# US 4,396,253 A · Electro-chromic display devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,396,253 A - Document ID: US4396253A - Status: Granted - Kind: A - Application number: 06/218,418 - Filed: 1980-12-19 - Granted: 1983-08-02 - Earliest claimed: 1979-12-24 - Assignees: Sharp Kabushiki Kaisha - Inventors: Hiroshi Kuwagaki; Hiroshi Hamada; Tadanori Hishida; Tomio Wada - Web page: https://patentgrep.com/patent/US4396253A ## CPC - G02F 1/1533: {structural features not otherwise provided for} - G02F 1/15: based on an electrochromic effect - G02F 1/1514: characterised by the electrochromic material, e.g. by the electrodeposited material - G02F 1/15165: {Polymers} - G02F 2001/1517: {Cyano complex compounds, e.g. Prussian blue} - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS ## Abstract An electro-chromic display device comprises an electro-chromic material and an electrolyte between a display electrode formed by a combination of a plurality of segments, and counter electrode disposed opposite thereto, and undergoes a reversible reaction for developing or erasing a color upon application of voltage or reverse polarity voltage. The counter electrode comprises a molded product obtained by molding under pressure a mixture of the powders of a solid oxidation-reduction type active material and an electrically conductive material. ## Claims ### Claim 1 An electro-chromic display device comprising: a pair of substrates defining a cell; a display electrode composed of a plurality of segments provided on one of said substrates; a counter electrode disposed opposite to said display electrode and electrically connected to a conductor for supplying electric current, said counter electrode being formed from a molded product comprising a mixture of a solid oxidation-reduction active powder material and a conductor powder, said molded product being obtained by pressure molding; and an electro-chromic material, and an electrolyte disposed between said electrodes. ### Claim 2 (depends on 1) A device as set forth in claim 1, wherein said active material is selected from the group consisting of MnO.sub.2, Mn.sub.2 O.sub.3, RFe(II) wherein R stands for NH.sub.4, H, K or Na, and M.sub.x WO.sub.3 wherein M stands for H, Li or Na and x is larger than 0.01, but smaller than 0.7. ### Claim 3 (depends on 1, 2) A device as set forth in claim 1 or 2, wherein said conductor in said mixture is selected from the group consisting of expanded graphite and active carbon. ### Claim 4 (depends on 1) A device as set forth in claim 1, wherein said active material and said conductor in said mixture have a mixing ratio by weight of 1:1 to 20. ### Claim 5 (depends on 1) A device as set forth in claim 1, wherein said molded product is obtained by molding at a temperature between room temperature and 100.degree. C. ### Claim 6 (depends on 1) A device as set forth in claim 1, wherein said conductor for supplying electric current is secured to the substrate at the display electrode side, and electrically connected to said counter electrode within said cell. ### Claim 7 (depends on 6) A device as set forth in claim 6, wherein said conductor for supplying electric current and said counter electrode are directly in contact with each other. ### Claim 8 (depends on 6) A device as set forth in claim 6, further including a conductive elastic material disposed between said conductor for supplying electric current and said counter electrode. ### Claim 9 (depends on 8) A device as set forth in claim 8, wherein said conductive elastic material comprises carbon fibers. ### Claim 10 (depends on 1) A device as set forth in claim 1, wherein said conductor for supplying electric current is secured to the other of said substrates, and a conductive elastic material is disposed between said conductor for supplying electric current and said counter electrode. ### Claim 11 (depends on 10) A device as set forth in claim 10, wherein said conductive elastic material comprises carbon fibers. ### Claim 12 (depends on 1) A device as set forth in claim 1, wherein said conductor for supplying electric current comprises an electric conductive wire which extends outwardly of said cell through an adhesive layer between said substrates to define an external terminal or be connected to a separate external terminal. ### Claim 13 (depends on 12) A device as set forth in claim 12, wherein said conductive wire is formed by at least one carbon filament. ### Claim 14 An electro-chromic display device comprising: a pair of substrates defining a cell; a display electrode composed of a plurality of segments provided on one of said substrates; a counter electrode disposed opposite to said display electrode and electrically connected to a conductor for supplying electric current, said counter electrode being formed from a molded product comprising a mixture of a solid oxidation-reduction active powder material and a conductor powder composed of expanded graphite, in the absence of a binder; and an electro-chromic material, and an electrolyte disposed between said electrodes. ### Claim 15 (depends on 1, 14) A device as set forth in either of claims 1 or 14, wherein said active material is selected from the group consisting of: MnO, MnO.sub.2, Mn.sub.2 O.sub.3, Mn.sub.3 O.sub.4, V.sub.2 O.sub.5, cobalt complex, iron complex, and Prussian blue.