Ricoh MP C307 Field Service Manual page 541

ADF Unit
Double-feed Detection (Optional)
A pair of ultrasound sensors are mounted in the ADF, one below the original feed path (emitter [A]) and the
other above the path (receiver [B]).
•
When the original passes between the sensors, an ultra-sound wave from the emitter sensor below passes
through the paper to the receiver above.
•
The receiver converts the signal generated by the vibration of the signal against the paper to an electrical
pulse and checks its level.
•
If a double feed occurs, the space between the sheets will generate a lower signal. When the receiver
detects this lower signal (lower than that of a single sheet) it causes the machine to issue Jam Code J099
(double-feed detected) and then original feed stops.
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