Methods for achieving improved color in microencapsulated electrophoretic devices

• US 7,667,684 B2
• Filed: 04/02/2004
• Issued: 02/23/2010
• Est. Priority Date: 07/08/1998
• Status: Expired due to Fees

• Current Assignee: E Ink Holdings Incorporated
• Original Assignee: E Ink Holdings Incorporated
• Inventors: Drzaic, Paul, Jacobson, Joseph M., Wilcox, Russell J., Morrison, Ian D.
• Primary Examiner(s): Lefkowitz; Sumati
• Assistant Examiner(s): Xiao; Ke
• Application Number:
  US10/817,464
• Publication Number:
  US 20040190114A1
• Time in Patent Office: 2,153 Days
• Field of Search: 345/107
• US Class Current: 345/107
• CPC Class Codes: B05D 5/06 to obtain multicolour or other optical effects B05D5/02 takes precedence
• CPC Class Codes: B41J 2/2117 Ejecting white liquids
• CPC Class Codes: B41J 3/4073 Printing on three-dimensional objects not being in sheet or web form, e.g. spherical or cubic objects B41J3/283, B41J3/286 take precedence; building up a 3D object using individual droplets from jetting heads B29C64/112
• CPC Class Codes: B41J 3/4076 printing on rewritable, bistable "electronic paper" by a focused electric or magnetic field
• CPC Class Codes: G02B 26/026 based on the rotation of particles under the influence of an external field, e.g. gyricons, twisting ball displays based on orientable dipolar particles G02F1/172; based on electrophoresis G02F1/167
• CPC Class Codes: G02F 1/133305 Flexible substrates, e.g. plastics, organic film
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 1/16757 Microcapsules
• CPC Class Codes: G02F 2202/28 Adhesive materials or arrangements
• CPC Class Codes: G09F 9/302 characterised by the form or geometrical disposition of the individual elements
• CPC Class Codes: G09F 9/372 the positions of the elements being controlled by the application of an electric field
• CPC Class Codes: H10K 10/462 Insulated gate field-effect transistors [IGFETs]
• CPC Class Codes: H10K 19/00 Integrated devices, or assemblies of multiple devices, comprising at least one organic element specially adapted for rectifying, amplifying, oscillating or switching, covered by group H10K10/00
• CPC Class Codes: H10K 85/30 Coordination compounds
• CPC Class Codes: H10K 85/60 Organic compounds having low molecular weight H10K85/10 - H10K85/50 take precedence

Abstract

A method for manufacturing a full color, reflective display includes the steps of depositing a first plurality of electrophoretic display elements in substantial registration with a first electrode and a second plurality of electrophoretic display elements in substantial registration with a second electrode. The electrophoretic display elements include a capsule containing a species of particles dispersed in a suspending fluid. The selective deposition of the display elements can be achieved by ink-jet printing methods, screen printing methods or other printing methods. In some embodiments the electrodes are printed onto the substrate before selective deposition of the display elements, while in other embodiments the substrate is provided having the electrodes already disposed on it. In still other embodiments, the sequence of printing of electrodes and electrophoretic display elements can be varied.

Claims

1. A color electrophoretic display comprising:

a first reflective surface comprising a first electrode of a first color and a second electrode of a second color;

a first display element comprising a plurality of first species of electrophoretic particles of said second color, said first reflective surface disposed adjacent a rear side of said first display element opposite its viewing side, said first element displaying said first color when said first reflective surface is substantially visible and displaying said second color when said first reflective surface is substantially obscured by said first species of particles;

a second reflective surface comprising a third electrode of a third color and a fourth electrode of a fourth color;

a second display element comprising a plurality of second species of electrophoretic particles of said fourth color, said second reflective surface disposed adjacent a rear side of said second display element opposite its viewing side, said second element displaying said third color when said second reflective surface is substantially visible and displaying said fourth color when said second reflective surface is substantially obscured by said second species of particles;

a third reflective surface comprising a fifth electrode of a fifth color and a sixth electrode of a sixth color; and

a third display element comprising a plurality of third species of electrophoretic particles of said sixth color, said third reflective surface disposed adjacent a rear side of said third display element opposite its viewing side, said third element displaying said fifth color when said third reflective surface is substantially visible and displaying said sixth color when said third reflective surface is substantially obscured by said third species of particles.

2. The color electrophoretic display of claim 1 wherein said first color is red, said third color is green and said fifth color is blue.

3. The color electrophoretic display of claim 1 wherein said first color is cyan, said third color is yellow and said fifth color is magenta.

4. The color electrophoretic display of claim 1 wherein said second, fourth and sixth colors are each selected from the group consisting of black and white.

5. A color electrophoretic display comprising:

a reflective surface comprising a first electrode of a first color and a second electrode of a second color;

a display element comprising a plurality of a species of electrophoretic particles of said second color, said reflective surface disposed adjacent a rear side of said display element opposite its viewing side, said display element displaying said first color when said reflective surface is substantially visible and displaying said second color when said reflective surface is substantially obscured by said species of particles.

6. The color electrophoretic display of claim 5 wherein said first color is any one of red, green and blue.

7. The color electrophoretic display of claim 5 wherein said first color is any one of cyan, yellow and magenta.

8. The color electrophoretic display of claim 5 wherein said second color is selected from the group consisting of black and white.