A developing device includes a developing container, a developing roller, a supplying roller, a first magnet including a first magnetic pole, a second magnet including a second magnetic pole and a third magnetic pole, a regulating member provided opposed to the third magnetic pole. During non-image formation, an operation in a mode in which the supplying roller is rotated in a direction opposite to a rotational direction of the supplying roller during image formation is executable. With respect to the rotational direction of the supplying roller during the image formation, a position where a magnet flux density of the third magnetic pole in a tangential direction to an outer peripheral surface of the supplying roller is zero is positioned downstream of an upstream end of the regulating member and upstream of the second magnetic pole.

A developing apparatus includes an electrostatic latent image bearer, a developing sleeve, a case, and an air filter. The case accommodates a two-component developer and the developing sleeve. The air filter is attached to the case. The air filter has a thickness of 2 to 20 mm and has a density gradient with a pressure loss of 2 to 40 Pa at a wind speed of 10 cm/s. The air filter forms an airflow sucked into the case from a gap between the developing sleeve and the case and forms an airflow discharged from the case through the air filter. The two-component developer accommodated in the case contains a magnetic particle a surface of which is coated with a resin layer. The resin layer contains at least one type of chargeable particle.

An optical scanning device (12) includes cleaning holders (511, 512), light transmitting members (52), a linear member (54), a winding motor (55), and stoppers (56a, 56b). The two cleaning holders (511, 512) are coupled to the linear member (54). The linear member 54 is driven to circulate by the winding motor (55), whereby the two cleaning holders (511, 512) move and each cleaning member slides on a corresponding one of the light transmitting members (52). When the cleaning holders (511, 512) come into contact with the respective stoppers (56a, 56b), the stoppers (56a, 56b) restrict movement of the respective cleaning holders (511, 512) in one of directions of extension of the light transmitting members (52). A contact determining section (913) determines, based on a current value of the winding motor (55), that the cleaning holder (511, 512) has come into contact with the stopper (56a, 56h).

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 rotatable image bearer, a transfer member, a cleaning member, a light irradiator, and a light transmissive member. The transfer member forms a transfer position at which a visible image on a surface of the image bearer is transferred to a recording medium conveyed through a conveyance path. The cleaning member forms a cleaning position at which a substance adhering to the surface of the image bearer after transfer is cleaned. The light irradiator is disposed at a back face side of the recording medium opposite a side at which the surface of the image bearer is disposed relative to the conveyance path. The light irradiator is configured to emit light onto the surface of the image bearer. The light is targeted between the transfer position and the cleaning position. The light transmissive member is disposed between the light irradiator and the image bearer.

There is provided an image forming apparatus including: an intermediate transfer belt; a photosensitive drum; a primary transfer member; a secondary transfer member; a first backup member; a first power supply electrically connected to the primary transfer member and to the secondary transfer member; and a first resistor electrically connected to the first power supply and to the primary transfer member. A first current route, in which the first resistor, the primary transfer member, and the photosensitive drum are connected in series in that order, is connected to the first power supply and to a basis potential. A second current route, in which the secondary transfer member and the first backup member are connected in series, is connected to the first power supply and to the basis potential. The first current route is connected in parallel to the second current route.

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 electrifier cleaning mechanism includes a cleaning member which makes contact with part of a long discharge member, a ball screw arranged in parallel with a longitudinal direction of the discharge member and rotatably supported, a drive source which rotates the ball screw in both of forward and reverse directions, a holding member which holds the cleaning member and has a screw hole in which a screw part of the ball screw is screwed, and rotation of which in a circumferential direction of the ball screw is regulated, and a pressing member which presses the holding member from a first end side of the discharge member toward a second end side thereof in the longitudinal 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.

Examples disclosed herein relate to magnetic carrier bead separation in dual-component printing. The present disclosure relates generally to a device, method, and system for magnetic carrier bead separation. In an example, a printing device includes a developer sump to hold a plurality of carrier beads. The example device also includes a roller to move a subset of the plurality of carrier beads from an attachment point on the roller to a release point through a rotation of the roller, wherein the subset of the plurality of carrier beads return towards the developer sump after they are released at the release point. The device includes a magnetic separator located between the release point and the attachment point that guides a magnetized carrier bead of the plurality of carrier beads away from the developer sump and the roller.