COLOR DISPLAY DEVICES

• US 20090251763A1
• Filed: 04/01/2009
• Published: 10/08/2009
• Est. Priority Date: 04/03/2008
• Status: Active Grant

• Current Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Original Assignee: SiPix Imaging, Inc. (E Ink Holdings Incorporated)
• Inventors: LIN, Craig, SPRAGUE, Robert A.
• Granted Patent: US 8,422,116 B2
• Time in Patent Office: Days
• US Class Current: 359/296
• CPC Class Codes: G02F 1/133526 Lenses, e.g. microlenses or Fresnel lenses
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 1/16762 having three or more electrodes per pixel
• CPC Class Codes: G02F 2001/1678 characterised by the composition or particle type
• CPC Class Codes: G02F 2203/34 Colour display without the use of colour mosaic filters

Abstract

The present invention is directed to color display devices which are capable of displaying multiple color states. The display device comprises 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, (b) filled with an electrophoretic fluid comprising at least two types of pigment particles dispersed in a solvent or solvent mixture, and (c) capable of displaying at least four color states. The display device may also comprise hiding layers or a brightness enhancement structure on the 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,

(b) filled with an electrophoretic fluid comprising at least two types of pigment particles dispersed in a solvent or solvent mixture, and

(c) capable of displaying at least four color states.

2. The display device of claim 1, further comprising blocking layers which are on the viewing side of the display device and are positioned corresponding to the designated electrodes.

3. The display device of claim 2, wherein said blocking layer is a black matrix layer.

4. The display device of claim 3, wherein the width of the black matrix layer is equal to or greater than the width of the designated electrode.

5. The display device of claim 2, wherein said blocking layer is a micro-structure or micro-reflector of a brightness enhancement structure.

6. The display device of claim 5, wherein the width of the base of the micro-structures or micro-reflector is equal to or greater than the width of the designated electrode.

7. The display device of claim 1, wherein said electrophoretic fluid comprises two types of pigment particles dispersed in a solvent or solvent mixture.

8. The display device of claim 7, wherein the two types of pigment particles carry opposite charge polarities.

9. The display device of claim 7, wherein the two types of pigment particles carry the same charge polarities but are of different electrophoretic mobilities.

10. The display device of claim 7, wherein one type of the pigment particles is white and the other type of the pigment particles is red, green or blue.

11. The display device of claim 7, wherein said solvent or solvent mixture is red, green or blue.

12. The display device of claim 1, wherein said electrophoretic fluid comprises three types of pigment particles dispersed in a solvent or solvent mixture.

13. The display device of claim 12, wherein the three types of pigment particles carry different charge polarities or different levels of the same charge polarity.

14. The display device of claim 12, wherein one type of the pigment particles is white and the other two types of the pigment particles are red and green, red and blue or green and blue.

15. The display device of claim 12, wherein said solvent or solvent mixture is red, green or blue.

16. The display device of claim 1, wherein driving electrodes are not aligned with the boundary of the display cell.

17. The display device of claim 1, wherein the pigment particles are driven to the designated electrode(s) all at once.

18. The display device of claim 1, wherein the pigment particles are driven to the designated electrode(s) in steps.

19. The display device of claim 1, wherein said driving electrodes are a grid of at least 2×

2.

20. The display device of claim 1, wherein the first layer is on the viewing side.

21. The display device of claim 1, wherein the second layer is on the viewing side.

22. The display device of claim 21, wherein said designated electrodes are not transparent.

23. The display device of claim 21, wherein said designated electrodes are opaque.

25. The display device of claim 7, comprising pixels wherein each pixel comprises two sub-pixels.

26. The display device of claim 7, comprising pixels wherein each pixel comprises three sub-pixels.

27. The display device of claim 7, comprising pixels wherein each pixel comprises four sub-pixels.

28. The display device of claim 1, wherein said display cells are microcups.

29. The display device of claim 1, wherein said display cells are microcapsules.