Control of reflectivity and bistability in displays using cholesteric liquid crystals

Abstract

It is demonstrated that the reflective properties and bistability of cholesteric liquid crystals can be controlled by proper surface treatment and dispersed polymers. Dispersing a polymer in the liquid crystal or using a cell with an inhomogeneous surface anchoring creates permanent defects which result in long-term bistability, high contrast at large viewing angles, and gray scale. The wide-angle, reflective feature makes cholesteric materials suitable for displays without backlights and bistability provides flicker-free operation.