Patent ID: 6870365

Claim:
A rotation detecting device having a magnetic moving body coupled to an object of detection, a magnet disposed facing the magnetic moving body, and a magneto-electric converter device made up of a plurality of magneto-resistance segments disposed at a predetermined pitch in a rotation direction of the magnetic moving body, changes in impressed magnetic field strength accompanying rotation of the magnetic moving body being detected by the magneto-electric converter device to detect the rotation direction of the magnetic moving body, wherein the magneto-electric converter device comprises at least six segments disposed at a predetermined pitch in a predetermined rotation direction of the magnetic moving body symmetrically about a centerline of the magnet perpendicular to the rotation direction of the magnetic moving body and these include at least two pairs of segments having their pitch centers disposed symmetrically about the centerline of the magnet and forming first and second bridge circuits for producing outputs along with rotation of the magnetic moving body and at least one pair of segments having its pitch center on the centerline of the magnet and forming a third bridge circuit for producing an output along with rotation of the magnetic moving body, and the rotation direction of the magnetic moving body is detected on the basis of a combination of these bridge circuit outputs.