| 摘要 |
PURPOSE:To attain the tracking control of a magnetic head in a reproduction mode by detecting the direction and the amount of variance of a magnetic head for reproduction from the track center from the output of a magnetic head for detection set at the side of the head for reproduction. CONSTITUTION:When magnetic heads 1a and 1b for position detection are deviated to the right side from the head scan direction 4, a part of the head 1a touches a guard band 60. Thus the reproduction output of the head 1a is reduced in response to the variance amount from the center of a recording track 3. In this case, however, the reproduction output of the head 1b has no change since the head 1b is set into the track 3. The reproduction outputs of both heads 1a and 1b are amplified by amplifiers 6 and 7 and then wave- detected by AM wave detectors 8 and 9. Then these outputs are supplied to a differential amplifier 10 and compared with each other. The direction and amount of variance from the track center are detected for a magnetic head 20 for reproduction. This detection signal is supplied to a controller 12 for reproduction head position via an amplifier 11. Thus the tracking control is possible with magnetic heads in a reproduction mode.
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