Cathode ray tube construction having defined processing and operational

Abstract

An improvement combination is provided in cathode ray tube construction for expediting improved tube processing and subsequent tube operation. The combination is incorporated in the funnel portion of the tube wherein a first low resistive electrical conductive coating is interiorly disposed in a substantially circumferential manner on the forward portion of the funnel nearest the screen. A high resistive electrical conductive coating is substantially circumferentially interiorly disposed on substantially the intermediate portion of the funnel being contiguous with the first coating, and making contact with a second low resistive electrical conductive coating interiorly disposed on substantially the rear portion of the funnel. This second coating extends into the forward region of the integral neck portion to facilitate electrical connection with the electron gun assembly positioned therein. A first button connector is oriented to traverse the wall of the forward region of the funnel and make connection with the first low resistive coating. Rearward from the first button, a second button connector traverses the wall of the funnel to provide a separate electrical connection for the second low resistive coating. During tube processing, utilization of this second button facilitates high voltage conditioning of the electron gun assembly by by-passing the high resistance coating; while in subsequent tube operation only the first button connector is utilized thereby effecting beneficial arc protection by incorporating the high resistive coating into the circuit.