Patent ID: 8773739

Claim:
An image reading device comprising: a conveying unit configured to convey a plurality of sheets one by one along a conveying path in a conveying direction, the conveying path having a reading position and a detection position upstream of the reading position in the conveying direction, each of the plurality of sheets having a leading edge and a trailing edge; a reading unit configured to read a sheet passing past the reading position, read data being acquired by the reading unit; a detecting unit configured to detect a sheet passing past the detection position; and a control unit configured to: control, based on a detection result of the detecting unit, the reading unit to start reading a sheet when the leading edge of the sheet reaches a position upstream of the reading position in the conveying direction by a first distance; control, based on the detection result of the detecting unit, the reading unit to stop reading the sheet when the trailing edge of the sheet reaches a position downstream of the reading position in the conveying direction by a second distance; determine an interspace between the trailing edge of the sheet and a leading edge of a subsequently-conveyed sheet that is conveyed subsequently to the sheet; and update the first distance and the second distance based on the interspace.