An image forming apparatus has a main body, a belt unit configured to accommodate a belt, a belt cleaning member and an accommodating unit. The belt cleaning unit is configured to remove waste toner adhered on the belt. The accommodating unit is configured to accommodate the toner removed by the belt cleaning unit. The apparatus further includes a drum unit having a drum cleaning member, and a waste toner conveying mechanism configured to convey the waste toner to the collecting unit. The conveying mechanism has a drum-side conveying unit configured to be connected with the drum cleaning member. Communication between the drum-side conveying unit and the collecting unit is enabled in association with movement of the drum unit from the outside position to the inside position, and disabled in association with movement of the drum unit from the inside position to the outside position.

An image forming apparatus includes a photosensitive member, a charger, a developing device, a transfer device, a scraper, and a controller. The controller performs an image formation process to form the developer image on the photosensitive member by using the developing device. The controller acquires, as a first value, at least one of a value of the charging current flowing in the charger and a value of the transferring current flowing in the transfer device. The controller calculates an accumulation current value by using result of an integral of a second value over time. The second value is an absolute value of the first value. The controller performs a scraping process in which the scraper scrapes the photosensitive member when the accumulation current value reaches a threshold value.

An image forming apparatus is described. An image forming apparatus may include an image forming apparatus body and a tandem type photosensitive unit slidable with respect to the body, wherein the unit includes: a frame; a plurality of photosensitive bodies; a plurality of developer cartridges, including developer carriers, detachably mountable on the frame; and a pressing portion provided on the frame for pressing each of the cartridges so that the developer carrier thereof is directed toward the corresponding photosensitive body, each of the cartridges is pivoted to be movable to an imaging position pressed by the pressing portion and a detached position released from the pressing by the pressing portion, and the body is provided with an abutting portion abutting the cartridge located on the detached position thereby pivoting the cartridge and moving the same to the imaging position when the unit is mounted on the body.

An image forming apparatus includes one or plural forming devices that form respective images on a recording medium that is being transported, a fixing device provided on a downstream side with respect to at least one of the forming devices in a direction of transport of the recording medium and that fixes the images formed on the recording medium, a delivering device that receives the recording medium transported in a first direction and discharges the recording medium in a second direction that is different from the first direction, and a supplying device that supplies the recording medium to any of the forming devices or to the delivering device. The forming devices, the fixing device, the delivering device, and the supplying device have respective housings and are each joinable to any of the other devices.

A fixing device includes an endless belt, a heater disposed inside the endless belt and being elongated in a longitudinal direction, the heater having a first end portion in the longitudinal direction and a second end portion opposite to the first end portion in the longitudinal direction, a resin frame having a recess portion opening toward an inner side of the endless belt, and a metal frame inserted into the recess portion of the resin frame. The metal frame has a first wall having a through-hole, and a second wall extending in a direction from the first end portion of the heater toward a second end portion of the heater, the second wall being disposed between the resin frame and the heater.

A developer cartridge is described. The developer cartridge detachably mountable on a tandem type photosensitive unit slidable to a drawn-out position and a mounted position with respect to an image forming apparatus body may include a casing; a developer carrier rotatably supported on one end portion of the casing for carrying a developer; a pair of upright portions arranged on another end portion of the casing at an interval from each other in the axial direction of the developer carrier to extend from another end portion of the casing in a detaching direction for the developer cartridge; and an elastically deformable coupling portion extending in the axial direction of the developer carrier for coupling the upright portions with each other.

An image-forming apparatus includes a main body, a belt unit detachably attachable to the main body, a coupling and a restricting part. The belt unit includes: a first roller defining an axis extending in an axial direction, a second roller opposing the first roller in a first direction perpendicular to the axial direction, and a belt looped over the first roller and the second roller. The coupling is configured to move in the axial direction to come into engagement with the first roller for inputting a drive force into the first roller. The restricting part is provided on the main body and is configured to restrict the first roller from moving in a second direction perpendicular to the axial direction and the first direction when the belt unit is attached to the main body.

An image forming apparatus has a main body, a belt unit configured to accommodate a belt, a belt cleaning member and an accommodating unit. The belt cleaning unit is configured to remove waste toner adhered on the belt. The accommodating unit is configured to accommodate the toner removed by the belt cleaning unit. The apparatus further includes a drum unit having a drum cleaning member, and a waste toner conveying mechanism configured to convey the waste toner to the collecting unit. The conveying mechanism has a drum-side conveying unit configured to be connected with the drum cleaning member. Communication between the drum-side conveying unit and the collecting unit is enabled in association with movement of the drum unit from the outside position to the inside position, and disabled in association with movement of the drum unit from the inside position to the outside position.

A toner, including a binder resin, a release agent, and a colorant, wherein a total amount of hydrocarbon compounds having 33 to 35 carbon atoms in the toner measured by ion attachment mass spectrometry (IAMS) is 40% to 70% in terms of a signal intensity ratio.

A developer cartridge is described. The developer cartridge detachably mountable on a tandem type photosensitive unit slidable to a drawn-out position and a mounted position with respect to an image forming apparatus body may include a casing; a developer carrier rotatably supported on one end portion of the casing for carrying a developer; a pair of upright portions arranged on another end portion of the casing at an interval from each other in the axial direction of the developer carrier to extend from another end portion of the casing in a detaching direction for the developer cartridge; and an elastically deformable coupling portion extending in the axial direction of the developer carrier for coupling the upright portions with each other.