In a case where a sheet jam detection unit detects that a sheet jam has occurred in an image bearing member, and determines that there is no sheet P at a nip portion, a printer control unit starts cleaning by a cleaning unit without waiting for removal of the sheet P causing the sheet jam.

An image forming method includes when an image forming device is in a non-image-forming stage, applying voltages to a surface of a photosensitive element and a surface of a developer element of the image forming device to form an electric field. Applying the voltages includes: forming a first potential difference between the photosensitive element and the developer element in a first stage, and forming a second potential difference between the photosensitive element and the developer element in a second stage. When a developer used by the developer element is a negatively charged developer, a direction of the first potential difference and a direction of the second potential difference are in a direction from the developer element to the photosensitive element. When positively charged, the direction of the first potential difference and the direction of the second potential difference are in a direction from the photosensitive element to the developer element.

A charge roller includes, in a surface thereof, recesses that have sizes that are equivalent to or larger than a volume average particle diameter of a toner accommodated in a developing unit and that are capable of collecting the toner retransferred to a photosensitive drum.

A drum cleaner in a drum unit removes toner from a photosensitive drum. A waste-toner conveyance pipe has a waste-toner discharge port and conveys toner removed from the photosensitive drum by the drum cleaner. A toner accommodation chamber accommodates toner to be supplied to a developing roller. A waste-toner accommodation chamber accommodates toner removed from the photosensitive drum. A toner cartridge rotatably moves relative to the drum unit between: a first position at which a waste-toner receiving port is separated from the waste-toner discharge port in a state where the toner cartridge is mounted on the drum unit; and a second position at which an internal space of the waste-toner accommodation chamber is in communication with an internal space of the waste-toner conveyance pipe through the waste-toner discharge port and the waste-toner receiving port in a state where the toner cartridge is mounted on the drum unit.

In an image forming apparatus which includes a plurality of image forming units each including an image bearing member, a contact charging member, and a developer bearing member for forming toner of normal polarity, and which, in a printing operation, applies a charging bias having a first direction, in a cleaning operation, applies a charging bias having a second direction, and recovers residual toner remaining on the image bearing member without used for printing by the developer bearing member, before performing the cleaning operation, when successively performing the printing operation on a plurality of recording materials including a first recording material and a second recording material, which is used for printing following the first recording material, the charging voltage larger in absolute value in the printing operation for the second recording material than in the printing operation for the first recording material is applied.

An image forming apparatus includes a discharging device for discharging the drum at a discharging portion opposing the surface of the drum; and a control unit for executing, during non-image formation, a cleaning operation for transferring the toner deposited on the transfer member onto the drum by applying a voltage from transfer voltage source to the transfer member. The control unit does not effect discharge by the discharging device for at least a region of the drum where a transfer voltage for transferring a normal-polarity toner of the toner deposited on the transfer member onto the drum is applied to the transfer member in the cleaning operation, and then passes the region of the drum through the charging portion in a state in which a voltage larger than a surface potential of the drum in a normal polarity side is applied to the charging member.

An image forming apparatus includes a rotatable image bearing member, a developing member to develop an electrostatic latent image at a developing portion, a transfer member to transfer a developer image to a recording member at a transfer portion; and a brush provided with a plurality of base materials 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. The developer remaining on the surface of the image bearing member is collected in the developing portion. An average distance between base materials of the brush with respect to a rotational axis direction of the image bearing member is larger than an average particle diameter of the developer, and is equal to or less than a length corresponding to a spatial frequency visually recognizable by a user when the image formed by the image forming apparatus is observed by the user.

An image forming apparatus (1) includes an image bearing member (50), a charging section (51), a developing section (52), and a cleaning member (81). The image bearing member (50) contains filler particles (87). The charging section (51) is either in contact with or positioned close to the image bearing member (50) and is configured to electrically charge the image bearing member (50) by generating a proximity discharge between the charging section (51) and the image bearing member (50). The developing section (52) supplies toner to the circumferential surface of the charged image bearing member (50). The cleaning member (81) has a degree of hardness equal to or higher than 65 and a degree of impact resilience equal to or lower than 30%. The cleaning member (81) is brought into pressure contact with the circumferential surface of the image bearing member (50) being rotated, by applying linear pressure equal to or higher than 15 gf/cm.

An image forming apparatus determines the replacement timing of a component of the image forming apparatus and includes: a rotatable body; a cleaner to remove developer adhered to the rotatable body; and a controller determining that a usable period of the cleaner is longer as a charge amount of the developer is smaller.

An image forming apparatus includes a photosensitive member that rotates at a first speed, an intermediate transfer member that rotates at a second speed lower than the first speed, and a collecting member disposed in a state in which a fixed surface is pressed against the rotating intermediate transfer member. The collecting member collects toner remaining on the intermediate transfer member after a toner image is secondarily transferred from the intermediate transfer member to a transfer material.