An image forming apparatus includes a rotatable photosensitive member, an image forming portion, a cleaning device, and a controller. The cleaning device includes a blade, a rotatable brush, and an applying portion. The controller controls the applying portion so as to apply a bias to the brush so that a potential of the brush has a polarity opposite to a normal charge polarity of toner. When a tensile strength of the brush is A (cn/dtex), a thickness of the brush is B (denier), a bristle density of the brush is C (kF/inch.sup.2), a length of the brush is D (mm), and an elastic deformation rate of the surface of the photosensitive member is E (%), the following relationships are satisfied: 48(%)≤E≤60(%), and 400≤{A×B.sup.2×C/D.sup.2}≤20408.

An image forming apparatus includes a rotatable photosensitive member; a charging portion, an exposure portion, a developing member, a transfer unit, a contact and separation portion, a charging voltage applying portion, a detecting portion, and a controller. The controller is capable of executing an operation in an image forming mode and an operation in a detecting mode. The controller carries out control so that a charging current flowing through a charging portion during charging of the photosensitive member in the operation in the detecting mode is lower than a charging current flowing through the charging portion during charging of the photosensitive member in the operation in the image forming mode.

An image forming apparatus includes a rotatable image bearing member about a rotational axis extending in the axial direction, a charging member, an accommodating portion accommodating toner charged to a predetermined polarity; a developing member, a transfer portion, a static eliminating portion, and a collecting member. In the axial direction, when A is a eliminating width with which the eliminating portion discharges the surface of the image bearing member, B is an effective charging width with which the charging member charges the surface, and C is a collection contacting width with which the collecting member contacts the surface, the formula A < B < C is satisfied. In the axial direction, a surface potential of the surface in an area outside the effective charging width, inside the collection contacting width and in contact with the collecting member is a first potential larger than 0 V in the same polarity direction as the predetermined polarity.

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.

An image forming apparatus including an image bearing member, a charging member, a developing roller, a transfer roller, and a brush configured to be brought into contact with a surface of the image bearing member on a side downstream of a transfer portion and upstream of a charging portion in a rotation direction of the image bearing member and in which, wherein, after the transfer of a developer image onto a transferred member, a developer remaining on the surface of the image bearing member is collected by the developing roller, the brush is disposed such that, in a cross section perpendicular to a rotation axis of the image bearing member, a contact region of the surface of the image bearing member in contact with the brush overlaps a virtual line containing the rotation axis of the image bearing member and extending upward from the rotation axis in a vertical direction.

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 imaging device having a photoconductive drum and a lubricant applicator brush, methods and apparatus teach application of the lubricant to the drum at a transfer nip and removing undeveloped toner particles. A first voltage is applied to the drum while the brush receives a voltage that switches more positive and more negative than the first voltage. It attracts to the brush from the drum negatively and positively charged toner. Embodiments contemplate amounts of voltages and frequencies of switching. An elongate rod contacts the brush downstream of the transfer nip to flicker off the toner particles from the brush. The rod can also have voltages applied and switched greater than and lesser than the voltages of the applicator brush to facilitate toner removal. A cleaning blade downstream of the transfer nip scrapes clean a surface of the drum.

In accordance with a first aspect of the present disclosure, a cleaning device includes a conveying member and a plurality of scraping pieces. The conveying member has a rotating shaft and a spiral blade formed around the rotating shaft. The conveying member is configured to be rotated around an axis to convey a toner removed from an image carrier in a direction of the axis. The plurality of scraping pieces are arranged in the direction of the axis. The plurality of scraping pieces are configured to be turnable so as to alternately come into contact with the rotating shaft and the spiral blade to scrape the toner adhered on the rotating shaft. A width of the scraping piece in the direction of the axis is equal to or below ½ of a gap between the adjacently arranged scraping pieces in the direction of the axis.

An image forming apparatus has a photoconductive member and a cleaning member arranged to face the photoconductive member at a cleaning position and configured to be applied with a cleaning bias to collect residual developing agent on the photoconductive member after the developed image is transferred. A controller of the image forming apparatus controls a transferring bias so that a transferring current representing a current flowing between the photoconductive member and a transferring member is controlled to become a target current value. Further, the controller calculates a cleaning position potential representing a surface potential of the photoconductive member at the facing position based on the transferring current and a charge potential representing a surface potential of the photoconductive member immediately after being charged by the charging device, and controls the cleaning bias based on the cleaning position potential as calculated.

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).