A compact and high-resolution video projector based on silicon light valves

We have developed a highly integrated liquid-crystal-on-silicon light valve for three-panel color projector. The silicon panel was designed and fabricated by a custom 0.5 μm, 3-metal CMOS technology with a spatial resolution of 1024×768 pixels. The pixel pitch was 13.8 μm and the fill factor was 91%. Six-bit digital data drivers and gamma-correction circuitry were integrated within the silicon panel for true gray scale and full color representation. The display panel was assembled with a mixed twisted nematic and birefringence liquid crystal cell for high contract ratio at CMOS compatible voltage. The contrast ratio was 100:1 at 3.5 Vrms. The optical system utilized a trichroic prism assembly for both the color separation and recombination. With this trichroic prism assembly incorporating three silicon light valves, a compact and high-resolution video projector was demonstrated.