Sheet finisher for an image forming apparatus

摘要

A sheet finisher for an image forming apparatus of the present invention includes a conveying device for conveying a sheet and a punch unit for punching the sheet being conveyed by the conveying device. A sheet edge sensor senses the edge of the sheet, which is being conveyed by the conveying device, parallel to the direction of sheet conveyance. A drive source moves the sheet edge sensor in a direction perpendicular to the direction of sheet conveyance. Another drive source moves the punch unit in the direction perpendicular to the direction of sheet conveyance in accordance with information output from the sheet edge sensor. A controller controls the two drive sources.