ILLUMINATION SYSTEM USING OPTICAL FEEDBACK

摘要

Disclosed is an illumination system using optical feedback to maintain a predetermined illumination output. The illumination system employs an electrically controllable optical filter (106) for filtering light incident thereon and a light detector (304). The light detector is in data communication with the electrically controllable optical filter. Some or all light filtered by the electrically controllable optical filter is detected by the light detector and compared to at least one predeterminated value. If the signal generated by the light detector differs when compared to the at least one predeterminated value, one or more filtering characteristics of electrically controllable optical filter are varied which, in turn, varies the amount of light filtered by the electrically controllable optical filter. The filtering characteristics of the electrically controllable optical filter continue to be varied until the signal generated by the light detector substantially matches the at least one predeterminated value.