Electrophoretic display and novel process for its manufacture

• US 6,751,008 B2
• Filed: 09/06/2002
• Issued: 06/15/2004
• Est. Priority Date: 03/03/2000
• Status: Expired due to Term

• Current Assignee: E Ink California, LLC (E Ink Corporation)
• Original Assignee: SiPix Imaging, Inc. (E Ink Holdings Incorporated)
• Inventors: Chan-Park, Mary, Liang, Rong-Chang, Zang, HongMei, Tseng, Scott C-J, Wu, George
• Primary Examiner(s): Dang, Hung Xuan
• Assistant Examiner(s): TRA, TUYEN Q
• Application Number:
  US10/237,522
• Publication Number:
  US 20030039022A1
• Time in Patent Office: 648 Days
• Field of Search: 359/296, 359/900, 345/105, 345/107, 204/600, 204/450, 430/32, 430/34, 430/38
• US Class Current: 359/296
• CPC Class Codes: B29C 39/026 characterised by the shape of the surface
• CPC Class Codes: B29C 39/06 continuously movable, e.g. along a production line
• CPC Class Codes: G02F 1/133305 Flexible substrates, e.g. plastics, organic film
• CPC Class Codes: G02F 1/133377 Cells with plural compartments or having plurality of liquid crystal microcells partitioned by walls, e.g. one microcell per pixel
• CPC Class Codes: G02F 1/1339 Gaskets; Spacers; Sealing of cells
• CPC Class Codes: G02F 1/167 by electrophoresis

Abstract

This invention relates to an electrophoretic display comprising cells of well-defined shape, size and aspect ratio which cells are filled with charged pigment particles dispersed in a solvent, and novel processes for its manufacture.

Claims

1. A process for manufacturing an electrophoretic display comprising the steps of:

a) filling a plurality of cells with an electrophoretic composition comprising charged particles dispersed in a dielectric solvent or solvent mixture and a dispersion of a sealing composition which has a specific gravity lower than that of said dielectric solvent or solvent mixture; and

b) forming a sealing layer on the electrophoretic composition by solvent evaporation.

2. The process of claim 1 wherein the sealing layer is further cured by radiation, heat, moisture or oxidation during or after solvent evaporation.

3. A process for manufacturing an electrophoretic display comprising the steps of:

a) filling a plurality of cells with an electrophoretic composition comprising charged particles dispersed in a dielectric solvent or solvent mixture;

b) overcoating onto said electrophoretic composition a sealing composition which is at least partially immiscible with said dielectric solvent or solvent mixture and has a specific gravity lower than said dielectric solvent or solvent mixture; and

c) sealing said cells by solvent evaporation.

4. The process of claim 3 wherein the sealing layer is further cured by radiation, heat, moisture or oxidation during or after solvent evaporation.