Image diffusion and cross-talk in passive matrix electrochromic displays

A passive matrix electrochromic display (ECD) working in transparent or reflective mode is described. In this paper, we report the main reasons of image diffusion and cross-talk in passive matrix ECD and initial computer simulation results of the 7 X 7 matrix display. These suggest that the insulation of electrolyte under each pixel and threshold (nonlinearity) of coloration current can in practice completely eliminate the image diffusion and cross-talk. The matrix addressed ECD based on solid polymer electrolyte and two complementary electrodes, (WO3 + 0.1TiO(2), TiO2-0.25CeO(2)), in which all pixels were insulated by negative photoresist material was elaborated. An additional protected thin film (0.2Li(2)O-0.2CeO2-0.6SiO(2)) deposited on working electrode was used to provide the enhanced threshold effect. The ECD exhibited excellent memory effect and substantially free from image diffusion and cross talk effects. (C) 2002 Elsevier Science B.V. All rights reserved.