Patent ID: 8253988

Claim:
An image reading apparatus comprising: a scanning unit that scans one line of an original in a main scanning direction to collect a reflected light; a photoelectric converter that converts the reflected light collected at the scanning unit to image data; a storage unit that temporarily stores therein the image data; an original moving unit that moves the original at a predetermined rate in a sub-scanning direction perpendicular to the main scanning direction; a scanner moving unit that moves the scanning unit in parallel to the sub-scanning direction; and a control unit that controls operations of the scanning unit, the photoelectric converter, the storage unit, the original moving unit, and the scanner moving unit, wherein the control unit, when scanning of the original is to be interrupted because of running out memory space for image data in the storage unit, controls the original moving unit to decelerate the original and then stop the original, the scanner moving unit to move the scanning unit by a sum of a distance from decelerating the original to stopping from a standby position in the sub-scanning direction and an acceleration distance in which the original is accelerated to a read rate, and then controls the scanning unit to scan the original while the scanner moving unit is moving the scanning unit in a direction opposite to the sub-scanning direction at a rate required for reading, and the scanner moving unit to return the scanning unit to the standby position after scanning of the original is finished, the control unit, when scanning of the original is to be restarted when memory space for image data becomes available in the storage unit, controls the original moving unit to accelerate the original to the rate required for reading and controls the scanner moving unit to move the scanning unit to scan the original.