Radiation sensitive low-torque transducer

Claim 1

A DEVICE FOR PRODUCING AN ELECTRICAL SIGNAL OUTPUT WHICH BEARS A PREDETERMINED FUNCTIONAL RELATIONSHIP TO THE POSITION OF A MOVABLE SHAFT MEMBER RELATIVE TO A FIXED MEMBER AND WHICH COMPRISES IN COMBINATION, IN A HOUSING IMPERVIOUS TO RADIATION: (1) A SOURCE OF RADIATION; (2) A RADIATION-SENSITIVE TARGET, POSITIONED SO AS TO RECEIVE AT LEAST A PORTION OF THE RADIATION FROM SAID SOURCE, AND PRODUCING AN ELECTRICAL SIGNAL OUTPUT IN RESPONSE TO THAT PORTION OF SAID RADIATION RECEIVED THEREON; (3) A FIXED MASK INTERPOSED BETWEEN SAID SOURCE OF RADIATION AND SAID TARGET, SAID MASK HAVING A SINGLE APERTURE, LOCATED SO AS TO LIMIT THE PORTION OF THE RADIATION FROM SAID SOURCE RECEIVED ON SAID TARGET TO A SPECIFIC REGION OF THE SURFACE OF SAID TARGET; (4) A MOVABLE SHAFT MEMBER; AND (5) A MOVABLE MASK OPERATIVELY CONNECTED TO SAID SHAFT MEMBER, CONFIGURED IN ACCORDANCE WITH A PREASSIGNED FUNCTION AND WHICH IN RESPONSE TO MOTION OF SAID MOVABLE SHAFT MEMBER ATTENUATES THE RADIATION FROM SAID SOURCE PERMITTED TO REACH SAID TARGET BY PASSING A SHADOW OF SAID MOVABLE MASK ACROSS SAID RADIATION SENSITIVE TARGET WHICH SHADOW MOVES ACROSS SAID APERTURE IN SAID FIXED MASK IN A DIRECTION GENERALLY PERPENDICULAR TO THE DIRECTION OF MOTION OF THE MOVABLE MASK, WHEREBY THE ELECTRICAL SIGNAL OUTPUT OF SAID DEVICE IS THE INTENDED FUNCTION OF SAID MOVABLE SHAFT MEMBER.