Patent ID: 7378839

Claim:
A magnetic encoder comprising: a magnetic medium extending in a direction and having first magnetized regions and second magnetized regions, which are disposed successively and alternately with each other on the medium and magnetized oppositely to one another along the medium extending and have different length from one another, and of which longer ones have a length λl and shorter ones have a length λs, and a magnetic sensor, which has an even number of SVGMR elements having a rectangular surface extending perpendicularly to the medium extending and facing the medium with a predetermined gap, and is movable relatively to the medium along the medium extending, wherein each of the even number of SVGMR elements is apart by a length λ defined by (λl+λs)/2 from each other along the medium extending, wherein each of the SVGMR elements is a lamination of a pinned magnetization layer, a non-magnetic conductive layer and a free magnetization layer in that order, the pinned magnetization layers in all of the SVGMR elements have magnetizations in a same direction along the medium extending, and the SVGMR elements show a minimum electric resistance, when an external magnetic field is applied to the SVGMR elements in the same direction as the magnetizations of the pinned magnetization layers of the SVGMR elements, and a maximum electric resistance, when an external magnetic field is applied to the SVGMR elements in a direction opposite to the magnetizations of the pinned magnetization layers of the SVGMR elements, and wherein the even number of SVGMR elements are electrically connected in series, and a signal output is taken out from electric terminals of the electrically connected SVGMR elements.