Image scanning device capable of obtaining at high speed a scanned image of high quality and appropriate magnification, image scanning method, image formation apparatus, and recording medium

摘要

An image scanning device includes a first scanner (141) scanning a top side of a transported document at a first scanning position (L1) to obtain a first scanned image, a second scanner (129) scanning the back side of the transported document at a second scanning position (L2) to obtain a second scanned image, a document feeder (63-70, 161) transporting a document at the second scanning position at a speed differing from the transportation speed at the first scanning position, and a controller (20) controlling the image scanning device. The controller sets, as a scanning form of a document, either one-side scanning of scanning one side of a document through one transportation, or dual-side scanning of scanning both sides of a document through one transportation. The controller also obtains a set magnification. The controller determines the transportation speed by the document feeder such that, when one-side scanning is set, the scanning magnification in a first direction corresponding to the document transportation direction at the first scanned image attains the set magnification, and when dual-side scanning is set, the scanning magnification in the first direction at the second scanned image attains the set magnification.