Electrophoretic displays

Patent metadata

Field	Value
Publication number	US-9664978-B2
Application number	US-201514638707-A
Country	US
Kind code	B2
Filing date	Mar 4, 2015
Priority date	Oct 16, 2002
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

A dielectrophoretic display comprises a substrate having walls defining at least one cavity, the cavity having a viewing surface and a side wall inclined to the viewing surface; a suspending fluid contained within the cavity; a plurality of at least one type of particle suspended within the suspending fluid; and means for applying to the fluid an electric field effective to cause dielectrophoretic movement of the particles to the side wall of the cavity.

First claim

The invention claimed is:

1. A display comprising:
a substrate having walls defining at least one cavity, the cavity having a viewing surface, a rear surface on the opposed side of the cavity from the viewing surface, and at least one side wall extending between the viewing surface and the rear surface;
a colored fluid contained within the cavity;
a plurality of electrically charged solid particles within the fluid;
a front electrode adjacent the viewing surface of the cavity;
a rear electrode adjacent the rear surface; and
a side electrode adjacent the side wall,
the display having a first optical state in which the solid particles lie adjacent the front electrode, a second optical state in which the solid particles lie adjacent the rear electrode and a third optical state in which the solid particles lie adjacent the side electrode.

2. A display according to claim 1 wherein the solid particles are white in color.

3. A display according to claim 1 wherein the cavity has a non-circular cross-section as seen from the viewing surface.

4. A display according to claim 3 wherein the cavity has a polygonal cross-section as seen from the viewing surface.

5. A display according to claim 1 wherein the substrate comprises a substantially rigid material having the at least one cavity formed therein, the substrate further comprising at least one cover member closing the at least one cavity.

6. A display according to claim 1 arranged to have light projected on to a surface on the opposed side of the display from the viewing surface.

7. A process for operating a display, the process comprising:
providing a substrate having walls defining at least one cavity, the cavity having a viewing surface, a rear surface on the opposed side of the cavity from the viewing surface, and at least one side wall extending between the viewing surface and the rear surface; a colored fluid contained within the cavity; a plurality of electrically charged solid particles within the fluid; a front electrode adjacent the viewing surface of the cavity; a rear electrode adjacent the rear surface; and a side electrode adjacent the side wall; and
applying to the front, rear and side electrodes electrical potentials effective to cause the solid particles fluid to assume:
(a) a first position in which the solid particles lie adjacent the front electrode, and the display shows a first optical state;
(b) a second position in which the solid particles lie adjacent the rear electrode and the display shows a second optical state; and
(c) a third position in which the solid particles lie adjacent the side electrode and the display shows a third optical state.

8. A process according to claim 7 wherein the solid particles are white in color.

9. A process according to claim 7 wherein the cavity has a non-circular cross-section as seen from the viewing surface.

10. A process according to claim 9 wherein the cavity has a polygonal cross-section as seen from the viewing surface.

11. A process according to claim 7 wherein the substrate comprises a substantially rigid material having the at least one cavity formed therein, the substrate further comprising at least one cover member closing the at least one cavity.

12. A process according to claim 7 further comprising projecting light on to a surface on the opposed side of the display from the viewing surface.

Assignees

• E Ink Corp

Inventors

• Arango Alexi C
• Jacobson Joseph M
• Amundson Karl Raymond
• Hertel Dirk

Classifications

• G02F1/1368

  in which the switching element is a three-electrode device {(G02F1/136277 takes precedence)} · CPC title

• G02F1/167 Primary

  by electrophoresis · CPC title

• G02F1/1681

  having two or more microcells partitioned by walls, e.g. of microcup type · CPC title

• G09G3/3446

  with more than two electrodes controlling the modulating element · CPC title

• G02F1/1676

  Electrodes · CPC title