An image forming apparatus includes a stopper member supported either in a storage posture stored in a storage part by turning in an upstream side or a restriction posture to prevent falling down of a sheet from a sheet stacking face by turning in a downstream side. The storage part has a first recess and a second recess deeper than the first recess. The stopper member has a pressed part supported in the second recess movably upward and downward and a main part supported in the first recess in the storage posture. When the pressed part is pressed downward in the storage posture, the pressed part is moved downward and the main part comes into contact with a downstream side edge of the first recess, the stopper member is turned around the downstream side edge into the restriction posture through a protrusion posture protruding above the sheet stacking face.

A sheet processing apparatus arranged in a space between an image reading section for reading an image and an image formation section for forming an image on a sheet includes a carry-in path guiding a sheet from a carry-in entrance; a relay roller provided in the carry-in path to relay and transport the sheet; a first transport path positioned on a downstream side of the relay roller and having a carry-in roller to transport the sheet from the carry-in path to the first collection tray; and a second transport path branched from the carry-in path and having a branch roller to transport the transported sheet to the second collection tray. The relay roller shifts the sheet in a direction crossing the transport direction while a front end of the sheet enters the first transport path or the second transport path, and arrives at the carry-in roller or the branch roller.

A sheet processing apparatus arranged in a space between an image reading section for reading an image and an image formation section for forming an image on a sheet includes a carry-in path guiding a sheet from a carry-in entrance; a relay roller provided in the carry-in path to relay and transport the sheet; a first transport path positioned on a downstream side of the relay roller and having a carry-in roller to transport the sheet from the carry-in path to the first collection tray; and a second transport path branched from the carry-in path and having a branch roller to transport the transported sheet to the second collection tray. The relay roller shifts the sheet in a direction crossing the transport direction while a front end of the sheet enters the first transport path or the second transport path, and arrives at the carry-in roller or the branch roller.

A sheet stacking tray that includes a single pneumatic baffle which uses the pressure differential caused by the flow of air across a horizontal planar surface of the pneumatic baffle to hold the lead edge of sheets driven by an input nip into the sheet stacking tray above a stack especially for longer and lighter weight sheets as they are driven by the input nip to a registration wall.

According to an embodiment, a sheet post-processing apparatus according to the embodiment includes a paddle member and a controller. The paddle member rotates around a rotating shaft, presses a plurality of sheets held on a processing tray against a stopper and aligns ends of the sheets in a sheet transport direction. After the ends of the sheets in the sheet transport direction are aligned, the controller further rotates the paddle member, and stops rotation of the paddle member in a state that the paddle member comes in contact with the sheets held on the processing tray.

A sheet conveying apparatus includes: a conveyor configured to convey a sheet along a conveyance path; a discharge tray configured to support the sheet discharged from the conveyance path; a sheet presser movable toward and away from a support surface of the discharge tray and configured to press the sheet being discharged, onto the support surface; a first stopper configured to limit a spaced distance between the sheet presser and the support surface to a first distance when the first stopper is located at a first position, and configured to allow the spaced distance to become greater than the first distance when the first stopper is located at a second position; and a position change mechanism configured to change a position of the first stopper between the first position and the second position.

A sheet stacking tray that includes a single pneumatic baffle which uses the pressure differential caused by the flow of air across a cross process curved bottom surface of the pneumatic baffle to hold the lead edge of sheets driven by an input nip into the sheet stacking tray above a stack especially for longer and lighter weight sheets as they are driven by the input nip to a registration wall.

A sheet binding processing apparatus includes a conveying portion, a conveying path for sheets, a stacking portion on which sheets from the conveying path are stacked, a first regulating portion for regulating a sheet bundle on the stacking portion in a crossing direction, a second regulating portion for regulating a sheet bundle in the conveying direction, a manual setting portion for setting sheets from an outside of the apparatus, and a binding device which binds a sheet bundle by a staple and moves in the crossing direction. An angular posture of the binding device located at a third position is different from an angular posture located at a first position. An angular posture of the binding device located at the third position is different from an angular posture located at a second position. The second position is located at a second side of the first position.

A medium transport device includes a feeding unit that transports a medium, a stack portion that receives the medium transported by the feeding unit between a support surface for supporting the medium in an inclined posture in which a downstream side in a transport direction is directed downward and an opposing surface opposing the support surface and stacks the medium, an alignment portion that aligns a downstream end of the medium stacked in the stack portion, a paddle that is provided between the feeding unit and the alignment portion in the transport direction and moves the medium toward the alignment portion by rotating while being in contact with the medium, and a control unit that controls an operation of the paddle, in which the control unit controls the operation of the paddle according to a condition.

A medium transport device includes a feeding unit that transports a medium, a stack portion that receives the medium transported by the feeding unit between a support surface for supporting the medium in an inclined posture in which a downstream side in a transport direction is directed downward and an opposing surface opposing the support surface and stacks the medium, an alignment portion that aligns a downstream end of the medium stacked in the stack portion, a paddle that is provided between the feeding unit and the alignment portion in the transport direction and moves the medium toward the alignment portion by rotating while being in contact with the medium, and a control unit that controls an operation of the paddle, in which the control unit controls the operation of the paddle according to a condition.