A sheet sorting device includes three or more trays including a predetermined tray detachable from an apparatus main body and a tray different from the predetermined tray, a discharge unit to discharge a sheet to any one of the three or more trays, a control unit, and a tray detection unit to detect that the predetermined tray is detached from the apparatus main body. The control unit sets a sheet discharge destination such that a sheet conforming to a preset condition is discharged to the predetermined tray through the discharge unit. Where the tray detection unit detects that the predetermined tray is detached from the apparatus main body, the control unit sets a sheet discharge destination that has been set to the predetermined tray to the tray different from the predetermined tray based on a state of each of the trays other than the detached predetermined tray.

A unit attaching detaching structure includes: a unit that is attachable to and detachable from an apparatus main body; a displacement portion that is provided on the apparatus main body and is displaceable to one side and another side; a detection unit that detects attachment of the unit when the displacement portion is displaced from the another side to the one side; a connecting portion that is separated from the detection unit in a direction intersecting with a direction of attaching/detaching of the unit, and is connected to the displacement portion so as to displace the displacement portion; a movement portion that is provided on the unit and displaces the displacement portion by moving the connecting portion when the unit is attached to the apparatus main body; and a returning unit that returns the displacement portion when the unit is detached from the apparatus main body.

A sheet conveyance device includes a sheet receiving part, a first discharge part, a sheet conveyance path, an escape conveyance path, a branch guide, an escape tray, a second discharge part, and a first sheet detection part. When a device failure occurs, the branch guide switches the conveyance direction such that the sheet remaining on the sheet conveyance path is discharged on the escape tray by the second discharge part, through the escape conveyance path sequentially. Then, the second discharge part stops a discharging of the sheet in a state where the sheet remains in the second discharge part when the sheet is a last sheet to be conveyed to the escape tray. Then, a receiving of a new sheet to the sheet receiving part from the image forming apparatus is inhibited while the first sheet detection part detects the last sheet.

An image forming apparatus includes a duct, a filter provided inside the duct, a first fan provided on an upstream side of the filter in an exhaust direction and a second fan provided on a downstream side of the filter in the exhaust direction. A first mode operation containing a first operation in which the first fan sends air to the filter and a second operation in which the second fan sends air to the filter after the first operation is performed at least once, and then a second mode in which the first fan sends air in the exhaust direction is performed.

An image forming apparatus includes a duct, a filter provided inside the duct, a first fan provided on an upstream side of the filter in an exhaust direction and a second fan provided on a downstream side of the filter in the exhaust direction. A first mode operation containing a first operation in which the first fan sends air to the filter and a second operation in which the second fan sends air to the filter after the first operation is performed at least once, and then a second mode in which the first fan sends air in the exhaust direction is performed.

A document conveyance apparatus includes a first conveyance path, a first image reading part, a curved second conveyance path, a third conveyance path, a branch guide, a first discharge port, a document stacking section, a second discharge port and a tray support part. The first conveyance path extends linearly. The curved second conveyance path is branched from the first conveyance path at a branch point. The third conveyance path is branched from the first conveyance path at the branch point and extends linearly. Through the first discharge port, the document conveyed along the second conveyance path is discharged. The document stacking section is provided with a discharge tray. Through the second discharge port, the document conveyed along the third conveyance path is discharged. To the tray support part, the detached discharge tray is supported such that the document discharged through the second discharge port is stacked.

A document conveyance apparatus includes a first conveyance path, a first image reading part, a curved second conveyance path, a third conveyance path, a branch guide, a first discharge port, a document stacking section, a second discharge port and a tray support part. The first conveyance path extends linearly. The curved second conveyance path is branched from the first conveyance path at a branch point. The third conveyance path is branched from the first conveyance path at the branch point and extends linearly. Through the first discharge port, the document conveyed along the second conveyance path is discharged. The document stacking section is provided with a discharge tray. Through the second discharge port, the document conveyed along the third conveyance path is discharged. To the tray support part, the detached discharge tray is supported such that the document discharged through the second discharge port is stacked.

A sorting device includes a base portion, a tray portion, and a tray driving portion. The tray driving portion includes a motor, a supporting shaft, an input member, an output member, a link mechanism, and an urging member. The input member includes a first boss portion movably supported on the supporting shaft, and is reciprocatable up and down along the supporting shaft. The output member has a second boss portion coupled with the first boss portion via a ratchet mechanism. The link mechanism converts a rotary motion of the output member to a linear motion of the tray portion. The ratchet mechanism operates such that, when a predetermined or heavier load is applied to the output member via the tray portion, the input member is pushed down against the urging force of the urging member and engagement between the first and second ratchet teeth is released.

A sheet discharger includes: an accommodator configured to accommodate sheets; a conveyor configured to convey and discharge a sheet to the accommodator; a detector configured to detect whether a jam of a sheet has occurred in the accommodator and a state of the jam; and a controller configured to control the conveyor to continue sheet discharge upon detection by the detector of the jam in a state where sheet discharge of a jammed sheet is possible.

A sheet conveying apparatus for conveying a sheet in a conveying direction includes a pair of conveying rollers receiving and conveying a sheet; an endless conveying belt conveying the sheet; a plurality of balls to be rotatable in any direction while nipping the sheet with the conveying surface; a pair of regulating guides disposed on both sides of the conveying belt; a guide moving unit that moves the pair of regulating guides; and a roller moving unit that moves at least one of the pair of conveying rollers to a nip position and a nip release position. Before a rear end of the sheet passes the pair of conveying rollers, the pair of conveying rollers is moved to the nip release position by the roller moving unit, and then, the guide moving unit makes each of the pair of regulating guides reach the guide position from the retracting position.