US Patent 7940341 Light source for a projector

A projector includes a plurality of illumination modules. Each illumination module includes a light source, such as a semiconductor light emitting diode, and an optical element configured to receive light from the light source and collimate the light into a beam. Light from the illumination modules is provided to a liquid crystal display panel, then a projection lens. In some embodiments, secondary optics, such as an array of Fresnel lenses or a reflective polarizer, are disposed between the illumination modules and the liquid crystal display panel. In some embodiments, the liquid crystal display panel is a low temperature polysilicon liquid crystal display.