Backlighting for bright liquid crystal display

摘要

A bright bulb with a parabolic or elliptical reflector project light through a duct with internal reflective walls to a liquid crystal display having the same or smaller area than the reflector area. The duct tapers from a circular entrance aperture to a rectangular exit aperture and enhances brightness and uniformity. An IR mirror between the lamp and the duct reflects heat to the lamp. A holographic diffuser at the exit aperture further improves uniformity. The LCD polarizer is mounted on the diffuser and spaced from the liquid crystal cell by an intervening cooling air passage to minimize heating of the cell. The display is suitable for HUD applications.