| 摘要 |
PURPOSE:To correct most suitably the geometrical distortion of a vertical line by modulating a longitudinal deflecting current by following the variation of a primary side voltage of a fly-back pulse transformer caused by the variation of a horizontal frequency. CONSTITUTION:When a parabolic waveform for correcting the geometrical distortion of a longitudinal line is inputted to a point (a), it is amplified by a differential amplifier, and a parabolic voltage is applied to the base of a transistor 24. Also, in a horizontal deflecting circuit, the collector pulse of the horizontal output transistor 24 is brought to a capacity division by capacitors 33, 34, and a regulated power source 3 varies the (b) point voltage of a fly-back transformer so that the voltage of a point (c) becomes constant. When a horizontal frequency is varied, the (b) point voltage is varied, by which base voltages of transistors 8, 9 are varied, therefore, the parabolic waveform of a point (d) is varied in accordance with the horizontal frequency, a current conducting to a deflecting coil 25 is modulated and the geometrical distortion of the vertical line is corrected. |
