Patent attributes
An illumination system for use in illuminating a spatial light modulator for a head up display system. The illumination system includes a high power light emitting diode (LED) array assembly; and, a Fresnel lens array operatively associated with the LED array assembly for receiving light produced by the LED and providing a nearly collimated light output for use by the spatial light modulator. Utilization of the ultra bright LED array and Fresnel lens array provides the capability of the illumination source to be made very thin, light weight, and efficient. The Fresnel lens array, which converges the light to be nearly collimated, enhances the harvest of the available flux thus increasing the system efficiency and providing a system that gives the illusion of having an image at infinity. Additional components such as holographic elements, optical compensation films, and brightness enhancement films can be used to tailor the light if required.
