Double-layered light shutter using long-pitch cholesteric liquid crystal cells

Abstract

We propose a double-layered light shutter device using two cholesteric liquid crystal (ChLC) cells. The proposed light shutter consists of a light-scattering layer using long-pitch cholesteric LCs and a light-absorption layer using dye-doped ChLCs. The light shutter has four switchable states: light scattering, light absorption, absorption and scattering, and transparent. The light shutter in the absorption and scattering state can block the background image and provide a black color. By switching of the proposed light shutter positioned at the rear side of a transparent display, we can operate a transparent display in various modes, not just showing the images produced by a transparent display along with the background.