Color reflective ferroelectric liquid crystal light valve with three spatial light modulators and increased light throughput

摘要

A color, high-throughput, ferroelectric liquid crystal-based light valve comprising a light input, a light output, a beam splitter, a color separator, reflective spatial light modulators, and a switchable half-wave plate. Light polarized parallel to a first direction is received through the light input. Light from the light input and reflected by the spatial light modulators is output from the light output. The reflective spatial light modulators are structured as a quarter-wave plates and each has a principal axis that switches through an angle &phgr;. The beam splitter has orthogonal directions of maximum transmissivity and maximum reflectivity, one of which is parallel to the first direction. The beam splitter is located and aligned relative to the light input, the light output, and the color separator to transmit or reflect the light from the light input towards the color separator, and to reflect or transmit, respectively, towards the light output the light reflected by each of the spatial light modulators and having a direction of polarization substantially orthogonal to the first direction. The switchable half-wave plate is located between the beam splitter and the color separator, is structured as a half-wave plate and has a principal axis that switches through an angle &thgr;, substantially equal to &phgr;/2. The switchable half-wave plate inverts the sense of the light valve during the balance period of each display period to enable the light valve to generate a positive image, and therefore be illuminated, during the balance period in addition to during the illumination period.