| 摘要 |
PURPOSE:To remove noises by compensating the absence of a synchronizing signal by constituting a synchronizing signal processing circuit, processing a vertical synchronizing signal used for control over the rotation of a rotary head, so that it will be suitable for IC-implementation. CONSTITUTION:Vertical synchronizing signal S1 is applied to AND gate circuit 1 together with output signal S6 of voltage ratio comparing circuit 5. Output signal S2 of the AND gate circuit 1 is applied to the reset input of R.S flip-flop circuit 2 together with output signal S5 of voltage comparing circuit 4. Output signal S7 of voltage comparing circuit 6 is applied to the set input of R.S flip-flop circuit 2, whose output signal S2 is applied to waveform converting circuit 3, output signal S4 of which is applied to voltage comparing circuits 4, 5 and 6 respectively. |
