A photosensitive drum is rotatably supported in a main body. A developing cartridge is detachably mountable on the main body in a state where the photosensitive drum is supported in the main body. The developing cartridge includes a developing device and a frame. The developing device includes a developing roller disposed in confrontation with the photosensitive drum to supply developer to the photosensitive drum when the developing cartridge is mounted in the main body, and a developer-accommodating portion configured to accommodate developer. The frame includes a waste-developer-accommodating portion configured to accommodate waste developer and supports the developing device that is movable relative to the frame. The frame is disposed on an opposite side of the developing roller from the photosensitive drum. An urging member is disposed between the frame and the developing device to urge the developing roller toward the photosensitive drum.

A cleaning device includes a cleaning unit and a movement mechanism. The cleaning unit includes: a cleaning part that has a contact surface extending along an axial direction of the conveyance roller and cleans the surface of the conveyance roller by bringing the contact surface into contact with the surface of the conveyance roller from below, and a cleaning housing that supports the cleaning part. The movement mechanism moves the cleaning unit between a cleaning position and a mounting and removing position below the cleaning position. The movement mechanism allows the cleaning part to be brought into contact with the conveyance roller at the cleaning position, allows the cleaning part to be disposed below the conveyance roller in a separated manner at the mounting and removing position and allows the cleaning unit to be mounted on or to be removed from an apparatus body.

A foreign substance collection apparatus includes: a frame body; a photosensitive drum; a cleaning roller which collects foreign substances from a surface of the photosensitive drum; a collecting roller which further collects the foreign substances having been collected by the cleaning roller from the cleaning roller; and a scraping member which scrapes off the foreign substances from the collecting roller. A foreign substance collecting portion included in the frame body has, in a posture during use: a first inner bottom surface which is positioned below the scraping member in a gravity direction; an outer bottom surface which is positioned further below the first inner bottom surface; and a connecting surface which intersects the first inner bottom surface and the outer bottom surface and which connects the first inner bottom surface and the outer bottom surface with each other.

An image forming apparatus includes: a toner image former that forms a toner image on an outer peripheral surface of a photosensitive rotating body and that transfers the toner image having been formed onto a transfer receiving object; a detector that detects a grayscale abnormality of the toner image on the photosensitive rotating body or the transfer receiving object; a cleaner that cleans the outer peripheral surface of the photosensitive rotating body; and a hardware processor that causes the cleaner to clean when the detector detects the grayscale abnormality at a same position in a main scanning direction per circumferential length of the photosensitive rotating body in a sub-scanning direction.

A photosensitive drum is rotatably supported in a main body. A developing cartridge is detachably mountable on the main body in a state where the photosensitive drum is supported in the main body. The developing cartridge includes a developing device and a frame. The developing device includes a developing roller disposed in confrontation with the photosensitive drum to supply developer to the photosensitive drum when the developing cartridge is mounted in the main body, and a developer-accommodating portion configured to accommodate developer. The frame includes a waste-developer-accommodating portion configured to accommodate waste developer and supports the developing device that is movable relative to the frame. The frame is disposed on an opposite side of the developing roller from the photosensitive drum. An urging member is disposed between the frame and the developing device to urge the developing roller toward the photosensitive drum.

A photosensitive drum rotates about a first axis extending in a first direction. A photosensitive drum is located at one end portion of a housing in a second direction. A cleaning roller cleans a surface of the photosensitive drum. The cleaning roller rotates about a second axis extending in the first direction. A cleaning electrode is electrically connected to the cleaning roller. The cleaning electrode is located at an outer surface of the housing in the first direction. The cleaning electrode is located at a tip end of the one end portion of the housing in the second direction. The cleaning electrode includes a contact surface and a guide surface. The contact surface contacts an electrical contact to which a voltage is supplied. The contact surface is perpendicular to the first direction. The guide surface guides the electrical contact to the contact surface when the drum cartridge is mounted.

An optical scanning device includes a light transmitting member, a guide rail, a holding member, and a cleaning member. The light transmitting member extends in a main scanning direction and transmits a light beam. The guide rail extends in the main scanning direction and is arranged parallel to the light transmitting member. The holding member extends in a cross direction intersecting the main scanning direction and moves in the main scanning direction along the guide rail. The cleaning member is held by the holding member and cleans a light emitting surface of the light transmitting member by means of movement of the holding member in the main scanning direction.

An image forming apparatus includes a rotatable image bearing member, a developing unit to develop an electrostatic latent image at a developing portion, a transfer unit to transfer a developer image to a recording member at a transfer portion; and a brush provided with a plurality of fibers contacting the image bearing member at downstream of the transfer portion and upstream of the developing portion in a rotational direction of the image bearing member. An average contacting pressure of the brush per one fiber to the image bearing member is smaller than a depositing force of the developer not transferred to the recording member to the image bearing member. As the brush in a state of not in contact with the image bearing member is viewed from a free end side of the fibers, an average number of the fibers included in a circumference of a diameter of 100 μm is more than one.

A cleaning unit is attachable to and detachable from a main body of an image forming apparatus including a photosensitive drum and a belt configured to contact the photosensitive drum. The cleaning unit includes: a frame; and a handle. The frame is configured to accommodate therein developing agent collected from the image forming apparatus. The handle includes: a pair of first parts; and a second part. Each of the pair of first parts extends from the frame in an extending direction perpendicular to an axial direction of the photosensitive drum in a state where the cleaning unit is attached to the main body. The pair of first parts includes a lock mechanism for locking the cleaning unit to the main body. The second part extends in the axial direction and connects the pair of first parts to each other.

A photosensitive drum is rotatably supported in a main body. A developing cartridge is detachably mountable on the main body in a state where the photosensitive drum is supported in the main body. The developing cartridge includes a developing device and a frame. The developing device includes a developing roller disposed in confrontation with the photosensitive drum to supply developer to the photosensitive drum when the developing cartridge is mounted in the main body, and a developer-accommodating portion configured to accommodate developer. The frame includes a waste-developer-accommodating portion configured to accommodate waste developer and supports the developing device that is movable relative to the frame. The frame is disposed on an opposite side of the developing roller from the photosensitive drum. An urging member is disposed between the frame and the developing device to urge the developing roller toward the photosensitive drum.