Patent ID: 9213210
Filing Date: 2015-12-15
Classification: G02F,G09F

Abstract:
1. A part for a directly addressable display device comprising at least one pixel cell, each pixel cell being arranged for displaying a symbol, which symbol is repeatedly switchable between an on-state and an off-state, wherein each pixel cell comprises: an electrically conducting electrochromic layer comprising electrochromic and electrochemically active organic polymer material being electrochemically switchable between two different visually detectable colouring states; a counter electrode layer comprising an electronically conductive material, wherein said counter electrode layer in a viewing direction is arranged behind said electrochromic layer; an electrolyte layer, which electrolyte layer is solidified and arranged spatially between, and in ionic contact with, said electrochromic layer and said counter electrode layer; wherein each pixel cell further comprises a symbol defining layer which is electronically and ionically insulating, arranged in direct ionic contact with said electrochromic layer, and which symbol defining layer comprises one or more openings which encloses said electrolyte layer and defines the shape of said symbol; said electrolyte layer, between said symbol defining layer and said counter electrode layer, covers and extends to the side of said one or more openings of the symbol defining layer; and said electrolyte comprises a composition comprising: a) a polyelectrolyte selected from one or more cationic polymers, wherein the electrolyte is substantially free of small cations.