Liquid crystal display device

• US 5,598,285 A
• Filed: 09/20/1993
• Issued: 01/28/1997
• Est. Priority Date: 09/18/1992
• Status: Expired due to Term

• Current Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Hitachi, Ltd.
• Inventors: Ohta, Masuyuki, Sasaki, Tohru, Kondo, Katsumi, Kawachi, Genshiro, Abe, Hidetoshi, Suzuki, Kenkichi, Terao, Hiromu, Ohwada, Junichi
• Primary Examiner(s): MILLER, CHARLES LELAND
• Assistant Examiner(s): Trice, Ron
• Application Number:
  US08/123,472
• Time in Patent Office: 1,226 Days
• Field of Search: 359/59, 359/87, 359/89
• US Class Current: 349/39
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 2201/122 having a particular pattern
• CPC Class Codes: G02F 2201/128 field shaping

Abstract

A liquid crystal display device has a plurality of pixel elements, the optical transmissivity of which is varied by suitable electrical signals. The liquid crystal display device has electrodes which apply electric fields to a liquid crystal layer, the electric fields having components in a direction generally parallel to the liquid crystal layer. Each pixel element has at least one pixel electrode which extends in a common direction as a signal electrode and common electrodes which extend over several pixel elements. The common electrodes may be on the same side of the liquid crystal layer as the pixel and signal electrodes, or they may be on opposite sides. Each pixel may have two pixel electrodes with the signal electrode disposed therebetween, and there are then a pair of common electrodes with the pixel electrodes therebetween. The common electrodes may be common to adjacent pixel elements. The pixel electrodes and the common electrodes may be separated by an insulating film.

Claims

1. A liquid crystal display device having a plurality of pixel elements and means for applying electrical signals to said plurality of pixel elements for varying the optical transmissivity thereof, said liquid crystal display device including:

a polarizer having at least one polarizing plate;

a liquid crystal layer extending in a plane parallel to said at least one polarizing plate;

a plurality of pixel electrodes, signal wiring electrodes and scanning wiring electrodes forming a plurality of thin film transistor devices corresponding to the plurality of pixel elements, said pixel electrodes extending in a common direction within each pixel element and said signal wiring electrodes extending in said common direction over more than one of said plurality of pixel elements; and

common electrodes spaced from said plurality of thin film transistor devices, said common electrodes extending in said common direction over said more than one of said plurality of pixel elements;

wherein said means for applying electrical signals is arranged to apply said electrical signals in such a way that electric fields between said pixel electrodes and said common electrodes have components in a direction parallel to the plane of said liquid crystal layer, thereby to vary the optical transmissivity of light passing through said at least one polarizing plate and said liquid crystal layer for each pixel element; and

wherein at least one of;

(a) there are a pair of pixel electrodes for each pixel element, said signal wiring electrodes extending between said pair of pixel electrodes at each pixel element, and said pair of pixel electrodes being disposed between a pair of common electrodes at each pixel element;

(b) said common electrodes are on an opposite side of said liquid crystal layer from said pixel electrodes;

(c) there is an insulating film between said pixel electrode and the common electrodes at each pixel element, and wherein said means for applying signals is arranged to apply a driving signal to said scanning wiring electrodes, said driving signal having a scanning period which is shorter than a time constant formed by a product of a specific resistance of said insulating film and a dielectric constant of said insulating film;

(d) at least one of said common electrodes is common to two adjacent ones of said plurality of pixel elements; and

(e) said liquid crystal display device has an optical anisotropic medium with a phase difference less than a product of a thickness of the liquid crystal layer and a refractive index anisotropy of the liquid crystal layer, a difference between an absolute value of the product of the thickness of the liquid crystal layer and the refractive index anisotropy of the liquid crystal layer and an absolute value of the phase difference of the anisotropic medium being between 0.21 μ

m and 0.36 μ

m, and wherein the angles between components of electric fields in a direction parallel to the plane of said liquid crystal layer and the direction of orientation of molecules at opposite surfaces of the liquid crystal layer are the same.

2. A liquid crystal display device according to claim 1, wherein at least (a) is provided.

3. A liquid crystal display device according to claim 1, wherein at least (b) is provided.

4. A liquid crystal display device according to claim 1, wherein at least (c) is provided.

5. A liquid crystal display device according to claim 1, wherein at least (d) is provided.

6. A liquid crystal display device according to claim 1, wherein at least (e) is provided.

7. A liquid crystal display device having at least one pixel element and means for applying electrical signals to said at least one pixel element for varying the optical transmissivity thereof, said least one pixel element comprising:

a polarizer including at least one polarizing plate;

a liquid crystal layer extending in a plane parallel to said at least one polarizing plate;

a transistor element having a pair of first electrodes, a second electrode between said pair of first electrodes and a gate electrode, said pair of first electrodes and said second electrode extending in a common direction; and

a pair of common electrodes extending in said common direction, said transistor element being disposed between said pair of common electrodes;

wherein said means for applying electrical signals is arranged to apply said signals in such a way that electric fields between said pair of common electrodes have components in a direction parallel to the plane of said liquid crystal layer, thereby to vary the optical transmissivity of light passing through said at least one polarizing plate and said liquid crystal layer.

8. A liquid crystal display device according to claim 7, wherein said transistor element and said common electrodes are on the same side of said liquid crystal layer.

9. A liquid crystal display device according to claim 8, having an insulating film extending over and in direct contact with said pair of first electrodes, said insulating film also being in contact with said liquid crystal layer.

10. A liquid crystal display device according to claim 9 wherein said insulating film is an organic polymer.

11. A liquid crystal display device according to claim 7, wherein said transistor element and said pair of common electrodes are on opposite sides of said liquid crystal layer.

12. A liquid crystal display device having at least one pixel element and means for applying electrical signals to each of said plurality of pixel elements for varying the optical transmissivity thereof, each of said plurality of pixel elements comprising:

a polarizer including at least one polarizing plate;

a liquid crystal layer extending in a plane parallel to said at least one polarizing plate;

a transistor element having a pair of first electrodes, a second electrode between said pair of first electrodes and a gate electrode, said pair of first electrodes and said second electrode extending in a common direction; and

a pair of common electrodes extending in said common direction, said transistor element being between said pair of common electrodes;

wherein said means for applying electrical signals is arranged to apply said signals in such a way that electric fields between said pair of said first electrodes and said pair of common electrodes have components in a direction parallel to the plane of said liquid crystal layer, thereby to vary the optical transmissivity of light through said at least one polarizing plate and said liquid crystal layer; and

wherein, for any one pixel element, each one of said pairs of common electrodes thereof forms a corresponding one of said pair of common electrodes of a pixel element adjacent to said any one pixel element.

13. A liquid crystal display device according to claim 12, wherein each of said pixel elements has a color filter associated therewith, said color filters of adjacent ones of said plurality of pixel elements overlapping at a location aligned with a common electrode of said adjacent ones of said plurality of pixel elements.

14. A liquid crystal display device including:

a pair of substrates;

a liquid crystal layer interposed between said pair of substrates;

common electrode lines formed on one substrate of said pair of substrates and having a connection portion connecting said common electrode lines to one another;

pixel electrode lines formed on said one substrate and disposed between said common electrode lines, each pixel electrode line including at least first and second electrically connected portions;

wherein an electric field is generated in said liquid crystal layer by applying a voltage between said common electrode lines and said pixel electrode lines, at least one first portion of said pixel electrode line being disposed in overlapping relation to said connection portion of said common electrode lines and being insulated therefrom, and a capacitance being formed between said connection portion of said common electrode lines and said at least one first portion of said pixel electrode lines.

15. A liquid crystal display device according to claim 14, wherein said electric field is generated in a direction substantially parallel to said one substrate.

16. A liquid crystal display device according to claim 14, wherein an insulating film is formed on said common electrode lines.

17. A liquid crystal display device according to claim 14, wherein at least two portions of said pixel electrode lines extending parallel to one another are formed in one pixel.

18. A liquid crystal display device according to claim 14, wherein at least one of said common electrode lines and said pixel electrode lines of a predetermined shape are formed in one pixel.

19. A liquid crystal display device according to claim 14, wherein at least one of said common electrode lines and said pixel electrode lines have a shape of a ring, a cross, a letter T, a letter π

, a letter I, or a ladder.

20. A liquid crystal display device according to claim 14, wherein a pretilt angle of liquid crystal molecules of said liquid crystal layer with respect to said one substrate is not more than 4°

.

21. A liquid crystal display device according to claim 14, wherein a dielectric constant anisotropy of said liquid crystal layer is positive, and an absolute value of an angle between components of said electric field in a direction parallel to said one substrate and a direction of orientation of liquid crystal molecules on said pair of substrates is less than 90°

, but not less than 45°

.

22. A liquid crystal display device according to claim 14, wherein a dielectric constant anisotropy of said liquid crystal layer is negative, and an absolute value of an angle between components of said electric field in a direction parallel to said one substrate and direction of orientation of liquid crystal molecules on said pair of substrates is less than 45°

, but not less than 0°

.

23. A liquid crystal display device according to claim 14, wherein a product of a thickness of said liquid crystal layer and a refractive index anisotropy of said liquid crystal layer is between 0.21 μ

m and 0.36 μ

m.

24. A liquid crystal display device according to claim 14, wherein said at least one first portion of said pixel electrode line is insulated from said connection portion of said common electrode lines by an insulating layer.

25. A liquid crystal display device according to claim 14, wherein at least one second portion of said pixel electrode line is disposed within a display area of a pixel of said liquid crystal display device.

26. A liquid crystal display device according to claim 25, wherein said at least one first portion of said pixel electrode is disposed outside of said display area of said pixel of said liquid crystal display device.

27. A liquid crystal display device including:

a pair of substrates;

a liquid crystal layer interposed between said pair of substrates;

signal electrode lines and scanning electrode lines formed on said one substrate and cross each other in a matrix form, wherein a plurality of pixels are formed by adjoining said signal lines and said scanning lines;

wherein each pixel of said pixels comprises;

a semiconductor switching element formed proximate to a crossing point of a corresponding signal electrode line and scanning electrode line;

common electrode lines formed on said one substrate and connected to each other over more than one of said plurality of pixels by a connection portion of said common electrode lines;

pixel electrode lines formed on said one substrate and disposed between said common electrode lines;

an insulating layer formed on at least said connection portion of said common electrode lines; and

wherein an electric field is generated in said liquid crystal layer by applying a voltage between said common electrode lines and said pixel electrode lines, at least a portion of said pixel electrode lines being formed on said insulating layer in overlapping relation to said connection portion of said common electrode lines, and a capacitance being formed between said connection portion of said common electrode lines and said pixel electrode lines.

28. A liquid crystal display device according to claim 27, wherein in at least one of said pixels said semiconductor switching element is a thin film transistor.

29. A liquid crystal display device according to claim 28, wherein in said at least one of said pixels a gate electrode of said semiconductor switching element is connected to said corresponding scanning electrode line.

30. A liquid crystal display device according to claim 27, wherein in at least one of said pixels said insulating layer is formed on said common electrode lines.

31. A liquid crystal display device according to claim 27, wherein in at least one of said pixels at least two portions of said pixel electrode lines extend parallel to one another.

32. A liquid crystal display device according to claim 27, wherein in at least one of said pixels, at least one of said pixel electrode lines and said common electrode lines have a shape of a ring, a cross, a letter T, a letter π

, a letter I, or a ladder.

33. A liquid crystal display device according to claim 27, wherein in at least one of said pixel s said pixel electrode lines on said connection portion of said common electrode lines are wider than other parts of said pixel electrode lines.

34. A liquid crystal display device according to claim 27, wherein a pretilt angle of liquid crystal molecules of said liquid crystal layer with respect to said one substrate is not more than 4°

.

35. A liquid crystal display device according to claim 27, wherein a dielectric constant anisotropy of said liquid crystal layer is positive, and an absolute value of an angle between components of said electric field in a direction parallel to said one substrate and a direction of orientation of liquid crystal molecules on said pair of substrates is less than 90°

, but not less than 45°

.

36. A liquid crystal display device according to claim 27, wherein a dielectric constant anisotropy of said liquid crystal layer is negative, and an absolute value of an angle between components of said electric field in a direction parallel to said one substrate and a direction of orientation of liquid crystal molecules on said pair of substrates is less than 45°

, but not less than 0°

.

37. A liquid crystal display device according to claim 27, wherein said signal electrode lines are connected to a signal electrode line driving circuit and said common electrode lines of at least one pixel are connected to a common electrode line driving circuit, said signal electrode line driving circuit supplying image signals, and at the same time said common electrode line driving circuit supplying an alternating current.

38. A liquid crystal display device according to claim 27, wherein said scanning electrode lines are connected to scanning electrode line driving circuits and said scanning electrode line driving circuits supply driving signals, wherein a scanning period of said driving signals is shorter than a time constant formed by a product of a specific resistance of said insulating layer of at least one of said pixels and a dielectric constant of said insulating layer of said at least one of said pixels.

39. A liquid crystal display device according to claim 27, wherein a pair of pixel electrode lines is provided in one of said pixels having one of said signal electrode lines extending between said pair of pixel electrode lines.

40. A liquid crystal display device according to claim 27, wherein a product of a thickness of said liquid crystal layer and a refractive index anisotropy of said liquid crystal layer is between 0.21 μ

m and 0.36 μ

m.

41. A liquid crystal display device according to claim 27, wherein in at least one of said pixels said at least one first portion of said pixel electrode line is insulated from said connection portion of said common electrode lines by an insulating layer.

42. A liquid crystal display device according to claim 27, wherein in at least one of said pixels at least one second portion of said pixel electrode lines is disposed within a display area of a pixel of said liquid crystal display device.

43. A liquid crystal display device according to claim 42, wherein in at least one of said pixels said at least one first portion of said pixel electrode lines is disposed outside of said display area of said pixel of said liquid crystal display device.

44. A liquid crystal display device comprising:

a pair of polarizing means;

a pair of substrates interposed between said pair of polarizing means;

a liquid crystal layer interposed between said pair of substrates;

common electrode lines formed on one substrate of said pair of substrates;

pixel electrode lines formed on said one substrate and disposed between said common electrode lines;

wherein an electric field is generated in said liquid crystal layer by applying a voltage between said pixel electrode lines and said common electrode lines, and having an absolute value of a difference |φ

_LC -φ

_P | which is less than 15°

, but not less than 3°

, wherein φ

_LC is an angle between components of said electric field in a direction parallel to Said one substrate and a direction of orientation of liquid crystal molecules on said pair of substrates, and φ

_P is an angle between components of said electric field in direction parallel to said one substrate and the polarization axis of one of said polarizing means.

45. A liquid crystal display device comprising:

a pair of substrates;

a liquid crystal layer interposed between said a pair of substrates;

signal electrode lines and scanning electrode lines formed on one substrate and crossing each other in a matrix form, wherein a plurality of pixels are formed by adjoining said signal electrode lines and scanning electrode lines;

an insulating film formed on said scanning electrode lines;

wherein each pixel of said pixels comprises;

a semiconductor switching element formed proximate to a crossing point between a corresponding signal electrode line and a scanning electrode line;

common electrode lines formed on said one substrate;

pixel electrode lines formed on said one substrate and disposed between said common electrode lines; and

wherein an electric field is generated in said liquid crystal layer by applying a voltage between said common electrode lines and said pixel electrode lines, and said pixel electrode lines are formed on said insulating film, and a load capacitance is formed between an overlapping portion of said scanning electrode lines and said pixel electrode lines.

46. A liquid crystal display device according to claim 45, wherein in at least one of said pixels said semiconductor switching element is a thin film transistor.

47. A liquid crystal display device according to claim 46, wherein in said at least one of said pixels a gate electrode of said semiconductor switching element is connected to said corresponding scanning electrode line.

48. A liquid crystal display device according to claim 45, wherein said insulating film is formed on at least one of said common electrode lines.

49. A liquid crystal display device according to claim 48, wherein in at least one of said pixels at least two portions of said pixel electrode lines extend parallel to one another.

50. A liquid crystal display device according to claim 45, wherein in at least one of said pixels said pixel electrode lines and/or said common electrode lines have a shape of a ring, a cross, a letter T, a letter π

, a letter I, or a ladder.

51. A liquid crystal display device according to claim 45, wherein in at least one of said pixels said pixel electrode lines at said overlapping portion is wider than at other parts of pixel electrode lines.

52. A liquid crystal display device according to claim 45, wherein a pretilt angle of liquid crystal molecules of said liquid crystal layer with respect to said one substrate is not more than 4°

.

53. A liquid crystal display device according to claim 45, wherein the dielectric constant anisotropy of said liquid crystal layer is positive, and the absolute value of the angle between components of electric field in a direction parallel to said one substrate and the direction of orientation of liquid crystal molecules on said pair of substrates is less than 90°

, but not less than 45°

.

54. A liquid crystal display device according to claim 45, wherein the dielectric constant anisotropy of said liquid crystal layer is negative, and the absolute value of the angle between components of electric field in a direction parallel to said one substrate and the direction of orientation of liquid crystal molecules on said pair of substrates is less than 45°

, but not less than 0°

.

55. A liquid crystal display device according to claim 45, wherein said signal electrode lines are connected to signal electrode line driving circuits and said common electrode line are connected to common electrode lines driving circuits, said signal electrode line driving circuits supply image signals, and at the same time said common electrode line driving circuits supply an alternating current.

56. A liquid crystal display device according to claim 45, wherein said scanning electrode lines are connected to scanning electrode line driving circuits and said scanning electrode line driving circuits supply driving signals, and a scanning period of said driving signals is shorter than the time constant formed by a product of a specific resistance of said insulating film and a dielectric constant of said insulating film.

57. A liquid crystal display device according to claim 45, wherein there are a pair of pixel electrode lines in one of said pixels with one of said signal electrode lines extending between said pair of pixel electrodes.

58. A liquid crystal display device according to claim 45, wherein a product of the thickness of said liquid crystal layer and a refractive index anisotropy of said liquid crystal layer is between 0.21 μ

m and 0.36 μ

m.

59. A liquid crystal display device comprising:

a pair of substrates;

a liquid crystal layer interposed between said pair of substrates;

signal electrode lines and scanning electrode lines formed on one substrate which cross each other in a matrix form, wherein a plurality of pixels are formed by adjoining said signal electrode lines and said scanning electrode lines;

scanning electrode line driving circuit connected to said scanning electrode lines for supplying driving signals;

wherein each pixel of said pixels comprises;

a semiconductor switching element formed in the vicinity of a crossing point between corresponding signal electrode line and scanning electrode line;

common electrode lines formed on one substrate of said pair of substrates and having a connection portion connecting said common electrode lines to one another over more than one of said plurality of pixels;

pixel electrode lines formed on said one substrate and disposed between said common electrode lines;

an insulating film formed on at least the connection portion of said common electrode lines; and

wherein an electric field is generated in said liquid crystal layer by applying the voltage between said common electrode lines and said pixel electrode lines, said pixel electrode lines being formed on said insulating film, and a scanning period of said driving signals is shorter than a time constant formed by a product of a specific resistance of said insulating film and a dielectric constant of said insulating film.

60. A liquid crystal display device according to claim 59, wherein in at least one of said pixels said electric field is generated in a direction substantially parallel to said one substrate.

61. A liquid crystal display device according to claim 59, wherein in at least one of said pixels said insulating film is formed on said common electrode lines.

62. A liquid crystal display device comprising:

a pair of substrates;

a liquid crystal layer interposed between said pair of substrates;

common electrode lines formed on one substrate of said pair of substrates and having a connection portion connecting said common electrode lines to one another;

pixel electrode lines formed on said one substrate and disposed between said common electrode lines; and

an insulating film formed on at least the connection portion of said common electrode lines;

wherein at least a portion of said pixel electrode lines extending transversely to said connection portion of said common electrode lines is formed on said insulating film and is in overlapping relation to said connection portion.

63. A liquid crystal display device including:

a pair of substrates;

a liquid crystal layer interposed between said pair of substrates;

signal electrode lines and scanning electrode lines formed on said one substrate and cross each other in a matrix form, wherein a plurality of pixels are formed by adjoining said signal lines and said scanning lines;

wherein each pixel of said pixels comprises;

a semiconductor switching element formed proximate to a crossing point of a corresponding signal electrode line and scanning electrode line;

common electrode lines formed on said one substrate and connected to each other over more than one of said plurality of pixels by a connection portion of said common electrode lines;

pixel electrode lines formed on said one substrate and disposed between said common electrode lines;

an insulating layer formed on at least said connection portion of said common electrode lines; and

wherein at least a portion of said pixel electrode lines is formed on said insulating layer in overlapping relation to said connection portion of said common electrode lines.

64. A liquid crystal display device comprising:

a pair of substrates;

a liquid crystal layer interposed between said pair of substrates;

signal electrode lines and scanning electrode lines formed on one substrate of said pair of substrates and crossing each other in a matrix form, wherein a plurality of pixels are formed by adjoining said signal electrode lines and said scanning electrode lines;

wherein each pixel of said pixels comprises;

a semiconductor switching element formed proximate to a crossing point between a corresponding signal electrode line and scanning electrode line;

at least one common electrode line of a plurality of common electrode lines formed on said one substrate within said pixel and having a connection portion connecting said plurality of common electrode lines to one another over more than one of said plurality of pixels, one of said at least one common electrode line being disposed adjacent to one of said signal electrode lines;

at least one pixel electrode line formed on said substrate within a display area of said pixel, said at least one pixel electrode line being connected to said semiconductor switching element and disposed adjacent to said one of said signal electrode lines so that said one of said at least one common electrode line is interposed therebetween; and

wherein a distance between said one of said at least one common electrode line and said one of said signal electrode lines of said pixel is smaller than a distance between portions of said at least one pixel electrode line adjacent to said one of said signal electrode lines and said one of said signal electrode lines.

65. A liquid crystal display device according to claim 64, wherein in at least one of said pixels said at least one pixel electrode line has a portion in overlapping relation to said connection portion of said common electrode lines and insulated therefrom.

66. A liquid crystal display device according to claim 64, wherein in at least one of said pixels said semiconductor switching element is a thin film transistor.

67. A liquid crystal display device according to claim 66, wherein in said at least one of said pixels a gate electrode of said semiconductor switching element is connected to said corresponding scanning electrode line.

68. A liquid crystal display device according to claim 64, wherein in at least one of said pixels an insulating layer is formed on said common electrode lines.

69. A liquid crystal display device according to claim 68, wherein said scanning electrode lines are connected to a scanning electrode line driving circuits and said scanning electrode line driving circuits supply driving signals, wherein a scanning period of said driving signals is shorter than a time constant formed by a product of a specific resistance of said insulating layer and a dielectric constant of said insulating layer.

70. A liquid crystal display device according to claim 64, wherein in at least one of said pixels at least two portions of said at least one pixel electrode line extends parallel to one another.

71. A liquid crystal display device according to claim 64, wherein in at least one of said pixels at least one of said at least one pixel electrode line and said at least one common electrode line has a shape of a ring, a cross, a letter T, a letter π

, a letter I, or a ladder.

72. A liquid crystal display device according to claim 64, wherein in at least one of said pixels said pixel electrode line has part on said connection portion of said at least one common electrode line which is wider than other parts of said at least one pixel electrode line.

73. A liquid crystal display device according to claim 64, wherein a pretilt angle of liquid crystal molecules of said liquid crystal layer with respect to said one substrate is not more than 4°

.

74. A liquid crystal display device according to claim 64, wherein a dielectric constant anisotropy of said liquid crystal layer is positive, and an absolute value of an angle between components of said electric field in a direction parallel to said one substrate and a direction of orientation of liquid crystal molecules on said pair of substrates is less than 90°

but not less than 45°

.

75. A liquid crystal display device according to claim 64, wherein a dielectric constant anisotropy of said liquid crystal layer is negative, and an absolute value of an angle between components of said electric field in a direction parallel to said one substrate and a direction of orientation of liquid crystal molecules on said pair of substrates is less than 45°

, but not less than 0°

.

76. A liquid crystal display device according to claim 64, wherein said signal electrode lines are connected to a signal electrode line driving circuit and said common electrode lines are connected to a common electrode line driving circuit, said signal electrode line driving circuit supplying image signals, and at the same time said common electrode line driving circuit supplying an alternating current.

77. A liquid crystal display device according to claim 64, wherein a pair of pixel electrode lines is provided in one of said pixels having one of said signal electrode lines extending between said pair of pixel electrode lines.

78. A liquid crystal display device according to claim 64, wherein a product of a thickness of said liquid crystal layer and a refractive index anisotropy of said liquid crystal layer is between 0.21 μ

m and 0.36 μ

m.

79. A liquid crystal display device comprising:

a pair of substrates;

a liquid crystal layer interposed between said pair of substrates;

common electrode lines formed on one substrate of said pair of substrates and having a connection portion connecting said common electrode lines to one another;

pixel electrode lines formed on said one substrate and disposed between said common electrode lines; and

an insulating film formed on at least the connection portion of said common electrode lines;

wherein at least a portion of said pixel electrode lines is disposed with respect to said connection portion of said common electrode lines on said insulating film so that a capacitance is formed therebetween.

80. A liquid crystal display device according to claim 79, wherein the at least a portion of said pixel electrode lines is in overlapping relation to said connection portion.

81. A liquid crystal display device according to claim 79, wherein the at least a portion of said pixel electrode lines extends transversely to said connection portion.