Magnetic sensing device unaffected by positioning error of magnetic field sensing elements

摘要

A sensing device outputs a square wave signal whose edges exactly correspond to edges of protruding or recessed portions of a rotary magnetic-material member, regardless of the positioning accuracy of a magnetic field detecting element with respect to the location of a magnet. The sensing device includes: a magnet for generating a magnetic field; a rotary magnetic material member for changing the magnetic field generated by the magnet, the rotary magnetic material member being disposed a predetermined distance apart from the magnet; and a magnetic field detecting element whose resistance changes in response to the change in the magnetic field induced by the magnetic field variation inducing means; wherein the surface of the magnet facing the magnetic field detecting element is slanted.