| 摘要 |
PROBLEM TO BE SOLVED: To stably determine double feeding even if the timing of becoming maximum in ultrasonic wave receiving strength is varied. SOLUTION: A CPU 102A acquires amplitude information of an ultrasonic wave received signal by sampling the ultrasonic wave received signal output from an ultrasonic wave receiving part 104 in a plurality of timings (a plurality of front-rear timings (TA, TB and TC) including the timing (TA) predicted that the ultrasonic wave receiving strength becomes maximum) based on the transmission timing (T0) of an ultrasonic wave by an ultrasonic wave transmission part 103, and determines whether or not a sheet-like member is doubly fed based on the amplitude information on the ultrasonic wave received signal sampled in the plurality of timings and a predetermined threshold value. COPYRIGHT: (C)2011,JPO&INPIT |
