| 摘要 |
PURPOSE:To obtain an unnecessary radiation preventing deice to be constructed with low cost without limitation on the structural design by insertion connecting an auxiliary coil in series or parallel with a horizontal deflection coil constituting a deflection yoke thereby suppressing an unnecessary signal. CONSTITUTION:Upon supply of scanning current to a horizontal deflection coil 1b and an auxiliary coil 10 connected in series, magnetic field in predetermined direction is produced as an effective field in the inner space of core at the linear section in the core 1a. Meanwhile, the leak field 6 around the bridged sections of the coils outside of the core 1a radiates externally. Upper and lower coils in the auxiliary coil 10 are wound to produce magnetic fields in reverse direction from the field of the deflection coil 1b, thus to cancel the leakage field. Since the auxiliary coil 10 is fixed to the outside of the deflection coil 1, the spatial field surrounded by the core 1a is scarcely influenced by the core 1a nor subjected to the leak field 11 at the linear section because the number of turn of the auxiliary coil 10 is considerably lower than that of the horizontal deflection coil 1b resulting in considerable reduction of the unnecessary signal level to the external space. |
