Capsules for electrophoretic displays and methods for making the same

• US 6,262,833 B1
• Filed: 10/06/1999
• Issued: 07/17/2001
• Est. Priority Date: 10/07/1998
• Status: Expired due to Term

• Current Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Original Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Inventors: Loxley, Andrew, Comiskey, Barrett
• Primary Examiner(s): Ben, Loha
• Application Number:
  US09/413,009
• Time in Patent Office: 650 Days
• Field of Search: 359/296, 359/452, 204/606, 204/450, 204/456, 345/107, 345/108, 356/441, 264/4
• US Class Current: 359/296
• CPC Class Codes: B01J 13/02 Making microcapsules or microballoons for medical preparations A61K9/50
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 1/16757 Microcapsules

Abstract

An encapsulated electrophoretic display is made of at least one display element. Each display element includes at least one capsule. The capsule contains at least two substantially immiscible fluids. The first fluid includes an additive, and the second fluid contains a plurality of particles.

Claims

1. An encapsulated electrophoretic display element comprising a capsule containing at least two substantially immiscible fluids, wherein a first fluid includes an additive and a second fluid includes a plurality of particles.

2. The display element of claim 1 wherein at least a portion of the particles of the second fluid is not substantially dispersible in the first fluid.

3. The display element of claim 1 wherein at least a portion of the plurality of particles has a surface treatment.

4. The display element of claim 1 wherein the additive comprises a dye.

5. The display element of claim 4 wherein the dye is substantially insoluble in the second fluid.

6. The display element of claim 4 wherein the dye is soluble in the first fluid.

7. The display element of claim 1 wherein the additive comprises a second plurality of particles.

8. The display element of claim 7 wherein at least a portion of the second particles is not substantially dispersible in the second fluid.

9. The display element of claim 7 wherein at least a portion of the second particles has a surface treatment.

10. The display element of claim 7 wherein the second particles are capable of moving under an electric field.

11. The display element of claim 7 wherein the second fluid is capable of being displaced by the second particles.

12. The display element of claim 1 wherein the first fluid comprises a polar substance and the second fluid comprises a non-polar substance.

13. The display element of claim 1 wherein the first fluid comprises a non-polar substance and the second fluid comprises a polar substance.

14. The display element of claim 1 wherein the particles of the second fluid are capable of moving under an electric field.

15. The display element of claim 1 wherein the first fluid is capable of being displaced by the particles of the second fluid.

16. The display element of claim 1 wherein the particles of the second fluid comprise at least two different species of particles, the species of particles differing in their size.

17. The display element of claim 1 wherein the particles of the second fluid comprise at least two different species of particles, the species of particles differing in their shape.

18. A process for creating an encapsulated electrophoretic display, comprising the steps of:

(a) forming a first mixture comprising an additive in a first fluid;

(b) forming a second mixture comprising a plurality of particles in a second fluid;

(c) combining the first mixture and the second mixture into a droplet, wherein the first mixture and the second mixture are substantially immiscible; and

(d) forming a capsule around the droplet.

19. The process of claim 18 wherein the additive comprises a dye.

20. The process of claim 18 wherein the additive comprises a second plurality of particles.

21. An encapsulated electrophoretic display comprising at least one display element, each display element comprising a capsule containing at least two substantially immiscible fluids, wherein a first fluid includes an additive and a second fluid includes a plurality of particles.

22. The display of claim 21 further comprising at least one electrode adjacent the display element.

23. The display of claim 21 wherein the additive comprises a dye.

24. The display of claim 21 wherein the additive comprises a second plurality of particles.