PURPOSE: To prevent paper breakage or rupture of a target by connecting a paper clip control part for releasing paper clipping of the target near a split to a split sensing part having a light switch.

CONSTITUTION: A target 22 for scanning paper in the width direction thereof and measuring paper quality and a light switch 24 for determining whether the target is on the paper or not are installed. A ghost produced when a split is present in the paper and the split width is narrower than the interval of the optical switch is sensed with a split sensing part 26. When the light switch determines a state of the target on the paper in a paper clipping mode, a command of the paper clipping is issued with a paper clip control part 32. When the ghost occurs, the paper clipping is released.