A post-processing apparatus includes a post-processing unit configured to receive sheets from an image forming apparatus, perform processing on the received sheets, and then discharge the processed sheets through a discharge port. A sensor is configured to detect a presence of an object at the discharge port. The sensor includes a first light emitter on a first side of the discharge port that is positioned to emit a light across a width of the discharge port, a reflector on a second side of the discharge port opposite the first side in a first direction, and a first light receiver positioned to receive light of the first light emitter from the reflector. A controller is configured to terminate the processing on the received sheets by the post-processing unit when the sensor detects the presence of the object at the discharge port.

A post-processing apparatus includes a post-processing unit configured to receive sheets from an image forming apparatus, perform processing on the received sheets, and then discharge the processed sheets through a discharge port. A sensor is configured to detect a presence of an object at the discharge port. The sensor includes a first light emitter on a first side of the discharge port that is positioned to emit a light across a width of the discharge port, a reflector on a second side of the discharge port opposite the first side in a first direction, and a first light receiver positioned to receive light of the first light emitter from the reflector. A controller is configured to terminate the processing on the received sheets by the post-processing unit when the sensor detects the presence of the object at the discharge port.

Provided are a post-processing apparatus, an image forming apparatus, and a post-processing method capable of avoiding the occurrence of a malfunction due to a failure to discharge a sheet bundle after a binding process. A plurality of sheets is loaded on a stack tray. A staple unit binds the plurality of sheets. A discharge roller discharges the sheet bundle bound by the staple unit from the stack tray. Each time a sheet is conveyed to the stack tray, an aligning unit moves between a first position in contact with the sheet loaded on the stack tray and a second position separating from the sheet. A detection processing unit detects a failure of discharging the sheet bundle by the discharging roller. A stop processing unit can stop the operation of the aligning unit when the discharge failure is detected by the detection processing unit.

Provided are a post-processing apparatus, an image forming apparatus, and a post-processing method capable of avoiding the occurrence of a malfunction due to a failure to discharge a sheet bundle after a binding process. A plurality of sheets is loaded on a stack tray. A staple unit binds the plurality of sheets. A discharge roller discharges the sheet bundle bound by the staple unit from the stack tray. Each time a sheet is conveyed to the stack tray, an aligning unit moves between a first position in contact with the sheet loaded on the stack tray and a second position separating from the sheet. A detection processing unit detects a failure of discharging the sheet bundle by the discharging roller. A stop processing unit can stop the operation of the aligning unit when the discharge failure is detected by the detection processing unit.

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.

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.

A sheet conveying device includes a separation member, a second conveyance member, a third conveyance member, and a first drive control portion. The separation member separates a sheet in contact with a first conveyance member from another at a first position where the first conveyance member comes into contact with the sheet. The second and third conveyance members are respectively downstream of the first and second positions. The first drive control portion stops driving the first conveyance member (1) after the leading edge of the sheet reaches the second position and before the trailing edge of the sheet passes through the first position when the sheet length is not exceeding a specific distance based on a distance between the first and third positions and (2) after the leading edge reaches the third position and before the trailing edge passes through the first position when the length exceeds the specific distance.

A transporting device sends a sheet with the rotation of a first drive roller with the sheet sandwiched between a first drive roller and a driven roller. The sheet is sent to a direction to which a back surface thereof is pressed against a guide surface, and is transported to a second drive roller in a state of being pressed against the guide surface after the guide surface pushing and bending a transport path toward a front surface side. A lifted amount of the sheet from the guide surface is monitored by a sensor, and the transportation is stopped in a case where the lifted amount is equal to or larger than a predetermined amount.

A conveyance unit includes a feeding unit that feeds a medium from a roll, a conveyance roller pair that conveys the medium toward a printing unit, an intermediate roller pair that conveys, toward the conveyance roller pair, the medium fed by the feeding unit, a first driving unit that rotates a first driving roller, and a load changing unit that changes a pressing load acting between a second driving roller and a second driven roller. A control unit can execute a first control that controls the load changing unit such that the pressing load is a first pressing load when the first driving roller is rotated in an intermittent conveyance, and execute a second control that controls the load changing unit such that the pressing load is not generated when the rotation of the first driving roller is stopped in the intermittent conveyance.

A postprocessing device includes a pair of folding rollers, a folding blade, a transport device, a roller driver, a blade driver, and a drive controller. The drive controller selectively performs one of a first rotation control, including controlling the roller driver to keep rotation speed of the pair of folding rollers constant, while the folding blade is moving away from a nip region, and a second rotation control, including controlling the roller driver to stop the rotation or slow down the rotation speed of the pair of folding rollers, while a tip portion of the folding blade is being withdrawn from a folded portion of a sheaf of sheets folded, and to restore the rotation speed of the pair of folding rollers to original rotation speed, after the tip portion of the folding blade has been removed from the folded portion of the sheaf of sheets folded.