| 摘要 |
PURPOSE:To atain a stable output signal at all times, by tracking the servo of a reproducing head against a minute fluctuation in the broadwise direction of a magnetic tape so as to hold the reproducing head at a normal position at all times to a recording track. CONSTITUTION:One reference track 30 is recorded on a magnetic tape 28 by a recording head 1. Further, two servo tracks 31, 32 for reproducing the track 30 are provided on a reproducing head 2, and they are in contact with the respective ridge of the track 30 at the normal position to the track 30. An output signal reproduced with these tracks 31, 32 is processed with a closed loop controlling circuit, and when the track 30 is shifted from the head 2 because of the positional fluctuation toward the broadwise direction of the tape 28, a reproduced output signal corresponding to the signal difference from the tracks 31, 32 is obtained, and a piezoelectric diaphragm 22 is displaced to the normal position to the track 30 by applying this signal to a piezoelectric oscillator 25. |
