| 摘要 |
PURPOSE:To detect a metallic piece effectively used to discriminate between the truth and fasehood of paper, etc., by detecting variation in resistance value of a magnetic resistance element with a magnetic field which varies when the metallic piece present in the paper, etc., passes in magnetic flux. CONSTITUTION:When paper currency P wherein a metallic piece 2 is present is carried and passed between detection heads 41 and 42, the distribution of a magnetic field 7 by permanent magnets 51 and 52 varies and the resistance values of magnetic resistance elements 61 and 62 also vary. Consequently, even when the metallic piece 2 is a magnetic material, its presence is detected securely. |
