| 摘要 |
PURPOSE:To make deterioration of a focus of a blue beam inconspicuous even in case a high resolution Braun tube has been used, by making the magnetizing amount of a blue lateral magnet less than that of a correcting magnet. CONSTITUTION:A rotatable blue lateral magnet 11 is provided opposite to a blue beam of a neck part of the image receiving tube, and to the side located between a red beam and blue beam of a neck part of the image receiving tube which is opposite to this magnet 11 is mounted a correcting magnet 12 of the same constitution as the magnet 11 so that it can be rotated. And the magnets 11 and 12 are magnetized so that the poles can face each other in the diameter direction on the circumferential face, and the magnetizing amount of the magnet 11 is made less than that of the magnet 12. Thus, it is possible to make deterioration of a focus of a blue beam inconspicuous even in case a high resolution Braun tube has been used. |
