Some uses of microencapsulation for electric paper

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.

What is claimed is:  
     
       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. 
     
     
       10. A display medium comprising: 
       
         at least one rotatable element having at least two portions, wherein the two portions have both optical and electrical characteristics such that the optical and electrical characteristics of at least one portion of the at least two portions differ from the optical and electrical characteristics of at least another portion of the at least two portions,  
       
       
         a layer of liquid substantially surrounding the at least one rotatable element,  
       
       
         a skin of a first compound surrounding the layer of liquid to form a microcapsule containing a single rotatable element substantially surrounded by a layer of liquid,  
       
       
         a substrate of a second compound at least partially surrounding the microcapsule. 
       
     
     
       11. The display medium of claim  10  wherein the at least one rotatable element comprises a substantially spherical element. 
     
     
       12. The display medium of claim  10  wherein the at least one rotatable element comprises two portions. 
     
     
       13. The display medium of claim  12  wherein one of the portions is colored black and the other portion is colored white. 
     
     
       14. The display medium of claim  12  wherein the at least one rotatable element comprises at least one substantially spherical element and each of the two portions substantially comprises a hemisphere. 
     
     
       15. The display medium of claim  10  wherein said substrate comprises a solid. 
     
     
       16. The display medium of claim  10  wherein said substrate comprises a liquid. 
     
     
       17. The display medium of claim  10  wherein said substrate substantially surrounds the microcapsule. 
     
     
       18. The display medium of claim  10  wherein said substrate completely surrounds the microcapsule. 
     
     
       19. The display medium of claim  10  wherein said substrate is adapted to be bonded to a surface. 
     
     
       20. The display medium of claim  18  wherein said substrate is an adhesive. 
     
     
       21. The display medium of claim  20  wherein said adhesive is a liquid. 
     
     
       22. The display medium of claim  21  wherein said adhesive is hardenable. 
     
     
       23. The display medium of claim  18  wherein the surface is substantially flat. 
     
     
       24. The display medium of claim  18  wherein the surface is deformable. 
     
     
       25. The display medium of claim  24  wherein the deformable surface comprises a fabric. 
     
     
       26. The display medium of claim  18  wherein the surface is non- planar.   
     
     
       27. The display medium of claim  10  wherein the at least one rotatable element comprises a plurality of rotatable elements.