One method used in conventional image-processing devices to ensure that a sheet present on the conveying path is properly discharged in such situations is to always rotate the conveying rollers a fixed amount when the operating state of the device stored in the nonvolatile memory indicates that the device was in the process of executing a reading operation. However, a device having this construction does not know the last position of the sheet before the power was interrupted. Therefore, the device must rotate the conveying rollers the maximum distance required to discharge a sheet from the conveying path when the sheet is positioned near the entrance to the conveying path in order to reliably discharge a sheet positioned anywhere along the conveying path. Consequently, when the sheet is positioned closer to the exit of the conveying path, for example, the conveying rollers will continue to be rotated unnecessarily after the sheet has been discharged.