6.5 Double-feed Detection Conditions
fi-4220C Image Scanner Operator’s Guide 95
ADF AND PAPER SPECIFICATION
6
6.5 Double-feed Detection Conditions
There are three double-feed detection modes: document thickness, document length, and both doc-
ument thickness and length. The following conditions must be satisfied in each of these detection
modes.
■ Detection by Document Thickness
Sheets of the same thickness shall be set in the ADF at a time.
• Document thickness: 0.065 to 0.15mm
• Printed area: 12% or less
• No black printed areas are allowed at the center area (26 x 10mm) at the leading edge of the
document.
• Punched holes are not allowed within 35mm of the vertical center line of the document.
• The deviation in the amount of the light transmitted through background areas must not be
less than 10%.
■ Detection by Document Length
Sheets of the same length shall be set in the ADF at a time.
• Document length deviation: 1% or less
• Punched holes are not allowed within 35mm of the vertical center line of the document.
■ Detection by Document Thickness and Length
Sheets of the same thickness and length shall be set in the ADF at a time.
• Document thickness: 0.065 to 0.15mm
• Document length deviation: 1% or less
• Printed area: 12% or less
• No black printed areas are allowed at the center area (26 x 10mm) at the leading edge of the
document.
• Punched holes are not allowed within 35mm of the vertical center line of the document.
• The deviation in the amount of the light transmitted through background areas must not be
less than 10%.