An image forming apparatus includes an apparatus body, a sheet supporting portion, a sheet feeding portion configured to feed a sheet supported on the sheet supporting portion, a sheet regulation portion configured to regulate a position of the sheet in a width direction, an image forming portion including an exposing portion configured to expose a charged surface of an image bearing member, the image forming portion being configured to form an image on the sheet fed by the sheet feeding portion, and a frame member provided inside the apparatus body. A position of the exposing portion is determined with respect to the frame member. A position of the sheet regulation portion is determined with respect to the frame member.

The present invention provides an image forming apparatus that reduces image artifacts caused by the back tension of a separating unit. A control unit decreases the number of rotations (the rotational speed) of a resist roller pair after the leading edge of a sheet reaches a transfer position.

An image forming apparatus includes: a photosensitive drum; a developing roller; a separation mechanism for moving the developing roller between a contacting position contacting the photosensitive drum and a separated position separated from the photosensitive drum; a first tray; a first sheet feed mechanism for feeding a sheet from the first tray toward the photosensitive drum; a first sheet sensor for detecting passage of the sheet at a prescribed position; and a controller configured to perform: when a printing operation is performed onto the sheet fed from the first tray, feeding the sheet in the first tray to the prescribed position and maintain the sheet; moving, on or after the first sheet sensor detects the sheet, the developing roller to the contacting position; and feeding, after a prescribed time period has elapsed since the first sheet sensor detects the sheet, the sheet from the prescribed position toward the photosensitive drum.

The present invention provides an image forming apparatus that reduces image artifacts caused by the back tension of a separating unit. A control unit decreases the number of rotations (the rotational speed) of a resist roller pair after the leading edge of a sheet reaches a transfer position.

An image forming apparatus includes a chassis having an opening, a cover, photosensitive members, an intermediate transfer belt, a primary-transfer member, a secondary-transfer roller, a cleaner device, an external-sheet inlet, a waste toner container, a connector, and a conveying roller, which is arranged within the feeding path to feed the recording sheet inserted through the external-sheet inlet in the feeding path. The conveying roller is mounted on the waste toner container and removable from the chassis along with the waste toner container.

A sheet conveyance apparatus includes a first conveyance portion configured to convey a sheet, a second conveyance portion configured to convey the sheet, the second conveyance portion including an abutment portion configured to form a loop on the sheet by being abutted against a leading edge of a sheet conveyed by the first conveyance portion, a curved guide portion, which is curved, configured to guide the sheet conveyed by the first conveyance portion to the second conveyance portion, and a rotary member arranged downstream of the first conveyance portion and upstream of the second conveyance portion in a sheet conveyance direction, and configured to be driven to rotate by a surface of the sheet that is guided by the curved guide portion, the surface sliding against the curved guide portion.

An image forming apparatus includes a chassis having an opening, a cover, photosensitive members, an intermediate transfer belt, a primary-transfer member, a secondary-transfer roller, a cleaner device, an external-sheet inlet, a waste toner container, a connector, and a conveying roller, which is arranged within the feeding path to feed the recording sheet inserted through the external-sheet inlet in the feeding path. The conveying roller is mounted on the waste toner container and removable from the chassis along with the waste toner container.

An image forming apparatus includes a chassis having an opening, a cover, photosensitive members, an intermediate transfer belt, a primary-transfer member, a secondary-transfer roller, a cleaner device, an external-sheet inlet, a waste toner container, a connector, and a conveying roller, which is arranged within the feeding path to feed the recording sheet inserted through the external-sheet inlet in the feeding path. The conveying roller is mounted on the waste toner container and removable from the chassis along with the waste toner container.

An image forming apparatus is provided. The image forming apparatus includes a chassis having an opening, a cover, photosensitive members, an intermediate transfer belt, a primary-transfer member, a secondary-transfer roller, a cleaner device, an external-sheet inlet, a waste toner container, a connector, and a conveying roller, which is arranged within the feeding path to feed the recording sheet inserted through the external-sheet inlet in the feeding path. The conveying roller is mounted on the waste toner container and removable from the chassis along with the waste toner container.

A unit accommodation apparatus includes a first unit and a second unit that are to be installed into and removed from an apparatus body through an opening in an installation-removal direction and are held by a unit holder. The unit holder includes a first positioner that is disposed opposite one lateral end of the first unit and the second unit and is detachably attached to the first unit and the second unit. A second positioner is disposed opposite another lateral end of the first unit and the second unit and holds the first unit and the second unit in a state in which the first unit and the second unit are detachably attached to the second positioner. The first positioner and the second positioner secure a relative position of the first unit relative to the second unit in a direction parallel to a hypothetical orthogonal plane perpendicular to the installation-removal direction.