line extending substantially in a first direction;

a first transistor including a first source electrode and a first drain electrode, the first drain electrode being electrically connected to the first pixel electrode;

a common electrode facing the first pixel electrode; and

a liquid crystal layer, which is disposed between the first pixel electrode and the common electrode, and comprises a plurality of liquid crystal molecules substantially vertically aligned with respect to a plane of the first pixel electrode or the common electrode in an absence of an electric field in the liquid crystal layer,

wherein;

the first pixel electrode includes first, second, third, and fourth domains, each of the first, second, third, and fourth domains being defined by an orientation direction of the liquid crystal molecules corresponding to the first pixel electrode when a voltage is applied to the first pixel electrode; and

the first source electrode is curved substantially in a “

U”

shape.

2. The display device of claim 1, wherein the first drain electrode includes at least two bent portions.

3. The display device of claim 1, wherein the first drain electrode includes a portion contacting the first pixel electrode at a boundary between at least two domains among the plurality of domains.

4. The display device of claim 1, wherein the first drain electrode includes:

a first portion including a first end portion facing the first source electrode, the first portion extending from the first end portion substantially in the first direction;

a second portion connected to the first portion and extending substantially in a second direction perpendicular to the first direction; and

a third portion connected to the second portion and extending substantially in the first direction,

wherein the third portion includes the portion contacting the first pixel electrode.

5. The display device of claim 4, wherein

the third portion includes a second end portion contacting the first pixel electrode, and

the second end portion is enlarged than other portion of the third portion adjacent to the second end portion.

6. The display device of claim 4, further comprising a storage electrode including a portion overlapping at least a portion of an end portion of the third portion.

7. The display device of claim 6, wherein the storage electrode includes a portion forming a substantially “

H”

shape.

8. The display device of claim 7, wherein:

the portion of the storage electrode forming the substantially “

H”

shape includes a horizontal portion; and

the third portion overlaps the horizontal portion.

9. The display device of claim 6, wherein the storage electrode includes a portion forming a substantially cross shape.

10. The display device of claim 9, wherein the third portion overlaps a center portion of the portion forming the substantially cross shape.

11. The display device of claim 6, further comprising a second pixel electrode insulated from the first pixel electrode,

wherein an area of the second pixel electrode is greater than an area of the first pixel electrode.

12. The display device of claim 11, wherein the second pixel electrode includes a first electrode part and a second electrode part that are connected to each other.

13. The display device of claim 12, wherein the first pixel electrode is disposed between the first electrode part and the second electrode part in a plan view.

14. The display device of claim 11, further comprising a second transistor electrically connected to the second pixel electrode.

15. The display device of claim 14, wherein:

the second pixel electrode includes fifth, sixth, seventh, and eighth domains, each of the fifth, sixth, seventh, and eighth domains being defined by an orientation direction of the liquid crystal molecules corresponding to the second pixel electrode when a voltage is applied to the second pixel electrode; and

the second transistor includes a second drain electrode contacting the second pixel electrode at a boundary of adjacent domains of the plurality of domains.

16. The display device of claim 15, wherein the storage electrode further includes a portion overlapping the second pixel electrode.

17. The display device of claim 16, wherein a portion of the second pixel electrode contacting the second drain electrode overlaps at least a portion of the storage electrode.

18. The display device of claim 1, further comprising an alignment layer that has been irradiated by light to generate pretilt of the liquid crystal molecules,

wherein the alignment layer is disposed between the first pixel electrode and the liquid crystal layer.

19. The display device of claim 1, further comprising a polymer disposed between the first pixel electrode and the common electrode, the polymer configured to facilitate pretilting of the liquid crystal molecules,

wherein the polymer comprises a photopolymerized material.

20. The display device of claim 19, wherein the polymer includes a portion disposed close to a surface of a display panel including the first pixel electrode, the surface of the display panel being disposed between the liquid crystal molecules and the first pixel electrode.

21. A display device, comprising:

a pixel electrode;

a data line extending substantially in a first direction;

a gate line extending substantially in a second direction;

a thin film transistor, the thin film transistor comprising;

a gate electrode connected to the gate line;

a semiconductor insulated from the gate electrode;

a source electrode connecting the data line and the semiconductor; and

a drain electrode spaced apart from the source electrode in a plan view, the drain electrode connecting the semiconductor and the pixel electrode;

a common electrode facing the pixel electrode; and

a liquid crystal layer disposed between the pixel electrode and the common electrode, the liquid crystal layer comprising a plurality of liquid crystal molecules which are substantially vertically aligned with respect to a plane of the pixel electrode or the common electrode in an absence of an electric field in the liquid crystal layer,

wherein;

the liquid crystal layer on the pixel electrode is divided into first, second, third, and fourth domains, each of the first, second, third, and fourth domains being defined by an orientation direction of the liquid crystal molecules when a voltage is applied to the pixel electrode; and

a space between the source electrode and the drain electrode forms a “

U”

shape in the plan view.

22. The display device of claim 21, further comprising a storage electrode overlapping the pixel electrode,

wherein the storage electrode comprises:

a first portion that extends from a first end to a second end substantially in the first direction and comprises a first connection point between the first end and the second end;

a second portion that is spaced apart from the first portion, extends from a third end to a fourth end substantially in the first direction, and comprises a second connection point between the third end and the fourth end; and

a third portion that is connected to the first connection point of the first portion and to the second connection point of the second portion, and extends along a boundary between the first domain and the second domain.

23. The display device of claim 22, wherein the drain electrode comprises:

a fourth portion facing the source electrode and extending substantially in the first direction;

a fifth portion connected to the fourth portion and extending substantially in a second direction perpendicular to the first direction; and

a sixth portion connected to the fifth portion and extending substantially in the first direction,

wherein the sixth portion is electrically connected to the pixel electrode through a contact hole.

24. The display device of claim 23, wherein the sixth portion includes a portion contacting the pixel electrode at a boundary between at least two domains among the first, second, third, and fourth domains.

25. The display device of claim 24, further comprising an alignment layer disposed on the pixel electrode,

wherein the alignment layer is irradiated by light to generate pretilt of the liquid crystal molecules.

26. The display device of claim 24, further comprising a polymer disposed between the pixel electrode and the common electrode, the polymer configured to facilitate pretilting of the liquid crystal molecules,

wherein the polymer comprises a photopolymerized material.

27. The display device of claim 22, wherein the drain electrode includes a portion contacting the pixel electrode at a boundary between at least two domains among the first, second, third, and fourth domains.

28. The display device of claim 27, further comprising an alignment layer disposed on the pixel electrode,

wherein the alignment layer is irradiated by light to generate pretilt of the liquid crystal molecules.

29. The display device of claim 27, further comprising a polymer disposed between the pixel electrode and the common electrode, the polymer configured to facilitate pretilting of the liquid crystal molecules,

wherein the polymer comprises a photopolymerized material.

30. The display device of claim 22, further comprising an alignment layer disposed on the pixel electrode,

wherein the alignment layer is irradiated by light to generate pretilt of the liquid crystal molecules.

31. The display device of claim 22, further comprising a polymer disposed between the pixel electrode and the common electrode, the polymer configured to facilitate pretilting of the liquid crystal molecules,

wherein the polymer comprises a photopolymerized material.

32. The display device of claim 21, wherein the drain electrode comprises:

a fourth portion facing the source electrode and extending substantially in the first direction;

a fifth portion connected to the fourth portion and extending substantially in a second direction perpendicular to the first direction; and

a sixth portion connected to the fifth portion and extending substantially in the first direction,

wherein the sixth portion is electrically connected to the pixel electrode through a contact hole.

33. The display device of claim 32, wherein the sixth portion includes a portion contacting the pixel electrode at a boundary between at least two domains among the first, second, third, and fourth domains.

34. The display device of claim 33, further comprising an alignment layer disposed on the pixel electrode,

wherein the alignment layer is irradiated by light to generate pretilt of the liquid crystal molecules.

35. The display device of claim 33, further comprising a polymer disposed between the pixel electrode and the common electrode, the polymer configured to facilitate pretilting of the liquid crystal molecules,

wherein the polymer comprises a photopolymerized material.

36. The display device of claim 32, further comprising an alignment layer disposed on the pixel electrode,

wherein the alignment layer is irradiated by light to generate pretilt of the liquid crystal molecules.

37. The display device of claim 32, further comprising a polymer disposed between the pixel electrode and the common electrode, the polymer configured to facilitate pretilting of the liquid crystal molecules,

wherein the polymer comprises a photopolymerized material.

38. The display device of claim 21, wherein the drain electrode includes a portion contacting the pixel electrode at a boundary between at least two domains among the first, second, third, and fourth domains.

39. The display device of claim 38, further comprising an alignment layer disposed on the pixel electrode,

wherein the alignment layer is irradiated by light to generate pretilt of the liquid crystal molecules.

40. The display device of claim 38, further comprising a polymer disposed between the pixel electrode and the common electrode, the polymer configured to facilitate pretilting of the liquid crystal molecules,

wherein the polymer comprises a photopolymerized material.

41. The display device of claim 21, further comprising an alignment layer disposed on the pixel electrode,

wherein the alignment layer is irradiated by light to generate pretilt of the liquid crystal molecules.

42. The display device of claim 21, further comprising a polymer disposed between the pixel electrode and the common electrode, the polymer configured to facilitate pretilting of the liquid crystal molecules,

wherein the polymer comprises a photopolymerized material.