| 摘要 |
A magnetic field generator is disposed on one surface side of a sheet-shaped object-to-be-detected (4) and contains a magnetic component. The magnetic field generator includes a first magnetic pole part that forms a first magnetic pole, and a second magnetic pole part that forms a second magnetic pole that has a reverse polarity of the first magnetic pole. The magnetic field generator generates a cross magnetic field that crosses the object-to-be-detected (4). An MR element (3) is disposed between the first magnetic pole part and the object-to-be-detected (4). The resistance value of the MR element (3) changes according to a change in a component of the cross magnetic field in a conveying direction. The position of the MR element (3) in the conveying direction is a position shifted along the conveying direction from the center position of the first magnetic pole part in the conveying direction, and located between both ends of the first magnetic pole part in the conveying direction. |
