| 摘要 |
<p>PURPOSE:To attain optimum tracking at the time of reproducing in a device writing data doubly on adjacent tracks by two heads with different head width each other by supplying pilot signals to the two heads to use the reproduced pilot signals and head width information. CONSTITUTION:Reproducing is performed from the shown recording track as follows. When a reproducing video signal is inputted from a terminal 17, respective pilot signals f1-f4 are added to an adder 22. On the other hand, the output of a BPF18 is detected at its envelope and compared with reference voltage (e) by a comparator 24 to discriminates whether a signal f1 is included in a recorded field or not. Consequently, the phase of a four-phase pulse is reset every time when the signal f1 is reproduced. Namely, a signal having always the same frequency as that of a pilot signal of a reproducing track reproducing a video signal is applied to a frequency converter 27 as a local signal and frequency components of 10kHz and 30kHz are extracted from the frequency-converted signal by BPFs 28, 29 and detected by envelope detecting circuits 30, 31. Output signals from the circuits 30, 31 are supplied to a control signal generating circuit 32, which outputs an autotracking controlling signal.</p> |
