LIGHTING DEVICE PROVIDED WITH DISCHARGE LAMP

摘要

This discharge lamp is provided with: a plurality of discharge lamps; a plurality of illuminance detection units that detect the illuminance of illuminating light irradiated by the plurality of discharge lamps; and an illuminance control unit that adjusts the input electric power for the plurality of discharge lamps on the basis of the discharge lamp illuminance that is detected. The illuminance control unit adjusts the electric power such that illuminance changes for discharge lamps having illuminance values that exceed an allowable threshold value determined on the basis of a reference illuminance value, out of the plurality of discharge lamps, toward a robust threshold value determined between the allowable threshold value and the reference illuminance value.