Liquid crystal display and method of performing display operation

A liquid crystal display and a method of operating such liquid crystal display in which display operation is performed by changing a director of said liquid crystal molecules mainly in a plane parallel to first and second substrate forming a liquid crystal display panel. Liquid crystal molecules in the liquid crystal display panel have a negative anisotropy of permittivity. The liquid crystal display comprises: a first common electrode disposed on the side of said first substrate; an insulating layer formed on the first common electrode; at least one pixel electrodes each of which is formed on the insulating layer and has a plurality of opening portions; a second common electrode disposed on the side of the second substrate. The first common electrode comprises at least a particular portion formed in a particular area which extends from a non-opening portion to an opening portion of the pixel electrode and in which the first common electrode overlaps the non-opening portion in a cross section perpendicular to the substrates.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, and advantages, of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which like reference numerals designate identical or corresponding parts throughout the figures, and in which:

FIG. 1 is a partial front view showing a structure of a liquid crystal display panel of a liquid crystal display according to a first embodiment of the present invention;

FIG. 2 is a partial cross sectional view taken on line

2—

2 of FIG. 1;

FIG. 3 is a partial cross sectional view taken on line

3—

3 of FIG. 1;

FIG. 4 is a schematic cross sectional view for illustrating the principle of liquid crystal drive operation of the liquid crystal display shown in FIG. 1;

FIG. 5 is is a partial front view showing a structure of a liquid crystal display panel of a liquid crystal display as a comparative example;

FIG. 6 is a partial cross sectional view taken on line

6-

6 of FIG. 5;

FIG. 7 is a partial front view showing a structure of a liquid crystal display panel of a liquid crystal display according to a second embodiment of the present invention;

FIG. 8 is a schematic view for illustrating a relationship between a shape of an end portion of an opening portion and an alignment direction of liquid crystal molecules;

FIG. 9 is a partial front view showing a structure of a liquid crystal display panel of a liquid crystal display according to a third embodiment of the present invention;

FIG. 10 is a partial cross sectional view taken on line

9—

9 of FIG. 9;

FIG. 11 is a partial front view showing a structure of a liquid crystal display panel of a liquid crystal display according to a fourth embodiment of the present invention;

FIG. 12 is a partial cross sectional view taken on line

12—

12 of FIG. 11;

FIG. 13 is a partial cross sectional view taken on line

13—

13 of FIG. 11;

FIG. 14 is a partial front view showing a structure of a liquid crystal display panel of a liquid crystal display according to a combination of the first, second and fourth embodiments of the present invention;

FIG. 15 is a partial front view showing a structure of a liquid crystal display panel of a liquid crystal display according to a combination of the first through fourth embodiments of the present invention;

FIG. 16 is a partial front view showing a structure of a liquid crystal display panel of a liquid crystal display according to a fifth embodiment of the present invention;

FIG. 17 is a partial front view showing a structure of a liquid crystal display panel of a liquid crystal display according to a sixth embodiment of the present invention; and

FIG. 18 is a partial front view showing a structure of a liquid crystal display panel of a liquid crystal display according to a seventh embodiment of the present invention.

1. A liquid crystal display having a first substrate, a second substrate parallel opposed to said first substrate, and a liquid crystal layer including liquid crystal molecules, wherein display operation is performed by changing a director of said liquid crystal molecules mainly in a plane parallel to said first and second substrate, said liquid crystal display comprising:

2. A liquid crystal display as set forth in claim 1, wherein said first common electrode is formed on said first substrate, and wherein said particular portion of said first common electrode has, in a cross section perpendicular to said substrates, a shape which covers whole area corresponding to said plurality of opening portions on said first substrate.

3. A liquid crystal display as set forth in claim 1, wherein said first common electrode comprises, in a cross section perpendicular to said substrates, common electrode side opening portions in an area which overlaps with said non-opening portion of said first substrate.

4. A liquid crystal display as set forth in claim 1, wherein said first common electrode is formed on said first substrate, and has a shape which covers said first substrate every pixel.

5. A liquid crystal display as set forth in claim 1, wherein said second common electrode is formed on whole area of said second substrate.

6. A liquid crystal display as set forth in claim 1, wherein a portion of said first common electrode corresponding to one pixel is directly coupled with a portion of said first common electrode corresponding to anther pixel which is adjacent to said one pixel in a predetermined direction.

7. A liquid crystal display as set forth in claim 1, further comprising an auxiliary conductive portion which is formed of a conductive material having lower resistivity than that of a conductive material forming said first common electrode and which is coupled with said first common electrode.

8. A liquid crystal display as set forth in claim 7, wherein said liquid crystal display is an active matrix type liquid crystal display which comprises a switching element for each pixel.

9. A liquid crystal display as set forth in claim 8, wherein said switching element is a thin film transistor.

10. A liquid crystal display as set forth in claim 9, wherein said auxiliary conductive portion is formed in the same layer as that of the gate electrode of said thin film transistor.

11. A liquid crystal display as set forth in claim 10, wherein said auxiliary conductive portion is formed by patterning an electrode material of said gate electrode, in the same process step as that of said gate electrode.

12. A liquid crystal display as set forth in claim 1, further comprising: a plurality of auxiliary conductive portions each of which is formed of a conductive material having lower resistivity than that of a conductive material forming said first common electrode;

13. A liquid crystal display as set forth in claim 1, wherein said first predetermined potential and said second predetermined potential are mutually equal potential.

14. A liquid crystal display as set forth in claim 13, wherein said first substrate, said second substrate and said liquid crystal layer compose a liquid crystal display panel; and

15. A liquid crystal display as set forth in claim 14, further comprising a potential adjusting means which adjust said first predetermined potential and said second predetermined potential applied to said first and second common electrodes.

16. A liquid crystal display as set forth in claim 1, wherein said second common electrode is formed of a transparent electrode material; and

17. A liquid crystal display as set forth in claim 1, wherein each of said plurality of opening portions of said pixel electrode has a parallelogram shape; and

18. A liquid crystal display as set forth in claim 1, wherein each of said plurality of opening portions of said pixel electrode has a parallelogram shape; and

19. A liquid crystal display as set forth in claim 18, wherein said plurality of opening portions are grouped into two groups; and

20. A liquid crystal display as set forth in claim 1, wherein each of said plurality of opening portions of said pixel electrode has a V-shape having short sides located along the alignment direction of said liquid crystal molecules and composed by combining two parallelograms which share a short side with each other and whose long sides are disposed symmetrically with respect to said alignment direction.

21. A liquid crystal display as set forth in claim 1, further comprising: a color layer for realizing color display on the side of said second substrate; and

22. A liquid crystal display having a first substrate, a second substrate opposed to said first substrate, and a liquid crystal layer including liquid crystal molecules, wherein display operation is performed by changing a director of said liquid crystal molecules mainly in a plane parallel to said first or second substrate, said liquid crystal display comprising:

23. In a liquid crystal display having a first substrate, a second substrate opposed to said first substrate, and a liquid crystal layer including liquid crystal molecules, wherein display operation is performed by changing a director of said liquid crystal molecules mainly in a plane parallel to said first or second substrate, a method of performing display operation comprising:

24. A method of performing display operation as set forth in claim 23, wherein a portion of said first common electrode corresponding to one pixel is directly coupled with a portion of said first common electrode corresponding to anther pixel which is adjacent to said one pixel in a predetermined direction.

25. A method of performing display operation as set forth in claim 23, further comprising forming a plurality of auxiliary conductive portions each of which is formed of a conductive material having lower resistivity than that of a conductive material forming said first common electrode;