Electrocapillary display sheet which utilizes an applied electric field to move a liquid inside the display sheet

• US 5,956,005 A
• Filed: 06/10/1997
• Issued: 09/21/1999
• Est. Priority Date: 12/29/1995
• Status: Expired due to Term

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Sheridon, Nicholas K.
• Primary Examiner(s): Brier, Jeffery
• Assistant Examiner(s): Bell, Paul A.
• Application Number:
  US08/872,264
• Time in Patent Office: 833 Days
• Field of Search: 345/107, 345/55, 345/48, 345/60, 345/49, 345/84, 345/30, 359/223, 359/228, 359/291, 359/296, 430/37, 430/38
• US Class Current: 345/84
• CPC Class Codes: G02B 26/004 based on a displacement or a deformation of a fluid
• CPC Class Codes: G09F 9/372 the positions of the elements being controlled by the application of an electric field

Abstract

There is disclosed an electrocapillary display sheet which utilizes three transparent sheets being spaced from each other and placed parallel to each other. The medial sheet has a plurality of reservoirs which are filled with a dyed or pigmented ink. Each of the reservoirs has an individually addressable voltage source to create an individual electric field. By activating each electric field, the ink from the corresponding reservoir flows out into the space between the medial sheet and one of the other two sheets in order to create a pixel. By removing the electric filed, the liquid which had created a pixel will retreat back into the reservoir.

Claims

1. A display device comprising:

a first non-conductive sheet;

a second non-conductive sheet;

a medial non-conductive sheet being located between said first and said second sheets;

a first sealed passage means between said first sheet and said medial sheet;

a second sealed passage means between said medial sheet and said second sheet;

said medial sheet having a plurality of first holes extending through said medial sheet and opening into each of said passage means;

said first sheet having a plurality of electrodes;

said medial sheet having a plurality of electrodes each associated with a corresponding one of said plurality of first holes;

each one of said plurality of electrodes of said medial sheet facing a corresponding one of said plurality of electrodes of said first sheet and being aligned with said corresponding electrode;

said medial sheet having a plurality of second holes extending through said medial sheet and opening into each of said passage means for providing a communication path between said first sealed passage means and said second sealed passage means;

a first liquid means;

said first liquid means filling at least said plurality of first holes;

said first liquid means being conductive;

a plurality of conductive means each being in contact with said first liquid means of a corresponding one of said plurality of first holes for providing electrical connection to said fist liquid means of said corresponding one of said plurality of first holes;

a first insulating layer insulating said plurality of electrodes of said first sheet from said first liquid means;

a second insulating layer insulating said plurality of electrodes of said medial sheet from said first liquid means;

a second liquid means being located at a plurality of locations in said second passage means;

said second liquid means at each of said plurality of locations associating with a corresponding one of said first holes;

said second liquid means being non-conductive;

a fluid means;

said fluid means filling said second holes of said medial sheet, said first sealed passage means and the remaining portions of said second sealed passage means; and

said plurality of electrodes of said first sheet, said first insulating layer, said plurality of electrodes of said medial sheet, said second insulating layer, and said plurality of conductive means, being so constructed and arranged relative to each other and said first holes that when one of said plurality of electrodes of said first sheet, a corresponding one of said plurality of electrodes of said medial sheet, and a corresponding one of said plurality of conductive means are activated, an electric field will be generated which will cause said first liquid means in a corresponding one of said plurality of first holes to flow into said first sealed passage means and retreat said second liquid means into said corresponding one of said plurality of first holes causing displacement of adjacent said fluid means through said first and second sealed passage means and corresponding said second holes.

2. The display device recited in claim 1, wherein said second sheet is transparent.

3. The display device as recited in claim 1, wherein each of said plurality of electrodes of said medial sheet completely surrounds a corresponding one of said plurality of said first holes.

4. The display device as recited in claim 3, wherein each of said second holes is surrounded by a plurality of adjacent said electrodes of said medial sheet.

5. The display device as recited in claim 4, wherein said fluid means is a liquid which is immiscible with said first and said second liquid means.

6. The display device as recited in claim 4, wherein said fluid means is a gas.

7. The display device as recited in claim 6, wherein said gas is air.

8. The display device as recited in claim 4, wherein said first insulating layer has a plurality of conductive means, each of said plurality of conductive means is aligned with one of said plurality of first holes.

9. The display device recited in claim 8, wherein said medial sheet is transparent.

10. The display device recited in claim 9, wherein said second sheet is transparent.

11. The display device recited in claim 1, wherein said first liquid means in said first passage means flows back into said first holes of said medial sheet when the electric field is removed and said second liquid means flows back into said second passage means.

12. The display device recited in claim 11, wherein said first liquid means is clear.

13. The display device recited in claim 12, wherein said second liquid means is pigmented.

14. The display device recited in claim 13, wherein said second sheet is transparent.

15. The display device recited in claim 11, wherein said second liquid means is dyed.

16. The display device recited in claim 11, wherein said second sheet is transparent.