An image forming apparatus 100 in which a charging process of a photosensitive member 1 is performed by forming a combined surface potential Vd(U+L) by superimposing, on a first charge potential Vd(U) formed on a surface of the photosensitive member 1 by a first corona charger 31, a second charge potential Vd(L) provided by the second corona charger 32 has a constitution including a control means 200 for executing an adjusting operation in which a superimposition start voltage Vg(L)A which is the second voltage Vg(L) at which formation of the combined surface potential Vd(U+L) is started is acquired by changing the second voltage Vg(L) applied to a grid electrode of the second corona charger in a state that the first charge potential Vd(U) is formed on the surface of said photosensitive member 1 and in which setting of the second voltage Vg(L) during the charging process is adjusted on the basis of the superimposition start voltage Vg(L).

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.

In a cleaning roller, a plurality of uneven portions are formed on a surface. A rotation shaft of the cleaning roller is inserted into a cylindrical hole of a cylindrical cleaning member in which the plurality of uneven portions are formed, and the clean member and a rotation shaft are fixed in a state where the cleaning member is twisted in a circumferential direction. The cleaning member, in which the plurality of uneven portions extending so as to twist in the circumferential direction are formed, is molded by rotating an extrusion molding die while extruding an extrusion molding material toward an extrusion molding hole of the extrusion molding die. An injection molding material with which the injection molding die is filled is solidified to mold the cleaning member and the cleaning member is stripped from the injection molding die by rotating the extrusion molding die around an axis.

An image forming apparatus, including: a photoconductor configured to be rotatable; a charger configured to charge the photoconductor; an overcurrent detector configured to output an overcurrent detection signal in response to detection of an overcurrent in the charger; and a controller, wherein the controller is configured to execute: an obtaining process of obtaining the overcurrent detection signal output from the overcurrent detector; a first counting process of counting a first number of detections based on the overcurrent detection signal obtained in the obtaining process, the first number of detections being the number of the overcurrent detection signals synchronized with a first cycle corresponding to one rotation of the photoconductor; and a first determining process of determining whether the first number of detections is not smaller than a first threshold which is not smaller than 2.

To provide a charging device that allows a discharging electrode to be cleaned without damaging a protruding portion at an end portion of the discharging electrode. The device is provided with: a discharging electrode including a plurality of protruding portions arranged along a predetermined direction, the discharging electrode discharging electricity from at least part of the protruding portions; a cleaner for cleaning at least some protruding portions included in the plurality of protruding portions; a cleaner conveyance mechanism for conveying the cleaner along the predetermined direction for performing the cleaning, such that the cleaner interferes with at least some protruding portions included in the plurality of protruding portions; and a cleaner height adjustment mechanism for adjusting a height of the cleaner in a vicinity of the protruding portion where the cleaner reaches at first.

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 parameter detection unit detects a first factor parameter that corresponds to change in layer thickness of an organic photosensitive layer in a photoreceptor drum and a second factor parameter other than the first factor parameter. A discharge voltage applying unit and a grid voltage applying unit are controlled by a first charging control unit and a second charging control unit. The first charging control unit determines a charging current for a discharge wire of the discharge voltage applying unit in accordance with a detection value of the first factor parameter, which has been detected by the parameter detection unit. On the other hand, the second charging control unit determines an output voltage that corresponds to a grid electrode of the grid voltage applying unit in accordance with a detection value of the second factor parameter, which has been detected by the second charging control unit.

An electrostatic collecting apparatus includes: a collecting rotating member rotatably arranged opposed to a surface of an object to be cleaned and to which a substance to be collected attaches; an adsorption force generating unit for generating an electrostatic adsorption force between the collecting rotating member and the substance to be collected; a removing member for coming in contact with a circumferential surface of the collecting rotating member, and removing the substance to be collected from the collecting rotating member; and a collecting portion for collecting the substance to be collected, which has been removed from the collecting rotating member by the removing member. The electrostatic collecting apparatus includes an adsorption force reducing unit for partially reducing the electrostatic adsorption force between the substance to be collected, which is borne on the collecting rotating member, and the collecting rotating member at around the circumferential surface of the collecting rotating member.

An electroconductive member for electrophotography including a support having electro-conductivity and an electroconductive layer on the outer surface of the support, the electroconductive layer including a matrix containing a crosslinked product of a first rubber and first electroconductive particles and domains each containing a crosslinked product of a second rubber and second electroconductive particles, wherein at least part of the first electroconductive particles are present as a primary particle in the crosslinked product of the first rubber, wherein, the first electroconductive particles of the matrix observed in a specific observation region have d1 of 200 nm or more, the second electroconductive particles in the domains observed therein have d2 of 50 nm or less, and 80 number % or more of the domains satisfy specific conditions.

An image forming apparatus has a photosensitive member, a plurality of corona chargers configured to charge the photosensitive member by corona discharge, a plurality of charge output circuits configured to output a charging voltage being applied to each of the corona chargers, a plurality of abnormal discharge detection circuits configured to output an abnormal discharge detection signal according to abnormal discharge occurring in each of the corona chargers, and a controller configured to have a common input port connected to the abnormal discharge detection circuits wherein the abnormal discharge detection signal output from each of the abnormal discharge detection circuits is input to the controller through the common input port. Each of the abnormal discharge detection circuits is connected to a corresponding one circuit out of the charge output circuits.