Microcell electrophoretic displays

• US 6,327,072 B1
• Filed: 04/06/2000
• Issued: 12/04/2001
• Est. Priority Date: 04/06/1999
• Status: Expired due to Term

• Current Assignee: E Ink Holdings Incorporated
• Original Assignee: E Ink Holdings Incorporated
• Inventors: Comiskey, Barrett, Wilcox, Russell J., Morrison, Ian
• Primary Examiner(s): Epps, Georgia
• Assistant Examiner(s): THOMPSON, TIMOTHY J
• Application Number:
  US09/543,486
• Time in Patent Office: 607 Days
• Field of Search: 345/107, 345/105, 345/108, 204/450, 204/600, 204/606, 359/452, 359/253, 359/296
• US Class Current: 359/296
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: G02F 1/167 by electrophoresis

Abstract

An electrophoretic display element includes at least one substrate and at least one cell defined by a cell wall. The cell is disposed on the substrate and contains a suspending medium. In some embodiments, the cell has a width that is not greater than about three times a height of the cell wall.

Claims

1. An electrophoretic display element comprising:

at least one substrate and

at least one cell, the cell defined by a cell wall and disposed on the substrate, wherein the cell has a width that is not greater than about three times a height of the cell wall.

2. The element of claim 1 wherein the cell has a width that is from about two to about three times a height of the cell wall.

3. The element of claim 1 in which the cell wall is less than 10 micrometers wide.

4. The element of claim 1 wherein the substrate comprises a control grid electrode structure.

5. The element of claim 4 wherein the cell comprises two laminated structures.

6. The element of claim 1 wherein the cell wall is formed at least in part with a technique selected from the group consisting of photolithography, sandblasting, screenprinting, embossing, laser etching and radiation curing.

7. The element of claim 1 wherein the substrate is permeable to a suspending fluid and substantially impermeable to electrophoretic particles, such that the suspending fluid and the particles fill a cavity defined by the cell walls.

8. The element of claim 1 wherein the substrate is coated with a polymer, the polymer being insoluble in a suspending medium contained within a cavity defined by the cell walls.

9. The element of claim 1 wherein a suspending fluid contained within a cavity defined by the cell walls comprises a substantially clear liquid.

10. The element of claim 1 wherein the width is in the range of 5 to 200 micrometers.

11. The element of claim 1 wherein the height is in the range of 10 to 100 micrometers.

12. An electrophoretic display element comprising at least one substrate and at least one cell defined by a cell wall and disposed on the substrate, the cell containing a suspending medium and a plurality of electrophoretic particles, wherein the cell has a shape that minimizes hydrodynamic motion within the suspending medium.

13. The element of claim 12 wherein the hydrodynamic motion comprises a convective current.

14. The element of claim 13 wherein the height is in the range of 10 to 100 micrometers.