| 摘要 |
PROBLEM TO BE SOLVED: To provide a color cathode-ray tube which can improve color purity with a lightweight and simple constitution, by further reducing the influence to an electron beam caused by the earth's magnetism, responding to the problem that the color purity is deteriorated, depending on beam landing deviations caused by the leakage of magnetic field having a tube axis direction component Bz and a vertical axis direction component By of the earth's magnetism, since the shield effect is weak to the earth's magnetism especially in the tube axis direction, and magnetic shield effect has limitations, even by use of an inner shield although the inner shield is used to avoid the influence to electron beams by the earth's magnetism, and to provide a shadow mask structure for the color cathode-ray tube. SOLUTION: In the vicinity of diagonal corners of a mask frame 20 which comprises sidewall parts 18 for fixing a shadow mask 17 and a bottom face part 19 formed at a virtually right angle with the side wall parts 18, and has a nearly L-shaped section and a frame-shape as a whole to support the shadow mask 17, a plurality of magnetic field control pieces 23 are arranged, in order to couple the sidewall parts 18 with the bottom face part 19 at prescribed angles. COPYRIGHT: (C)2003,JPO
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