| 摘要 |
PROBLEM TO BE SOLVED: To provide a device for detecting magnetic materials, which can obtain an accurate magnetic signal by eliminating the residual magnetic influence, since the accurate magnetic signal can not be detected because size and polarity of residual magnetism change due to the magnetic field strength and the polarity if the magnetic sheet material is made from ferromagnetic material and magnetized through an unintentional cause. SOLUTION: The device for detecting the magnetic materials arranges a permanent magnet 12 as a means for generating the direct current magnetic field, as well as a magnetic detecting unit 13 comprising a primary winding 16 and a secondary winding 17, along with a direction of magnetic sheet transportation, in order of the direct current magnetic field generator 12 and the magnetic detecting unit 13. The device applies the alternating current to the primary winding 16 and the saturated magnetic field to the magnetic sheet material and also detects the magnetic signal with the secondary winding 17 of the magnetic detecting unit 13. COPYRIGHT: (C)2004,JPO
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