| 摘要 |
PURPOSE: A heater for a cathode ray tube is provided to obtain high insulation between the heater and a cathode with high heat radiation efficiency, reduce the number of heater manufacture processes and improve productivity of the heater. CONSTITUTION: A heater for a cathode ray tube has a surface coated with magnesium oxide as an insulation film by using electrophoretic coating method. Insulating solution is prepared by mixing magnesium oxide powder of average particle diameter 5-15μm and purity more than 99% with electrolyte of magnesium nitrate and aluminium nitrate and ethanol. After immersing a heat source of the heater, 3% rhenium-tungsten alloy coil, as a negative electrode and a platinum body as a positive electrode into the insulation solution, a voltage of 50-100V is applied to form a magnesium oxide film. The magnesium oxide film is sintered at a high temperature. The thickness of the film is 65-90μm.
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