Liquid crystal display device of an in-plane switching mode including a black matrix layer

• US 6,937,312 B2
• Filed: 03/26/2003
• Issued: 08/30/2005
• Est. Priority Date: 03/28/2002
• Status: Expired due to Term

• Current Assignee: NLT Technologies, Ltd.
• Original Assignee: NEC LCD Technologies Limited (NEC Corporation)
• Inventors: Kuroha, Shoichi, Kadotani, Tsutomu
• Primary Examiner(s): NGO, HUYEN LE
• Application Number:
  US10/396,562
• Publication Number:
  US 20030184693A1
• Time in Patent Office: 888 Days
• Field of Search: 349/141, 349/139, 349/110, 345/100
• US Class Current: 349/141
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]

Abstract

A black matrix layer 14 is formed on a counter substrate 13 along the direction where a scanning line 2 extends, so that it continuously covers the upper parts of a common electrode line 3a, the scanning line 2, a space between the common electrode line 3a and the scanning line 2, a TFT 5, a space between the scanning line 2 and a common electrode line 3b, and the common electrode line 3b, and in the portion opposed to the signal line, the black matrix layer is eliminated.

Claims

1. A liquid crystal display device, comprising:

an active matrix substrate including a switching element, a pixel electrode;

a first common electrode line, and a second common electrode line,

said switching element being arranged in the vicinity of a crossing portion of a scanning line and a signal line,

said pixel electrode being connected to said switching element;

a third common electrode line being arranged to generate a lateral electric field between said pixel electrode and said third common electrode line;

a counter substrate opposed to said active matrix substrate being provided with a black matrix layer; and

a liquid crystal disposed between said active matrix substrate,

wherein said black matrix layer is extended along an extending direction of said scanning line without overlapping a region between said first common electrode line and said second common electrode line.

2. The liquid crystal display device according to claim 1, wherein said pixel electrode and said third common electrode comprise a curved part including an odd number of bends within one picture element, and

wherein said signal line comprises a portion adjoining at least one of said pixel electrode and said third common electrode line and comprising a curved part including an odd number of bends.

3. The liquid crystal display device according to claim 2, wherein said signal line comprises a wide width portion in the portion adjoining to said pixel electrode.

4. The liquid crystal display device according to claim 2, wherein said counter substrate includes a plurality of color layers in which end portions are mutually superposed by adjoining picture elements.

5. The liquid crystal display device according to claim 4, wherein said color superposing region is arranged above the signal line of the active matrix substrate.

6. The liquid crystal display device according to claim 1, wherein said signal line comprises a wide width portion in the portion adjoining to said pixel electrode.

7. The liquid crystal display device according to claim 1, wherein said counter substrate includes a plurality of color layers in which end portions are mutually superposed by adjoining picture elements.

8. The liquid crystal display device according to claim 7, wherein said color superposing region is arranged above the signal line of the active matrix substrate.

9. The liquid crystal display device according to claim 1, wherein said scanning line comprises a first scanning line adjacent to said first common electrode line and a second scanning line adjacent to said second common electrode line.

10. The liquid crystal display device according to claim 9, wherein said black matrix layer extends along an extending direction of said first scanning line such that said black matrix layer covers said first common electrode line, said first scanning line, a space between said first common electrode line and said first scanning line, and said switching element.

11. The liquid crystal display device according to claim 9, wherein said black matrix layer extends along an extending direction of said second scanning line such that said black matrix layer covers said second common electrode line, said second scanning line, and a space between said second common electrode line and said second scanning line.

12. The liquid crystal display device according to claim 9, wherein said black matrix layer extends along an extending direction of said first scanning line such that said black matrix layer continuously covers said first common electrode line, said first scanning line, a space between said first common electrode line and said first scanning line, and said switching element.

13. The liquid crystal display device according to claim 9, wherein said black matrix layer extends along an extending direction of said second scanning line such that said black matrix layer continuously covers said second common electrode line, said second scanning line, and a space between said second common electrode line and said second scanning line.

14. The liquid crystal display device according to claim 1, wherein said black matrix layer comprises a black matrix layer including a resin.

15. The liquid crystal display device according to claim 1, wherein said black matrix layer comprises a black matrix layer including a black pigment which is distributed in an organic resin material.

16. The liquid crystal display device according to claim 1, wherein said first common electrode and said second common electrode extend along said extending direction of said scanning line.

17. The liquid crystal display device according to claim 1, wherein said third common electrode extends substantially along a direction other than said extending direction of said scanning line.

18. The liquid crystal display device according to claim 1, wherein said black matrix layer extends along an extending direction other than an extending direction of said signal line.

19. The liquid crystal display device according to claim 1, wherein said black matrix layer covers a portion of said signal line other than a portion of said signal line which is disposed in said region between said first common electrode line and said second common electrode line.

20. The liquid crystal display device according to claim 1, wherein said black matrix layer does not cover a portion of said signal line which is disposed in said region between said first common electrode line and said second common electrode line.

21. The liquid crystal display device according to claim 1, wherein a portion of said counter substrate, which is opposed to said signal line of said active matrix substrate, is not provided with the black matrix layer such that light leak phenomenon in a peripheral portion of a display picture element region is eliminated.

22. The liquid crystal display device according to claim 21, wherein said peripheral portion of said display picture element region includes a vicinity of a curved signal line.

23. The liquid crystal display device according to claim 1, wherein said third common electrode line comprises a shield common electrode.

24. The liquid crystal display device according to claim 1, wherein a width (L) of said shield common electrode is greater than a width of said signal line.

25. The liquid crystal display device according to claim 24, wherein said width (L) of said shield common electrode is projected to both sides of said signal line by a factor of said width (L).

26. The liquid crystal display device according to claim 24, wherein said width (L) satisfies a condition 4 μ

m≦

L≦

10 μ

m, and more preferably, wherein said width (L) satisfies a condition 6 μ

m≦

L≦

10 μ

m.

27. The liquid crystal display device according to claim 1, wherein at least one of said first common electrode line and said second common electrode line comprise an opaque conductive material.

28. The liquid crystal display device according to claim 1, wherein said third common electrode line comprises a transparent conductive material.

29. A liquid crystal display device, comprising:

an active matrix substrate including a switching element, a pixel electrode, and a common electrode line, wherein said common electrode line comprises a first common electrode line, a second common electrode line, and a third common electrode line;

a counter substrate opposed to said active matrix substrate; and

a black matrix layer provided on said counter substrate,

wherein said switching element is arranged in the vicinity of a crossing portion of a scanning line and a signal line, and

wherein said black matrix layer is extended along an extending direction of said scanning line without overlapping a region between said first common electrode line and said second common electrode line.

30. The liquid crystal display device according to claim 29, further comprising a liquid crystal layer disposed between said active matrix substrate and said counter substrate.

31. The liquid crystal display device according to claim 29, wherein said pixel electrode is connected to said switching element.

32. The liquid crystal display device according to claim 29, wherein said third common electrode line is arranged to generate a lateral electric field between said pixel electrode and said third common electrode line.

33. The liquid crystal display device according to claim 29, wherein said pixel electrode and said third common electrode comprise a curved part including an odd number of bends within one picture element.

34. The liquid crystal display device according to claim 29, wherein said signal line comprises a portion adjoining at least one of said pixel electrode and at least one of said first common electrode, said second common electrode, and said third common electrode.

35. The liquid crystal display device according to claim 34, wherein said portion comprises a curved part including an odd number of bends.

36. A liquid crystal display device, comprising:

an active matrix substrate;

a counter substrate opposed to said active matrix substrate;

a liquid crystal display layer between said active matrix substrate and said counter substrate; and

a black matrix layer provided on said counter substrate,

wherein said black matrix layer is formed on a portion of said counter substrate other than a portion of said counter substrate which is opposed to a signal line.