An image forming apparatus includes a plurality of photosensitive members; a scanner unit including light sources, a rotatable polygonal mirror, and reflecting members; and a fixing portion. Parts of the laser beams emitted from the light sources are reflected by the rotatable polygonal mirror toward the fixing device side, and rest parts of the laser beams are reflected by the rotatable polygonal mirror toward a side opposite from the fixing device side. Of the parts of the laser beams reflected by the rotatable polygonal mirror toward the fixing device side, the laser beam reflected toward the reflecting member provided at a position remotest from the rotatable polygonal mirror travels downward relative to a horizontal direction. A rotational axis of the rotatable polygonal mirror is inclined relative to a vertical direction.

A sheet discharge apparatus includes a discharge and sheet support unit, a detection unit, a rotation member having a first abutting portion positioned above the sheet support unit, and a pressing member provided rotatably independent of the rotation member. The discharge unit nips and discharges a sheet in a sheet discharge direction. The sheet support unit supports the discharged sheet. The rotation member rotates when the first abutting portion is pressed by the sheet. The detection unit detects a position of the rotation member. A second abutting portion of the pressing member abuts against the sheet at a position downstream from a position at which the discharge unit nips the sheet and upstream from the first abutting portion in the sheet discharge direction. The pressing member presses the sheet discharged from the discharge unit downward using the second abutting portion, regardless of a position of the rotation member.

An image forming apparatus includes a tray which is movable between a housed position at which the tray is housed in a housing portion of a body and a drawn-out position, a first cartridge detachably attached to the tray and including a first developing roller, and a second cartridge detachably attached to the tray and including a second developing roller. In a contacting state where (i) the first cartridge and the second cartridge are attached to the tray, (ii) the tray is in the housed position, (iii) the first developing roller contacts a first photosensitive drum, and (iv) the second developing roller contacts a second photosensitive drum, a position of a first projection of the first cartridge and a position of a first holder to which a first memory is fixed at least partially overlap each other with respect to the vertical direction.

A drive transmission device includes a first gear, a second gear, a switch arm, a third gear, a first sector gear including a first teeth portion and rotatable about a second axis in a predetermined direction, a second sector gear including a second teeth portion and engaging the first sector gear movably with play in the predetermined direction, a lever, a solenoid, and a first urging member. The switch arm has a cam contact surface, and the second sector gear includes a cam configured to contact the cam contact surface. When the first sector gear rotates in the predetermined direction for a predetermined amount from a state where the third gear engages the first gear and where the first teeth portion and the second teeth portion disengage from the second gear, the first teeth portion engages the second gear, and the second teeth portion disengages from the second gear.

A blowing device is equipped with a blowing portion and a holder. The blowing portion has a cylindrical body that stores a rotating body, and includes: a suction inlet arranged on a side surface perpendicular to the axial direction of the cylindrical body; and an exhaust outlet arranged on a part of the peripheral surface of the cylindrical body. The holder has a wall that faces the peripheral surface of the blowing portion with a gap between the wall and the peripheral surface, and holds the blowing portion inside. The holder includes: a suction portion that communicates with the suction inlet; and an exhaust portion that causes the exhaust outlet to communicate with the outside and the gap.

A sheet stacker includes a sheet stacking member, a biasing force applier, an angle setter, and a regulator. The sheet stacking member has an upstream portion in a sheet conveyance direction. The upstream portion is movable in a vertical direction. The biasing force applier is configured to apply a biasing force to bias the sheet stacking member upward. The angle setter is configured to set an angle of the sheet stacking member in the sheet conveyance direction, relative to a sheet conveying portion, between a first angle and a second angle. The regulator is configured to regulate movement of the sheet stacking member in a case in which the upstream portion of the sheet stacking member is located closer to the sheet conveying portion at either the first angle or the second angle.

A sheet discharge device includes: at least one processor; a conveyance unit configured to convey a sheet along a conveyance path; a discharge unit to which the sheet is discharged; a storage unit that is provided in a middle of the conveyance path and temporarily stores the sheet; an alignment unit provided in the discharge unit and configured to align the sheet in a width direction intersecting a convey direction of the sheet, in which the processor is configured to change a method of aligning the sheets by the alignment unit between a case where storage control for storing the sheets in the storage unit is performed and a case where the storage control is not performed.

An image forming apparatus, including: a sheet cassette; an image former; a fixer; a discharge tray; a conveyor configured to convey a sheet along a conveyance passage; a return conveyor configured to convey the sheet from a branch position between the fixer and the discharge tray to a merge position between the sheet cassette and the image former along a return passage which is branched from the conveyance passage at the branch position, passes below the sheet cassette, and merges with the conveyance passage at the merge position; a switchback roller disposed between the branch position and the discharge tray in the conveyance passage and configured to convey the sheet to the discharge tray when it rotates forwardly and to the return passage when it rotates backwardly; and an intermediate conveyance roller disposed in the return passage at a height level intermediate between the fixer and the sheet cassette.

An image forming apparatus includes an image forming unit including an image bearing member, and a casing on which a discharge port is formed, the casing including a first frame, a second frame disposed below the first frame in a vertical direction, a side cover, and a top cover, the first frame including a side plate that supports an end, in a longitudinal direction, of the image bearing member. At least one of the top cover and the first frame includes a first pillar portion. The second frame includes a second pillar portion. The side cover includes a third pillar portion disposed between the first pillar portion and the second pillar portion in the vertical direction, the third pillar portion being provided at a position at least partially overlapping with the first pillar portion and the second pillar portion when viewed in the vertical direction.

A sheet processing system according to an embodiment includes a tray that supports a sheet on opposite sides of the sheet orthogonal to a conveyance direction of the sheet. The tray includes a first adjustable support and second adjustable support positioned opposite the first adjustable support in the direction orthogonal to the conveyance direction of the sheet. A skew sensor detects a skew angle of the sheet conveyed to the tray. A corner sensor detects positions of each corner on a front end in the downstream direction of the sheet conveyed to the tray. A controller controls movement of the first and second adjustable supports based on the detected skew angle and the detected positions of each corner on the front end of the sheet conveyed to the tray so that the sheet is conveyed to the tray without jamming.