Photosensitive calibrated kerf control

Claim 1

A SCANNER HEAD FOR A PATTERN TRACER COMPRISING A BODY MEMBER DEFINING A CENTRAL AXIS, SCANNING MEANS WITHIN SAID BODY HAVING A LIGHT SENSITIVE DEVICE AND MEANS DEFINING A CENTER OF SCAN IN APPROXIMATE ALIGNMENT WITH SAID AXIS, A CIRCULAR PLATE MEMBER SECURED TO SAID BODY NORMAL TO SAID AXIALLY ALIGNED WITH SAID CENTRAL AXIS, A CYLINDRICAL MEMBER HAVING AN INNER CYLINDRICAL BEARING SURFACE SURROUNDING SAID PLATE MEMBER AND A FLANGE DEFINING AN INNER CIRCULAR CAM SURFACE, THE AXIS OF SAID CAM SURFACE AND THE AXIS OF SAID INNER BEARING SURFACE BEING NON-COEXTENSIVE WITH ONE ANOTHER AND PARALLEL WITH SAID CENTRAL AXIS, A ROLLER CARRIED BY SAID PLATE MEMBER ENGAGEABLE WITH SAID CAM SURFACE, A PIN CARRIED BY SAID PLATE MEMBER DIAMETRICALLY OPPOSITE SAID ROLLER, A SPRING CONSTRAINED BETWEEN SAID PIN AND SAID CAM SURFACE TO HOLD SAID ROLLER AGAINST SAID CAM SURFACE, A LENS FIXEDLY ATTACHED TO SAID BODY MEMBER WITH ITS FOCAL AXIS COEXTENSIVE WITH SAID CENTRAL AXIS, A PRISM HAVING OPPOSITELY FACING PARALLEL SURFACES MOUNTED ON SAID BODY MEMBER FOR ROTATION ABOUT AN AXIS PARALLEL TO SAID FACING SURFACES AND PERPENDICULARLY INTERSECTING SAID CENTRAL AXIS; AN ASSEMBLY HAVING AN OUTER BEARING SURFAFE MATING WITH SAID INNER BEARING SURFACE MEANS ON SAID ASSEMBLY DEFINING A PAIR OF RADIALLY ALIGNED SLOTS, MEANS IN ENGAGEMENT WITH SAID SUPPORT FLANGE MEMBER AND PASSING THROUGH SAID SLOTS, AND MEANS ON SAID ASSEMBLY IN ENGAGEMENT WITH SAID PRISM FOR ROTATING SAID PRISM ABOUT ITS AXIS OF ROTATION RESPONSIVE TO ROTATION OF SAID CYLINDRICAL MEMBER.