Patent ID: 8159212

Claim:
A magnetic encoder comprising a magnetic medium having a certain curvature and a magnetic sensor, in which the magnetic sensor has a magnetic sensor element and a magnetic sensor holding mechanism for elastically holding the magnetic sensor element so as to oppose to the magnetic medium, the magnetic sensor element having a magnetoresistive element for detecting a magnetic field caused from the magnetic medium and capable of reciprocatively sliding relative to the magnetic medium, wherein the magnetic sensor holding mechanism includes two fixing portions provided on each side of the magnetic sensor holding mechanism so as to be located in a single flat surface, a rectangular sensor holding portion located on a flat surface in parallel to the flat surface where the two fixing portions are provided, for holding the-magnetic sensor element so as to oppose to the magnetic medium, and elastic arms each extending from an area in the vicinity of a vertex of the rectangular sensor holding portion so as to surround about a half of the periphery of the sensor holding portion and to be connected to a respective end portion of the respective fixing portion to thereby connect therebetween, and the elastic arm of the magnetic sensor holding mechanism imparts a torsion elasticity acting around an axis in the direction in which the magnetic medium reciprocatively slides, a torsion elasticity acting around an axis in the direction perpendicular to the direction in which the magnetic medium reciprocatively slides and in parallel to the surface of the magnetic medium, and an elastic force in the direction perpendicular to the surface of the magnetic medium, to the magnetic sensor element on the sensor holding portion toward the magnetic medium.