Improved Temperature Range for Active Matrix Addressed Liquid Crystal Display

Direct-element-driven liquid crystal displays (LCDs) are now being used in automobiles built around the world. Newly available dot matrix, graphic-type LCDs offer the potential for more sohisticated display functions. However, conventional multiplexed LCDs do not provide the display performance or environmental capability needed in automobile dashboards. Active-matrix, thin-film-transistor (TFT) addressed LCDs, such as the Panelvision MiniGraphic Display, offer superior visual and environmental performance, comparable to direct-element-driven LCDs. Experiments are described to extend the operating temperature range of the MiniGraphic Display to -40 to +85 degrees Centigrade. Problems encountered in using improved liquid crystal fluids are described, together with the experimental results.