Image intensifying x-radiation inspection system with periodic beam scanning

Claim 1

A CLOSED CIRCUIT TELEVISION SYSTEM INCLUDING A SOURCE OF X-RADIATION FOR PROJECTION ONTO A WORKPIECE AND PRODUCE A WORKPIECE IMAGE, AN X-RADIATION SENSITIVE CAMERA TUBE FOR CONVERTING DETECTED RADIATION INTO ELECTRICAL SIGNALS REPRESENTATIVE OF THE WORKPIECE IMAGE, SAID TUBE INCLUDING A TARGET LAYER SENSITIVE TO X-RADIATION AND ADAPTED TO BE EXPOSED TO X-RADIATION REPRESENTATIVE OF THE WORKPIECE IMAGE, SAID LAYER OPERATIVE TO INTEGRATE THE EXPOSURE OF THE WORKPIECE IMAGE, MEANS FOR SCANNING SAID LAYER WITH AN ELECTRON BEAM AT A GIVEN FRAME RATE, MEANS FOR SELECTIVELY BIASING SAID TUBE AT A LEVEL OF BIAS TO RESTRAIN SAID ELECTRON BEAM FROM SCANNING SAID TARGET LAYER; AN ON-OFF GENERATOR OPERATIVE TO PERIODICALLY VARY THE LEVEL OF SAID BIAS ON SAID TUBE TO PERIODICALLY PERMIT SAID ELECTRON BEAM TO SCAN SAID LAYER TO PRODUCE AN INTERMITTENT IMAGE, AND THEREBY PERMIT SAID LAYER TO BUILD UP ITS ELECTRICAL CHARGE, STORAGE MEANS CONNECTED FROM SAID CAMERA TO RECORD SINGLE FRAME TELEVISION IMAGES FOR STORING SAID IMAGES AND TO PROVIDE AN OUTPUT OF A CONTINUOUS SEQUENCE OF OUTPUT VIDEO SIGNALS, READ-OUT MEANS, AND MEANS FOR CONNECTING THE OUTPUT OF SAID STORAGE MEANS TO SAID READOUT MEANS FOR CONTINUOUSLY INDICATING ONE OF THE INTERMITTENT IMAGES OF SAID WORKPIECE IMAGE, SAID STORAGE MEANS BEING A SCAN-CONVERSION TUBE HAVING READ, STORAGE, AND WRITE SECTIONS, SAID READ-OUT MEANS BEING A TELEVISION MONITOR.