Some uses of microencapsulation for electric paper

• US 5,604,027 A
• Filed: 01/03/1995
• Issued: 02/18/1997
• Est. Priority Date: 01/03/1995
• Status: Expired

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Sheridon, Nicholas K.
• Primary Examiner(s): Ryan, Patrick
• Assistant Examiner(s): Lee, C.
• Application Number:
  US08/368,120
• Time in Patent Office: 777 Days
• Field of Search: 428/320.2, 428/323, 428/402.2, 428/402.21, 264/4, 264/7
• US Class Current: 428/323
• 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: G09F 9/372 the positions of the elements being controlled by the application of an electric field
• CPC Class Codes: Y10T 428/249994 Composite having a component wherein a constituent is liquid or is contained within preformed walls [e.g., impregnant-filled, previously void containing component, etc.]
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/2984 Microcapsule with fluid core [includes liposome]
• CPC Class Codes: Y10T 428/2985 Solid-walled microcapsule from synthetic polymer

Abstract

Bichromal balls have two hemispheres, typically one black and one white, each having different electrical properties. Each ball is enclosed within a spherical shell and then a space between the ball and shell is filled with a liquid to form a microsphere so that the ball is free to rotate in response to an electrical field. The microspheres can then be mixed into a substrate which can be formed into sheets or can be applied to any kind of surface. The result is a film which can form an image from an applied electrical field.

Claims

1. A display medium comprising:

a plurality of bichromal balls, each having two hemispheric surfaces, one surface differing from the other in both color and electrical characteristics

a layer of liquid surrounding each ball,

a skin of a first compound surrounding the layer of liquid to form a microcapsule, and

a substrate of a second compound within which all of said microcapsules are encapsulated.

2. The medium of claim 1 wherein said substrate is a solid.

3. The medium of claim 1 wherein said substrate is a liquid.

4. A display medium comprising:

a plurality of bichromal balls, each having two hemispheric surfaces, one surface differing from the other in both color and electrical characteristics

a layer of liquid surrounding each ball,

a skin of a first compound surrounding the layer of liquid, and

a substrate of a second compound within which all of said microcapsules are encapsulated, which substrate is adapted to be bonded to a surface.

5. The medium of claim 4 wherein said adhesive layer is hardenable.

6. The medium of claim 4 wherein said adhesive layer is a liquid.

7. The surface of claim 4 wherein said surface is flat.

8. The surface of claim 4 wherein said surface is not flat.

9. The surface of claim 4 wherein said surface is a fabric.