Electrophoretic device, driving method of electrophoretic device, and electronic apparatus

• US 20020150827A1
• Filed: 03/19/2002
• Published: 10/17/2002
• Est. Priority Date: 03/19/2001
• Status: Active Grant

• Current Assignee: E Ink Holdings Incorporated
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Kawai, Hideyuki, Yamamoto, Hirokazu
• Granted Patent: US 6,788,450 B2
• Time in Patent Office: Days
• US Class Current: 430/20
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 1/16757 Microcapsules

Abstract

There is provided an electrophoretic device which comprises an electrophoretic layer containing dispersion medium and electrophoretic particles dispersed in the dispersion medium, controls the position of the electrophoretic particles according to the electric potential applied to electrodes, and can maintain the electrophoretic particles at a desired position for a long time by using the dispersion medium formed of mixture consisting of a plurality of substances having small mutual solubility.

Claims

1. An electrophoretic device comprising an electrophoretic layer containing dispersion medium and electrophoretic particles dispersed in the dispersion medium with the position of the electrophoretic particles controlled according to the electric potential applied to electrodes;

the dispersion medium being mixture of a plurality of substances, and mutual solubility of the substances being low.

3. An electrophoretic device according to claim 1 or claim 2, at least one of the plurality of substances being non-fluid at normal temperature, and fluid at non-normal temperature.

4. An electrophoretic device according to any one of claims 1 to 3, the plurality of substances being different from each other in refractive index thereof.

5. An electrophoretic device according to any one of claims 1 to 4, the dispersion medium being mixture of at least one kind of substance selected among long chain alcohols including hexadecyl alcohol and octadecyl alcohol, phenols including phenol and cresol, aromatic ketones including benzophenone and benzaldehyde, decanes, and dodecanes, with at least one kind of substance selected among paraffin, waxes, or waxes mainly consisting thereof, and saturated hydrocarbons.

6. An electrophoretic device according to any one of claims 1 to 5, the dispersion medium containing dispersing agent.

7. An electrophoretic device according to any one of claims 1 to 6, the dispersion medium with the electrophoretic particles dispersed therein being sealed in an area demarcated by bulkheads disposed between the electrodes.

8. An electrophoretic device according to any one of claims 1 to 6, dispersion medium with the electrophoretic particles dispersed therein being contained in a micro capsule, and sealed between the electrodes.

9. An electrophoretic device according to claim 8, micro capsule being disposed uniform in thickness and flat between the electrodes.

10. An electrophoretic device according to any one of claims 3 to 9 comprising a heating means for heating the dispersion medium.

11. An electrophoretic device according to any one of claims 3 to 10 comprising a cooling means for cooling the dispersion medium.

12. An electrophoretic device according to any one of claims 3 to 11 applying electric potential to the electrodes with the electrophoretic layer in non-normal temperature condition.

15. An electronic apparatus comprising a display body and a driving circuit for feeding drive signal to the display body, the display body comprising an electrophoretic device according to any one of claims 1 to 12.

2. An electrophoretic device in which an electrophoretic layer containing dispersion medium and electrophoretic particles dispersed in the dispersion medium is disposed between a pair of electrodes;

the dispersion medium being mixture of a plurality of substances, and mutual solubility of the substances being low.

13. A driving method of an electrophoretic device comprising an electrophoretic layer containing dispersion medium and electrophoretic particles dispersed in the dispersion medium with the position of the electrophoretic particles controlled according to the electric potential applied to electrodes;

the dispersion medium being formed of mixture consisting of a plurality of substances, and fluid at electrophoretically operational temperature in the electrophoretic layer and optically opaque solid at temperature lower than the electrophoretically operational temperature; and

the electric potential being applied to the electrodes with the temperature of the electrophoretic layer being set to be the electrophoretically operational temperature.

14. A method for driving an electrophoretic device comprising an electrophoretic layer containing dispersion medium and electrophoretic particles dispersed in the dispersion medium disposed between a pair of electrodes;

the dispersion medium being formed of mixture consisting of a plurality of substances and fluid at electrophoretically operational temperature for performing electrophoretic operation (26)in the electrophoretic layer, and optically opaque solid at temperature lower than the electrophoretically operational temperature; and

the electric potential being applied to the electrodes with the temperature of the electrophoretic layer being set to be the electrophoretic operational temperature.