| 摘要 |
<p>PURPOSE:To discriminate exactly a recording speed by making the second reference pilot signal same in frequency as a pilot signal shifted by one track against the first reference pilot signal and discriminating the recording speed by the change of the period of a difference frequency signal obtained in the generating period of the second reference signal. CONSTITUTION:By inserting an inverter 17 and a change-over switch 18 and making even the polarities of difference frequency signal detecting components inputted to a gate 11, a tracking error signal 400 is generated. The second reference pilot signal the same in frequency as the pilot signal shifted by one track against the first reference pilot signal is generated time-divisionally. A gate circuit 12 is opened by a gate signal 600 corresponding to the generating section of the second reference pilot signal and makes pass a difference detecting output of fH outputted from a detector 8, sending it to a waveform arranging circuit 15. During a section where the gate circuit 12 is closed, a value held by a hold circuit 14 is sent to the waveform arranging circuit 15 and the waveform arranging circuit 15 arranges the waveform of an inputted signal, outputting it to a recording speed discriminating circuit 16.</p> |
