| 摘要 |
PURPOSE:To correct the astigmatism by arranging the solenoid coils at the upper and lower left and the upper and lower right of the neck section then supplying the parabolic wave synchronous with the horizontal and vertical deflection current to each coil to produce the tetra-pole magnetic field. CONSTITUTION:The solenoid coils 19, 20, 21, 22 are arranged at the upper and lower left and the upper and lower right of the neck section 14 surrounding a focus electrode then each coil is connected in series to produce the tetra-pole magnetic field. Thereafter the parabolic wave synchronous with the horizontal deflection current or the parabolic or triangular wave of reverse polarity synchronous with the triangular wave and the vertical deflection wave is supplied simultaneously to produce the tetra-pole magnetic field synchronous with each deflection current. Consequently the astigmatism caused by the deflection can be eliminated completely. |
