ADF Unit
SM 7-27 D0CA/D0C9/D0C8/D0CB
7.2.5 DOUBLE-FEED DETECTION (OPTIONAL)
A pair of ultrasound sensors are mounted in the A D F, 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.