Method of producing luminescent screens for cathode ray tubes

Claim 1

A METHOD OF PRODUCING A CATHODE RAY TUBE HAVING A SELECTIVE DUAL DECAY CHARACTERISTIC VIEWING SCREEN THEREIN, SAID SCREEN BEING FORMED BY THE STEPS OF: MIXING A FIRST INGREDIENT CONSISTING OF POTASSIUM FLUORIDE AND MAGNESIUM FLUORIDE IN SUBSTANTIALLY THE MOLAR RATIO OF 2.2:1 TO 1.8:1 WITH ACTIVATOR AMOUNTS OF MANGANESE FLUORIDE RANGING FROM ABOUT .003 TO ABOUT .014 MOL, FIRING SAID FIRST INGREDIENT AT AN ELEVATED TEMPERATURE; MIXING A SECOND INGREDIENT CONSISTING OF POTASSIUM FLUORIDE IN SUBSTANTIALLY THE MOLAR RATIO OF ABOUT 1.1:1 TO 1:10 IN THE PRESENCE OF ACTIVATORS IN THE AMOUNTS OF ABOUT .001 MOL OF MANGANESE IN THE PRESENCE OF ABOUT .04 MOL OF ZINC SULPHATE, FIRING SAID SECOND INGREDIENT AT AN ELEVATED TEMPERATURE, BLENDING SAID FIRST AND SECOND INGREDIENTS IN AMOUNTS RANGING FROM ONE PART OF SAID FIRST INGREDIENT TO TEN PARTS OF SAID SECOND INGREDIENT, AND DEPOSITING SAID BLEND OF FIRST SAID SECOND INGREDIENTS ON A SURFACE OF SAID CATHODE RAY AND SECOND INGREDIENTS ON A SURFACE OF SAID CATHODE RAY TUBE TO FORM A VIEWING SCREEN THEREIN CHARACTERIZED BY ITS SELECTIVE DUAL DELAY LIGHT CHARACTEISTIC.