ELECTROPHORETIC DISPLAY AND PROCESS FOR ITS MANUFACTURE

• US 20080007815A1
• Filed: 04/27/2007
• Published: 01/10/2008
• Est. Priority Date: 03/03/2000
• Status: Active Grant

• Current Assignee: E Ink California, LLC (E Ink Corporation)
• Original Assignee: SiPix Imaging, Inc. (E Ink Holdings Incorporated)
• Inventors: Wu, Zarng-Arh, Chan-Park, Mary, LIANG, Rong-Chang, Zang, HongMei, Tseng, Scott
• Granted Patent: US 7,715,088 B2
• Time in Patent Office: Days
• 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 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 0.01μ

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 0.02μ

to about 15μ

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 0.1μ

to about 4μ

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 0.01μ

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 0.01μ

to about 50μ

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 0.5μ

to about 8μ

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 0.1μ

to about 50μ

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 0.5μ

to about 15μ

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 1μ

to about 8μ

as measured in the center of the cell.

25. 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.

26. The electrophoretic display of claim 25 wherein said sealing composition is a UV curable composition.

27. The electrophoretic display of claim 26 wherein said sealing composition comprises a thermoplastic or thermoset precursor.

13. 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 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 0.01μ

below the top surface of the partition wall.

14. The electrophoretic display of claim 13 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.

15. The electrophoretic display of claim 14 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.

16. The electrophoretic display of claim 15 wherein said filler is selected from the group consisting of silica, CaCO₃, BaSO₄, TiO₂, metal particles, metal oxides and carbon black.

17. The electrophoretic display of claim 13 wherein the contact point of the interface and the partition wall is about 0.02μ

to about 15μ

below the top surface of the partition wall.

18. The electrophoretic display of claim 17 wherein the contact point of the interface and the partition wall is about 0.1μ

to about 4μ

below the top surface of the partition wall.

19. The electrophoretic display of claim 13 wherein the top surface of the sealing layer is at least about 0.01μ

above the top surface of the partition wall.

20. The electrophoretic display of claim 19 wherein the top surface of the sealing layer is about 0.01μ

to about 50μ

above the top surface of the partition wall.

21. The electrophoretic display of claim 20 wherein the top surface of the sealing layer is about 0.5μ

to about 8μ

above the top surface of the partition wall.

22. The electrophoretic display of claim 13 wherein the sealing layer has a thickness in the range of from about 0.1μ

to about 50μ

as measured in the center of the cell.

23. The electrophoretic display of claim 22 wherein the sealing layer has a thickness in the range of from about 0.5μ

to about 15μ

as measured in the center of the cell.

24. The electrophoretic display of claim 23 wherein the sealing layer has a thickness in the range of from about 1μ

to about 8μ

as measured in the center of the cell.

28. The electrophoretic display of claim 13 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.