Automatic exposure control for photographic copiers

Claim 1

A CONTINUOUS FLOW PHOTOGRAPHIC REPRODUCING DEVICE COMPRISING, A DOCUMENT TRANSPORT FOR FEEDING DOCUMENTS IN CERTAIN TIMED SEQUENCE ALONG A PREDETERMINED PATH TO A PHOTOGRAPH STATION FOR PHOTOGRAPHIC REPRODUCTION THEREAT, CAMERA MEANS FOR SEQUENTIALLY PHOTOGRAPHING SAID DOCUMENTS UPON ARRIVAL AT SAID PHOTOGRAPH STATION, A LIGHT SOURCE ADAPTED WHEN ENERGIZED TO PROVIDE ILLUMINATION OF SAID DOCUMENTS FOR PHOTOGRAPHING, SAID LIGHT SOURCE PROJECTING LIGHT UPON A PREDETERMINED PORTION OF SAID PATH EXTENDING THROUGHOUT SAID PHOTOGRAPH STATION AND A CERTAIN AREA ADJACENT AND IN ADVANCE THEREOF ALONG SAID PATH, A PHOTOELECTRIC CELL ADAPTED TO COLLECT LIGHT ENERGY IMPINGING UPON THE DOCUMENT TO BE NEXT PHOTOGRAPHED, UNDER CONDITIONS WHERE SAID SUCH NEXT DOCUMENT IS ADAPTED SAID PHOTOGRAPH STATION AND WITHIN SAID CERTAIN AREA, AN ELECTRICAL POWER SOURCE FOR ENERGIZING SAID LIGHT SOURCE, AND AN ELECTRONIC FAST RESPONSIVE NETWORK FOR VARYING THE ENERGIZATION OF SAID LIGHT SOURCE BY SAID POWER SOURCE, SAID ELECTRONIC FAST RESPONSIVE NETWORK INCLUDING ELECTRONIC SWITCHING MEANS CONNECTED IN SERIES WITH SAID LIGHT SOURCE AND SAID POWER SOURCE AND MEANS FOR CONTROLLING SAID SWITCHING MEANS, SAID CELL OPERATIVELY CONNECTED TO SAID CONTROLLING MEANS FOR AUTOMATICALLY CONTROLLING THE SWITCHING MEANS IN RESPONSE TO VARIATIONS IN INTENSITY OF SAID COLLECTED LIGHT TO CAUSE SAID NETWORK TO VARY SAID ENERGIZATION INVERSELY TO SAID LIGHT INTENSITY VARIATIONS.