Photographic exposure apparatus

Claim 1

PHOTOGRAPHIC APPARATUS COMPRISING, IN COMBINATION, AN ELECTRIC LAMP HAVING A BRIGHTNESS WHICH IS AN EXPONENTIAL FUNCTION OF THE VOLTAGE APPLIED TO SAID LAMP; AN ALTERNATING CURRENT GENERATOR COUPLED WITH SAID LAMP FOR SUPPLYING CURRENT TO SAID LAMP AT A FREQUENCY AND VOLTAGE PROPORTIONAL TO THE RATE AT WHICH SAID GENERATOR IS OPERATED; DRIVE MEANS FOR MOVING PHOTOGRAPHIC IMAGERECORDING MATERIAL THROUGH SAID APPARATUS RELATIVE TO SAID LAMP TO EFFECT THE EXPOSURE OF SAID MATERIAL BY LIGHT FROM SAID LAMP AND FOR OPERATING SAID GENERATOR; SPEED GOVERNING MEANS COUPLED WITH SAID DRIVE MEANS FOR REGULATING THE SPEED OF MOVEMENT OF SAID MATERIAL AND OPERATION OF SAID GENERATOR WITHIN A PREDETERMINED RANGE OF SPEEDS; AND FREQUENCY RESPONSIVE IMPEDANCE MEANS ELECTRICALLY COUPLED WITH SAID LAMP AND SAID GENERATOR FOR SO VARYING THE IMPEDANCE TO FLOW OF CURRENT FROM SAID GENERATOR TO SAID LAMP AS TO LINEARIZE THE RELATIONSHIP BETWEEN THE BRIGHTNESS OF SAID LAMP AND THE VOLTAGE IMPRESSED ACROSS SAID LAMP THROUGHOUT A PREDETERMINED RANGE OF ALTERNATING CURRENT FREQUENCIES WHEREBY VARIATIONS IN LAMP BRIGHTNESS AND RATE OF MOVEMENT OF SAID IMAGE-RECORDING MATERIAL COMPENSATE FOR ONE ANOTHER TO INSURE A SUBSTANTIALLY CONSTANT EXPOSURE OF SAID MATERIAL DURING MOVEMENT OF SAID MATERIAL RELATIVE TO SAID LAMP AT A RATE WITHIN SAID PREDETERMINED RANGE OF SPEEDS.