Optical projection contour inspection system

Claim 1

AN OPTICAL PROJECTION CONTOUR INSPECTION SYSTEM HAVING A LARGE TRACING AREA, COMPRISING IN COMBINATION; A WIDE ANGLE CAMERA-TYPE OBJECTIVE LENS HAVING A PREDETERMINED OPTICAL AXIS, SAID LENS BEING THE TYPE WHEREIN AT LEAST SOME OF THE RAYS FROM EVERY PORTION OF AN OBJECT PASS THROUGH THE LENS AT A PREDETERMINED POINT IN THE LENS ON ITS OPTICAL AXIS AND EMERGE TO FORM AN IMAGE WHICH IS PROPORTIONAL TO ITS DISTANCE FROM THIS POINT IN THE LENS, THEREBY PROVIDING A FIELD OF VIEW DEFINED BY AN IMAGINARY CONE WITH ITS APEX AT SAID POINT, A VIEWING SCREEN POSITIONED IN SPACED RELATION TO SAID LENS ALONG SAID AXIS FOR RECEIVING PROJECTED LIGHT THROUGH SAID LENS, A TRACING STYLUS ELEMENT MOUNTED FOR TRACING MOVEMENT ON A WORK SURFACE TO BE INSPECTED, A FOLLOWER STYLUS ELEMENT CORRESPONDING TO SAID TRACING STYLUS ELEMENT RIGIDLY CONNECTED FOR CONJOINT MOVEMENT WITH SAID TRACING STYLUS ELEMENT IN A TRACING AREA SUBSTANTIALLY LARGER THAN THE AREA OF SAID LENS, THE MOVEMENT OF SAID FOLLOWER STYLUS BEING WHOLLY WITHIN A FIELD VIEWED BY SAID LENS AND AT A DISTANCE THEREFROM ALONG SAID AXIS, AND MEANS FOR ILLUMINATING SAID FOLLOWER STYLUS, SAID LENS THEREBY PROJECTING A REAL IMAGE OF THE OUTLINE OF SAID FOLLOWER STYLUS ON SAID VIEWING SCREEN IN ANY OF THE POSITIONS OF THE FOLLOWER STYLUS WITHIN SAID LARGE TRACEABLE AREA.