Patent ID: 8434753
Filing Date: 2013-05-07
Classification: B26D,B26F,B65H,G03G

Abstract:
1. A sheet processing apparatus comprising: a conveying portion which conveys a sheet; a pair of shift rollers which nips and conveys the sheet conveyed by the conveying portion and is capable of moving in a sheet width direction orthogonal to a sheet conveying direction to move the sheet in the sheet width direction; a moving portion which moves the pair of shift rollers in the sheet width direction; a punching portion which punches a hole at an upstream end portion of the sheet in the sheet conveying direction; a pressing portion which presses an upstream end of the sheet in the sheet conveying direction; and a controller configured to control a skew correction operation and a punch positioning operation so that after a first loop is formed on the sheet to correct skew of the sheet while the sheet is conveyed by the conveying portion with its downstream end in the sheet conveying direction abutted against the pair of shift rollers, the pair of shift rollers conveys the sheet to release the first loop, and then the pressing portion presses an upstream end of the sheet, nipped by the pair of shift rollers, in the sheet conveying direction to correct skew of the sheet by forming a second loop on the sheet and to position the upstream end of the sheet with reference to the punching portion after the moving portion moves the pair of shift rollers in the sheet width direction to correct lateral registration of the sheet.