Display device with crossing electrodes with specific ratio for gray scale

• US 5,404,236 A
• Filed: 07/08/1994
• Issued: 04/04/1995
• Est. Priority Date: 04/20/1990
• Status: Expired due to Fees

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Verhulst, Antonius G. H., Van Haaren, Johannes A. M. M., Hartmann, Wilbert J. A. M.
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Parker, Kenneth
• Application Number:
  US08/272,434
• Time in Patent Office: 270 Days
• Field of Search: 359/54, 359/55, 359/56, 359/61, 359/84, 359/87, 359/88, 340/784, 340/793, 345/43, 345/103, 345/149, 345/89
• US Class Current: 349/143
• CPC Class Codes: G02F 1/134336 Matrix
• CPC Class Codes: G02F 1/134345 Subdivided pixels, e.g. for grey scale or redundancy
• CPC Class Codes: G09G 3/2074 using sub-pixels
• CPC Class Codes: G09G 3/3607 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127

Abstract

An electro-optic display device with grey scale set by areas of crossing electrodes. In one embodiment, there are 3 strip-shaped sub electrodes with a width relationship of 4:2:1, and two strip shaped column electrodes with a relationship of 8:1. In a second embodiment, there are 4 strip-shaped sub electrodes with a width relationship of 8:4:2:1, and two strip shaped column electrodes with a relationship of 16:1.

Claims

1. A display device comprising an electro-optical medium between two supporting plates comprising a plurality of display cells at the area of crossings of strip-shaped row and column electrodes, the column and row electrodes being divided into strip-shaped sub-electrodes characterized in that the column electrodes are divided into three strip-shaped sub-electrodes having a width ratio 4:

2;

1 and the row electrodes are divided into two strip-shaped sub-electrodes the sub-electrodes of the row electrodes at the area of the crossing having a width ratio of at least 8;

1.

2. A display device as claimed in claim 1, characterized in that each strip-shaped sub-electrode of a row electrode is passed to the exterior at different sides of the cross-bar system.

3. A device as claimed in claim 2, characterized in that at least one sub-electrode is located at least partially between portion of another sub-electrode.

4. A device as claimed in claim 2, characterized in that the electro-optical medium is a ferro-electric liquid crystal material.

5. A device as claimed in claim 1, characterized in that at least one sub-electrode is located between parts of other sub-electrodes.

6. A device as claimed in claim 5, characterized in that the electro-optical medium is a ferro-electric liquid crystal material.

7. The device as claimed in claim 5, characterized in that a sub-electrode is at least partially surrounded by another sub-electrode having the next larger surface.

8. A device as claimed in claim 7, characterized in that a sub-electrode which is the next larger in surface area size substantially entirely surrounds a sub-electrode.

9. A device as claimed in claim 7, characterized in that the electro-optical medium is a ferro-electric liquid crystal material.

10. A device as claimed in claim 8, characterized in that the electro-optical medium is a ferro-electric liquid crystal material.

11. A device as claimed in claim 1, characterized in that the electro-optical medium is a ferro-electric liquid crystal material.

12. A device as claimed in claim 1, characterized in that the electro-optical medium is a ferro-electric liquid crystal material.

13. The display device of claim 1 wherein the narrowest and the widest of the sub-electrodes of a column electrode are passed to the exterior at one and the same side of the cross-bar system.

14. A device as claimed in claim 13, characterized in that at least one sub-electrode is located at least partially between portions of another sub-electrode.

15. A display device comprising an electro-optical medium between two supporting plates comprising a plurality of display cells at the area of crossings of strip-shaped row and column electrodes, the column and row electrodes being divided into strip-shaped sub-electrodes characterized in that the column electrodes are divided into four strip-shaped sub-electrodes having a width ratio 8:

4;

2;

1 and the row electrodes are divided into two strip-shaped sub-electrode the sub-electrodes of the row electrodes at the area of the crossing having a width ratio of at least 16;

1.

16. A display device as claimed in claim 15, characterized in that each strip-shaped sub-electrode of a row electrode is passed to the exterior at different sides of the cross-bar system.

17. A device as claimed in claim 16, characterized in that at least one sub-electrode is located between parts of the other sub-electrodes.

18. A device as claimed in claim 15, characterized in that at least one sub-electrode is located at least partially between portions of another sub-electrode.

19. The device as claimed in claim 18, characterized in that a sub-electrode is at least partially surrounded by another sub-electrode having the next lager surface.

20. A device as claimed in claim 19, characterized in that a sub-electrode is the next larger in surface area size substantially entirely surrounds a sub-electrode.

21. A device as claimed in claim 19, characterized in that the electro-optical medium is a ferro-electric liquid crystal material.

22. A device as claimed in claim 15, characterized in that the electro-optical medium is a ferro-electric liquid crystal material.

23. The display device of claim 15 wherein the narrowest and the widest of the sub-electrodes of a column electrode are passed to the exterior at one and the same side of the cross-bar system.

24. A device as claimed in claim 23, characterized in that at least one sub-electrode is located at least partially between portions of another sub-electrode.