A sheet stacking system includes a conveyor for carrying sheets from a conveyor intake end to a conveyor discharge end and a hopper at the discharge end for receiving the sheets and guiding them as they fall in a cascade path onto a platform. The hopper has a backstop facing the discharge end of the conveyor and a first accumulator that includes a carrier and a support extending from the carrier through the backstop. The support is configured to rotate from a retracted position to an extended position relative to the backstop, and the carrier is movable linearly and vertically relative to the backstop with the support in the extended position from a raised location with the support outside the cascade path to a lowered location with the support in the cascade path.

In accordance with an embodiment, a sheet processing apparatus comprises a first tray, a second tray, a third tray, a lower supporting plate, a drive section and a control device. The second tray is located at the lower part of the first tray. The third tray is located at a downstream side with respect to the second tray in a sheet conveyance direction. The lower supporting plate can support the sheet from the lower part. The drive section drives the lower supporting plate. The control device controls the drive section to arrange the lower supporting plate at the downstream side with respect to a conveyance starting point of the sheet in the sheet conveyance direction in a case of skipping the first tray and the second tray to convey the sheet to the third tray.

A media stacker may comprises a stacking platform; and a pair of a guiding tracks above the stacking platform and extending from a media receiving side of the media stacker in a media advance direction along opposite sides of a media transport path; wherein at least one guiding track of the pair of guiding tracks is movable between a support position and a release position to guide and support the media sheet above the stacking platform and to release the media sheet to drop from the guiding track to the stacking platform.

A media stacker may comprises a stacking platform; and a pair of a guiding tracks above the stacking platform and extending from a media receiving side of the media stacker in a media advance direction along opposite sides of a media transport path; wherein at least one guiding track of the pair of guiding tracks is movable between a support position and a release position to guide and support the media sheet above the stacking platform and to release the media sheet to drop from the guiding track to the stacking platform.

In accordance with an embodiment, a sheet processing apparatus comprises an axis of rotation; a standby section configured to buffer a sheet; a processing section configured to execute a post processing on sheets moved from the standby section; a first paddle configured to be mounted in the axis of rotation and be rotated around the axis of rotation to contact with the sheet supplied from the standby section to draw the sheet into a stopper; and a second paddle configured to be mounted in the axis of rotation at a predetermined angle with respect to the first paddle and draw the sheet into the stopper after the first paddle is separated from the sheet after a drawing-in operation of the sheet by the first paddle.

In accordance with an embodiment, a sheet processing apparatus comprises an axis of rotation; a standby section configured to buffer a sheet; a processing section configured to execute a post processing on sheets moved from the standby section; a first paddle configured to be mounted in the axis of rotation and be rotated around the axis of rotation to contact with the sheet supplied from the standby section to draw the sheet into a stopper; and a second paddle configured to be mounted in the axis of rotation at a predetermined angle with respect to the first paddle and draw the sheet into the stopper after the first paddle is separated from the sheet after a drawing-in operation of the sheet by the first paddle.

According to an embodiment, a sheet processing apparatus includes a first tray, a second tray, a discharge member, and a guide. The guide is provided to the second tray and changes a transport angle of sheets with respect to the second tray when the sheets are sent from a transport path toward the discharge member without passing through the first tray.

According to an embodiment, a sheet processing apparatus includes a first tray, a second tray, a discharge member, and a guide. The guide is provided to the second tray and changes a transport angle of sheets with respect to the second tray when the sheets are sent from a transport path toward the discharge member without passing through the first tray.

In accordance with an embodiment, a sheet processing apparatus comprises a first tray, a second tray, a third tray, a lower supporting plate, a drive section and a control device. The second tray is located at the lower part of the first tray. The third tray is located at a downstream side with respect to the second tray in a sheet conveyance direction. The lower supporting plate can support the sheet from the lower part. The drive section drives the lower supporting plate. The control device controls the drive section to arrange the lower supporting plate at the downstream side with respect to a conveyance starting point of the sheet in the sheet conveyance direction in a case of skipping the first tray and the second tray to convey the sheet to the third tray.

A post-processing apparatus includes an ejection tray receiving a recording medium that is ejected, an elastic member urging the ejection tray upward in a vertical direction, a moving mechanism causing the ejection tray to move up and down in the vertical direction, and a driving source driving the moving mechanism.