According to one embodiment, a sheet post-processing apparatus has a sheet discharge tray, a drive motor, a power transmission breaker, a first power transmitter, a second power transmitter, and a load reducer. The sheet discharge tray stacks sheets. The drive motor raises and lowers the sheet discharge tray. The power transmission breaker can cut off power transmission from the drive motor to the sheet discharge tray when an upward external force is applied to the sheet discharge tray. The load reducer provides a reverse load to the sheet discharge tray in a reverse direction to the load generated on the sheet discharge tray due to stacking of the sheets. The load reducer is connected to the first power transmitter.

A sheet discharging apparatus includes an apparatus body, a sheet discharge member provided in the apparatus body, and a movable tray including a sheet supporting surface. A movable member in the movable tray is moved by being pressed by the sheet supported on the sheet supporting surface, and a detecting portion detects a presence of the sheet supported on the sheet supporting surface in response to a position of the movable member. The movable member includes an extension portion extending out of the movable tray toward the apparatus body, and the apparatus body is provided with an opening portion through which the extension portion extends. The opening portion is formed such that the extension portion is movable along a moving direction of the movable tray within the apparatus body, and the detecting portion detects a position of the movable member by detecting the extension portion.

A medium discharge device includes a discharge roller pair that is provided with a discharge driving roller and a discharge driven roller which drivably rotates in contact with the discharge driving roller, and a medium receiving tray which receives the medium that is fed and discharged by the discharge roller pair, in which the medium receiving tray includes a guide member which guides such that a tip end of the medium which is discharged from the discharge roller pair enters the medium mounting surface at a predetermined angle, and the guide member is provided to be elastically displaceable in an advancing and retreating direction with respect to the medium mounting surface of the medium receiving tray and is displaced in a direction coming close to the medium mounting surface according to raising of a pressing load due to the medium that is discharged to the medium receiving tray.

A medium discharge device includes a discharge roller pair that is provided with a discharge driving roller and a discharge driven roller which drivably rotates in contact with the discharge driving roller, and a medium receiving tray which receives the medium that is fed and discharged by the discharge roller pair, in which the medium receiving tray includes a guide member which guides such that a tip end of the medium which is discharged from the discharge roller pair enters the medium mounting surface at a predetermined angle, and the guide member is provided to be elastically displaceable in an advancing and retreating direction with respect to the medium mounting surface of the medium receiving tray and is displaced in a direction coming close to the medium mounting surface according to raising of a pressing load due to the medium that is discharged to the medium receiving tray.

A sheet discharging device has a discharge roller pair and a sheet discharge tray arranged selectively either in a first position where the sheet discharge tray is stowed along a side surface of an apparatus main body or in a second position where the sheet discharge tray, swung downward from the first position, protrudes beyond the side surface. The sheet discharge tray has a hook member holding, with one of rotation shafts of the discharge roller pair acting as an engagement shaft, the sheet discharge tray in the first position by engaging with the engagement shaft. As a result of the discharge roller pair being rotated with the sheet discharge tray located in the first position, an engagement releasing member fixed to the engagement shaft releases the engagement of the hook member with the engagement shaft, and the sheet discharge tray moves to the second position.

A post-processing apparatus includes a storing unit in which plural recording media are stored for performing post-processing and a transport member that transports a recording medium to the storing unit as a result of rotating while being in contact with a surface of the recording medium. The transport member includes a blade that comes into contact with a recording medium and a reinforcing portion that reinforces a strength of a portion of the blade that does not come into contact with the recording medium.

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.

A medium discharge device includes a discharge roller pair that is provided with a discharge driving roller and a discharge driven roller which drivably rotates in contact with the discharge driving roller, and a medium receiving tray which receives the medium that is fed and discharged by the discharge roller pair, in which the medium receiving tray includes a guide member which guides such that a tip end of the medium which is discharged from the discharge roller pair enters the medium mounting surface at a predetermined angle, and the guide member is provided to be elastically displaceable in an advancing and retreating direction with respect to the medium mounting surface of the medium receiving tray and is displaced in a direction coming close to the medium mounting surface according to raising of a pressing load due to the medium that is discharged to the medium receiving tray.

A medium discharge device includes a discharge roller pair that is provided with a discharge driving roller and a discharge driven roller which drivably rotates in contact with the discharge driving roller, and a medium receiving tray which receives the medium that is fed and discharged by the discharge roller pair, in which the medium receiving tray includes a guide member which guides such that a tip end of the medium which is discharged from the discharge roller pair enters the medium mounting surface at a predetermined angle, and the guide member is provided to be elastically displaceable in an advancing and retreating direction with respect to the medium mounting surface of the medium receiving tray and is displaced in a direction coming close to the medium mounting surface according to raising of a pressing load due to the medium that is discharged to the medium receiving tray.

A sheet feeder includes an apparatus main body, a sheet housing unit, and a sheet feeding unit. The sheet housing unit includes a housing space, a lift plate, an elevating mechanism, and a side fence. The elevating mechanism includes a pair of first wires, a pair of second wires, first pulleys, second pulleys, a reel, and a pair of first connecting members. The reel winds up the pair of first wires and the pair of second wires. The pair of first connecting members are connected to be relatively movable with respect to the lift plate in a vertical direction, causes a relative position to vary with respect to the lift plate in a vertical direction in accordance with a weight of the plurality of sheets loaded on the lift plate, and causes the lift plate to move upward when the weight is lighter than a predetermined value.