| 摘要 |
In a multi-track magnetic signal reproducing apparatus, a plurality of MR heads including MR (Magneto-Resistance Effect) elements are provided, corresponding to tracks on a magnetic tape. At the time of reproduction, constant current from a constant-current power supply is sequentially supplied, as a pulse-shaped current for detecting a signal, to each MR element by switching a switch in response to a prescribed clock signal. An output voltage from each MR element, related to reproduction of a magnetic signal on a corresponding track, is sequentially provided to one input side of a differential amplifier. In the differential amplifier, the offset voltage of each MR element provided to the other input side and the above-described output voltage are differentially amplified, and only voltage due to the reproducing magnetic signal of each track is accurately extracted. Accordingly, the supply of pulse-shaped current effectively suppresses an increase in the amount of consumption current regardless of the number of tracks on the tape (or the number of heads), and since the amplifier is shared between the tracks, the number of necessary terminals for such a multi-track MR head is reduced.
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