Patent ID: 7566137

Claim:
An illumination maintenance system for maintaining a desired illumination profile in a space throughout at least a portion of a day, the space being illuminable by both daylight and electric light, the system comprising: a sensor for sensing an illumination level in at least a portion of the space; a plurality of dimmable electric lamps providing the electric light to supplement the daylight illumination of the space, the electric lamps arranged in one or more zones in the space, the zones defining predefined volumes of the space, each zone having at least one lamp; a control system controlling the dimming levels of the plurality of electric lamps, the at least one lamp of each zone being controlled to a dimming level to achieve a desired illumination level in the respective zone according to the desired illumination profile and compensate for the daylight illumination in the space throughout at least the portion of the day; wherein the dimming level of each lamp is selected by the control system from one of a plurality of lighting presets, each lighting preset comprising a combination of dimming levels of the lamps, and wherein the control system adjusts the dimming level of the electric lamps toward a preset that will result in an appropriate supplementing of the daylight illumination to achieve the desired illumination profile in the space.