Canon DR-5010C - Manual (Page 62)

60 Using the Scanner
Other Functions
The scanner is equipped with a function that stops the scanner when it detects
documents that are not fed correctly.
Double Feed Detection Function
The scanner is equipped with a Double Feed Detection function that
automatically detects when two or more documents are fed at the same time
(double feed) while doing continuous scanning.
There are two methods for multiple feed detection as shown below, the
detection method is selected by the ISIS/TWAIN driver.
Detecting Double Feed by Document Length
This function uses the length of the first document as the standard, and then
detects a multiple scan and stops scanning when a document is 1.96" (50
mm) longer or shorter than the standard.
Detecting Double Feed with Ultrasonic Waves
This function uses ultrasonic waves to detect the gap between two pages of
a document to determine that multiple documents have been fed and then
stops scanning.
Note
• Ultrasonic double feed detection works when the documents overlap by
1.96" (50 mm) or more.
• If the documents are stuck together with static electricity, the ultrasonic
double feed detection will not correctly detect them as a double feed.
Skew Detection Function
If long documents are skewed, then they may rub against the feed slot or the
edges of the feed path and be damaged. The scanner is equipped with a Skew
Detector function that detects when a skewed document hits the edge of the
feed slot. When a skewed document is detected, an error message is displayed
and scanning stops.
Note
Small documents are not detected by the sensor even if they are skewed.