| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that deterioration in the purity or the like is caused when the deviation of the electron beam of a picture tube due to the characteristics of the picture tube device itself in which a degausser is installed cannot be corrected. SOLUTION: The degaussing of a shadow mask is performed by allowing a degaussing electric current generating circuit 20 to generate a degaussing electric current which is the alternating voltage waveform of a short cycle based on a supply electric current from a direct current power source, and to supply the degaussing electric current to a degaussing coil 10 wound in the direction to reduce the deviation of the electron beam of the picture tube 30. Magnetism remains in the shadow mask because it is difficult to make the positive/negative peak current value of the degaussing electric current same. However, the irradiation position of the electron beam is adjusted in the direction in which the deviation decreases, because the degaussing coil 10 is wound in the direction to reduce the deviation of the electron beam of the picture tube 30.
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