A corona discharge device including a corona electrode provided with multiple sharpened tip portions in a row includes a cleaning member which cleans the tip portions of the corona electrode while reciprocating along a predetermined movement direction set in advance with the tip portions biting into the cleaning member. A cleaning position at a surface of the cleaning member is different in a direction intersecting a longitudinal direction of the corona electrode between when the cleaning member moves toward one side in the movement direction and when the cleaning member moves toward another side in the movement direction.

An image forming apparatus includes a movable photosensitive member, first and second corona chargers, an adjusting mechanism, a developing device, a detecting member configured to detect a surface potential of the photosensitive member at a plurality of positions with respect to the widthwise direction of the photosensitive member, an input portion, and a display portion. In accordance with input of an instruction to the input portion, the detecting portion detects at least two surface potentials of three surface potentials including the surface potential of the photosensitive member after being charged by the first and second corona chargers, the surface potential of the photosensitive member after being charged by the first corona charger, and the surface potential of the photosensitive member after being charged by the second corona charger. A detection result of the detecting member is displayed at the display portion.

Disclosed is an image forming apparatus wherein a controller performs a first adjusting operation and thereafter the controller performs a second adjusting operation. In the first adjusting operation, a voltage applied to a first grid electrode by a first voltage applying portion is set so that a surface potential of an image bearing member charged by a first corona charger becomes a first target value. In the second adjusting operation, a voltage applied to a second grid electrode by a second voltage applying portion is set so that a surface potential of the image bearing member charged by the first corona charger and a second corona charger becomes a second target value whose absolute value is larger than the first target value.

An electrification adjustment apparatus includes a first electrification adjuster facing the recording material conveyed for supplying charges each with one polarity, and a second electrification adjuster facing the recording material downstream of the first electrification adjuster in a conveying direction for supplying charges each with opposite polarity to that of the charge supplied by the first electrification adjuster. In the electrification adjustment apparatus, an electrostatic capacity between the recording material surface facing the second electrification adjuster, and an electrode partially or entirely formed from the conveyor member is smaller than the one between the recording material surface facing the first electrification adjuster and an electrode partially or entirely formed from the conveyor member. Either front or back surface of the recording material is in contact with the conveyor member in a region between the first and the second electrification adjusters.

An image forming apparatus includes a controller substrate, a first mounting portion for a first hard disk drive, a second mounting portion for a second hard disk drive, a first connector electrically connecting the controller substrate and the first hard disk drive, a second connector electrically connecting the controller substrate and the second hard disk drive. The second connector is shifted toward a side downstream of the first connector in a hard disk drive inserting direction so as to be prevented from overlapping with the first connector as seen in a vertical direction. In the second mounting portion, a through hole extending in the vertical direction is formed at a position where the through hole overlaps with the first connector as seen in the vertical direction.

A charging device includes a first charging unit and a second charging unit. The first charging unit electrostatically charges a surface of an image bearing member that comes into contact with a medium onto which an image is to be ultimately transferred. The first charging unit is disposed in correspondence with an entire region of the image bearing member in a first scanning direction. The second charging unit is disposed in an overlapping region where a non-passing region of a small-width medium and a passing region of a maximum-usable-width medium overlap when viewed in the first scanning direction. The small-width medium has a width smaller than a maximum usable width of the maximum-usable-width medium. The second charging unit electrostatically charges the overlapping region.

A movable member includes a frame, a mounting portion, a rotatable image bearing member, a charging member, and a cleaning member. The cleaning member includes a base portion including a first surface positioned on one side of the frame, a second surface positioned on the other side of the frame, and a third surface, and includes a projected portion. The projected portion includes a first side surface positioned on the aforementioned the other side and a second side surface positioned on the aforementioned one side. The first side surface is positioned between the first surface and the second surface. The first side surface constitutes an end surface of the projected portion on the aforementioned the other side with respect to the axial direction, and the second side surface constitutes an end surface of the projected portion on the aforementioned one side with respect to the axial direction.

An image forming apparatus includes a corona charger including a discharging wire and a grid electrode for charging a photosensitive drum at a charging position and an exposure device for exposing the drum charged by the charger at an exposure position which is at a downstream side of the charger (in a rotational direction of the drum) at the charging position. The grid electrode includes a first portion having openings and a second portion having only a non-opening portion in a charging region for charging the drum in a longitudinal direction of the charger, and the second portion includes a downstream side peripheral portion at a downstream end of the grid electrode with respect to the rotational direction. In a cross-section orthogonal to the longitudinal direction and including the charging region, the downstream side peripheral portion is intersected by a straight line passing through the exposure position and the wire.

An image forming apparatus includes an image bearing drum; an exposing unit for exposing the drum; an electric circuit board provided substantially perpendicularly to an apparatus installing floor; a driving unit for supplying a driving force; a first metal plate supporting the exposing unit; a second metal plate supporting the electric circuit board; and a third metal plate supporting the driving unit. At least one of the first, second and third plates is provided at each of four sides of the apparatus, the four sides being substantially perpendicular to the floor. The first, second and third plates are electrically connected with each other.

An image forming apparatus includes a photosensitive member, a corona charger including a discharging electrode and a grid electrode having a surface layer containing carbon atoms as a main component and configured to electrically charge the photosensitive member under application of a voltage to the discharging electrode and the grid electrode, and an output portion configured to output information on a lifetime of the grid electrode. The output portion outputs the information on the basis of an index value of an amount of use of the grid electrode correlating with a product of a value of a grid current flowing through the grid electrode and a time of flowing of the grid current through the grid electrode.