Magnetoresistance effect type magnetic head apparatus.

摘要

A magnetoresistance effect type magnetic head apparatus has a magnetoresistance effect sensing element (5), means (3) for applying a bias magnetic field to the sensing element (5), a detecting circuit (81) for obtaining a detecting signal, a low pass filter (32) for deriving an unwanted signal component from the detecting signal, and means for applying a cancelling magnetic field to the sensing element (5) so as to eliminate the unwanted signal component. An additional sensing element (25) may also be provided to detect an external magnetic field (HN), and a corresponding signal is generated which is applied to a first sensing element (5) so as to cancel the effects of the external magnetic field (HN).