Light valve with twisted perpendicular liquid crystal with a negative dielectric anisotropy

DETAILED DESCRIPTION In carrying out principles of the present invention in accordance with a preferred embodiment thereof, a liquid crystal device includes a liquid crystal cell having first and second alignment layers having alignment grooves.
The grooves extend in one direction on one of the layers and in a different direction on the other.
The alignment layers define a containment volume between them and a perpendicular alignment liquid crystal mixture is placed in the containment volume.
The alignment grooves of one alignment layer are oriented at an angle of between about 45.
degree.
and 90.
degree.
with respect to the alignment grooves of the other layer, and, after assembly of the liquid crystal cell, the entire cell is rotated relative to the output polarizer of the projection system until an optimum optical overshoot or optimum optical rise time is observed.