Color Writable Cholesteric Liquid Crystal Display and its operation principle

Color Writable Cholesteric Liquid Crystal Display (CHLCD) and its operation principle were developed. By applying strong-enough electric field (ex: +/- 10V/100Hz square wave for 4um cell gap) to specific pixels, we could choose the color and directly write it to color CHLCD, because the pressure we released was canceled by the electric field. By applying appropriate electric field and/or pressure, gray levels could be achieved. In the application that we wrote a different color to CHLCD on which a written color existed, the electric field and the pressure had to be coordinated (ex: +/- 5.5V/10Hz, 1kgw/cm2), and other approaches were also proposed.