ELECTROSTATICALLY ADDRESSABLE ELECTROPHORETIC DISPLAY

• US 20080150888A1
• Filed: 01/08/2008
• Published: 06/26/2008
• Est. Priority Date: 07/20/1995
• Status: Active Grant

• Current Assignee: E Ink Holdings Incorporated
• Original Assignee: E Ink Holdings Incorporated
• Inventors: Albert, Jonathan D., Jacobson, Joseph M., Comiskey, Barrett
• Granted Patent: US 8,384,658 B2
• Time in Patent Office: Days
• US Class Current: 345/107
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G09G 2300/0434 Flat panel display in which a field is applied parallel to the display plane
• CPC Class Codes: G09G 3/344 based on particles moving in a fluid or in a gas, e.g. electrophoretic devices electrophoretic devices per se G02F1/167
• CPC Class Codes: G09G 3/3446 with more than two electrodes controlling the modulating element

Abstract

Novel addressing schemes for controlling electronically addressable displays include a scheme for rear-addressing displays, which allows for in-plane switching of the display material. Other schemes include a rear-addressing scheme which uses a retroreflecting surface to enable greater viewing angle and contrast. Another scheme includes an electrode structure that facilitates manufacture and control of a color display. Another electrode structure facilitates addressing a display using an electrostatic stylus. Methods of using the disclosed electrode structures are also disclosed. Another scheme includes devices combining display materials with silicon transistor addressing structures.

Claims

1. A method for addressing an electrophoretic display which includes at least one cavity containing charged particles, the method comprising the steps of:

(a) providing three or more electrodes adjacent each cavity; and

(b) applying a sequence of potentials to said three or more electrodes to control the movement of said charged particles inside said cavity,

wherein at least two of said three or more electrodes are disposed in the same plane, and the sequence of potentials causes the charged particles to move between said at least two electrodes in the same plane.

2. A method according to claim 1 wherein there are at least four electrodes disposed in the same plane, the four electrodes comprising two first electrodes and two second electrodes, and wherein the method comprises driving the charged particles adjacent the two first electrodes, thereby producing a first optical state in said cavity, and driving the charged particles adjacent the two second electrodes, thereby producing in said cavity a second optical state different from the first optical state.

3. A method according to claim 1 wherein at least four electrodes are provided adjacent each cavity, the electrodes being of differing colors.

4. A method according to claim 1 wherein the at least one cavity is surrounded by a capsule wall so that the charged particles are held within a capsule.

5. A method according to claim 4 wherein the capsule is held within a binder.

6. A method according to claim 1 wherein the charged particles are present in a fluid which is dispersed in a binder.

14. An electrophoretic display according to claim 6 wherein the charged particles are present in a fluid which is dispersed in a binder.

7. A method for addressing an electrophoretic display which includes at least one capsule containing charged particles, the method comprising the steps of:

(a) providing three or more electrodes adjacent each capsule; and

(b) applying a sequence of potentials to said three or more electrodes to control the movement of said charged particles inside each capsule, such that the particles are prevented from traversing said capsule until at least one electrode of said three or more electrodes is at a potential high enough to overcome the effects of at least one other electrode of said three or more electrodes.

8. A method according to claim 7 wherein said three electrodes comprise a first elongate electrode lying in a first plane;

a second elongate electrode lying in a second plane spaced from the first plane and extending substantially perpendicular to the first elongate electrode; and

a third planar electrode lying in a third plane spaced from the first and second planes, the third electrode lying on the opposed side of the second electrode from the first electrode,

the second electrode having an aperture extending therethrough, said capsule being disposed in said aperture.

9. An electrophoretic display comprising:

walls defining a cavity containing charged particles; and

three or more electrodes disposed adjacent said capsule,

wherein a sequence of voltage potentials applied to said three or more electrodes causes said charged particles to move within said capsule responsive to said sequence of voltage potentials,

at least two of said three or more electrodes being disposed in the same plane such that the sequence of potentials causes the charged particles to move between said at least two electrodes in the same plane.

10. An electrophoretic display according to claim 9 wherein there are at least four electrodes disposed in the same plane, the four electrodes comprising two first electrodes and two second electrodes, and wherein the sequence of potentials drives the charged particles adjacent the two first electrodes, thereby producing a first optical state in said cavity, and drives the charged particles adjacent the two second electrodes, thereby producing in said cavity a second optical state different from the first optical state.

11. An electrophoretic display according to claim 9 wherein at least four electrodes are provided adjacent each cavity, the electrodes being of differing colors.

12. An electrophoretic display according to claim 9 wherein the at least one cavity is surrounded by a capsule wall so that the charged particles are held within a capsule.

13. An electrophoretic display according to claim 12 wherein the capsule is held within a binder.

15. An electrophoretic display comprising:

at least one capsule containing charged particles; and

three or more electrodes adjacent each capsule; and

wherein a sequence of voltage potentials applied to said three or more electrodes controls the movement of said charged particles inside each capsule, such that the particles are prevented from traversing said capsule until at least one electrode of said three or more electrodes is at a potential high enough to overcome the effects of at least one other electrode of said three or more electrodes.

16. An electrophoretic display according to claim 15 wherein said three electrodes comprise a first elongate electrode lying in a first plane;

a second elongate electrode lying in a second plane spaced from the first plane and extending substantially perpendicular to the first elongate electrode; and

a third planar electrode lying in a third plane spaced from the first and second planes, the third electrode lying on the opposed side of the second electrode from the first electrode,

the second electrode having an aperture extending therethrough, said capsule being disposed in said aperture.