Effect of waveform slew-rate on bistable cholesteric displays

Since the typical peak-to-peak voltage needed to drive the bistable cholesteric display is two to three times higher than that for super twist nematic (STN) displays, the transient current can be excessively large and detrimental to most semiconductor drivers. To reduce the maximum switching current, the voltage transition time should be restricted in addition to reducing the peak voltage. In this paper, we studied the effect of slew-rate on the maximum output current, average output power and the dynamic optical responses. Based on circuit theory, we obtained a good agreement between experimental and calculated results. The optimal settings can be incorporated into our driving scheme so that low voltage and current requirements can be met for very large-scale integration (VLSI) implementation.