The present application discloses a post-processing apparatus including a second tray which receives a sheet stack ejected from a first tray, a pushing mechanism including a pushing portion which pushes the sheet stack against the second tray, a motion detector which detects a motion of the pushing mechanism, and a controller including an ejection controller which controls an ejector. When the ejector ejects the sheet stack, the pushing mechanism moves the pushing portion in a first direction away from the second tray. When the ejector finishes ejection of the sheet stack, the pushing mechanism moves the pushing portion in a second direction which is opposite to the first direction. Unless the motion detector detects the motion of the pushing mechanism moving the pushing portion in the first direction when the ejector ejects the sheet stack, the ejection controller executes interruption control of stopping the ejection of the sheet stack.

To provide a sheet stacking apparatus and image forming system capable of improving alignment characteristics also in the case where an aligning section is not able to act on a sheet discharged onto a stacking tray, the sheet stacking apparatus and image forming system include a stacking tray stacking discharged sheets, a pair of aligning sections capable of shifting in a width direction to align the width direction crossing a direction in which the sheet to stack on the stacking tray is discharged, and a control section that controls a relative position of the aligning sections and the sheet to discharge so that one of the pair of the aligning sections regulates a shift of the sheet stacked on the stacking tray to one direction side in the width direction, when a sheet with a predetermined width in the width direction of the sheet is discharged to the stacking tray.

To provide a sheet stacking apparatus and image forming system capable of improving alignment characteristics also in the case where an aligning section is not able to act on a sheet discharged onto a stacking tray, the sheet stacking apparatus and image forming system include a stacking tray stacking discharged sheets, a pair of aligning sections capable of shifting in a width direction to align the width direction crossing a direction in which the sheet to stack on the stacking tray is discharged, and a control section that controls a relative position of the aligning sections and the sheet to discharge so that one of the pair of the aligning sections regulates a shift of the sheet stacked on the stacking tray to one direction side in the width direction, when a sheet with a predetermined width in the width direction of the sheet is discharged to the stacking tray.

A sheet post-processing device includes a folding portion, a discharge portion, a stacking tray, a shift unit, a pair of alignment members, and a controller. The pair of alignment members include first and second alignment members at one and the other side of sheets stacked on the stacking tray. When a sheet bundle sorted and stacked on the stacking tray includes a folded sheet, executes a second alignment mode in which it performs, for sheets shifted to a first position at one side on the stacking tray, alignment with only the first alignment member and, for sheets shifted to a second position at the other side, alignment with only the second alignment member, or does not perform alignment process.

A document conveyance device includes a supply tray, a discharge tray, a conveyance part, a discharge part, and a lifting and lowering part. The lifting and lowering part lifts the supply tray and the discharge part according to a feeding of the document. When the feeding of the document to the document conveyance path is completed and then the supply tray is lifted, in a small number of documents discharge state where the height of the documents stacked on the discharge tray is less than the specified value, the lifting and lowering part positions the supply tray at a taking out position depart upward from the specified value by a predetermined space.

A document conveyance device includes a supply tray, a discharge tray, a conveyance part, a discharge part, and a lifting and lowering part. The lifting and lowering part lifts the supply tray and the discharge part according to a feeding of the document. When the feeding of the document to the document conveyance path is completed and then the supply tray is lifted, in a small number of documents discharge state where the height of the documents stacked on the discharge tray is less than the specified value, the lifting and lowering part positions the supply tray at a taking out position depart upward from the specified value by a predetermined space.

A paper sheet accumulating device includes an accumulating part in which paper sheets are accumulated, an impeller that sends the paper sheets to the accumulating part, and a support mechanism that supports the impeller. The support mechanism includes a first rotation shaft that supports the impeller rotatable, a support member provided with the first rotation shaft, a second rotation shaft that supports the support member rotatable in a direction of the support member moving toward and away from the accumulating part, and a biasing member that biases the support member in a direction of the impeller moving toward the paper sheets accumulated in the accumulating part.

A paper sheet accumulating device includes an accumulating part in which paper sheets are accumulated, an impeller that sends the paper sheets to the accumulating part, and a support mechanism that supports the impeller. The support mechanism includes a first rotation shaft that supports the impeller rotatable, a support member provided with the first rotation shaft, a second rotation shaft that supports the support member rotatable in a direction of the support member moving toward and away from the accumulating part, and a biasing member that biases the support member in a direction of the impeller moving toward the paper sheets accumulated in the accumulating part.

A printing apparatus includes a media bin and a sensor, directed toward the media bin, having a first emitter and a receiver. The printing apparatus further includes a second emitter to emit photons toward the optical sensor, and a controller. The controller determines presence of a print media on the media bin based on a count of photons received from a source other than the first emitter, including the second emitter.

A printing apparatus includes a media bin and a sensor, directed toward the media bin, having a first emitter and a receiver. The printing apparatus further includes a second emitter to emit photons toward the optical sensor, and a controller. The controller determines presence of a print media on the media bin based on a count of photons received from a source other than the first emitter, including the second emitter.