Electronic writing and erasing pencil

• US 7,095,404 B2
• Filed: 09/25/2003
• Issued: 08/22/2006
• Est. Priority Date: 10/16/2001
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Williams, R. Stanley, Vincent, Kent D., Zhang, Xiao-An
• Primary Examiner(s): Eisen, Alexander
• Application Number:
  US10/670,479
• Publication Number:
  US 20040041799A1
• Time in Patent Office: 1,062 Days
• Field of Search: 345/107, 345/105, 345/179, 359/296, 359/290
• US Class Current: 345/179
• CPC Class Codes: G06F 3/03545 Pens or stylus

Abstract

An electronic writing instrument for rewritable electronic writing surfaces. A self-powered, untethered, pencil-like instrument uses a perpendicular fringe field for changing the orientation of pixels composed of bistable, bichromal colorant elements. An appendix hereto describes bistable, bichromal, molecular colorant.

Claims

1. An electronic stylus apparatus comprising:

a portable power source;

connected to the power source, at least one electrode for producing a localized, emanating, electric field wherein the field is of a strength sufficient to reorient electronic picture elements formed of an electrically bistable, molecular colorant.

2. The apparatus as set forth in claim 1 comprising:

connected between said power source and said electrode electronic circuitry for switching the polarity of said electric field.

3. The apparatus as set forth in claim 1 comprising:

connected between said power source and said electrode electronic circuitry for selectively varying the intensity of said electric field.

4. The apparatus as set forth in claim 1 comprising:

said at least one electrode is adapted for writing and erasing electrically bistable, bichromal, molecular colorant.

5. The apparatus as set forth in claim 1 comprising:

a hand-held cylindrical pencil shaped body wherein said power source and electrode are incorporated therein such that said apparatus is used in the manner of a conventional writing instrument.

6. The apparatus as set forth in claim 1 comprising:

electronic circuitry for maintaining a substantially constant electrical field output of the apparatus.

16. The apparatus as set forth in claim 1, said colorant comprising:

a molecular system, said system including electrochromic, switchable molecules, each of said molecules being selectively switchable between at least two optically distinguishable states, wherein said system is distributable on the substrate thereby forming an erasably writable surface.

17. The apparatus as set forth in claim 16 comprising:

said molecules exhibit an electric field induced band gap change.

18. The apparatus as set forth in claim 17 comprising:

said electric field induced band gap change occurs via a mechanism selected from a group including (1) molecular conformation change or an isomerization, (2) change of extended conjugation via chemical bonding change to change the band gap, and (3) molecular folding or stretching.

7. A method for electronic erasable writing, the method comprising:

providing a surface having picture elements defined by a bistable, molecular colorant element; and

moving a portable, electrical fringe field, emanating substantially perpendicular to said surface and tuned for changing orientation of molecules of the colorant element across said surface in a manner substantially identical to conventional handwriting.

8. The method as set forth in claim 7 comprising:

providing a writing-erasing instrument for producing said perpendicular fringe field such that said field is localized to emanating from a tip of said instrument.

9. The method as set forth in claim 7 comprising:

switching polarity of said perpendicular fringe field from a first polarity for writing operations to a second polarity for erasing operations.

10. The method as set forth in claim 7 wherein the strength of the perpendicular fringe field is tunable such that the marking pixel width and erasing pixel width of said tip is adjustable.

11. The method as set forth in claim 7 wherein providing said surface includes using a bistable, bichromal, molecular colorant.

12. An erasable writing system comprising:

an electronically writable-erasable surface having a layer of bistable, bichromal, molecular colorant thereon; and

a portable, electronic stylus adapted for writing and erasing said colorant.

13. The system as set forth in claim 12, said colorant comprising:

said surface including a substrate; and

said colorant including a molecular system, said molecular system including electrochromic, switchable molecules, each of said molecules being selectively switchable between at least two optically distinguishable states, wherein said molecular system is distributable on the substrate thereby forming the writable-erasable surface.

14. The system as set forth in claim 13 comprising:

said molecules exhibit an electric field induced band gap change.

15. The system as set forth in claim 14 comprising:

said electric field induced band gap change occurs via a mechanism selected from a group including (1) molecular conformation change or an isomerization, (2) change of extended conjugation via chemical bonding change to change the band gap, and (3) molecular folding or stretching.

19. An electronic stylus apparatus comprising:

means for providing electrical power, wherein said means is incorporated portably with said apparatus;

connected to the means for providing electrical power, at least one electrode means for producing a localized, emanating, electric field wherein the field is of a strength sufficient to reorient electronic picture elements formed of an electrically bistable, molecular colorant.

20. An erasable writing system comprising:

surface means for forming an electronically writable-erasable surface wherein said surface means includes colorant means for imaging on said surface means and wherein said colorant means further comprises a layer of individually bistable, bichromal, molecules; and

a portable, electronic stylus means for writing and erasing said colorant means.

21. The system as set forth in claim 20, said colorant means comprising:

a molecular system, said molecular system including electrochromic, switchable molecules, each of said molecules being selectively switchable between at least two optically distinguishable states, wherein said molecular system is substantially uniformly distributed on said surface means.