Photographic shutter mechanism

Claim 1

A PHOTOGRAPHIC EXPOSURE CONTROL DEVICE COMPRISING, IN COMBINATION, MEANS DEFINING AN EXPOSURE APERTURE, AT LEAST ONE FIRST SHUTTER BLADE MOVABLE FROM A COVERING TO AN UNCOVERING POSITION RELATIVE TO SAID APERTURE TO INITIATE AN EXPOSURE THERETHROUGH, AT LEAST ONE SECOND SHUTTER BLADE, MOVABLE FROM AN UNCOVERING TO A COVERING POSITION WITH RESPECT TO SAID APERTURE TO TERMINATE SAID EXPOSURE, FIRST AND SECOND BIASING MEANS RESPECTIVELY URGING SAID FIRST BLADE TOWARD ITS UNCOVERING POSITION MEANS SAID SECOND BLADE TOWARD ITS COVERING POSITION MEANS CREATING A FIRST MAGNETIC FIELD FOR RETAINING SAID FIRST BLADE IN ITS COVERING POSITION AGAINST THE FORCE OF SAID FIRST BIASING MEANS, MEANS ASSOCIATED WITH SAID FIRST BLADE AND MOVABLE THEREWITH FOR RETAINING SAID SECOND BLADE IN ITS UNCOVERING POSITION AGAINST THE FORCE OF SAID SECOND BIASING MEANS WHILE SAID FIRST BLADE IS IN ITS COVERING POSITTION, FIRST ELECTRICALLY ACTUATED MEANS ADAPTED UPON ACTUATION TO SO DIMINISH SAID FIRST MAGNETIC FIELD AS TO ALLOW SAID FIRST BLADE TO MOVE TO ITS UNCOVERING POSITION, SECOND ELECTRICALLY ACTUATED MEANS ADAPTED UPON ACTUATION TO CREATE A SECOND MAGNETIC FIELD FOR RETAINING SAID SECOND BLADE IN ITS UNCOVERING POSITION AGAINST THE FORCE OF SAID SECOND BIASING MEANS, AND MEANS FOR SIMULTANEOUSLY ACTUATING SAID FIRST AND SECOND ELECTRICALLY ACTUATED MEANS, THE STATIC INERTIA OPPOSING MOVEMENT OF SAID FIRST BLADE AWAY FROM ITS COVERING POSITION BENG SUCH THAT SAID SECOND MAGNETIC FIELD HAS ATTAINED SUBSTANTIALLY ITS PEAK FORCE BEFORE SAID FIRST BLADE MOVES AWAY FROM ITS COVERING POSITION.