Display unit and drive method therefor

• US 20040070724A1
• Filed: 07/10/2003
• Published: 04/15/2004
• Est. Priority Date: 11/12/2001
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Matsui, Takeshi, Shinozaki, Kenji, Takahashi, Kenichi
• Granted Patent: US 7,084,853 B2
• Time in Patent Office: Days
• US Class Current: 349/187
• CPC Class Codes: G02F 1/1508 using a solid electrolyte
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: G02F 1/163 Operation of electrochromic cells, e.g. electrodeposition cells; Circuit arrangements therefor
• CPC Class Codes: G02F 2001/164 the electrolyte is made of polymers
• CPC Class Codes: G09G 3/3622 using a passive matrix G09G3/3674 - G09G3/3696 take precedence

Abstract

An electrochemical display apparatus in which simple matrix driving is realized, whereby apparatus constitution can be simplified, and the price of the apparatus can be lowered. The electrochemical display apparatus performs display by use of electrochemical deposition/dissolution of a metal. The display apparatus is driven by a simple matrix driving system, in which a deposition overvoltage at the time of deposition of metallic ions as the metal is used as a threshold in the simple matrix driving. A driving voltage is set to be not more than two times the deposition overvoltage. The electrochemical display apparatus includes transparent electrodes and counter electrodes, the display is performed by utilizing deposition/dissolution of the metal on the transparent electrodes, and the potential difference between the metal to be deposited on the transparent electrodes and the counter electrodes is set to be less than the deposition overvoltage. Ideally, the same metal as the metal which is deposited is used for constituting the counter electrodes.

Claims

1. A display apparatus for performing display by use of electrochemical deposition/dissolution of a metal, wherein said apparatus is driven by a simple matrix driving system, and a deposition overvoltage at the time of deposition of metallic ions as said metal is used as a threshold in said simple matrix driving.

2. The display apparatus as set forth in claim 1, wherein a driving voltage is set to be not more than two times said deposition overvoltage.

3. The display apparatus as set forth in claim 1, wherein said metal subjected to deposition/dissolution is at least one selected from the group consisting of bismuth, copper, silver, lithium, iron, chromium, nickel, and cadmium.

4. The display apparatus as set forth in claim 1, wherein said apparatus comprises transparent electrodes and counter electrodes, and display is performed through deposition/dissolution of said metal on said transparent electrodes.

5. The display apparatus as set forth in claim 4, wherein the potential difference between said metal to be deposited on said transparent electrodes and said counter electrodes is less than said deposition overvoltage.

6. The display apparatus as set forth in claim 4, wherein a polymeric solid state electrolyte layer is provided between said transparent electrodes and said counter electrodes.

7. The display apparatus as set forth in claim 6, wherein a matrix polymer constituting said polymeric solid state electrolyte layer is at least one selected from polyethylene oxide, polyethyleneimine, and polyethylene sulfide represented by —

(C—

C—

O)n-, —

(C—

CN)n-, or —

(C—

C—

S)n-, or polymeric materials having these background chain structure and further having branched chains, or polymethyl methacrylate, polyvinylidene fluoride, polyvinylidene chloride, and polycarbonates.

8. The display apparatus as set forth in claim 6, wherein said polymeric solid state electrolyte layer contains a metallic salt or an alkylammonium salt as an electrolyte salt.

9. The display apparatus as set forth in claim 6, wherein said polymeric solid state electrolyte layer contains at least one selected from the group consisting of water, ethyl alcohol, isopropyl alcohol, propylene carbonate, dimethyl carbonate, ethylene carbonate, γ

-butyrolactone, acetonitrile, sulfolane, dimethoxyethane, dimethylformamide, and dimethyl sulfoxide, as a plasticizer.

10. The display apparatus as set forth in claim 6, wherein said polymeric solid state electrolyte layer contains a coloring material.

11. The display apparatus as set forth in claim 10, wherein said coloring material is at least one selected from inorganic pigments, organic pigments, or dyes.

12. The display apparatus as set forth in claim 11, wherein said coloring material is a white inorganic pigment.

13. The display apparatus as set forth in claim 12, wherein said white inorganic pigment is at least one selected from the group consisting of titanium dioxide, calcium carbonate, magnesium oxide, and aluminum oxide.

14. The display apparatus as set forth in claim 10, wherein said polymeric solid state electrolyte layer is comprised of a plurality of layers, and said coloring material is contained in only a part of said layers.

15. The display apparatus as set forth in claim 6, wherein said polymeric solid state electrolyte layer contains a reducing agent or an oxidizing agent for restraining side reactions.

16. The display apparatus as set forth in claim 4, wherein said transparent electrodes comprise SnO₂, In₂O₃, or a mixture thereof as a main constituent.

17. The display apparatus as set forth in claim 4, wherein said counter electrodes are comprised of a thin metallic film.

18. The display apparatus as set forth in claim 4, wherein said apparatus comprises third electrodes independent from said transparent electrodes and said counter electrodes.

19. The display apparatus as set forth in claim 18, wherein said third electrodes are formed in an electrically insulated condition in the same plane as said transparent electrodes or said counter electrodes.

20. The display apparatus as set forth in claim 19, wherein said third electrodes are potential detecting electrodes.

21. A method of driving a display apparatus for performing display by use of electrochemical deposition/dissolution of a metal by a simple matrix driving system, wherein said simple matrix driving is conducted by using a deposition overvoltage at the time of deposition of metallic ions as said metal as a threshold.

22. The method of driving a display apparatus as set forth in claim 21, wherein a driving voltage is set to be not more than two times said deposition overvoltage.

23. The method of driving a display apparatus as set forth in claim 21, wherein said simple matrix driving is conducted by transparent electrodes and counter electrodes so as to effect deposition/dissolution of said metal on said transparent electrodes, thereby performing said display.

24. The method of driving a display apparatus as set forth in claim 23, wherein the potential difference between said metal to be deposited on said transparent electrodes and said counter electrodes is set to be less than said deposition overvoltage.