| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique capable of detecting multi-feed of manuscripts and issuing an alarm even when a force converter is not provided.SOLUTION: When a manuscript to be read is detached from a manuscript tray and arrives at a transport roller, an image reading device stores a reaction force estimation value R for a predetermine period of time corresponding to a multi-feed determination section determined with the arrival time as a reference (S120). The reaction force estimation value R is an estimated value of the reaction force from the manuscript which acts on the motor for driving the roller pair to hold and transport the manuscript. The image reading device calculates the average value RA of reaction force estimation values R for the section (S130). When the average value RA is equal to or more than a threshold value TH (Yes for S140), the image reading device determines that multi-feed of manuscripts has occurred, and sounds an alarm (S150). When the average value RA is less than the threshold value TH (No for S140), the image reading device does not sound an alarm. |
