| 摘要 |
<p>PROBLEM TO BE SOLVED: To simplify the structure and to enable high precision tracking control even in a narrow track by detecting only a pilot signal recorded in one adjacent track out of the two adjacent tracks so as to perform the control. SOLUTION: At the time of reproducing, odd-numbered tracks and even- numbered tracks 11 to 17 and 12 to 18 are alternately scanned by heads 21 and 22 positioned opposite to each other at 180 degrees in repeating the 1st-4th scanning of 11 to 14 and then 15 to 18 as one set. A signal j outputted from a detector 3 by detecting an amplitude of a P1 pilot signal contained in a regenerative signal i is turned into a signal k by an S & H 4, and this is changed by a selecting polarity inverter 5 with a polarity signal r. A ripple of a frequency for making the round of the track is removed from an output signal l of the inverter 5 by a filter 7 to output an error signal h, and AFT control is performed by a controller 8 with the signal h. Thus, by simple constitution, the pilot signal is selected to meet the optimum fringe amt. of the head, and even a narrow track can be controlled with high accuracy.</p> |
