| 摘要 |
PURPOSE:To obtain a high productivity cathode-ray tube eliminated with a crack due to thermal distortion, by simultaneously heating outer edge and center parts of a stem. CONSTITUTION:A coiled heater 14, the other heat source for heating a center part 8b of a stem 8, is approximately wound to the periphery of a tip tube 3 protruded from the center part 8b of the stem 8. At exhaust work in a cathode- ray tube 1, the cathode-ray tube 1 is heated from the outside by one heat source 7 and electric conduction current in a high frequency coil 6, while the heater 14 is electrically conducted to heat the center part 8b in such a manner as to decrease a gradient of temperature, between the center part 8b and outer edge part 8a, correspondingly to a quantity of heat applied to the stem 8 from the outside. The exhaust work is performed while discharging gas in each part by the above heating process. Accordingly, the center part 8b is also heated simultaneously by the heater 14, and a crack is never caused in the stem 8. |
