COLOR CATHODE-RAY TUBE

PROBLEM TO BE SOLVED: To provide a color cathode-ray tube preventing the thermal transfer phenomenon of electron beam passing holes, shortening the initial stabilization time of an image, improving the resolution of the image, and preventing a color gradation phenomenon by supplementing the initial doming quantity of a shadow mask by thermal expansion in a short time. SOLUTION: The heater 70 of a heating means is provided on a frame 62, and a prescribed voltage is applied to the heater 72 to heat and expand the frame 82 before a shadow mask 61 is heated by thermoelectrons and this heat is transferred to the frame 62. The doming phenomenon of hole sections 61b due to the thermal expansion of the shadow mask 61 can be supplemented by the thermal expansion of the frame 62. A color cathode-ray tube supplementing the initial doming phenomenon of the shadow mask 61, shortening the stabilization time of the initial screen formed on the cathode-ray tube, and preventing the distortion and color gradation phenomenon of an image is obtained.