Patent ID: 6045725
Filing Date: 2000-04-04
Classification: G02B,G02F

Abstract:
An optical device comprising:a pair of substrates disposed in parallel, aligned and opposing spaced apart relationship, at least one of said substrates being transparent;at least one transparent electrode disposed on an inwardly facing side of the transparent substrate;at least one counter electrode;a peripheral spacer provided between said pair of substrates along peripheral portions thereof;an electrolytic solution provided in a space between said pair of substrates and bounded by said peripheral spacer, said electrolytic solution comprising: a mixed solvent comprising dimethylsulfoxide as a first solvent and at least one second solvent selected from the group consisting of acetonitrile, propylene carbonate and dioxolane; a silver halide salt having a first halide anion and a supporting salt selected from alkali metal halide salts or alkaline earth metal salts, said supporting salt having a second halide anion different from said first halide anion, said electrolytic solution being liquid at low temperatures and remaining free from freezing even after being maintained at temperatures about -30.degree. C. for a period of about 12 hours; anda driver applying a variable voltage to said at least one transparent electrode and said counter electrode, such that said silver salt is deposited or dissolved in response to said applied voltage, thereby causing the electrolytic solution to be colored or to be colorless, respectively.