| 摘要 |
PURPOSE:To ensure the correct interlace, by supplying the compensating signal for up-down pincushion distortion to a vertical output circuit only in a vertical scanning period. CONSTITUTION:The vertical synchronized blanking pulse PB is supplied to a blanking circuit 20. With application of the blanking, the vertical sawtooth wave signal S'V has a waveform C. Therefore the modulation output to be balanced of a vertical flyback time TR is set at zero. As a result, the compensating signal S'CR is delivered from a balanced modulator 4 as shown by a waveform D which lacks the signals only in the time TR. Thus the driving signal S'D delivered from a comparator 6 has a waveform F, and no horizontal parabola wave signal exists at all to the flyback pulse PR. In this connection, a transistor Q3 is turned on and off at the same time point in both n-field and (n+1)-field. As a result, the coincidence is obtained for the timing of vertical deflection, and the raster has the correct interlace. |
