Patent ID: 7939794

Claim:
A lighting system, comprising: an optical integrating chamber comprising a base, a mask separated from the base, and a cavity formed in at least one of the base and the mask, wherein: opposing surfaces of the base and mask are reflective, at least one of the opposing reflective surfaces exhibits a diffuse reflectivity, and the mask is sized and positioned relative to the base so as to constructively occlude an active area of the base with respect to a region to be illuminated by reflected light emerging from the chamber between the base and mask; at least one solid state light emitting element for emitting visible light, each solid state light emitting element being coupled to supply visible light to enter the optical integrating chamber in such a manner that substantially all light emitted from each solid state light emitting element reflects diffusely at least once within the interior of the optical integrating chamber before emission from the chamber toward the region; a detector for detecting electromagnetic energy from the region of a wavelength at least substantially absent from a spectrum of the reflected light; and a controller for controlling an amount of visible light supplied to the cavity by the at least one solid state light emitting element, wherein the controller receives a detection signal from the detector.