We have been developing a new practical driving methods fitted to our electrochromic display (ECD). Our latest and improved method consists of temperature compensation circuit, which assures uniform contrast, and constant voltage supply, which provide on-segments uniform color in spite of different areas of segments. With this drive method, high con trast display can be accomplished without overcharge, and the contrast ratio can be brought up as high as 5. Another driving method is also introduced, which is a simplified version of the method mentioned above. This method assures long-life-cycle time (over 5 × 106 cycles) and is suitable for watch or clock application.
The combination of high contrast driver and long-life driver opens the potential applicability of the ECD in the automobile-display instruments by its excellent readability.