| 摘要 |
PURPOSE: A color cathode ray tube is provided to mitigate a deterioration of a color degree of purity owing to a metamorphosis of a mask body at a fabrication process. CONSTITUTION: A color cathode ray tube comprises a vacuum external container(10) which has a panel(23/24) having a valid portion(20) of a rectangle shape. A fluorescent screen(25) is formed at an inner plane of the valid portion, and a shadow mask(31) of a rectangle shape is installed so as to be opposed to the fluorescent screen. The shadow mask(31) is formed with a curved surface opposed to the fluorescent screen and has a valid portion of a rectangle shape, at which a plurality of electronic beams through holes are formed. The shadow mask has a shadow frame of a rectangle shape which is installed at a peripheral part of the mask body. The shadow mask and the panel have a long shaft and a short shaft so as to be intersected each other, and the valid plane of the mask body(29) has a curvature of 0-3*10¬-4(1/mm) according to a vertical axis direction. In the valid plane of the mask body, a curvature of a center part is less than that of a peripheral part.
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