Reflective liquid crystal device with polarizing beam splitter

摘要

A reflective liquid crystal device includes a polarising beam splitter, a polarisation preserving reflector and a retarder arrangement including at least two retarders. A first of the retarders is disposed between the beam splitter and the reflector, and a second of the retarders is disposed between the first retarder and the reflector, and at least one of the first and second retarder including a liquid crystal layer which is switchable between a dark device state and a bright device state. In the dark state, the retarder arrangement rotates the plane of polarisation of plane-polarised light directed by the beam splitter towards the reflector by substantially n180, where n is an integer, and in a bright device state the first retarder has a retardation of substantially /2 and the second retarder has a retardation of substantially /4.