| 摘要 |
<P>PROBLEM TO BE SOLVED: To perform magnetic inspection accurately and stably even if great variation occurs in a signal level of magnetism. <P>SOLUTION: Magnetic information 13a constituted of signal values obtained by scanning a large size printed matter by a magnetic head 11a is previously stored in a storing unit 13. A minimum value retrieval unit retrieves a non-magnetic signal value based on a minimum value from the magnetic information 13a as a reference value. A threshold determination unit 12d determines an extract range constituted of upper and lower limit threshold values by using the reference value. An approximate curve calculation unit 12e calculates an approximate curve by using the signal values within the extract range. A correction processing unit 12f performs correction processing by subtracting a value of the approximate curve from a total signal value. A magnetic inspection unit 12g performs magnetic inspection by using the corrected signal value. <P>COPYRIGHT: (C)2013,JPO&INPIT |
