| 摘要 |
PROBLEM TO BE SOLVED: To provide a remanent magnetism removing method and device for business forms to improve the reliability of the image pattern detection on the business forms enclosed in envelopes by reducing the effects of remanet magnetism on business forms. SOLUTION: The remanent magnetism removing device for business forms removes the remanent magnetism on the business forms 10a, 10b, 10c, ... having image patterns 12a, 12b, 12c, ... formed with ink or toner containing magnetic material at predetermined locations. It comprises a magnetizing unit 4 which generates a 1st magnetic field in a certain direction with an intensity matching the saturation magnetic flux density or higher in the magnetization curve of the image patterns 12a, 12b, 12c, ... and passes the business forms 10a, 10b, 10c, ... through this 1st magnetic field, and a demagnetizer 5 which generates an alternating magnetic field gradually changing from the intensity matching the saturation magnetic flux density of the magnetization curve down to zero and passes the business forms 10a, 10b, 10c, ... through this alternating magnetic field. COPYRIGHT: (C)2006,JPO&NCIPI
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