An illumination obscurement device for controlling the obscurement of illumination from a light source which is optimized for use with a rectangular, arrayed, selective reflection device. In a preferred embodiment, a rotatable shutter with three positions is placed between a light source and a DMD. The...http://www.google.de/patents/US6220730?utm_source=gb-gplus-sharePatent US6220730 - Illumination obscurement device
