A device for displaying 3D-images which employs a parallax-barrier based on a switchable, cholesteric liquid crystal cell

摘要

A display device for producing 3D images employs a cholesteric liquid crystal cell (2) in a switchable parallax barrier (2,3,4) in front of a display unit (1). The display unit typically emits unpolarised light (e.g. OLED or PDP), but it may also be an LCD. The barrier further comprises a quarter wave plate (3) interposed between a linear polariser (4) and the cholesteric cell (2) at the front of the device. The barrier has three states: in the OFF state no light is transmitted and the liquid crystal is in its planar texture; in the fully-ON state, a 2D image is obtained while in the partially-ON state only some regions of the barrier are completely transmissive and a 3D image is obtainable. In further embodiments a reflector (5) alone or in combination with a further quarter-wave plate (6) improves the recycling of light.