A pair of ultrasound sensors is 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 ultrasound wave from the emitter-sensor below pass 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.

This double feed detection will not function with originals that have:

  • Folds, wrinkles, tears
  • Holes
  • Imperfectly fused images
  • Perforations
  • Taped connections
  • Taped surfaces

Feeding such originals could cause false detection of double-feeds.

The service technician can also switch double-feed detection off/on with SP6-040-001 (Page Keeper: Mount Select, Default 0: Off).

Do not change the settings of SP6-040-005 (Page Keeper: Clear Select).