| 摘要 |
PROBLEM TO BE SOLVED: To reduce the influence of the variation of an external magnetic field to an electron beam at a low cost and to prevent degradation of the color purity of a color cathode-ray tube. SOLUTION: Band-like magnetic shields 9 each formed of a metal plate is mounted to the whole surface or certain parts of peripheral parts 41b of a color selection electrode 41 facing a phosphor screen of a color cathode-ray tube. Since the phosphor band stripes of the phosphor screen are arranged in the vertical direction of the screen in this case, the magnetic shields 9 are mounted to positions corresponding to upper and lower parts of the screen. The magnetic shields 9 can absorb an external magnetic field in a Z-axis direction and can reduce magnetic flux affecting an electron beam, so that magnetic shield capability in the Z-axis direction can be secured at a low cost without using a conventionally used canceler used, and degradation of the color purity of the color cathode-ray tube can be prevented. The color selection electrode 41 can be formed into a thin plate and etching accuracy can be improved in forming a perforated part 41a by mounting the magnetic shields 9.
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