Patent ID: 6310475
Filing Date: 2001-10-30
Classification: G01D,G07D

Abstract:
A magnetic sensor for detecting magnetic fields deriving from a magnetic body to detect any magnetic body on a non-magnetic body by moving relative to said non-magnetic body in prescribed relative moving directions along the surface of the non-magnetic body, comprising:a magnetizing magnet in which a line connecting the N and S poles thereof is a direction substantially orthogonal to, and of which one pole is a magnetizing side pole arranged either in contact with or in proximity to, the surface of said non-magnetic body; anda magnetism detecting element comprising two magnetic detectors arranged along a magnetic field detecting direction, said magnetic field detecting direction being orthogonal to said relative moving directions in a surface parallel to said surface of the non-magnetic body, whereinsaid magnetizing magnet and said magnetism detecting element are disposed along a line parallel to the relative moving directions, and whereinsaid magnetic body is magnetized by said magnetizing magnet along with the movement relative to said non-magnetic body, and magnetic fields according to the quantity of the magnetized part of the magnetic body are differentially detected by the two magnetic detectors of said magnetism detecting element.