| 摘要 |
PURPOSE:To always obtain a stable reproduced output signal even in case of wear in the front end side of a main magnetic pole, by moving the main magnetic pole toward a recording medium in accordance with the reproduced output signal value due to a perpendicular magnetic recording head so that this reproduced output signal value is a certain value. CONSTITUTION:The reproduced output signal is reduced according as spacing between a main magnetic pole 13 an a recording medium 17 is increased because of wear of the front end part of the main magnetic pole 13 in the reproducing operation. This reduction is detected as the difference between the reproduced output signal and a reference signal by a differential amplifier 21. If this difference occurs, a head driving device 18 is operated by a head driving circuit 19, and only parts of a soft magnetic material 15, the main magnetic pole 13, and a main magnetic pole supporting material 14 in a vertical magnetic recording head are pushed in toward the recording medium 17 by a proper extent. They are pushed in until the reproduced output signal from a coil 10 coincides with the reference signal, and spacing between the main magnetic pole 13 and the recording medium 17 is reduced. Thus, the level of the reproduced output signal is always kept at an optimum certain value even in case of wear of the main magnetic pole 13. |
