MAGNETO-RESISTANCE EFFECT TYPE MAGNETIC HEAD

摘要

PURPOSE:To read out only <=5Hz signals in an accurate and assured way, by setting the space at >=2.5mm. and <=6mm. between a ferromagnetic thin film having a magneto-resistance effect formed on a nonmagnetic substrate and a magnetic medium. CONSTITUTION:The space is set at >=2.5mm. and <=6mm. between a ferromagnetic thin film 3 having a magneto-resistance effect and a magnetic medium 4 for an MR head 1 for reproduction of address signals of an audio tape recorder which enables access of the absolute address. A positive application is secured for the spacing loss which reduces as the signal magnetic flux density of the medium 4 goes further away from the medium 4. As a result, only <=5Hz signals are read out and amplified by a differential amplifier 8 and preamplifier 9 to be led to a microcomputer 15 after the deletion of noises through a Schmitt trigger 14. Thus an access operation is possible without using any band pass filter.