COLOR DISPLAY DEVICES

• US 20090273827A1
• Filed: 04/29/2009
• Published: 11/05/2009
• Est. Priority Date: 05/01/2008
• Status: Active Grant

• Current Assignee: E Ink Holdings Incorporated
• Original Assignee: SiPix Imaging, Inc. (E Ink Holdings Incorporated)
• Inventors: Sprague, Robert A., Lin, Craig
• Granted Patent: US 8,072,675 B2
• Time in Patent Office: Days
• US Class Current: 359/296
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• CPC Class Codes: G09G 3/3446 with more than two electrodes controlling the modulating element

Abstract

The present invention is directed to color display devices in which each display cell is capable of displaying three color states. The display fluid filled in the display cells comprises two types of pigment particles. The color display device may further comprise a brightness enhancement structure on its viewing side.

Claims

1. A display device comprising a plurality of display cells, wherein each of said display cells is

(a) sandwiched between a first layer comprising a common electrode and a second layer comprising a plurality of driving electrodes, wherein at least one of the driving electrodes is a designated electrode and the remaining driving electrodes are non-designated electrodes,

(b) filled with an electrophoretic fluid comprising a group of white particles and a group of black particles dispersed in a solvent or solvent mixture, and

(c) capable of displaying three color states.

2. The display device of claim 1, wherein said solvent or solvent mixture is colored.

3. The display device of claim 2, wherein the two groups of particles carry opposite charge polarities.

4. The display device of claim 2, wherein the solvent or solvent mixture is red, green or blue.

5. The display device of claim 2, wherein the driving electrodes are not aligned with the boundary of the display cell.

6. The display device of claim 2, wherein the driving electrodes are aligned with the boundary of the display cell.

7. The display device of claim 2, wherein the pigment particles are driven to the designated electrode(s) in steps.

8. The display device of claim 2, wherein said driving electrodes are a grid of at least 2×

2.

9. The display device of claim 2, wherein the total area of the non-designated electrodes is at least three times the total area of the designated electrode(s).

10. The display device of claim 2, wherein the first layer is on the viewing side.

11. The display device of claim 2, wherein the second layer is on the viewing side.

12. The display device of claim 2, further comprising a brightness enhancement structure on its viewing side.

13. The display device of claim 12, wherein said micro-structures or micro-reflectors have a top angle of about 5°

to about 50°

.

14. The display device of claim 1, wherein said solvent or solvent mixture is clear and colorless and the display device further comprising a colored background layer.

15. The display device of claim 14, wherein the two groups of particles carry opposite charge polarities.

16. The display device of claim 14, wherein the background layer is red, green or blue.

17. The display device of claim 14, wherein the boundary of the second layer is not aligned with the boundary of the fluid area in a microcup.

18. The display device of claim 17, wherein at least one designated electrode for the white particles and at least one designated electrode for the black particles are within the boundary of the fluid area.

19. The display device of claim 14, wherein the boundary of the second layer is aligned with the boundary of the fluid area in a microcup.

20. The display device of claim 14, wherein the pigment particles are driven to the designated electrode(s) in steps.

21. The display device of claim 14, wherein said driving electrodes are a grid of at least 2×

2.

22. The display device of claim 14, further comprising a brightness enhancement structure on its viewing side.

23. The display device of claim 14, further comprising blocking layer in positions corresponding to the designated electrodes.

24. The display device of claim 14, wherein the designated electrodes are non-transparent and said second layer is the viewing side.

25. The display device of claim 14, wherein the total area of the non-designated electrodes is at least three times the total area of the designated electrode(s).