Illumination responsive photographic shutter apparatus

Claim 1

AN EXPOSURE CONTROL MECHANISM FOR A CAMERA HAVING A HOUSING, COMPRISING: (A) DIAPHRAGM MEANS HAVING A PLURALITY OF APERTURES AND SELECTIVELY POSITIONABLE ON SAID HOUSING SO THAT THERE IS A UNIQUE POSITION OF SAID DIAPHRAGM MEANNS WHICH CAUSES EACH APERUTURE TO BE INDIVIDUALLYY ALIGNED WITH THE OPTICAL AXIS OF THE CAMERA; (B) SHUTTER MEANS OPERABLY POSITIONED RELATIVE TO SAID OPTICAL AXIS FOR SELECTIVELY COVERING AND UNCOVERING THE APERTURE ALIGNED WITH SAID OPTICAL AXIS SO THAT THE AMOUNT OF LIGHT AVAILABLE FOR EXPOSURE DEPENDS UPON THE AREA OF THE APERTURE ALIGNED WITH SAID OPTICAL AXIS AND THE TIME THE LATTER IS UNCOVERED BY SAID SHUTTER MEANS; AND (C) AN ELECTRICAL CIRCUIT TO CONTROL THE TIME THAT SAID SHUTTER MEANS UNCOVERS A GIVEN APERTURE WHICH IS ALIGNED WITH NSAID OPTICAL AXIS IN ACCORDANCE WITH AT LEAST TWO ELECTRICAL PARAMETERS, ONE FUNCTIONALLY RELATED TO THE LEVEL OF BRIGHTNES OF A SCENE BEING PHOTOGRAPHED AND THE OTHER FUNCTIONALLY RELATED TO THE UNIQUE POSITION OF SAID DIAPHRAGM MEANS WHICH CAUSES SAID GIVEN APERTURE TO BE INDIVIDUALLY ALIGNED WITH SAID OPTICAL AXIS; AND (D) SAID ELECTRICAL CIRCUIT BEING CONSTRUCTED AND ARRANGED SO THAT THE AMOUNT OF LIGHT CAUSING EXPOSURE WHEN A GIVEN APEROTURE IS INDIVIDUALLY ALIGNED WITH SAID OPTICAL AXIS REMAINS SUBSTANTIALLY CONSTANT OVER A RANGE OF LEVELS OF SCENE BRIGHTNESS.