Postprocessing apparatus, and image forming apparatus and image forming system including the postprocessing apparatus

An image forming apparatus comprising a postprocessing apparatus, wherein the postprocessing apparatus comprises:

• a stacking unit configured to stack and process a sheet;
• an abutting unit that is provided on the stacking unit and configured to abut a rear end of the sheet to correct a conveying direction of the sheet;
• a conveying unit comprising a rotating body that conveys the sheet to abut the sheet against the abutting unit on the stacking unit;
• a shift conveying unit that is provided at an upstream side of the stacking unit and configured to shift the sheet in a width direction and conveys the sheet;
• and
• a width direction detector configured to detect a width direction position of the sheet, wherein
• when the sheet is shifted by the shift conveying unit by a predetermined amount until a side of the sheet is detected by the width direction detector, conveyed onto the stacking unit, passed to the conveying unit, and abutted against the abutting unit, distances A and B are nearly the same, where the distance A is a distance from a conveying direction position of the side of the sheet detected by the width direction detector to the rear end of the sheet and the distance B is a distance from the conveying unit on the stacking unit to the abutting unit.

An image forming system comprising a postprocessing apparatus, wherein the postprocessing apparatus comprises:

• a stacking unit configured to stack and process a sheet;
• an abutting unit that is provided on the stacking unit and configured to abut a rear end of the sheet to correct a conveying direction of the sheet;
• a conveying unit comprising a rotating body that conveys the sheet to abut the sheet against the abutting unit on the stacking unit;
• a shift conveying unit that is provided at an upstream side of the stacking unit and configured to shift the sheet in a width direction and conveys the sheet;
• and
• a width direction detector configured to detect a width direction position of the sheet, wherein
• when the sheet is shifted by the shift conveying unit by a predetermined amount until a side of the sheet is detected by the width direction detector, conveyed onto the stacking unit, passed to the conveying unit, and abutted against the abutting unit, distances A and B are nearly the same, where the distance A is a distance from a conveying direction position of the side of the sheet detected by the width direction detector to the rear end of the sheet and the distance B is a distance from the conveying unit on the stacking unit to the abutting unit.