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IMPORTANT
• When a double feed is detected, documents already fed through
the feed inlet are transported to the eject outlet, and operation
stops.
• The message that appears when a double feed is detected
depends on the Rapid Recovery System setting specified in the
ISIS/TWAIN driver.
See “When the Rapid Recovery System is
for details.
• Double feed detection in the Count-Only mode is set in the User
Mode, and double feeds are detected ultrasonically.
Feed Control Setting” on p. 79.)
Detecting Double Feeds by Document Length
This detection method is effective when scanning documents with
pages of the same size. The length of the first page scanned serves
as a standard for comparing subsequent pages, and when a page is
detected to be approximately two inches (50 mm) longer or shorter
than the standard, a double feed is detected and document transport
is stopped.
Ultrasonic Double-Feed Detection
This detection method is effective when scanning documents with
pages of different sizes. The space between overlapping pages is
detected ultrasonically, and document transport stops when a double
feed is detected.
IMPORTANT
• Ultrasonic double-feed detection works only when the document
pages overlap by at least two inches (50 mm).
• If documents stick together due to static electricity, Ultrasonic
Double-Feed Detection may not function correctly.
• If the presence of adhesive notes or labels on pages is detected as
a double feed and you do not want to remove them for scanning, a
non-detection zone can be specified in the ISIS/TWAIN driver
settings.
Double-Feed Retry
When a double feed is detected with Ultrasonic double-feed detection,
this function transports the double fed pages back to the feeder inlet
and tries scanning again. You can set this function from the User
Mode.
(See “Double-Feed Retry Setting” on p. 79.)
Skew Detection Function
If a long document page becomes skewed as it is fed, the page may
press against the edge of the feed inlet or transport path and be
damaged.
Ultrasonic Double-Feed
Detection Sensor