An example sheet guide devices comprises a housing and a guide member coupled to the housing. The housing is to receive a stack of sheets to staple. The guide member includes a cylinder shaft, a counterbalance component, and guide arm. The cylinder shaft is rotatable and disposed within the housing. The counterbalance component is disposed with the cylinder shaft to shift a center of gravity of the guide member in a first direction. The guide arm is disposed off-center from a central axis of the cylinder shaft in a second direction.

A sheet conveyor unit is connected to downstream side of an upstream side unit in a sheet conveying direction. The sheet conveyor unit includes a convey guide for receiving a sheet discharged from outlet of the upstream side unit. The convey guide is constituted of a pair of guide members disposed to face each other with a predetermined space therebetween. The guide members have the same shape and include base parts having guide surfaces that form a sheet conveying path when combined to face each other, and inclined parts bent to directions apart from the guide surfaces from one end of the base parts in the sheet conveying direction so as to form a receiving port. The convey guide is attached selectively to one of positions different in at least one of a height direction and the sheet conveying direction with respect to an apparatus main body.

One embodiment of the present disclosure provides a post-processing apparatus for an image forming apparatus which arranges paper ejected from an ejection part of an image forming apparatus on a fence for post-processing. The post-processing apparatus includes a paddle guide which includes a paddle arm to which a paddle wing is coupled and a pusher positioned adjacent to the ejection part and stands by at a home position until the paper is ejected, a driving part which vertically moves the paddle guide, rotates when the paper is ejected from the ejection part to move the paddle guide downward so that the pusher presses the paper downward and drops the paper on a stacking base, and a paddle wing which vertically moves according to a vertical movement of the paddle guide, moves downward according to a downward movement of the paddle guide, arranges the paper dropped on the stacking base toward the fence positioned adjacent to the stacking base, and then, moves upward with an upward movement of the paddle guide according to operation of the driving part, wherein vertical movements of the pusher and the paddle wing are performed by a vertical movement of the paddle guide performed due to single unit periodic operation of the driving part.

A sheet conveyor is provided for transporting a sheet. The sheet conveyor includes a supplying conveyor, a receiving conveyor and a sheet guidance unit. The receiving conveyor includes a support surface arranged for supporting the sheet on a contact side of the sheet and an attraction unit arranged for attracting the sheet to the support surface. The supplying conveyor includes a transport belt being arranged for advancing the sheet in a transport direction along a transport path towards the support surface of the receiving conveyor; the sheet having two side edge portions relative to the transport path. The sheet guidance unit is arranged at a downstream end of the transport path for guiding the sheet towards the receiving conveyor, wherein said sheet guidance unit includes a lifting element arranged for lifting both side edge portions of the sheet away from the support surface while a middle portion of the sheet in between both side edge portions is guided towards the support surface.

According to an embodiment, a sheet processing apparatus includes a transport unit and a holding unit. The transport unit transports a first sheet to a first position. The transport unit transports a second sheet, which is transported after the first sheet, to a second position displaced to the upstream side of a sheet transport direction relative to the first position. The transport unit transports a third sheet, which is transported after the second sheet, to a third position displaced to the downstream side of the sheet transport direction relative to the second position. In the case where the second sheet is transported to the second position, the holding unit holds the first sheet at the first position. In the case where the third sheet is transported to the third position, the holding unit holds the second sheet at the second position.

According to an embodiment, a sheet processing apparatus includes a transport unit and a holding unit. The transport unit transports a first sheet to a first position. The transport unit transports a second sheet, which is transported after the first sheet, to a second position displaced to the upstream side of a sheet transport direction relative to the first position. The transport unit transports a third sheet, which is transported after the second sheet, to a third position displaced to the downstream side of the sheet transport direction relative to the second position. In the case where the second sheet is transported to the second position, the holding unit holds the first sheet at the first position. In the case where the third sheet is transported to the third position, the holding unit holds the second sheet at the second position.

A sheet stacking device includes a sheet stacker, a pair of sheet restrictors, and a stacking adaptor. The sheet stacker has a first sheet stacking face on which a bundle of sheets is stacked. The sheet stacker includes a leading end support to support a leading end of the bundle of sheets in a feeding direction by a second sheet stacking face and a pair of cutouts disposed upstream from the leading end support. The pair of sheet restrictors slide in the pair of cutouts in a width direction orthogonal to the feeding direction to regulate a position of the bundle of sheets. The stacking adaptor is detachably attached to the sheet stacker to cover the pair of cutouts. The stacking adaptor has a third sheet stacking face to support a portion of the bundle of sheets disposed at the pair of cutouts.

A sheet stacking device includes a sheet stacker, a pair of sheet restrictors, and a stacking adaptor. The sheet stacker has a first sheet stacking face on which a bundle of sheets is stacked. The sheet stacker includes a leading end support to support a leading end of the bundle of sheets in a feeding direction by a second sheet stacking face and a pair of cutouts disposed upstream from the leading end support. The pair of sheet restrictors slide in the pair of cutouts in a width direction orthogonal to the feeding direction to regulate a position of the bundle of sheets. The stacking adaptor is detachably attached to the sheet stacker to cover the pair of cutouts. The stacking adaptor has a third sheet stacking face to support a portion of the bundle of sheets disposed at the pair of cutouts.

A post-processing apparatus includes a first conveyor, a second conveyor, a third conveyor, and a conveyance passage corrector. The first conveyor conveys a sheet conveyed along a first conveyance passage downstream from the first conveyor. The second conveyor conveys the sheet along a second conveyance passage. The third conveyor conveys the sheet along a third conveyance passage. The conveyance passage corrector includes a retracting mechanism to retract from a joining position at which the third conveyance passage joins to the first conveyance passage and turns a conveyance direction of the sheet toward the first conveyor when the sheet enters from the third conveyance passage to the first conveyance passage.

An image forming apparatus includes an image forming portion, a reversing portion configured to reverse the sheet received through a first feeding passage by feeding the sheet in a first direction and then in a second direction opposite to the first direction, a sheet feeding portion provided in a second feeding passage branching from the first feeding passage on a side upstream of the reversing portion with respect to the first direction, a first guiding surface forming the second feeding passage for guiding a first surface of the sheet fed by the feeding portion, and a second guiding surface for guiding a second surface, opposite from the first surface, of the sheet fed from the reversing portion in the second direction. The second guiding surface is movable with movement of the first guiding surface for opening the second feeding passage.