INSPECTION SYSTEM FOR DETECTING DEFECTS IN REGULAR DRAWINGS IN PARTICULAR IN PHOTOGRAPHIC MODEL PLATES USED FOR MAKING SHADOW MASKS FOR COLOR TELEVISION IMAGE TUBES

摘要

INSPECTION SYSTEM FOR DETECTING DEFECTS 66 IN REGULAR DRAWINGS OR NETWORKS 60 IN WHICH THE ELEMENTS 62 CONSTITUTING SUCH DRAWINGS OR NETWORKS HAVE PERIODIC VARIATIONS, WHICH INCLUDE MEANS FOR SCANNING AND DETECTING THE ELEMENTS OF A DRAWING TO SIGNAL OF OUTPUT PROVIDING AN INDICATION OF THIS DRAWING AND OF THE MEANS FOR REALIZING A SELF-CORRESPONDENCE OF THIS OUTPUT SIGNAL WHICH INCLUDE MEANS FOR DELAYING THE SAME OUTPUT SIGNAL, THIS SYSTEM BEING CHARACTERIZED IN THAT THE SCANNING RATE OR SPEED OF THE SCANNING MEANS AND DETECTION IS VARIABLE OR CONSTANT WHERE, RESPECTIVELY, THE DURATION OF THE DELAY PROVIDED BY THE SAID MEANS OF DELAY IS CONSTANT OR VARIABLE.