| 摘要 |
PURPOSE:To perform tracking control which has no blind sectors and does not cause malfunction in case of dropout or the like due to flaws, etc. on a tape, by generating an error signal as a tracking error signal when a pilot signal frequency is not detected for a certain time and a main signal is lower than a certain level. CONSTITUTION:A pulse 27B having the same period as drum rotation is applied to a terminal 26, and a timing 27A is generated from a circuit 27 in accordance with this pulse 27B and is applied to an RS latch 19 and a D-FF20 to apply the timing of the pulse 27B to AND circuits 23 and 24. The level of a pilot signal fB is detected from a rise detecting circuit 13 to send out a pulse. Peak holding circuit 17 and a comparator 18 detect the level of a reproduced signal and apply it to the AND circuit 24, and the detection signal of the signal fB from the D-FF20 and the pulse 27B of a main signal area of PCM are applied to the circuit 24; and if the signal fB is not detected for a certain time in the period of the timing 27A and the level of the PCM area is reduced to a half or lower, the circuit 24 goes to level ''0'', and the output is outputted as an error signal voltage through an RS latch 25 and a switch 16A from an adding circuit 8 to a terminal 9.
|
