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 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.

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.

In an image forming apparatus, the image bearing member has a surface and configured to rotate about an axis. The collection device is in contact with the surface, and configured to collect materials adhered to the surface. The developing roller is configured to provide a charged toner having a first polarity. The processor is configured to perform: executing a print job in a printing period; executing, in a non-printing period, a first process in which the image bearing member is rotated at least one rotation while a holding bias is applied to the collection device, the holding bias having a second polarity opposite to the first polarity; and executing, in a non-printing period after the first process, a second process in which the image bearing member is rotated while an ejection bias is applied to the collection device, the ejection bias having the first polarity.

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.

In an image forming apparatus, the image bearing member has a surface and configured to rotate about an axis. The collection device is in contact with the surface, and configured to collect materials adhered to the surface. The developing roller is configured to provide a charged toner having a first polarity. The processor is configured to perform: executing a print job in a printing period; executing, in a non-printing period, a first process in which the image bearing member is rotated at least one rotation while a holding bias is applied to the collection device, the holding bias having a second polarity opposite to the first polarity; and executing, in a non-printing period after the first process, a second process in which the image bearing member is rotated while an ejection bias is applied to the collection device, the ejection bias having the first polarity.

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 including a cleaning member having a belt cleaning blade and a conductive brush. A value of a charging current that is generated when charging residual toner with the conductive brush is smaller when a color mode is executed compared to that when a monochrome mode is executed.

An electrostatic collecting device includes a rotatable collecting body including a collecting member for forming a collecting portion in contact with an object-to-be-cleaned and formed of an insulator, wherein the rotatable collecting body rubs the object-to-be-cleaned in the collecting portion with the collecting member by rotation thereof, and collects, in the collecting member, a substance-to-be-collected from the object-to-be-cleaned moved relative to the collecting portion; a removing member for removing the substance-to-be-collected from the collecting member; and a charge-removing member provided opposed to the object-to-be-cleaned on a side downstream of the collecting portion with respect to a movement direction of the object-to-be-cleaned relative to the collecting portion. The charge-removing member constitutes at least a part of at least one of the rotatable collecting body and the removing member. The charge-removing member is electrically connected to an electric conductor which is in non-contact with the object-to-be-cleaned.

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.