Patent ID: 8198886

Claim:
A magnetic detecting device for detecting bidirectional magnetic fields comprising: a first and a second magnetoresistive element using the magnetoresistive effect that changes the electric resistances thereof depending on an external magnetic field, the first and the second magnetoresistive element each including a pinned magnetic layer, a free magnetic layer, and a nonmagnetic conductive layer between the pinned magnetic layer and the free magnetic layer, thus acting as a giant magnetoresistive element whose electric resistance changes depending on the relationship between the magnetizations of the pinned magnetic layer and the free magnetic layer, the first and the second magnetoresistive element having the same layer structure as each other except that the nonmagnetic conductive layers have different thicknesses from each other, wherein a first interlayer coupling magnetic field acts between the free magnetic layer and the pinned magnetic layer of the first magnetoresistive element, a second interlayer coupling magnetic field acts between the free magnetic layer and the pinned magnetic layer of the second magnetoresistive element, and the thicknesses of the nonmagnetic conductive layers of the first and the second magnetoresistive element are set so that the first interlayer coupling magnetic field becomes positive and the second interlayer coupling magnetic field becomes negative; a first fixed resistor connected to the first magnetoresistive element in series and a second fixed resistor connected to the second magnetoresistive element in series, the first and the second fixed resistor having the same layer structure as each other, the first and the second fixed resistor having an electric resistance independent of the external magnetic field; wherein the first and second magnetoresistive elements each have the same direction in their magnetization directions of the pinned magnetic layers; and wherein the first and second magnetoresistive elements have opposite direction with each other in their magnetization directions of the free magnetic layers, under a condition of no external magnetic field.