Multiple sheet detector apparatus and method
View Patent ↗A detector for a deposit accepting apparatus of an automated banking machine or for another sheeting handling system 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.
1. An article bearing processor readable instructions operative to cause at least one processor to cause at least one apparatus to carry out a method comprising:
a) directing a sound signal through a pathway through which sheet media moves;
b) acquiring at least one receiver signal responsive to the sound signal, wherein at least a portion of the at least one receiver signal is produced responsive to the sound signal after having passed through the sheet media moving in the pathway;
c) producing a first output representative of changes in phase of the at least one receiver signal relative to a first reference signal;
d) producing a second output representative of changes in phase of the at least one receiver signal relative to a second reference signal, wherein the first and second reference signals differ in phase;
e) acquiring a plurality of samples of the first and second outputs;
f) comparing the samples of the first and second outputs to determine information corresponding to changes in phase of the sound signal after having passed through the sheet media;
g) responsive to (f), moving the sheet media with at least one transport.
2. The article according to claim 1 , wherein (e) includes: acquiring a first pair of output values associated with a first sample of the first and second outputs; and acquiring a second pair of output values associated with a second sample of the first and second outputs, wherein the second sample follows the acquisition of the first sample in time, wherein (f) includes comparing the second pair of samples and the first pair of samples.
3. The article according to claim 1 , wherein in (c) and (d) the first and second reference signals differ in phase by ninety degrees.
4. The article according to claim 1 , wherein in (c) and (d) the first and second reference signals differ in phase by substantially ninety degrees.
5. The article according to claim 1 , wherein (f) includes determining information representative of a change in a phase of the sound signal that is more than 180 degrees.
6. The article according to claim 1 , wherein (f) includes determining information representative of whether the sheet media in the pathway corresponds to at least one of a single sheet and multiple sheets.
7. The article according to claim 1 , further comprising:
h) determining changes in amplitude in the sound signal;
wherein (g) includes: responsive to (f) and (g), moving the sheet media with at least one transport.