In an image forming apparatus, a charging process of a photosensitive member 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 by a first corona charger, a second charge potential Vd(L) provided by a second corona charger. The apparatus includes a controller 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 the photosensitive member 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).

A charging device includes a housing, a corona wire stretched in the housing, and a positioning member supporting the corona wire and determining a distance between the corona wire and a photoconductor, the positioning member being provided at an end of the housing. The positioning member has a vertex extending in a direction intersecting a corona-wire-stretching direction in which the corona wire is stretched. An elastic member is provided in a gap between the positioning member and the corona wire supported at the vertex, the gap spreading in the corona-wire-stretching direction.

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.

A charging device includes a housing, a corona wire stretched in the housing, and a positioning member supporting the corona wire and determining a distance between the corona wire and a photoconductor, the positioning member being provided at an end of the housing. The positioning member has a vertex extending in a direction intersecting a corona-wire-stretching direction in which the corona wire is stretched. An elastic member is provided in a gap between the positioning member and the corona wire supported at the vertex, the gap spreading in the corona-wire-stretching direction.

An image forming apparatus in which occurrence of an image failure in association with contamination caused by an external additive, such as silica, adhering to a charging unit is suppressed. The image forming apparatus is configured to charge an image bearing member through use of the charging unit, and uses toner having, on a surface thereof, strontium titanate particles and silica particles having predetermined physical properties.

To provide an electrophotographic member causing less change in toner conveyance even used in a high-temperature and high-humidity environment. The electrophotographic member has an electro-conductive substrate, an elastic layer on the substrate and a coating layer on the elastic layer. The elastic layer has a first protrusion on a surface thereof on a side opposite to a side facing the substrate. The electrophotographic member has, on an outer surface thereof, a second protrusion derived from the first protrusion. The outer surface of the electrophotographic member has one or more of electrical insulating first region(s) and an electro-conductive second region. The elastic layer has an elastic modulus of 0.5 MPa or more to 3.0 MPa or less and the coating layer has an elastic modulus of 5.0 MPa or more to 100.0 MPa or less as measured in an environment of a temperature of 30 C. and a relative humidity of 80%.

In an image forming mode in which, a first image forming portion forms a toner image on the first image bearing member and a second image forming portion does not form a toner image on the second image bearing member, thereby forming an image on a recording material, a first voltage smaller than a minimum value of absolute values of a plurality of voltages applied to a plurality of grid electrodes of the first image forming portion and larger than an absolute value of a target potential of a surface of the second image bearing member in the image forming mode is applied to one of the plurality of grid electrodes of the second image forming portion, and no voltage is applied to the other grid electrodes except the grid electrode to which the first voltage is applied among the plurality of grid electrodes of the second image forming portion.

A cleaning member includes plural bristles including tips that come into contact with an object to be cleaned having a surface including recesses and projections; and a brush base to which the bristles are attached. The bristles each have a non-circular cross-section including a projecting portion that projects toward an outer periphery, at least the projecting portion having a size such that the projecting portion is capable of entering the recesses in the object to be cleaned.

A feeding apparatus includes a feeding unit, an ion generating unit and a controller. The ion generating unit irradiates the sheet fed by the feeding unit with the ion. The controller acquires an information on the fed sheet and to controls the ion generating unit. The controller operates the ion generating unit in a case that the information of the sheet is a first information, and does not operate the ion generating unit in a case that the information of the sheet is a second information.

A photosensitive drum is rotatable about a first axis extending in a particular direction. A frame rotatably supports the photosensitive drum. A developing roller is rotatable according to driving force about a second axis extending in the particular direction. A surface of the developing roller contacts a surface of the photosensitive drum through toner. A resistance generating member generates a resistance torque TQ1 serving as resistance between the frame and photosensitive drum in a case where the photosensitive drum rotates relative to the frame. In a case where the developing roller rotates according to the driving force in a state where the surface of the developing roller contacts the surface of the photosensitive drum through toner, the resistance torque TQ1 is smaller than a torque TQ2 that causes the photosensitive drum to rotate due to friction between the surface of the developing roller and the surface of the photosensitive drum.