Multiple viewing mode display having a public view, a restricted private view and a mirror mode.

摘要

A multiple viewing mode display comprises a display device, such as a liquid crystal display device (1, 2, 6), disposed behind a controllable liquid crystal device (3, 7) with a reflective polariser (4) therebetween. The controllable device (7) has a substantially uniform unpatterned alignment and is controllable to provide any of the following modes: a public viewing mode in which the image is visible in a wide viewing region; private viewing mode in which the image is visible in a more restricted viewing region; and a minor mode in which the display acts as a mirror with incident light being reflected by the reflective polariser (4). In at least one of these modes, the controllable device (7) has a liquid crystal director structure which is twisted. The restricted viewing region may be inside the first viewing region. The reflective polarizer may be a dual brightness enhancement film (DBEF). The controllable device 7 may be a layer of nematic liquid crystal which may include a chiral dopant and may be dual frequency.