SPECIAL DOCUMENT DECISION DEVICE, IMAGE READER, AND SPECIAL DOCUMENT DECIDING METHOD AND COMPUTER-READABLE STORAGE MEDIUM STORED WITH PROGRAM IMPLEMENTING THE SAME METHOD

摘要

PROBLEM TO BE SOLVED: To detect metal fiber mixed with a document with invariably high precision. ;SOLUTION: This special document decision device is equipped with a microwave sensor 161 which outputs a 1st detection signal by irradiating a pressure plate with a microwave to make a scan before a document is mounted on contact glass and detecting the reflected wave of the irradiation microwave and also outputs a 2nd detection signal by scanning the document by irradiation with the microwave after the document is mounted on the contact glass and covered with the pressure plate and detecting the reflected wave of the irradiation microwave, a signal processing part 162 which decides whether or not metal fibers is mixed with the document by comparing the level of the 2nd detection signal with the 1st detection signal as a reference signal, and a control unit 180 which decides whether or not the document is a special document according to the decision result of the signal processing part 162.;COPYRIGHT: (C)1998,JPO