A new electric field controlled reflective optical storage effect in mixed liquid crystal systems

A new electric field controlled reflective optical storage effect has been discovered in mixed nematic-cholesteric liquid crystal systems. Ion motion produced by a dc electric field is used to emulsify the initially transparent mixture and give it a milky white appearance. This state remains after the dc signal is removed. The material can be returned to its initial state by applying an audio-frequency signal. The reflective contrast ratio of 7 to 1, flat construction, low voltage and power writing capability, and storage with continuous readout requiring no maintaining power make the new effect seem attractive for indicator-type applications using solid state addressing circuitry.