| 摘要 |
PURPOSE:To access plural disks with different format by detecting two track servo frequencies when highly accurate track position control is applied by a track servo signal so as to detect a recording format of the disk. CONSTITUTION:A reproducing signal of a magnetic head is inputted by an AGC amplifier 1 of a magnetic disk device, servo signals S1, S2 arranged by a half track each and positioned around the track are fed to amplifiers 2, 3 and inputted to tuning circuits 4, 5 separately. Combined waveforms b, b' of two frequencies f1, f2 are fed to a track switching circuit 6. The circuit 6 switches the output from the tuning circuits 4, 5 to be outputted to detection circuits 7, 8 or 8, 7 respectively. Then smoothing circuits 9, 10 process its output to apply the highly accurate position control by a track servo signal to detect two track servo frequencies. |
