Magnetic detector with improved noise resistance characteristics

Abstract

Disclosed is a magnetic detector in which a GMR device is operated within the limited range of a magnetic field so as to optimize changes in resistance value of the GMR device and to improve noise resistance. The magnetic detector comprises a magnet (4) for generating a magnetic field, a rotary member (2) of magnetic material arranged with a predetermined gap left relative to the magnet and provided with projections capable of changing the magnetic field generated by the magnet, and a giant magnetoresistance device (3) of which resistance value is changed depending on the magnetic field changed by the rotary member of magnetic material. The giant magnetoresistance device is arranged in such a position with a predetermined gap relative to the magnetic field generating means that the giant magnetoresistance device is subject to a bias magnetic field applied with the intensity of magnetic field in a predetermined range, e.g., 100±150 [Oe], where the giant magnetoresistance device exhibits a high resistance change rate.

Dependencies are inferred from the claim text.