MAGNETIC SENSOR DEVICE

摘要

A magnetic sensor device comprises a first magnet (6) and a second magnet (7) which are disposed on mutually opposite sides of a conveyance path (2), and each of the magnetic poles of the first magnet (6) faces the magnetic pole of the second magnet (7) different therefrom. The first magnet (6) and the second magnet (7) generate a cross magnetic field wherein the magnetic field strength in a spacing direction, which is perpendicular to a conveyance direction, is within a predetermined range. An AMR element (10) is positioned in a strong magnetic field strength region, in which the magnetic field strength of the cross magnetic field in the spacing direction is within a predetermined range, and detects, as a change in a resistance value, a change in the component of the cross magnetic field in the conveyance direction caused by an object (5) to be detected. A multi-layer board (9) outputs the change in the resistance value detected by the AMR element (10) to a processing circuit (15).