Abstract: 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.

Abstract: Post-processing apparatus for performing given process subsequently to image forming process by image forming apparatus is disclosed. Post-processing apparatus includes: first ejector which ejects sheet; first tray which temporarily holds sheet; second tray situated downstream of first tray in ejection direction of sheet; a tray driver which moves second tray downwardly from first height position; blower which forms airstream between second tray and lower surface of sheet; and controller which controls blower and tray driver. Controller includes: blower controller which causes blower to blow air over time period in synchronization with first time period from start to end of sheet ejection by first ejector; and tray controller which causes tray driver to move second tray downwardly from first height position after first time period.

Abstract: A sheet stacking device includes a sheet stacking section, pairs of ejection rollers, an airflow generator, and an airflow guide. The airflow guide has a center exhaust port and paired side exhaust ports. An airflow is blown out from the center exhaust port toward a central part of the lower surface of the sheet in a sheet width direction perpendicular to a conveyance direction of the sheet. Airflows are blown out from the respective paired side exhaust ports toward respective sides of the lower surface of the sheet. An amount of the airflow blown out from the center exhaust port is larger than those of the airflows blown out from the respective paired side exhaust ports.

Abstract: A sheet alignment device includes a driven roller, a drive roller, a displacement driving device, an information acquisition portion, and a displacement control portion. The drive roller is configured to rotate in a first rotation direction and in contact with an upper surface of each of sheets conveyed onto a tilt tray, to feed the sheets toward a base end portion of the tilt tray. The drive roller is configured to rotate in a second rotation direction and in contact with an uppermost surface of the sheets, to discharge the sheets from the tilt tray. The displacement control portion is configured to, when the drive roller rotates in the first rotation direction, control a holding position of the drive roller in accordance with the number of the sheets on the tilt tray and thickness information of each of the sheets acquired by the information acquisition portion.

Abstract: A sheet stacking tray includes a first stacking portion, a second stacking portion, and a base portion. In a sheet widthwise direction perpendicular to the sheet discharge direction, the first stacking portion includes a first sheet stacking surface having a first stacking width within a range from one half of a sheet width of a maximum-size sheet to be discharged up to the sheet width of the maximum-size sheet. The second stacking portion includes a second sheet stacking surface having a second stacking width smaller than the first stacking width. A border between the first stacking portion and the second stacking portion lies on a discharge-direction upstream side of a contact point where a leading end portion of the maximum-size sheet comes into contact with the sheet stacking part while the sheet is discharged.

Abstract: A first motor causes a first conveying roller pair to rotate, and a second motor causes a second conveying roller pair and an aligning rotational member to rotate. A control portion temporarily stops the first motor each time a sheet member reaches a position at which the sheet member is subjected to punching. Each time the sheet member reaches the position at which the sheet member is subjected to punching, the control portion continuously operates the second motor if the sheet member unreaches a position at which the sheet member is nipped by the second conveying roller pair, and otherwise temporarily stops the second motor.

Abstract: A sheet alignment device includes a driven roller, a drive roller, a displacement driving device, an information acquisition portion, and a displacement control portion. The drive roller is configured to rotate in a first rotation direction and in contact with an upper surface of each of sheets conveyed onto a tilt tray, to feed the sheets toward a base end portion of the tilt tray. The drive roller is configured to rotate in a second rotation direction and in contact with an uppermost surface of the sheets, to discharge the sheets from the tilt tray. The displacement control portion is configured to, when the drive roller rotates in the first rotation direction, control a holding position of the drive roller in accordance with the number of the sheets on the tilt tray and thickness information of each of the sheets acquired by the information acquisition portion.

Abstract: A sheet stacking tray includes a first stacking portion, a second stacking portion, and a base portion. In a sheet widthwise direction perpendicular to the sheet discharge direction, the first stacking portion includes a first sheet stacking surface having a first stacking width within a range from one half of a sheet width of a maximum-size sheet to be discharged up to the sheet width of the maximum-size sheet. The second stacking portion includes a second sheet stacking surface having a second stacking width smaller than the first stacking width. A border between the first stacking portion and the second stacking portion lies on a discharge-direction upstream side of a contact point where a leading end portion of the maximum-size sheet comes into contact with the sheet stacking part while the sheet is discharged.

Abstract: 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.

Abstract: A first motor causes a first conveying roller pair to rotate, and a second motor causes a second conveying roller pair and an aligning rotational member to rotate. A control portion temporarily stops the first motor each time a sheet member reaches a position at which the sheet member is subjected to punching. Each time the sheet member reaches the position at which the sheet member is subjected to punching, the control portion continuously operates the second motor if the sheet member unreaches a position at which the sheet member is nipped by the second conveying roller pair, and otherwise temporarily stops the second motor.

Abstract: In a sheet post-processing device, the front end portion of a sheet (P) transported onto a post-processing tray makes contact with a paper discharge tray, and thus it is possible to prevent the sheet (P) from being curled excessively. When the first sheet (P) in a stack of sheets to be subjected to post-processing in a post-processing portion is transported onto the paper discharge tray, the standby position of a drive roller forming a paper discharge roller pair is set between the maximum separate position and a nip position on a driven roller.

Abstract: A post-processing unit in an image forming apparatus includes a stapler, an exit tray, a height detector, and a shifting controller. The stapler staples a sheet sheaf. The exit tray is configured to be elevated and lowered and to receive the sheet sheaf stapled by the stapler. The height detector detects a height of the sheet sheaf on the exit tray. The shifting controller shifts the sheet sheaf to be ejected in a situation in which the stapler staples one location at a trailing end of the sheet sheaf in a conveyance direction of the sheet sheaf. The shifting controller shifts the sheet sheaf in a front-rear direction, which is a direction perpendicular to a vertical direction and to the conveyance direction of the sheet sheaf, so that the stapled location in the sheet sheaf on the exit tray matches a detection point of the height detector.

Abstract: A sheet conveying device is provided in a paper sheet discharge portion of an image forming apparatus. The sheet conveying device includes, inside thereof, a pair of conveyance guides forming a curved path. A stiffening member is attached to an upper conveyance guide. The stiffening member includes a first pressing portion on the downstream side in the conveyance direction, and a guide portion on the upstream side. The first pressing portion is positioned at a lower position than a nip portion of a pair of discharge rollers. The guide portion is positioned at an upper position than the nip portion. The guide portion is narrower in the width direction than the first pressing portion.

Abstract: A sheet processing device includes an exit tray and a sheet alignment mechanism. On the exit tray, ejected sheets or ejected sheet sheaves subjected to stapling are stacked. When at least a sheet is ejected, the sheet alignment mechanism aligns the sheets in a manner to be in contact with and catch opposite ends of the sheets stacked on the exit tray from a base end side of the exit tray. When a sheet sheaf is ejected, the sheet alignment mechanism comes in contact with a plurality of points on a topmost surface of the sheet sheaves stacked on the exit tray to detect a height difference between the plurality of points.

Abstract: In a sheet post-processing device, the front end portion of a sheet (P) transported onto a post-processing tray makes contact with a paper discharge tray, and thus it is possible to prevent the sheet (P) from being curled excessively. When the first sheet (P) in a stack of sheets to be subjected to post-processing in a post-processing portion is transported onto the paper discharge tray, the standby position of a drive roller forming a paper discharge roller pair is set between the maximum separate position and a nip position on a driven roller.

Abstract: An image forming system includes an image forming apparatus, a post-processing apparatus, a fixed member, a first connector, a connecting member, and a second connector. The mage forming apparatus includes the fixed member on which the first connector is mounted and the post-processing apparatus includes connecting member on which the second connector is mounted. The connecting member is movable in a front-back direction and configured so as to be displaced between an engaging position in which the connecting member is engaged with the fixed member and a disengaging position in which the connecting member is disengaged from the fixed member. The first connector and the second connector are disconnected from each other when the connecting member is set to the disengaging position, and connected to each other when the connecting member is set to the engaging position.

Abstract: A sheet conveying device is provided in a paper sheet discharge portion of an image forming apparatus. The sheet conveying device includes, inside thereof, a pair of conveyance guides forming a curved path. A stiffening member is attached to an upper conveyance guide. The stiffening member includes a first pressing portion on the downstream side in the conveyance direction, and a guide portion on the upstream side. The first pressing portion is positioned at a lower position than a nip portion of a pair of discharge rollers. The guide portion is positioned at an upper position than the nip portion. The guide portion is narrower in the width direction than the first pressing portion.

Abstract: A sheet processing device includes an exit tray and a sheet alignment mechanism. On the exit tray, ejected sheets or ejected sheet sheaves subjected to stapling are stacked. When at least a sheet is ejected, the sheet alignment mechanism aligns the sheets in a manner to be in contact with and catch opposite ends of the sheets stacked on the exit tray from a base end side of the exit tray. When a sheet sheaf is ejected, the sheet alignment mechanism comes in contact with a plurality of points on a topmost surface of the sheet sheaves stacked on the exit tray to detect a height difference between the plurality of points.

Abstract: An image forming system includes an image forming apparatus, a post-processing apparatus, a fixed member, a first connector, a connecting member, and a second connector. The mage forming apparatus includes the fixed member on which the first connector is mounted and the post-processing apparatus includes connecting member on which the second connector is mounted. The connecting member is movable in a front-back direction and configured so as to be displaced between an engaging position in which the connecting member is engaged with the fixed member and a disengaging position in which the connecting member is disengaged from the fixed member. The first connector and the second connector are disconnected from each other when the connecting member is set to the disengaging position, and connected to each other when the connecting member is set to the engaging position.

Abstract: A cam driving mechanism has: a cam; a motor which drives the cam; a gear train which transmits, while reducing the speed of, the output of the motor to the cam; a pulse disk which is formed integrally with a gear coupled in the gear train and in which a plurality of slits are formed at equal intervals; a home position detecting member which is arranged coaxially with the pulse disk so as to be rotatable independently thereof and which, by meshing with another gear coupled in the gear train, rotates at a lower rotation speed than the pulse disk; and a cam position detecting sensor which has a detecting portion including a light-emitting portion and a light-receiving portion, the cam position detecting sensor detecting the amount of driving of the cam based on the number of slits of the pulse disk that have passed through the detecting portion, the cam position detecting sensor detecting the home position of the cam based on the timing with which the home position detecting member shields the detecting portion.