HEATER STRUCTURE FOR CATHODE RAY TUBE

摘要

PURPOSE: A heater structure for a cathode ray tube is provided to inhibit a dielectric breakdown between the cathode and heater caused due to the increase of breakdown of the heater. CONSTITUTION: A cathode ray tube comprises a heater having a surface on which an insulating layer and a blackening layer are formed. The surface of the heater is coated with an alumina film having a sintering strength of 65 to 75g. The sintering strength of the alumina film is obtained by sintering the heater at the temperature of 1450 to 1550°C.