Patent ID: 8366103

Claim:
A sheet post-processing apparatus that performs a post-process to a sheet delivered from an image forming apparatus and accumulated temporarily, the sheet post-processing apparatus comprising: a sheet conveying unit that conveys a sheet; a sheet accumulating feed path that is arranged on a downstream side of the sheet conveying unit in a sheet conveying direction and being capable of accumulating therein a plurality of sheets; a stopping member that stops a leading edge of a sheet conveyed into the sheet accumulating feed path; a width aligning unit that aligns a width of the sheet stopped by the stopping member and accumulated in the sheet accumulating feed path; a plurality of pressing members that are arranged at a position on the downstream side of the sheet conveying unit in the sheet conveying direction and arranged to be movable toward an upstream side or a downstream side in the sheet conveying direction along the feed path; and a control unit that performs control to cause: the sheet conveying unit to convey a sheet into the sheet accumulating feed path; the stopping member to stop the leading edge of the sheet; and the width aligning unit to align the width of a sheet every time a sheet is accumulated in the sheet accumulating feed path, wherein: the sheet conveying unit is arranged movably in the sheet conveying direction and conveys a sheet by nipping the sheet by a nip of a pair of rollers, the sheet post-processing apparatus further includes a driving unit that drives the sheet conveying unit to the upstream side or the downstream side in the sheet conveying direction, the plurality of pressing members that are arranged movably in synchronization with the sheet conveying unit, press down a trailing edge of the sheet stopped by the stopping member, and the control unit performs control to cause: the sheet conveying unit to move toward the upstream side in the sheet conveying direction to a position where the plurality of pressing members are away from the sheet after the trailing edge of the sheet passes through the nip of the pair of rollers, so that the sheet is conveyed into the sheet accumulating feed path; and the sheet conveying unit to move toward the downstream side in the sheet conveying direction to a position where the plurality of pressing members press down the trailing edge of the sheet toward the downstream side in the sheet conveying direction.