Electrode for display devices

• US 5,446,577 A
• Filed: 10/31/1994
• Issued: 08/29/1995
• Est. Priority Date: 01/05/1993
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Martin Marietta Corporation
• Inventors: Bennett, Russell N., Hannan, Michael J., Kokonaski, William E., Boxall, Larry G.
• Primary Examiner(s): Sugarman, Scott J.
• Assistant Examiner(s): Robbins, Thomas
• Application Number:
  US08/332,613
• Time in Patent Office: 302 Days
• Field of Search: 359/265, 359/267, 359/268, 359/269, 359/271, 359/273, 359/274
• US Class Current: 359/273
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: G02F 2001/1552 Inner electrode, e.g. the electrochromic layer being sandwiched between the inner electrode and the support substrate

Abstract

Display devices incorporating an improved working electrode are disclosed. The devices comprise a transparent outer layer, a first electrode having a reflective surface facing the transparent layer, an electrochromic material located between the reflective surface and the outer transparent layer, an electrolyte in contact with the electrochromic material and a second electrode located behind the first electrode. The first electrode is ion-permeable, allowing ions to pass through and contact the electrochromic material in order to alter the optical properties of the material. The electrochromic material is preferably a conductive polymer such, as polyaniline. The display devices are capable of changing reflectance and/or color by the application of an electric potential to the electrodes.

Claims

1. A display device comprising:

a) a substantially transparent outer layer;

b) a first electrode located behind said outer layer, and comprising a reflective surface facing said outer layer and including means for allowing ions to pass through said first electrode;

c) an electrochromic material disposed between said reflective surface and said outer layer and adapted to change optical properties by the insertion or extraction of ions therefrom;

d) an electrolyte in contact with said electrochromic material and said first electrode; and

e) a second electrode located behind said outer layer, and at a greater distance from said outer layer than said first electrode;

wherein said display device is substantially flexible thereby allowing said device to conform to an irregular surface.

2. A display device according to claim 1, wherein said outer layer is a flexible plastic selected from the group consisting of polyethylene, polytetrafluoroethylene, polyester and polyethylene terephthalate.

3. A display device according to claim 1, wherein said first electrode comprises a flexible plastic substrate disposed against said reflective surface and having perforations therein.

4. A display device according to claim 1, wherein said first electrode comprises a flexible metallized fabric.

5. A display device according to claim 1, wherein said reflective surface allows for flexibility, and comprises a metal selected from the group consisting of Au, Ag, AI, Pt, Rh, and Ir.

6. A display device according to claim 1, wherein said means for allowing ions to pass through said first electrode comprises slits, holes or a combination thereof.

7. A display device according to claim 1, wherein said flexible electrochromic material comprises a conductive polymer.

8. A display device according to claim 7 wherein said conductive polymer is selected from the group consisting of polyaniline, polyacetylene, polypyrrole, polythiophene, polyphenylene, polyphenylene vinylene, polyphenylene sulfide, polyphenyldiamine, poly(N,N'"'"'diphenyl (benzidine)) and derivatives, copolymers and bilayers thereof.

9. A display device according to claim 1, wherein said electrolyte comprises polyvinyl alcohol, polyethylene carbonate or propylene carbonate.

10. A display device according to claim 1, wherein said second electrode comprises a flexible metal layer.

11. A display device according to claim 1, wherein said second electrode comprises a flexible layer of material that serves as an ion source.

12. A display device according to claim 11, wherein said layer of material is substantially the same composition as said electrochromic material.

13. A display device according to claim 1, wherein said second electrode is opaque.

14. A display device according to claim 1, wherein said second electrode is substantially transparent.

15. A display device according to claim 1, wherein said second electrode is disposed on one side of a perforated flexible plastic substrate and said first electrode is disposed on the other side of said perforated plastic substrate.

16. A display device according to claim 15, wherein said second electrode comprises a perforated metal layer having a layer of material disposed thereon that serves as an ion source and is of substantially the same composition as said electrohromic material.

17. A display device according to claim 1, wherein said display device further comprises a flexible barrier layer disposed between said first electrode and said second electrode to substantially prevent unwanted ions from contacting said first electrode.

18. A display device comprising:

a) a substantially transparent first outer layer;

b) a first electrode located behind said first outer layer, and comprising a reflective surface facing said first outer layer and including means for allowing ions to pass through said first electrode;

c) an electrochromic material disposed between said reflective surface and said first outer layer and adapted to change optical properties by the insertion or extraction of ions therefrom;

d) an electrolyte in contact with said electrochromic material;

e) a second electrode located behind said first outer layer, and at a greater distance from said first outer layer than said first electrode;

f) a second substantially transparent outer layer opposing said first outer layer and beyond said second electrode with respect to said first electrode; and

g) a third electrode located between said second outer layer and said second electrode;

wherein said display device is substantially flexible thereby allowing said device to conform to an irregular surface.

19. A display device according to claim 18, wherein said third electrode comprises a reflective surface, the surface facing said second outer layer, having means for allowing ions to pass therethrough and having an electrochromic material disposed thereon.

20. A display device according to claim 19, wherein said electrochromic material disposed on said reflective surface of said third electrode comprises a conductive polymer.