DOUBLE FEEDING DETECTION DEVICE FOR SHEET MATERIAL AND IMAGE FORMATION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a double feeding detection device capable of improving detection precision of a double feeding detection sensor of ultrasonic type and to provide an image formation device having an intersheet function to detect effectively double feeding per type of paper. SOLUTION: This double feeding detection device is constituted in such a way that it sets a first threshold value set on a side close to a reception signal value at the time of normal conveyance between a reception signal value at the time of double feeding of sheet materials and the reception signal value at the time of normal conveyance and a second threshold value set on a side close to the reception signal value at the time of double feeding, compares a reception signal outputted continuously by an ultrasonic receiver with the first threshold value or the second threshold value selected from a storage means, and determines that double feeding occurs when there is a reception signal exceeding the second threshold value after determining that there is a reception signal exceeding the first threshold value from among the reception signals. COPYRIGHT: (C)2005,JPO&NCIPI