A sheet processing apparatus includes: a processing tray section having a sheet mounting surface on which a transported sheet is mounted and a processing section that performs processing on the sheet; a side edge alignment section that is provided on the processing tray section and aligns a side edge of the sheet; a lower support section that is provided downstream of the processing tray section in a transport direction of the sheet and supports the sheet from below; and a discharge tray located below the lower support section. The side edge alignment section performs a shift operation of shifting the sheet in a shift direction orthogonal to the transport direction of the sheet. The lower support section moves in the shift direction in conjunction with a movement of the sheet in a state of supporting the sheet from below during the shift operation by the side edge alignment section.

A medium discharge includes a first tray having a first medium receiving surface, a second tray having a second medium receiving surface for receiving the medium discharged from the first tray, a discharge section that discharges the medium disposed on the first tray to the second tray, and a push-down portion that is located downstream of a downstream end of the first medium receiving surface in the medium discharge direction, and that is located at a place deviated from the discharge section in a width direction that is a direction intersecting with the medium discharge direction, and pushes down a part of an upstream end of the medium to be discharged in the medium discharge direction.

A post-processing apparatus includes a post-processing device, an ejection device, and an ejection tray. The post-processing device executes post-processing on a medium on which an image is formed by an image forming apparatus. The ejection device ejects the medium on which the post-processing is executed by the post-processing device. The ejection tray holds the medium ejected by the ejection device. The ejection tray includes a main tray having an upper face inclined downward in an ejection direction, and a movable tray being rotatably supported by the main tray between a stacking position at which the medium ejected by the ejection device remains stacked on the upper face of the main tray and an ejection position at which the medium ejected by the ejection device slides along the upper face of the main tray.

According to one embodiment, a sheet post-processing device includes a first tray to receive sheets from an image forming unit, a second tray to receive sheets from the first tray, and a third tray to receive sheets from the second tray. The third tray is movable relative to the second tray. A bundle claw is configured to move sheets in a first direction from the second tray to the third tray. A controller is configured to move the third tray relative to the second tray according to the sheets on the second tray. Depending on various characteristics of the sheets on the second tray or the presence of sheets already on the third tray, the position of the third tray may be changed to reduce possible misalignments of sheets in the transfer from the second to third tray.

A medium discharging device includes a first tray, a second tray receiving a medium from the first tray, a supporter which is configured to be displaced from a retreat position in the first tray and an advance position above the second tray and which supports the medium, an aligner which is provided in the supporter and that aligns a first end portion which is an upstream end portion in a discharge direction of the medium supported by the supporter, to be displaced together with the supporter, and a restrictor configured to be displaced between a restriction position where an upstream movement of the first end portion of the medium in a position of the aligner in the discharge direction and a non-restriction position where the movement is not restricted, when the supporter is in the advance position.

There is provided a stacking apparatus capable of stably conveying and stacking sheets without occurrence of damage or buckling of the sheets in the structure of discharging the curled sheets one by one. In regard to each of a plurality of clamp guides which project toward stacking trays from conveyance means to guide sheets S, the projecting position varies in accordance with a size and an amount of stacked sheets Sa on the stack trays. The stacking tray comprises an inclined surface and a curved surface. An upper guide is located to face the inclined surface by a predetermined interval, and the upper guide is located not to face the curved surface or is located to face it by an interval larger than a predetermined interval.

A dual-stage rapid sheet stacking system is provided. In one embodiment, the dual-stage rapid stacker comprises a landing platform and a first actuator configured to control a vertical position of the landing platform. A vertical position sensor is configured to monitor the vertical position of the landing platform. A CPU is configured to receive a signal from the vertical position sensor and, in response to the received signal, to send a corresponding command to the first actuator such that the first actuator maintains a minimum sheet drop distance. A sliding catch tray unit, is mounted on a plurality of suspension rails. The dual-stage rapid sheet stacking system comprises a second actuator configured to receive commands from the CPU to control a horizontal position of the sliding catch tray unit. The dual-stage rapid sheet stacking system is configured to stack a plurality of sheets on the landing platform and then discharge, a plurality of sheets through the sliding catch tray unit.

According to an embodiment, a sheet processing apparatus includes a first tray, a second tray, a first member, and a second member. The first member presses a first portion of a sheet toward the second tray when the sheet is moved from the first tray to the second tray located below the first tray. The second member is interlocked with the first member, and when the sheet is moved from the first tray to the second tray, presses a second portion of the sheet toward the second tray, the second portion being located downstream of the first portion in a transport direction of the sheet to the first tray.

A sheet discharging device includes: a medium supporting portion configured to support a transported medium, the medium supporting portion being configured to swing; a stacking portion which is provided vertically below the medium supporting portion and on which the medium dropped from the medium supporting portion is stacked, the stacking portion being configured to move up and down; and a detecting portion that detects swinging of the medium supporting portion, in which the detecting portion detects the swinging of the medium supporting portion when the medium on the rising stacking portion comes into contact with a lower surface of the medium supporting portion.

A discharging device includes: a pair of medium supporting portions that are provided so as to face each other in a width direction intersecting a transporting direction in which a medium is transported and that support the medium that is transported; and a stacking portion that is provided vertically below the pair of medium supporting portions and on which the medium that drops from the pair of medium supporting portions is stacked, each of the pair of medium supporting portions is configured to move in the width direction, the pair of medium supporting portions are configured to be arranged, after the medium is dropped onto the stacking portion, at positions at which a distance in the width direction becomes a predetermined distance, and the predetermined distance varies in accordance with a width of the medium stacked on the stacking portion.