Restart shifting in the scanned image data is minimized and the resulting image quality is improved even when scanning pauses and resumes. A dot impact printer 10 issues a command to stop media conveyance when available capacity in the image buffer 41A goes below a stop buffering level, and continues scanning by the scanner 111, 112 until a conveyance stop delay period passes and then stops scanning. When the available capacity exceeds a resume buffering level after the conveyance stop delay period has passed, the dot impact printer 10 applies a command to resume media transportation and scanning, prohibits storing the scanned image data from the scanners 111, 112 until a resume drive delay time passes, and resumes storing data after the resume drive delay time passes.