Patent ID: 7862025
Filing Date: 2011-01-04
Classification: B42C,B65H

Abstract:
1. A sheet post-processing apparatus comprising: a processing tray that receives sheets subjected to image formation from an image forming apparatus; a sheet discharge tray that stacks the sheets discharged after processing in a post process; and a sheet aligning device having: a vertical aligning device that aligns the sheets conveyed to the processing tray in a conveying direction, a horizontal aligning device comprising a first horizontal aligning plate and a second horizontal aligning plate that align the sheets conveyed to the processing tray in a direction perpendicular to the conveying direction, and a control unit that controls a first horizontal aligning operation by moving the first horizontal aligning plate and the second horizontal aligning plate to a standby position which corresponds to the width of the sheets conveyed thereto, controls a second horizontal aligning operation by reciprocating the first horizontal aligning plate and by fixing the second horizontal aligning plate, and increases, in subjecting the sheets to staple processing, when a number of the sheets conveyed thereto exceeds a predetermined number, a number of times of the second horizontal aligning operation or the aligning operation of the vertical aligning device to be larger than a number of times of the second horizontal aligning operation or the aligning operation of the vertical aligning device at a number of sheets equal to or smaller than the predetermined number of sheets.