| 摘要 |
PURPOSE:To simplify the manufacturing of a stable heat-absorbing film, by sintering a mixture of a powder of a high-melting-point metal or its oxide and an inorganic binder on the inside surface of a one-end-closed metal sleeve belonging to an indirectly-heated cathode and housing a heater. CONSTITUTION:An indirectly-heated cathode for a cathode-ray tube or the like is made of a heater 2, a one-end-closed metal sleeve 1 housing the heater, and an electron emitter 4 filled in a cup 3 attached to the outside of the closed- end wall of the sleeve. A slurry-like mixture, in which a powder of tungsten or the like and a powder of an inorganic binder such as sintered alumina are dispersed in an organic solvent, is applied to the inside surface of the metal sleeve 1 and then sintered to make a heat-absorbing film 5 high in heat absorption efficiency and mechanical strength and stable at a high temperature in a vacuum. The heat-absorbing film 5 is thus manufactured in a relatively simple manner.
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