Abstract: An image forming apparatus includes a main housing, a movable drawer, and a process cartridge attachable to the drawer. The process cartridge includes a drum unit, and a developing unit. The drum unit includes a drum housing, and a photosensitive drum rotatable about a first axis extending in a first direction. The photosensitive drum is positioned at one end portion of the drum housing at one side in a second direction. The developing unit includes a developing casing, a developing roller, and a developing handle for detaching the process cartridge from the drawer toward another side in the second direction. The developing roller is positioned at one end portion of the developing casing at the one side in the second direction. The developing handle is positioned apart from the drum unit toward the another side in the second direction.

Abstract: An image forming apparatus includes: a photosensitive drum; a magnetic roller; a transfer belt; a drum cleaning roller for collecting toner on the photosensitive drum and discharging collected toner to the photosensitive drum; a belt cleaner; a waste toner accommodating unit; and a controller configured to perform a printing operation for forming an image on a sheet and a cleaning operation for cleaning the drum cleaning roller. The controller is configured to perform: when performing the printing operation, collecting toner on the photosensitive drum using the drum cleaning roller; and when performing the cleaning operation, discharging the toner on the drum cleaning roller collected in the collecting to the photosensitive drum; transferring the toner on the photosensitive drum onto the transfer belt; and collecting the toner on the transfer belt using the belt cleaner so that the collected toner is accommodated in the waste toner accommodating unit.

Abstract: An image forming apparatus including a motor, a photosensitive drum, a developing roller, a main memory, and a controller. The controller is configured to perform storing a first rotation number and a second rotation number in the main memory. The first rotation number is the rotation number of the photosensitive drum rotated in a first state where the photosensitive drum rotates and the developing roller is stopped. The second rotation number is the rotation number of the photosensitive drum rotated in a second state where the photosensitive drum rotates and the developing roller rotates. The controller is further configured to perform, in a case where the photosensitive drum rotates, determining a total deterioration quantity of the photosensitive drum which is a cumulative deterioration quantity of the photosensitive drum based on the first rotation number and the second rotation number.

Abstract: An image-forming apparatus includes: a photosensitive drum, a motor, and a drum gear train configured to transmit a driving force from the motor to the photosensitive drum. The drum gear train includes a first gear, a second gear and a first clutch. The first gear is rotatable about a first axis upon receipt of the driving force. The second gear is rotatable about the first axis and configured to receive the driving force from the first gear and to transmit the driving force to the photosensitive drum. The first clutch is switchable between a first transmission state where the driving force is transmitted from the first gear to the second gear and a first transmission cutoff state where the transmission of the driving force from the first gear to the second gear is cut off.

Abstract: An image forming apparatus including a motor, a photosensitive drum, a developing roller, a main memory, and a controller. The controller is configured to perform storing a first rotation number and a second rotation number in the main memory. The first rotation number is the rotation number of the photosensitive drum rotated in a first state where the photosensitive drum rotates and the developing roller is stopped. The second rotation number is the rotation number of the photosensitive drum rotated in a second state where the photosensitive drum rotates and the developing roller rotates. The controller is further configured to perform, in a case where the photosensitive drum rotates, determining a total deterioration quantity of the photosensitive drum which is a cumulative deterioration quantity of the photosensitive drum based on the first rotation number and the second rotation number.

Abstract: An image-forming apparatus includes: a photosensitive drum, a motor, and a drum gear train configured to transmit a driving force from the motor to the photosensitive drum. The drum gear train includes a first gear, a second gear and a first clutch. The first gear is rotatable about a first axis upon receipt of the driving force. The second gear is rotatable about the first axis and configured to receive the driving force from the first gear and to transmit the driving force to the photosensitive drum. The first clutch is switchable between a first transmission state where the driving force is transmitted from the first gear to the second gear and a first transmission cutoff state where the transmission of the driving force from the first gear to the second gear is cut off.