A charging member for an image forming apparatus may include a conductive support and a surface layer on the conductive support and not in contact with a photosensitive member. The surface layer may comprise a urethane foam including foam cells and having a foam structure based on the foam cells, the foam cells including open cells.

Provided is an electrophotographic electroconductive member including an electroconductive support and an electroconductive layer on the support, an electroconductive member is used, in which an electroconductive layer has a matrix comprising a first rubber, and domains dispersed in the matrix, the domains each comprising a second rubber and an electronic electroconductive agent, and for impedance measured by applying an AC voltage with an amplitude of 1 V to the electroconductive layer while varying frequencies between 1.0×10.sup.−2 Hz to 1.0×10.sup.7 Hz under a specific environment, when a double logarithmic plot with a frequency on an abscissa and an impedance on an ordinate is obtained, a slope on a high frequency side is −0.8 or more and —0.3 or less, and the impedance a low frequency side is from 1.0×10.sup.3 to 1.0×10.sup.7Ω.

An example charging member has a surface layer including a binder resin, first particles, and second particles, the first and second particles being dispersed in the binder resin, the first particles include acrylic resin particles having an average particle diameter of about 16 μm to about 35 μm, and the second particles include spherical silica particles having an average particle diameter of about 3 μm to about 10 μm. The content of the first particles is in a range of about 5 parts by weight to about 20 parts by weight and when a mass of the first particles is M1 and a mass of the second particles M2, the condition of 0.2≤M1/(M1+M2)≤0.8 is satisfied.

An electrophotographic roller includes: a mandrel and an elastic layer on the mandrel, and having a crown shape in which a diameter decreases from a central position O in a longitudinal direction of the mandrel toward an end portion. When a position of the end portion in the longitudinal direction of the elastic layer is defined as X2, a position between the O and the X2 is defined as X1, a distance between the O and the X1 is defined as L1, and a distance between the X1 and the X2 is defined as L2, L1=0.6×(L1+L2). When outer diameters of the electrophotographic roller at O, X1 and X2 are defined as Do, DX1 and DX2, respectively, and Z1=(Do−DX1)/2 and Z2=(DX1−DX2)/2 are defined, Z1, Z2, L1 and L2 satisfy (Z2/L2)<1.931×(Z1/L1).

An image forming apparatus includes an electrophotographic photoreceptor having a friction coefficient of a surface of 0.8 or less; a charging device including a charging member that is in contact with and charges the surface of the electrophotographic photoreceptor and includes a conductive base material, an elastic layer provided on the conductive base material and having a storage elastic modulus G of 5.0 MPa or less at 100 Hz, and a surface layer provided on the elastic layer; an electrostatic latent image forming device that forms an electrostatic latent image on the charged surface of the electrophotographic photoreceptor; a developing device that develops the electrostatic latent image formed on the surface of the electrophotographic photoreceptor to form a toner image by a developer containing a toner; and a transfer device that transfers the toner image to a surface of a recording medium.

It is an object of the present invention to provide an electrophotographic photosensitive member capable of suppressing the environmental fluctuation in the electrical characteristics. The present invention provides the electrophotographic photosensitive member in which the surface layer contains the compound having the specific structure.

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.

A charging member, including: a conductive support; and a conductive body mounted on the conductive support, in which the conductive body includes an elastic layer located on the conductive support, a resin layer located on the elastic layer, and a coating layer located on the resin layer to form an outermost surface of the conductive body, and the coating layer contains a polysiloxane compound having a molecular structure that includes an Si—O—Zr bond.

A cylindrical shaft of a roller has facing surfaces which form a depression-protrusion-shaped portion of a joint of the cylindrical shaft and which face or make contact with each other and moreover which extend in a direction non-parallel to an axial direction of the cylindrical shaft, and the facing surfaces are inclined at a predetermined engagement angle with respect to a circumferential direction. A generating line of a circumferential surface of a coating layer that coats an outer circumference of the cylindrical shaft and a generating line of a circumferential surface of a photosensitive drum cross each other at a crossing angle smaller than the engagement angle.

One end portion and the other end portion of a rotating member, which face each other and form a joint portion, have a shape with projections and recesses. Projections of one end portion fit in recesses of the other end portion, while projections of the other end portion fit in recesses of the one end portion, so that the one end portion and the other end portion are interlocked. The projections have a first corner portion rounded in an arc, while the recesses have a second corner portion rounded in an arc in which the first corner portion fits. The first corner portion has a larger radius of curvature than that of the second corner portion.