Electrophoretic display and process for its manufacture

• US 9,081,250 B2
• Filed: 08/23/2013
• Issued: 07/14/2015
• Est. Priority Date: 03/03/2000
• Status: Expired due to Fees

• Current Assignee: E Ink California, LLC (E Ink Corporation)
• Original Assignee: E Ink California, LLC (E Ink Corporation)
• Inventors: Liang, Rong-Chang, Chan-Park, Mary, Tseng, Scott C-J, Wu, Zarng-Arh George, Zang, HongMei
• Primary Examiner(s): TRA, TUYEN Q
• Application Number:
  US13/974,980
• Publication Number:
  US 20140057056A1
• Time in Patent Office: 690 Days
• Field of Search: 359/296, 359/900, 345/107, 430/32, 430/321, 430/394
• US Class Current: 1/1
• 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. A process for forming an electrophoretic display, comprising the steps of:

a) dispersing a sealing composition in an electrophoretic fluid comprising charged pigment particles dispersed in a dielectric solvent,

b) filling display cells with the electrophoretic fluid and the sealing composition,

c) separating the sealing composition from the electrophoretic fluid and forming a supernatant layer on top of the electrophoretic fluid, and

d) sealing the filled display cells by interfacial polymerization while the sealing composition is on top of the electrophoretic fluid.

2. The process of claim 1, wherein said sealing composition comprises a thermoplastic precursor or a thermoset precursor.

3. The process of claim 2, wherein the thermoplastic precursor or the thermoset precursor is immiscible with the dielectric solvent and has a specific gravity lower than that of the dielectric solvent and the pigment particles.

4. The process of claim 1, wherein said sealing composition is a solution comprising a thermoplastic or thermoset precursor.

5. The process of claim 1, wherein said sealing composition is a UV curable composition.

6. The process of claim 1, wherein said sealing composition comprises a volatile solvent.

7. The process of claim 1, wherein the volatile solvent is immiscible with the dielectric solvent.

8. The process of claim 1, wherein the electrophoretic fluid is at least partially compatible with the sealing composition.

9. The process of 1, wherein step (d) further comprises UV curing of the sealing composition after interfacial polymerization.