An example system includes an advancement mechanism to drive print media into a stacking region, a movable media guide arrangement and a controller. The movable media guide arrangement includes a pair of opposing media guides to receive opposing edges of a print medium therein and a translation mechanism to move the opposing media guides between at least two positions, the at least two positions including a deployed position and a retracted position. The controller is to actuate the translation mechanism to move the opposing media guides into the deployed position when the advancement mechanism transports a print medium into the stacking region and to actuate the translation mechanism to move the opposing media guides to the retracted position to release the print medium.

The present application discloses a post-processing apparatus which performs a predetermined process after an image formation process performed by an image formation apparatus. The post-processing apparatus includes an ejection tray, which supports a sheet stack, in which sheets are stacked, and a curl prevention portion including a first tray cursor, which abuts an upper surface of the sheet stack on the ejection tray to prevent the sheet stack from curling. The curl prevention portion includes an angle changer, which changes an inclination angle of the first tray cursor with respect to the ejection tray. The angle changer sets the inclination angle to a first value when a number of sheets is a first number. The angle changer sets the inclination angle to a second value different from the first value when the number of the sheets is a second number different from the first number.

The present application discloses a post-processing apparatus which performs a predetermined process after an image formation process performed by an image formation apparatus. The post-processing apparatus includes an ejection tray, which supports a sheet stack, in which sheets are stacked, and a curl prevention portion including a first tray cursor, which abuts an upper surface of the sheet stack on the ejection tray to prevent the sheet stack from curling. The curl prevention portion includes an angle changer, which changes an inclination angle of the first tray cursor with respect to the ejection tray. The angle changer sets the inclination angle to a first value when a number of sheets is a first number. The angle changer sets the inclination angle to a second value different from the first value when the number of the sheets is a second number different from the first number.

A medium conveyance device includes a first loading base that has a first loading surface formed thereon and is movably supported on a main body, a second loading base that has a second loading surface formed thereon and is movably supported on the first loading base so that the second loading surface is positioned next to with the first loading surface and so that the second loading surface overlaps with the first loading surface, a mechanism that converts motion of the first loading base into motion of the second loading base so that the second loading base is arranged in a position corresponding to a position in which the first loading base is arranged, and an elastic member that is elastically deformed when the second loading base is not arranged in a position corresponding to a position in which the first loading base is arranged.

A medium conveyance device includes a first loading base that has a first loading surface formed thereon and is movably supported on a main body, a second loading base that has a second loading surface formed thereon and is movably supported on the first loading base so that the second loading surface is positioned next to with the first loading surface and so that the second loading surface overlaps with the first loading surface, a mechanism that converts motion of the first loading base into motion of the second loading base so that the second loading base is arranged in a position corresponding to a position in which the first loading base is arranged, and an elastic member that is elastically deformed when the second loading base is not arranged in a position corresponding to a position in which the first loading base is arranged.

A medium ejection apparatus includes a placement mount on which media are placed, a restriction part that moves between a restriction position at which the restriction part restricts media ejected toward the placement mount and a retracted position retracted from the restriction position, and a processor that controls the restriction part by adjusting a restriction frequency on the basis of at least either an amount of movement of the restriction part from the retracted position to the restriction position or ejection intervals at which the media are ejected toward the placement mount, the restriction frequency being a frequency with which the restriction part performs a restriction operation for the media.

A sheet discharge apparatus includes a discharge roller pair, the discharge roller pair including a drive roller and a driven roller, a holder member configured to rotatably hold the driven roller, a first conveyance guide including a first guide portion, a second conveyance guide configured to support the holder member movably in a separating direction, the second conveyance guide including a second guide portion which forms a conveyance path, together with the first conveyance guide, and a regulation portion configured to regulate a movement of the holder member to be movable within a range of a first distance in the separating direction from a position where the driven roller is in contact with the drive roller, wherein the first distance is smaller than a second distance which is a distance between the first guide portion and the second guide portion in the separating direction.

A sheet discharge apparatus includes a discharge roller pair, the discharge roller pair including a drive roller and a driven roller, a holder member configured to rotatably hold the driven roller, a first conveyance guide including a first guide portion, a second conveyance guide configured to support the holder member movably in a separating direction, the second conveyance guide including a second guide portion which forms a conveyance path, together with the first conveyance guide, and a regulation portion configured to regulate a movement of the holder member to be movable within a range of a first distance in the separating direction from a position where the driven roller is in contact with the drive roller, wherein the first distance is smaller than a second distance which is a distance between the first guide portion and the second guide portion in the separating direction.

A sheet stacking device includes a stacking tray, an aligning mechanism, a pair of alignment members, and a pair of height detectors. The pair of alignment members can move independently in a sheet width direction and in an up and down direction, and contact side edges in the sheet width direction of sheets stacked on the stacking tray, from both sides in the sheet width direction, so as to align the sheets in the sheet width direction. The pair of height detectors allow the pair of alignment members to contact an upper surface of the sheets near side edges of the sheets, so that sheet heights on both sides in the sheet width direction are detected. The sheet stacking device can individually correct heights of the pair of alignment members when aligning the sheets, based on the sheet heights detected by the pair of height detectors.

A post-processing device, includes a tray that accepts a carried sheet and places thereon; a post-processing unit that performs a post-processing to the sheet placed on the tray; and a controller that controls an operation of the post-processing unit. The controller that: obtains both of: a first sheet type specified by a user; and a second sheet type detected by a media detector that is installed on a sheet carrying path; and controls the operation of the post-processing unit based on the second sheet type when the first sheet type and the second sheet type are different.