A sheet feeder includes an ejection tray, an ejector, an aligner, a pressing member, a friction member, and a switching device. The ejection tray stacks sheets. The ejector ejects a sheet to the ejection tray. The aligner is disposed downstream of the ejector in a direction of ejection of the sheet. The aligner is rotatable in a normal direction and a reverse direction. The pressing member applies pressure between the sheet and the aligner to enable the aligner to convey the sheet by rotation in the normal direction and the reverse direction. The friction member contacts the sheet ejected on the ejection tray to prevent conveyance of the sheet. The switching device switches contact and separation of the friction member with respect to the sheet.

A printing apparatus includes a stacking portion on which a print medium printed by a printing unit configured to perform printing is stacked, a discharge unit configured to convey the print medium printed by the printing unit to the stacking portion, a passage forming portion arranged above the stacking portion so as to face the stacking portion and configured to form a discharge passage of the print medium together with the stacking portion, and an outlet port located in a downstream end of the discharge passage in a conveying direction of the print medium. In the outlet port, the passage forming portion extends to the downstream side of the stacking portion in the conveying direction.

A printing apparatus includes a stacking portion on which a print medium printed by a printing unit configured to perform printing is stacked, a discharge unit configured to convey the print medium printed by the printing unit to the stacking portion, a passage forming portion arranged above the stacking portion so as to face the stacking portion and configured to form a discharge passage of the print medium together with the stacking portion, and an outlet port located in a downstream end of the discharge passage in a conveying direction of the print medium. In the outlet port, the passage forming portion extends to the downstream side of the stacking portion in the conveying direction.

A printing apparatus comprises a sheet eject tray; a movable guide arranged on an upstream side of the sheet eject tray in a direction of conveyance of a sheet and is configured to be able to move to a protruding position and a retracted position; and a driving mechanism configured to cause the movable guide to move to the protruding position when a leading edge of a sheet is conveyed along the movable guide and cause the movable guide to move to the retracted position when a trailing edge of a sheet is conveyed along the movable guide, wherein the protruding position includes a first position at which the movable guide presses a sheet to the sheet eject tray and a second position between the first position and the retracted position.

A sheet stacking apparatus includes a sheet alignment mechanism configured for aligning a sheet in a predetermined reference position; a gripper arrangement configured to grip the aligned sheet at at least two spaced-apart points of the sheet and to release the sheet on a stack; and a holder configured to hold the sheet in position on the stack while the gripper arrangement releases the sheet. The gripper arrangement is movable along a predetermined trajectory for moving the sheet from the reference position to a stacking position.

A sheet stacking apparatus includes a sheet alignment mechanism configured for aligning a sheet in a predetermined reference position; a gripper arrangement configured to grip the aligned sheet at at least two spaced-apart points of the sheet and to release the sheet on a stack; and a holder configured to hold the sheet in position on the stack while the gripper arrangement releases the sheet. The gripper arrangement is movable along a predetermined trajectory for moving the sheet from the reference position to a stacking position.

A sheet processing apparatus for processing sheets includes: a stack tray on which a sheet is stacked; a discharge roller pair composed of first and second rollers and configured to discharge a sheet onto the stack tray, the second roller being configured to be movable between a pressure contact position to contact with the first roller and a retracting position to separate from the first roller; and a pressure contact/separation mechanism for moving the second roller from the retracting position to the pressure contact position. The pressure contact/separation mechanism changes the timing at which the second roller reaches the pressure contact position according to the type of a sheet to be discharged.

A sheet processing apparatus for processing sheets includes: a stack tray on which a sheet is stacked; a discharge roller pair composed of first and second rollers and configured to discharge a sheet onto the stack tray, the second roller being configured to be movable between a pressure contact position to contact with the first roller and a retracting position to separate from the first roller; and a pressure contact/separation mechanism for moving the second roller from the retracting position to the pressure contact position. The pressure contact/separation mechanism changes the timing at which the second roller reaches the pressure contact position according to the type of a sheet to be discharged.

A post-processing device includes a processing tray on which a medium on which recording was performed by a recording unit is loaded, a rear end alignment unit that aligns a rear end (an example of an end portion) of the medium on the processing tray, a post-processing unit that performs post-processing on the medium aligned by the rear end alignment unit, and a pressing member that presses the rear end of the medium. The post-processing unit is configured to be movable. The pressing member is provided to be rotatable in conjunction with movement of the post-processing unit, in a state in which the pressing member is in contact with the medium aligned by the rear end alignment unit.

Example printer finishing apparatus are described herein. An example printer disclosed herein includes an alignment guide, a track to align a sheet relative to the alignment guide, a clamp to move between a raised position and a lowered position relative to the sheet, and a force applicator coupled to the clamp. The force applicator is to cause the sheet to engage the alignment guide when the clamp is in the lowered position.