Abstract:
One object is to correct with a high accuracy a plurality of magnetic sensors arranged inside a small magnetic detection apparatus. The magnetic detection apparatus that detects magnetism of a paper sheet being transported includes a plurality of magnetic sensors arranged in a linear manner in a direction orthogonal to a transport direction of the paper sheet; an excitation member having a plate-shape that extends in an arrangement direction of the plurality of magnetic sensors; and a control unit that generates a calibration magnetic field by passing an electric current in the arrangement direction through the excitation member, and obtains a correction value for correcting variation in sensitivity of the plurality of magnetic sensors based on detection results of the calibration magnetic field detected by the plurality of magnetic sensors.
Abstract:
A magnetic property determination apparatus that detects a magnetic property of each magnetic material included in a paper sheet transported through a transport path and determines the magnetic materials. The magnetic property determination apparatus includes a magnetic detection unit that generates on the transport path a bias magnetic field having a magnetic field direction inclined to a transport surface of the paper sheet by a specific angle and detects the magnetic charge of the magnetic materials by detecting variation of the bias magnetic field; and a magnetization unit that is arranged upstream of the magnetic detection unit in the transport direction and magnetizes the magnetic materials by generating on the transport path a magnetization magnetic field having a magnetic field direction oriented in a direction different from the direction of the bias magnetic field. At a position at which the magnetic detection unit detects the magnetism, the magnetic materials are in a state in which the magnetic materials are magnetized in mutually different magnetization directions according to coercive force thereof.