Electromagnetophoretic display system and method

• US 6,847,347 B1
• Filed: 08/17/2000
• Issued: 01/25/2005
• Est. Priority Date: 08/17/2000
• Status: Expired due to Term

• Current Assignee: E Ink Holdings Incorporated
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Kazmaier, Peter M., Mahabadi, Hadi, Noolandi, Jaan, Sharp, James, Torres, Francisco E.
• Primary Examiner(s): Tung, Kee M.
• Assistant Examiner(s): TRAN, TAM D
• Application Number:
  US09/643,670
• Time in Patent Office: 1,622 Days
• Field of Search: 345/107, 345/85, 345/86, 359/296
• US Class Current: 345/107
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: G02F 1/094 based on magnetophoretic effect
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 1/1673 by magnetophoresis
• CPC Class Codes: G02F 1/16757 Microcapsules
• CPC Class Codes: G02F 1/1685 Operation of cells; Circuit arrangements affecting the entire cell
• CPC Class Codes: H01F 1/0054 Coated nanoparticles, e.g. nanoparticles coated with organic surfactant
• CPC Class Codes: H01F 1/44 of magnetic liquids, e.g. ferrofluids particles in a bonding agent H01F1/28, H01F1/36, H01F1/37
• CPC Class Codes: H01F 1/445 the magnetic component being a compound, e.g. Fe3O4 H01F1/447 takes precedence

Abstract

The present invention comprises an electromagnetophoretic ink material for use as electronic and magnetic display elements. In particular, the present invention relates to the preparation and use of microencapsulated aspect elements having both an electrostatic layer and a magnetic layer, and that can be addressed to produce a display aspect by the application of external electric fields and external magnetic fields.

Claims

1. An electromagnetophoretic ink material comprising

an encapsulating structure;

a first aspect medium within said encapsulating structure, and

a plurality of second aspect elements within said encapsulating structure;

wherein each of said plurality of second aspect elements is configured to translationally displace within said encapsulating structure under the influence of an applied gradient field, and

wherein each of said plurality of second aspect elements is further configured to translationally displace within said encapsulating structure under the influence of an applied vector field.

2. The electromagnetophoretic ink material of claim 1, further comprising

a plurality of third aspect elements within said encapsulating structure;

wherein each of said plurality of third aspect elements is configured to translationally displace within said encapsulating structure under the influence of said applied vector field.

3. The electromagnetophoretic ink material of claim 2,

wherein each of said plurality of third aspect elements is further configured to translationally displace within said encapsulating structure under the influence of said applied gradient field.

4. The electromagnetophoretic ink material of claim 3, further comprising

a plurality of fourth aspect elements within said encapsulating structure;

wherein each of said plurality of fourth aspect elements is configured to translationally displace within said encapsulating structure under the influence of said applied vector field.

5. The electromagnetophoretic ink material of claim 4,

wherein said each of said plurality of fourth aspect elements is further configured to translationally displace within said encapsulating structure under the influence of said applied gradient field.

6. The electromagnetophoretic ink material of claim 5,

wherein said each of said plurality of second aspect elements comprises

a second aspect inner layer, and

a second aspect outer layer, and

wherein said each of said plurality of third aspect elements comprises

a third aspect inner layer, and

a third aspect outer layer, and

wherein said each of said plurality of fourth aspect elements comprises

a fourth aspect inner layer, and

a fourth aspect outer layer.

7. The electromagnetophoretic ink material of claim 6,

wherein each of said plurality of second aspect elements has more volume than each of said plurality of third aspect elements, and

wherein each of said plurality of third aspect elements has more volume than each of said plurality of fourth aspect elements.

8. The electromagnetophoretic ink material of claim 6, wherein

said second aspect inner layer is selected from the group consisting of magnetite particles, ferromagnetic particles, paramagnetic particles, and superparamagnetic particles;

said third aspect inner layer is selected from the group consisting of magnetite particles, ferromagnetic particles, paramagnetic particles, and superparamagnetic particles; and

said fourth aspect inner layer is selected from the group consisting of magnetite particles, ferromagnetic particles, paramagnetic particles, and superparamagnetic particles.

9. The electromagnetophoretic ink material of claim 8, wherein

said second aspect outer layer, said third aspect outer layer, and said fourth aspect outer layer comprises a polymeric shell containing material, where said material is selected from the group consisting of anionic, cationic, electron accepting, and electron donating groups.

10. The electromagnetophoretic ink material of claim 8, wherein

said second aspect outer layer comprises a first coating with a Zeta potential,

said third aspect outer layer comprises a second coating with a Zeta potential,

said fourth aspect outer layer comprises a third coating with a Zeta potential, and

said first aspect medium comprises a dielectric liquid,

wherein said first coating acquires an electrostatic charge when in contact with said dielectric liquid,

wherein said second coating acquires an electrostatic charge when in contact with said dielectric liquid, and

wherein said third coating acquires an electrostatic charge when in contact with said dielectric liquid.

11. The electromagnetophoretic ink material of claim 1,

wherein said gradient field is a magnetic field.

12. The electromagnetophoretic ink material of claim 1,

wherein said vector field is an electric field.

13. A display system comprising

a plurality of electromagnetophoretic ink material of claim 1,

supporting material, and

an addressing system,

wherein said plurality of electromagnetophoretic ink material are bounded by said supporting material, and

wherein said addressing system is configured to introduce a first vector field and a first gradient field to a subset of said plurality of electromagnetophoretic ink material.

14. A method of addressing electromagnetophoretic ink material to present an aspect,

said method comprising

introducing a vector field to said electromagnetophoretic ink material in a first direction, and

introducing a gradient field to said electromagnetophoretic ink material in said first direction.

15. A method of addressing electromagnetophoretic ink material to present an aspect,

said method comprising

introducing a vector field to said electromagnetophoretic ink material in a first direction, and

introducing a gradient field to said electromagnetophoretic ink material in a second direction,

wherein said second direction is antiparallel to said first direction.

17. The method of claim 15,

wherein said vector field is an electric field.

18. The method of claim 15,

wherein said gradient field is a magnetic field.

16. A method of addressing electromagnetophoretic ink material to present an aspect,

said method comprising

introducing a first vector field to said electromagnetophoretic ink material in a first direction,

introducing a gradient field to said electromagnetophoretic ink material in said second direction, and then

introducing a second vector field to said electromagnetophoretic ink material in said second direction,

wherein said second direction is antiparallel to said first direction, and

wherein the magnitude of said second vector field is less than the magnitude of said first vector field.

19. The method of claim 16,

wherein said first vector field is an electric field, and

wherein said second vector field is an electric field.

20. The method of claim 16,

wherein said gradient field is a magnetic field.