A sheet stacking device includes a discharge port, an alignment wall, a discharge tray, an alignment belt, and a guide part. The alignment wall extends in an upper-and-lower direction below the discharge port. The discharge tray is provided so as to be capable of moving up and down along the alignment wall. The alignment belt with endless is stretched along the alignment wall in the upper-and-lower direction. The alignment belt has an inner circumferential surface facing the alignment wall and an outer circumferential surface with which an upstream edge of the sheet stacked on the discharge tray comes into contact, and circulates at a same speed as the discharge tray in synchronization with the discharge tray. The guide part is configured to be provided between the alignment wall and the alignment belt. With the guide part, the inner circumferential surface of the alignment belt slides in contact.

A medium transport device includes a feeding unit that can be disposed at a contact position and a retracted position, a first restriction member that rotates between a restriction position and a release position, and a transport guide positioned on a side opposite to the feeding unit with a transport path interposed therebetween. When the first restriction member is positioned at the restriction position, the first restriction member maintains a state in which the feeding unit is positioned at the retracted position by the tip end contacting the feeding unit. When the first restriction member is positioned at the restriction position, the tip end thereof is positioned closer to the mounting portion side than the position of the rotation axis of the first restriction member in the transport direction.

Sheet collating device for accumulating sheets from at least one hopper, comprising: a lower transport path and an upper transport path; a switchable guide for directing the sheets from the at least one hopper to the lower or the upper transport path; left and right upper drive shafts connected to a right and a left upper drive pulleys supporting a pair of upper belts, a drive direction of the pair of upper belts being changed dependent on what transport path of the upper and lower transport paths is selected; first and second lower drive shafts connected to a right and a left lower drive pulleys supporting first and second pairs of lower belts; and a first series of right paddles mounted on the first pair of lower belts and a first series of left paddles mounted on the second pair of lower belts for registering a collated set of sheets.

In some examples, a substrate handling system includes a sheet processing machine and at least one alignment device that includes at least four stops. At least one stop is configured as a front stop, at least one stop is configured as a rear stop, and at least two stops are configured as lateral stops. The at least two lateral stops are arranged opposite one another, and the at least one front stop and the at least one rear stop are arranged opposite one another. The alignment device includes at least one support element that is configured as a propping element for propping at least one partial stack of sheets in the alignment device. Further, at least one respective support element is arranged at the at least two lateral stops and at the at least one rear stop.

A sheet alignment apparatus includes a supporting portion configured to support a sheet, a first alignment member configured to abut an end portion in a first direction of the sheet supported by the supporting portion and align a position of the sheet in the first direction, a first moving unit configured to move the first alignment member in the first direction, a second alignment member configured to abut an end portion in a second direction of the sheet supported by the supporting portion and align a position of the sheet in the second direction, the second direction being perpendicular to the first direction, and a second moving unit configured to move the second alignment member in the second direction, wherein the first moving unit is disposed below the supporting portion, and wherein the second moving unit is disposed above the supporting portion.

A medium aligning device includes a stacking tray that stacks a medium discharged by a discharge section that discharges the medium, a side end aligning portion that is movable in a width direction that is a direction intersecting with a medium discharge direction of the discharge section, and positions and aligns a side end in the width direction of the medium stacked on the stacking tray, a rear end aligning portion that is movable in the width direction and positions and aligns a rear end that is an upstream end of the medium stacked on the stacking tray in the discharge direction, and a transmission portion that transmits the movement of the side end aligning portion in the width direction to the rear end aligning portion, in which a play in the width direction is provided between the side end aligning portion and the transmission portion.

A sheet feeder, which is included in an image forming apparatus, includes a sheet loader, an air blowing device, a regulator, a sheet attracting device, and a sheet conveying body. The sheet loader loads a sheet bundle including a sheet and a subsequent sheet placed below the sheet. The air blowing device blows air and lifts the sheet over the sheet bundle. The regulator regulates movement of the subsequent sheet, and includes an opposing portion located upper end and separated from the sheet loader toward the downstream side of the sheet conveying direction and an inclined portion upwardly inclined relative to a vertical axis from a same position as the sheet loader to the downstream side of the sheet conveying direction. The sheet attracting device attracts the sheet lifted over the sheet bundle. The sheet conveying body conveys the sheet in a sheet conveying direction.

A medium aligning apparatus includes a load tray including a load surface on which a medium discharged from a discharge member that discharges a medium is loaded, a first aligning surface that aligns a plurality of mediums loaded on the load tray by positioning rear ends of the mediums, and a second aligning surface that aligns the mediums by positioning the rear ends of the mediums loaded on the load tray. In the medium aligning apparatus, the first aligning surface and the second aligning surface are switchable, and an angle formed between a wall surface in the discharge tray that receives the mediums discharged from the load tray, the wall surface having the rear ends of the mediums come in contact therewith, and the second aligning surface is smaller than an angle formed between the wall surface and the first aligning surface.

A sheet post-processing device comprises: a processing tray; a discharge tray; and a discharge rollers pair. The discharge rollers pair is constituted by a discharge roller which contacts the uppermost surface of sheets stacked in the processing tray and a discharge roller which contacts the lowermost surface of the sheets stacked in the processing tray). The sheet post-processing device discharges a sheet from the processing tray to the discharge tray by rotating the discharge rollers pair in the forward direction, and causes the sheet to be drawn into the processing tray by rotating the discharge roller in the reverse direction in a state in which the rotation of the discharge roller is stopped.

A conveying apparatus includes: receiving trays including (i) a lowest tray, (ii) a first receiving tray different from the lowest tray, and (iii) at least one second receiving tray including one second receiving tray disposed just below the first receiving tray; a conveying mechanism; and a supporter supporting the receiving trays. The conveying apparatus further includes a transmission mechanism configured to perform at least one of: transmission of upward movement of the first receiving tray from a receiving position to an upper position, to downward movement of the one second receiving tray from the receiving position to a lower position; and transmission of the downward movement of the one second receiving tray to the upward movement of the first receiving tray.