LED projector with two liquid crystal on silicon light valves and a fly's eye integrator

We present a projection system with two liquid crystal on silicon light valves that are illuminated by light-emitting diode light Sources (LEDs). The LED illumination system is designed with a fly's eye integrator. Using this integrator we combine for each primary color two LEDs into one bright source to illuminate the light valve. In the color management system a wire-grid polarizer is Used to combine two beams with opposite state of polarization. The contrast behavior Of our two LCOS approach is investigated with a basic model and ray tracing. The consequences Of rising this polarizer are discussed. We present contrast, Uniformity and light output measurements of a concept demonstration set-Up. (C) 2008 Elsevier B.V. All rights reserved.