Dark trace cathode ray tube

Claim 1

ELECTRO-OPTICAL TRANSLATION MEANS COMPRISING A CATHODE RAY TUBE HAVING AN ELECTRON GUN FOR DEVELOPING A SCANNING CATHODE RAY BEAM WITH A SIGNAL MODULATED INTENSITY BETWEEN PREDETERMINED LIMITS AND A STORAGE SCREEN OF THE IONIC CRYSTAL SIGNAL STORAGE TYPE LOCATED WITHIN THE ENVELOPE OF SAID TUBE, SAID SCREEN COMPRISING A LAYER OF DARK TRACE IONIC MATERIAL RESPONSIVE TO AN IMPINGING CATHODE RAY BEAM TO DEVELOP ELEMENTAL AREAS OF CORRESPONDING VARIABLE OPACITY OF A BACKING OF A SHEET OF LIGHT TRANSPARENT ELECTRICALLY CONDUCTING MATERIAL, IN COMBINATION WITH ERASING AND PROJECTION ILLUMINATION MEANS COMPRISING A SOURCE OF ULTRAVIOLET RADIATION POSITION WITHIN THE ENVELOPE OF SAID TUBE, AND MEANS ELECTRICALLY CONNECTED TO SAID SOURCE OF ULTRAVIOLET RADIATION FOR SELECTIVELY ENERGIZING SAID SOURCE OF ULTRAVIOLET RADIATION TO A FIRST ENERGY RADIATING CONDITION AT WHICH SAID SOURCE OF ULTRAVIOLET RADIATION ILLUMINATES SAID LAYER OF SAID STORAGE SCREEN AND TO A SECOND ENERGY RADIATING CONDITION AT WHICH SAID SOURCE OF ULTRAVIOLET RADIATION ERASES SAID LAYER OF SAID STORAGE SCREEN.