An image forming apparatus includes a charging unit that charges an image bearing member, a developing unit that forms a toner image on an latent image formed on the image bearing member, a transfer unit that transfers the toner image onto a transfer material, a charge neutralizer that neutralizes a charge of the image bearing member downstream of a transfer portion and upstream of a charging portion in a rotating direction of the image bearing member, a conductive collecting unit that collects a material adhering on the image bearing member downstream of the transfer portion and upstream of the charging portion, wherein the developing unit collects residual toner on the image bearing member, an voltage application unit sets a potential difference between the voltage applied to the collecting unit and the surface electric potential of the image bearing member not more than a discharge threshold.

An image forming apparatus includes a photosensitive drum, a development roller configured to supply developer to the photosensitive drum, a transfer roller configured to transfer a developer image formed on the photosensitive drum to a recording material, and a cleaning roller being in contact with the photosensitive drum, configured to clean a part of the recording material adhered to the photosensitive drum, wherein the diameter of the transfer roller is greater than the diameter of the development roller and the diameter of the cleaning roller is greater than the diameter of the development roller.

A developing device includes first and second chambers, a partition wall, first and second feeding screws, a developing roller, a supplying roller, a first magnet including a first magnetic pole, a second magnet including second to fourth magnetic poles, and a guiding portion. With respect to a supplying roller rotational direction, in a position downstream of the third magnetic pole, a magnetic flux density of the fourth magnetic pole in a normal direction is 20% of a maximum value thereof is a first position positioned downstream of a second position where a line connecting a lowermost end of the guiding portion and a supplying roller center crosses an outer peripheral surface of the supplying roller, and upstream of a third position where a line connecting an uppermost end of the first feeding screw and the supplying roller center crosses the outer peripheral surface of the supplying roller.

According to one embodiment, an image forming apparatus includes a printer, a memory, a processor, and a display. The printer forms an image according to the operation of a person. The memory stores contact history information indicating the history of contact of a person. The processor acquires information on contact infection of a virus at a site contacted by a specific person from the contact history information stored in the memory. The display shows information on the contact infection of the virus.

An image forming apparatus includes a rotatable image bearing member, a developing member, a transfer member, and a brush contacting a surface of the image bearing member in a contact portion downstream of a transfer portion and upstream of a developing portion with respect to a rotational direction of the image bearing member. The toner which is not transferred onto a toner image receiving member is collected by the developing member. In a charging series, the toner is positioned on the same side as a normal charge polarity of the toner relative to the brush. In the contact portion, a maximum value of a contact pressure of 0.7 gf/mm.sup.2 or more and 3.5 gf/mm.sup.2 or less, a maximum contact area ratio is 18% or more and 74% or less, and a Clark-Evans index of the brush is 1 or more.

A drum cartridge includes: a photosensitive drum rotatable about a drum axis extending in an axis direction; a drum cleaner including a cleaning member cleaning a circumferential surface of the photosensitive drum, and a cleaning housing accommodating transfer residual toner removed from the circumferential surface of the photosensitive drum by the cleaning member; a first drum side plate supporting a first end portion of the photosensitive drum; a second drum side plate located distant from the first drum side plate in the axis direction and supporting a second end portion of the photosensitive drum; a pipe located between the first drum side plate and the second drum side plate in the axis direction and extending in the axis direction; and a conveyor device conveying the transfer residual toner from the cleaning housing to the pipe.

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.

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.

A process cartridge includes a developer carrier including a dielectric portion and a conductive portion on a surface thereof, a regulation member, and an image carrier disposed so as to come into contact with the developer carrier. The developer carrier and the image carrier are rotationally driven such that a surface of the developer carrier and a surface of the image carrier move at linear velocities different from each other at a contact portion, and the developer remaining on the image carrier after the developer image is transferred from the image carrier, is collected by the developer carrier at the contact portion.

An image forming apparatus includes a photosensitive member, a charging member, an exposing device, a developing device, a transfer member, a brush, a voltage applying portion, and a control portion controlling a surface potential of the photosensitive member at the brush contacting position. When a value of subtracting a value of the surface potential of the photosensitive member in the brush contacting position from a value of the brush voltage is defined as a contacting position potential difference, the control portion controls the surface potential of the photosensitive member in the brush contacting position so that the contacting position potential difference is changed from a first potential difference to a second potential difference in a predetermined direction which is either one of an increasing direction or a decreasing direction, and then the contacting position potential difference is changed from the second potential difference to a third potential difference in the predetermined direction.