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 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.

A control unit performs control to make a direction of an electric field generated in a first area of an image carrier forming a transfer portion during image forming operation, relative to a voltage applied to a brush member in a state where the first area passes through a contact portion, different from a direction of an electric field generated in a second area of the image carrier forming the contact portion, relative to the voltage applied to the brush member during a period when operation is shifted from first operation in which the image carrier is rotated at a first speed to second operation in which the image carrier is rotated at a second speed different from the first speed, during non-image forming operation different from the image forming operation.

A control unit performs control to make a direction of an electric field generated in a first area of an image carrier forming a transfer portion during image forming operation, relative to a voltage applied to a brush member in a state where the first area passes through a contact portion, different from a direction of an electric field generated in a second area of the image carrier forming the contact portion, relative to the voltage applied to the brush member during a period when operation is shifted from first operation in which the image carrier is rotated at a first speed to second operation in which the image carrier is rotated at a second speed different from the first speed, during non-image forming operation different from the image forming operation.

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.

A control unit performs control to make a direction of an electric field generated in a first area of an image carrier forming a transfer portion during image forming operation, relative to a voltage applied to a brush member in a state where the first area passes through a contact portion, different from a direction of an electric field generated in a second area of the image carrier forming the contact portion, relative to the voltage applied to the brush member during a period when operation is shifted from first operation in which the image carrier is rotated at a first speed to second operation in which the image carrier is rotated at a second speed different from the first speed, during non-image forming operation different from the image forming operation.

An image forming apparatus includes a transfer unit configured to transfer second charged images superposed with one another onto a holding surface of a recording medium on which at least one first charged image has been electrostatically held and a static eliminating unit disposed upstream from the transfer unit in a transport direction of the recording medium and configured to remove static electricity from the recording medium electrostatically holding the at least one first charged image.

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 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.

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.