Electroluminescent device and method

Claim 1

A CERAMIC-TYPE ELECTROLUMINESCENT DEVICE, THE OPERATIVE PORTION OF WHICH INCLUDES A METALLIC SUBSTRATE, A CONTINUOUS LAYER THEREOVER COMPRISING PHOSHOR HAVING A MATRIX COMPRISING ZINC SULFIDE AND INCLUDING COPPER AS ACTIVATOR EMBEDDED IN LIGHT-TRANSMITTING CERAMIC MATERIAL, AND A LIGHT-TRANSMITTING ELECTRODE LAYER OVER SAID PHOSPHOR-CERAMIC LAYER, THE OPERATIVE PORTION OF SAID DEVICE MIXING IN PREDETERMINED PROPORTIONS AND IN FINELY DIVIDED STATUS SAID PHOSPHOR AND A CERAMIC FRIT WHICH WILL FUSE TO FORM A CONTINUOUS LIGHT-TRANSMITTING LAYER AT A TEMPERATURE OF LESS THAN 750*C.; INCLUDING AS AN ADDITIVE TO SAID PHOSPHOR-FRIT MIXTURE AND THROUGHOUT SAID PHOSPHOR-FRIT MIXTURE FROM 0.01% TO 1% BY WEIGHT OF SAID MIXTURE OF VINELY DIVIDED METALLIC SALT, THE CATION OF WHICH IS READILY OXIDIZED TO A HIGHER VALENCE STATE, AND WHICH METALLIC SALT IS FREE FROM ANY ELEMENT OF THE GROUP CONSISTING OF IRON, COBALT, NICKEL AND CHROMIUM; PLACING SAID FINELY DIVIDED MIXTURE PROXIMATE TO A METALLIC SUBSTRATE; HEATING SAID SUBSTRATE AND SAID FINELY DIVIDED MIXTURE AT A PREDETERMINED TEMPERATURE FOR A PREDETERMINED TIME TO FORM A CONTINUOUS PHOSPHOR-CERAMIC LAYER ADHERENT TO SAID SUBSTRATE; AND THEREAFTER PLACING AN ADDITIONAL LIGHT-TRANSMITTING ELECTRODE OVER SAID FORMED CONTINUOUS PHOSPHOR-CERAMIC LAYER TO COMPLETE THE OPERATIVE PORTION OF SAID DEVICE.