| 摘要 |
PURPOSE:To switch the correction of coma aberration (VCR) and to resolve a correction lack on a vertical axis end by forming a 1st current control system constituted of a pair of subcoils out of two pairs and a pair of diodes connected in parallel with reverse polarity and connecting a 2nd current control system consisting of a serial circuit constituted of a resistor and a choke coil in parallel with the 1st current control system. CONSTITUTION:The subcoils 1a, 1b of upper and lower U-shaped cores generate a pin cushion magnetic field in the same direction as a vertical deflection coil magnetic field and the subcoils 2a, 2b of right and left rod-shaped cores generate a barrel magnetic field in the reverse direction against the vertical deflection coil magnetic field. In both the upper and lower and right and left subcoils, their magnetic fields are applied to a center beam stronger than side beams to correct VCR. Consequently, vertical deflection current flowing into the right and left subcoils 2a, 2b is suddenly increased from a part corresponding to the leading edge part of a diode pair 3 and VRT correction lack which may be generated by adding VCR correction based upon the right and left subcoils 2a, 2b to VCR correction based upon the upper and lower subcoils 1a, 1b can be resolved. |
