Patent ID: 7598835

Claim:
A magnetic sensor comprising: a plurality of full-bridge-connected giant magnetoresistive effect elements, each giant magnetoresistive effect element having a spin valve film including a pinned layer, a conductive spacer layer, and a free layer, wherein the spin valve films have narrow zonal portions each of which extends in the longitudinal direction comprising: bias magnet films provided at both ends of the free layer in the longitudinal direction for producing in the free layer a bias magnetic field in the longitudinal direction of the free layer, whereby the direction of magnetization in each magnet domain in the free layer can stably be maintained in the predetermined direction when an external magnetic field is not present, and initializing coils being energized under a predetermined condition to thereby generate an initializing magnetic field for returning the direction of magnetization in each magnetic domain in the free layer to the longitudinal direction of the free layer, whereby the direction of magnetization in each magnetic domain in the free layer can assuredly be returned to the initial state even if the direction of magnetization is disturbed by applying a strong magnetic field to the free layer.