APPARATUS FOR MAINTAINING ILLUMINANCE OF EXPOSED BEAM SOURCE

摘要

PURPOSE: An apparatus for maintaining the illuminance of an exposed beam source is provided to reduce the manufacturing cost of articles by increasing the productivity of articles per time. CONSTITUTION: An illuminance maintaining apparatus comprises a voltage supplying device(210) for supplying the voltage to a beam source(10). A voltage varying device(220) varies the voltage supplied to the beam source(10) from the voltage supplying device(210). The illuminance of the beam radiated from the beam source(10) is sensed by an illuminance sensing device(230). A microcomputer(240) is provided to control the voltage variation of the voltage varying device(220) such that the illuminance detected by the illuminance sensing device(230) is maintained with a predetermined illuminance.