| 摘要 |
PURPOSE:To obtain a cathode-ray tube which is short in whole length by a construction wherein the cathode-ray tube employs an electron gun with an ion trap utilizing the magnetic field of a magnet as the magnetic field for ion trapping, part of a deflecting coil holder being composed of the magnet. CONSTITUTION:In place of a band 42 for tightening a deflecting coil holder 41, an ion trapping magnet 3 comprising a magnet 31, a pole-tip 32, and a non- magnetic spring 33 is used. Accordingly, the ion trapping portion of an electron gun 2 can be moved to the position of the deflecting coil holder 41 which is close to the fluorescent screen and by that much the whole length of a cathode- ray tube can be shortened. In addition a non-magnetic screw 32 in place of the spring may be used to put the ends of pole-tips 32a close to each other, while the coil and the magnet may be fixed to a neck 11. Furthermore, without employing individual magnet and pole-tip, the whole may be constructed of a permanent magnetic material. |
