| 摘要 |
PURPOSE:To enable the uniform metal-deposited film to be always formed on the inner wall surface of the neck of the captioned tube as well as to obtain the captioned cathode-ray tube with small internal discharge, by using a high frequency power source for heating by high frequency and by applying intermittently the predetermined high frequency current on a heating coil. CONSTITUTION:A heating coil is connected to a high frequency power source 41; a metal wire is annealed in accordance with a curve 51 and cooled along a curve 511 till the coil is transferred to the next high frequency power source 42. Next, the heating coil is connected to the high frequency power source 42, the metal wire is heated in accordance with the curve 51 in order to evaporate a part thereof and then cooled along a curve 521. Thus, whenever the coil is transferred to high frequency power sources 43-47, the metal wire is heated along curves 53-58 cooling periods are provided along curves 531-571 therebetween and finally cooled along a curve 581. Consequently, unevenness in the thickness of metal deposited film can be eliminated and the uniform film can be formed on the inner wall surface of a neck. |
