Patent ID: 6175296
Filing Date: 2001-01-16
Classification: G01D

Abstract:
A potentiometer comprising a plurality of giant magnetoresistive effect elements that contain exchange bias layers, pinned magnetic layers whose orientations of magnetization axes are fixed in one direction by the exchange bias layers, non-magnetic layers, and free magnetic layers whose orientations of magnetization axes are freely rotated by an external magnetic field;said plurality of giant magnetoresistive effect elements formed on a substrate, said elements electrically connected with each other such that a differential output from said elements is obtained; anda rotatable magnetic coding member disposed opposite to the giant magnetoresistive effect elements on said substrate, said magnetic coding member disposed such that a line passes through an intermediate position of the giant magnetoresistive effect elements, said line extending from a neutral point of said magnetic coding member and parallel to a central axis of rotation of said magnetic coding memberwherein, of the plurality of giant magnetoresistive effect elements, first and second giant magnetoresistive effect elements are disposed along a first straight line, each of the first and second giant magnetoresistive effect elements having the orientation of magnetization of the pinned magnetic layer magnetized in a predetermined orientation orthogonal to the first straight line,third and fourth giant magnetoresistive effect elements are disposed along a second straight line parallel with the first straight line, each of the third and fourth giant magnetoresistive effect elements having the orientation of magnetization of the pinned magnetic layer magnetized in an orientation 180 degrees opposite from the predetermined orientation, andthe first, second, third and fourth giant magnetoresistive effect elements are sequentially connected to form a Wheatstone bridge.