High efficiency liquid crystal display projection system

摘要

A transmitting-type liquid crystal display projection system including a planar light source which emits planar white beam or planar R/G/B beams in succession is provided. A first polarization filter receives the planar light source and polarizes the same to be in a first polarization state. A liquid-crystal light valve receives the polarized planar light source, and converts the first polarization state to a second polarization state having a corresponding gray level. A second polarization filter receives a light output from the liquid crystal light valve to produce a second polarization light beam. A projection unit projects the second polarization light beam onto a display plane. Using the same planar light source, a polarization beam splitting (PBS) device with a refection-type liquid crystal light valve can be used to achieve the reflection-type projection system.