Electrophoretic display

• US 7,715,088 B2
• Filed: 04/27/2007
• Issued: 05/11/2010
• Est. Priority Date: 03/03/2000
• Status: Expired due to Fees

• Current Assignee: E Ink California, LLC (E Ink Holdings Incorporated)
• Original Assignee: SiPix Imaging, Inc. (E Ink Holdings Incorporated)
• Inventors: Wu, Zarng-Arh George, Chan-Park, Mary, Liang, Rong-Chang, Zang, HongMei, Tseng, Scott C-J
• Primary Examiner(s): Martinez; Joseph
• Assistant Examiner(s): Tra; Tuyen Q
• Application Number:
  US11/741,682
• Publication Number:
  US 20080007815A1
• Time in Patent Office: 1,110 Days
• Field of Search: 359/296, 345/49, 345/105, 345/107, 204/450, 204/600, 430/32, 430/34, 430/38
• US Class Current: 359/296
• CPC Class Codes: B29C 2035/0827 using UV radiation
• CPC Class Codes: B29C 35/0888 using transparant moulds
• CPC Class Codes: B29C 35/0894 provided with masks or diaphragms
• CPC Class Codes: B29C 59/046 for layered or coated substantially flat surfaces
• CPC Class Codes: B29C 71/04 by wave energy or particle radiation , e.g. for curing or vulcanising preformed articles during moulding, e.g. in a mould B29C35/08
• CPC Class Codes: G02F 1/1339 Gaskets; Spacers; Sealing of cells
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 1/1679 Gaskets; Spacers; Sealing of cells; Filling or closing of cells
• CPC Class Codes: G02F 1/1681 having two or more microcells partitioned by walls, e.g. of microcup type

Abstract

This invention relates to an electrophoretic display comprising a plurality of cells, each of said cells comprises: a) partition walls; b) an electrophoretic fluid filled therein; c) a polymeric sealing layer to enclose the electrophoretic fluid within the cell; and d) an interface between the electrophoretic fluid and the sealing layer.

Claims

1. An electrophoretic display comprising a plurality of cells, each of said cells comprises:

a) a partition wall surrounding the cell;

b) an electrophoretic fluid filled therein;

c) a sealing layer on top of said electrophoretic fluid to enclose the electrophoretic fluid within the cell; and

d) an interface between the electrophoretic fluid and the sealing layer, wherein the contact point of the interface and the partition wall is at least about 0.01 μ

m below the top surface of the partition wall.

2. The electrophoretic display of claim 1 wherein said sealing layer is formed from a sealing composition comprising a material selected from the group consisting of polyvalent acrylate or methacrylate, cyanoacrylates, polyvalent vinyl, polyvalent epoxide, polyvalent isocyanate, polyvalent allyl, and oligomers or polymers containing crosslinkable functional groups.

3. The electrophoretic display of claim 2 wherein said sealing composition further comprises an additive selected from the group consisting of surfactants, antioxidants, initiators, catalysts, crosslinkers, thickeners, polymer binders, pigments, dyes and fillers.

4. The electrophoretic display of claim 3 wherein said filler is selected from the group consisting of silica, CaCO₃, BaSO₄, TiO₂, metal particles, metal oxides and carbon black.

5. The electrophoretic display of claim 1 wherein the contact point of the interface and the partition wall is about 0.02 μ

m to about 15 μ

m below the top surface of the partition wall.

6. The electrophoretic display of claim 5 wherein the contact point of the interface and the partition wall is about 0.1 μ

m to about 4 μ

m below the top surface of the partition wall.

7. The electrophoretic display of claim 1 wherein the top surface of the sealing layer is at least about 0.01 μ

m above the top surface of the partition wall.

8. The electrophoretic display of claim 7 wherein the top surface of the sealing layer is about 0.01 μ

m to about 50 μ

m above the top surface of the partition wall.

9. The electrophoretic display of claim 8 wherein the top surface of the sealing layer is about 0.5 μ

m to about 8 μ

m above the top surface of the partition wall.

10. The electrophoretic display of claim 1 wherein the sealing layer has a thickness in the range of from about 0.1 μ

m to about 50 μ

m as measured in the center of the cell.

11. The electrophoretic display of claim 10 wherein the sealing layer has a thickness in the range of from about 0.5 μ

m to about 15 μ

m as measured in the center of the cell.

12. The electrophoretic display of claim 11 wherein the sealing layer has a thickness in the range of from about 1 μ

m to about 8 μ

m as measured in the center of the cell.

13. The electrophoretic display of claim 1 wherein the sealing layer is formed from a sealing composition having a specific gravity lower than that of the electrophoretic fluid.

14. The electrophoretic display of claim 13 wherein said sealing composition is a UV curable composition.

15. The electrophoretic display of claim 14 wherein said sealing composition comprises a thermoplastic or thermoset precursor.

16. An electrophoretic display which comprises:

A) two electrode plates;

B) an array of cells, each of the cells comprises;

a) a partition wall surrounding the cell;

b) an electrophoretic fluid filled therein;

c) a sealing layer on top of said electrophoretic fluid to enclose the electrophoretic fluid within the cell; and

d) an interface between the electrophoretic fluid and the sealing layer, wherein the contact point of the interface and the partition wall is at least about 0.01 μ

m below the top surface of the partition wall.

17. The electrophoretic display of claim 16 wherein said sealing layer is formed from a sealing composition comprising a material selected from the group consisting of polyvalent acrylate or methacrylate, cyanoacrylates, polyvalent vinyl, polyvalent epoxide, polyvalent isocyanate, polyvalent allyl, and oligomers or polymers containing crosslinkable functional groups.

18. The electrophoretic display of claim 17 wherein said sealing composition further comprises one or more additive selected from the group consisting of surfactants, antioxidants, initiators, catalysts, crosslinkers, thickeners, polymer binders, pigments, dyes and fillers.

19. The electrophoretic display of claim 18 wherein said filler is selected from the group consisting of silica, CaCO₃, BaSO₄, TiO₂, metal particles, metal oxides and carbon black.

20. The electrophoretic display of claim 16 wherein the contact point of the interface and the partition wall is about 0.02 μ

m to about 15 μ

m below the top surface of the partition wall.

21. The electrophoretic display of claim 20 wherein the contact point of the interface and the partition wall is about 0.1 μ

m to about 4 μ

m below the top surface of the partition wall.

22. The electrophoretic display of claim 16 wherein the top surface of the sealing layer is at least about 0.01 μ

m above the top surface of the partition wall.

23. The electrophoretic display of claim 22 wherein the top surface of the sealing layer is about 0.01 μ

m to about 50 μ

m above the top surface of the partition wall.

24. The electrophoretic display of claim 23 wherein the top surface of the sealing layer is about 0.5 μ

m to about 8 μ

m above the top surface of the partition wall.

25. The electrophoretic display of claim 16 wherein the sealing layer has a thickness in the range of from about 0.1 μ

m to about 50 μ

m as measured in the center of the cell.

26. The electrophoretic display of claim 25 wherein the sealing layer has a thickness in the range of from about 0.5 μ

m to about 15 μ

m as measured in the center of the cell.

27. The electrophoretic display of claim 26 wherein the sealing layer has a thickness in the range of from about 1 μ

m to about 8 μ

m as measured in the center of the cell.

28. The electrophoretic display of claim 16 wherein the sealing layer is formed from a sealing composition having a specific gravity lower than that of the electrophoretic fluid.

29. The electrophoretic display of claim 28 wherein the sealing composition is a UV curable composition.

30. The electrophoretic display of claim 29 wherein the sealing composition comprises a thermoplastic or thermoset precursor.

31. An electrophoretic display comprising an array of display cells, wherein said display cells are filled with an electrophoretic fluid and top-sealed with a polymeric sealing layer formed from a sealing composition having a specific gravity lower than that of the electrophoretic fluid.

32. The electrophoretic display of claim 31, wherein said sealing composition is a thermoplastic or thermoset precursor composition.

33. The electrophoretic display of claim 32, wherein said thermoplastic or thermoset precursor composition comprises a material selected from the group consisting of polyvalent acrylates or methacrylates, cyanoacrylates, polyvalent vinyls, polyvalent epoxides, polyvalent isocyanates, polyvalent allyls, and oligomers or polymers comprising a crosslinkable functional group.

34. The electrophoretic display of claim 31, which display is in the form of a roll.

35. The electrophoretic display of claim 31, wherein said display cells are sandwiched between two conductor layers.