Multiple sheet detector apparatus and method

摘要

A detector for a deposit accepting apparatus of an automated banking machine includes an ultrasonic transmitter driven by a driving signal operative to cause the ultrasonic transmitter to transmit an ultrasonic sound signal through a sheet pathway of the detector. The detector also includes an ultrasonic receiver operative to generate a receiver signal responsive to the ultrasonic sound signal. The detector further includes first and second correlation filters. The first and second correlation filters are operative to generate first and second outputs responsive to the receiver signal. At least one processor is operative responsive to the first and second outputs of the correlation filters to determine information associated with changes in phase of the ultrasonic sound signal and to distinguish between single and multiple sheets in the pathway responsive to the information associated with changes in phase.