| 摘要 |
PURPOSE:To attain stably tracking at the time of reproduction by recording a signal by a magnetic head of which head width is smaller than a track pitch, and at the reproducing time, using suitably a 4-frequency pilot signals. CONSTITUTION:At the reproducing time, pilot signals f1-f4 are separated from a reproducing signal by an LPF32, applied to a mixer 33 and mixed with a pilot signal generated from a circular frequency generator 27. The mixed signal has the relation shown in (b) and (c). In case of a long recording mode B, a reproduced pilot signal and the pilot signal generated in the frequency generator 27 are generated in the same order and mixed with the same signal. In case of a high quality recording mode A, a different pilot signal is mixed. The output of the mixer 33 is supplied to BPFs 34a, 34b and their center frequency values are set up to fa and fb respectively. Therefore, signals fa, fb are separated and detected by detectors 35a, 35b. Thus, suitable tracking control can be attained without adding an exclusive rotary head. |
