The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 15, 1980
Filed:
Feb. 14, 1977
Jacques Cognard, Areuse, CH;
Ebauches, S.A., Neuchatel, CH;
Abstract
In a sandwich type electro-optic display device which includes a transparent conductive substrate, an electrochromic layer (e.g. tungsten oxide applied to the substrate), a counterelectrode spaced from the electrochromic layer and a conductive medium, e.g. an acidic liquid ion conductive medium (sulfuric acid-glycerine solution) located in the space between the two electrodes; a protective layer deposited in situ on the electrochromic layer resulting from the doping of the liquid electrolyte with a salt of a cation having an ionic radius no less than 0.99 Angstrom units according to the classification of Pauling. Soluble isopolytungstic acid is formed at the interface between the electrochromic layer and the conductive medium as an 'interfacial layer'. The great cation salt selected is Ba.sup.++ and complexes with the polyacid to form a precipitate upon said electrochromic layer to form a protective layer therefor substantially inhibiting further attack on said electrochromic layer by the acidic conductive medium.