Abstract: A drive scheme for a cholesteric liquid crystal display device comprises supply of a drive signal to the electrode arrangement of a cell comprising a layer of cholesteric liquid crystal material. The drive signal comprises at least one initial pulse that drives the cholesteric liquid crystal material into the homeotropic state; a relaxation period that allows the cholesteric liquid crystal material to relax into the planar state; and a drive sequence during which the root mean square voltage of the drive signal, determined over periods within which the cholesteric liquid crystal does not relax, increases monotonically. The drive sequence reduces the reflectivity of the cholesteric liquid material without any fluctuations.

Abstract: A decorative panel (1) comprises a transparent front substrate (2) having a foreground image printed thereon, the foreground image having varying transparency across its area. Behind the foreground image, is at least one layer (3) of optically reflective or absorptive material which has a reflectance or absorptance that is changeable in response to an external stimulus and which transmits incident light that is not reflected or absorbed. Behind the at least on layer of reflective material, is a background layer (4) on which light transmitted by the at least one layer of optically reflective or absorptive material is incident and which is not transparent.