Flexible electro-optic displays

• US 6,922,276 B2
• Filed: 12/22/2003
• Issued: 07/26/2005
• Est. Priority Date: 12/23/2002
• Status: Expired due to Term

• Current Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Original Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Inventors: Goenaga, Alberto, Steiner, Michael L., Wilcox, Russell J., Zhang, Libing, Holman, Mavyn M.
• Primary Examiner(s): Spector, David N.
• Application Number:
  US10/707,571
• Publication Number:
  US 20040233509A1
• Time in Patent Office: 582 Days
• Field of Search: 345/107, 359/296
• US Class Current: 359/296
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 1/1679 Gaskets; Spacers; Sealing of cells; Filling or closing of cells

Abstract

An encapsulated electrophoretic medium comprises a plurality of capsules dispersed in a polymeric binder, each of the capsules comprising a capsule wall, a suspending fluid contained within the capsule wall, and a plurality of electrically charged particles suspended in the suspending fluid and capable of moving therethrough upon application of an electric field to the medium, the polymeric binder having a shear modulus of at least about 10 mPa at 20° C., and preferably over the range of 10-50° C.

Claims

1. An encapsulated electrophoretic medium comprising a plurality of capsules dispersed in a polymeric binder, each of the capsules comprising a capsule wall, a suspending fluid contained within the capsule wall, and a plurality of electrically charged particles suspended in the suspending fluid and capable of moving therethrough upon application of an electric field to the medium, the polymeric binder having a shear modulus of at least about 10 mPa at 20°

C.

2. An encapsulated electrophoretic medium according to claim 1 wherein the polymeric binder has a shear modulus of at least about 25 mPa at 20°

C.

3. An encapsulated electrophoretic medium according to claim 1 wherein the polymeric binder has a shear modulus of at least about 50 mPa at 20°

C.

4. An encapsulated electrophoretic medium according to claim 1 wherein the polymeric binder has a shear modulus of at least about 10 mPa over a temperature range of at least 10 to 50°

C.

5. An encapsulated electrophoretic medium according to claim 1 wherein the polymeric binder comprises a polyurethane.

6. An electro-optic display comprising:

a layer of an encapsulated electrophoretic medium comprising a plurality of capsules dispersed in a polymeric binder, each of the capsules comprising a capsule wall, a suspending fluid contained within the capsule wall, and a plurality of electrically charged particles suspended in the suspending fluid and capable of moving therethrough upon application of an electric field to the medium, the polymeric binder having a shear modulus of at least about 10 mPa at 20°

C.; and

at least one electrode adhered to the layer of encapsulated electrophoretic medium, the binder having a peel strength from the electrode of at least about 2 lb/inch.

7. An electro-optic display according to claim 6 wherein the binder has a peel strength from the electrode of at least about 4 lb/inch.

8. An electro-optic display according to claim 6 wherein the polymeric binder comprises a polyurethane.

9. An electro-optic display comprising a support member having a support surface, a plurality of spacer members extending in one direction away from the support surface, a protective sheet contacting the ends of the spacer members remote from the support surface, and an electro-optic medium supported by the protective sheet.

10. An electro-optic display according to claim 9 further comprising a second protective sheet disposed on the opposed side of the electro-optic medium from the protective sheet contacting the ends of the spacer members.

11. An electro-optic display according to claim 9 wherein the electro-optic medium has the form of an interrupted layer, the electro-optic medium not being present immediately adjacent the areas of the protective sheet contacting the ends of the spacer members.

12. An electro-optic display according to claim 9 wherein the electro-optic medium is an encapsulated electrophoretic medium.

13. An electro-optic display according to claim 9 further comprising a layer of resilient material disposed between the support surface and the protective sheet.

14. An electro-optic display according to claim 13 wherein the resilient material comprises a solid foam.

15. An electro-optic display according to claim 9 wherein the electro-optic medium comprises a rotating bichromal member medium or an electrochromic medium.

16. An electro-optic display according to claim 9 wherein the electro-optic medium comprises a suspending fluid and a plurality of electrically charged particles, the suspending fluid and the particles being present as a plurality of discrete droplets, the electrophoretic medium further comprising a continuous phase of polymeric material surrounding droplets.

17. An electro-optic display according to claim 9 wherein the electro-optic medium comprises a suspending fluid and a plurality of electrically charged particles, the suspending fluid and the particles being retained within a plurality of cavities formed in a carrier medium.

18. A tensioned member display comprising a support member having a support surface, a plurality of spacer members extending in one direction away from the support surface, a plurality of tensioning members each extending upon tension between at least two of the spacer member, and an electro-optic medium through which the support members pass, the electro-optic medium being supported spaced from the support surface by the tensioning members passing through the electro-optic medium.

19. A tensioned member display according to claim 18 wherein the support members are arranged in two parallel rows with the tensioning members extending parallel to each other between one support member in each row.

20. A tensioned member display according to claim 18 further comprising at least one protective layer sheet disposed adjacent the electro-optic medium.

21. A tensioned member display according to claim 18 further comprising at least one electrode disposed adjacent the electro-optic medium.

22. A tensioned member display according to claim 18 further comprising at least one of a load distributing member and a layer of resilient material disposed between the electro-optic medium and the support surface.

23. A tensioned member display according to claim 18 wherein the electro-optic medium is an encapsulated electrophoretic medium.

24. A tensioned member display according to claim 18 wherein the electro-optic medium comprises a rotating bichromal member medium or an electrochromic medium.

25. A tensioned member display according to claim 18 wherein the electro-optic medium comprises a suspending fluid and a plurality of electrically charged particles, the suspending fluid and the particles being present as a plurality of discrete droplets, the electrophoretic medium further comprising a continuous phase of polymeric material surrounding the droplets.

26. A tensioned member display according to claim 18 wherein the electro-optic medium comprises a suspending fluid and a plurality of electrically charged particles, the suspending fluid and the particles being retained within a plurality of cavities formed in a carrier medium.

27. An electrophoretic medium comprising a suspending fluid and a plurality of electrically charged particles suspended in the suspending fluid and capable of moving therethrough upon application of an electric field to the medium, the suspending fluid and the particles being present as a plurality of discrete droplets, the electrophoretic medium further comprising a continuous phase of polymeric binder surrounding the droplets, the polymeric binder having a shear modulus of at least about 10 mPa at 20°

C.

28. An encapsulated electrophoretic medium according to claim 27 wherein the polymeric binder has a shear modulus of at least about 25 mPa at 20°

C.

29. An encapsulated electrophoretic medium according to claim 27 wherein the polymeric binder has a shear modulus of at least about 50 mPa at 20°

C.

30. An encapsulated electrophoretic medium according to claim 27 wherein the polymeric binder has a shear modulus of at least about 10 mPa over a temperature range of at least 10 to 50°

C.

31. An encapsulated electrophoretic medium according to claim 27 wherein the polymeric binder comprises a polyurethane.

32. An electro-optic display comprising:

a layer of an electrophoretic medium comprising a suspending fluid and a plurality of electrically charged particles suspended in the suspending fluid and capable of moving therethrough upon application of an electric field to the medium, the suspending fluid and the particles being present as a plurality of discrete droplets, the electrophoretic medium further comprising a continuous phase of polymeric binder surrounding the droplets, the polymeric binder having a shear modulus of at least about 10 mPa at 20EC; and

at least one electrode adhered to the layer of electrophoretic medium, the binder having a peel strength from the electrode of at least about 2 lb/inch.

33. An electro-optic display according to claim 32 wherein the binder has a peel strength from the electrode of at least about 4 lb/inch.

34. An electro-optic display according to claim 32 wherein the polymeric binder comprises a polyurethane.