The present invention relates to an electrophotographic photoreceptor comprising: a conductive support; and a photosensitive layer disposed on the conductive support, wherein the photosensitive layer includes a polyester resin containing a dihydric phenol residue and a dicarboxylic acid residue, and the dihydric phenol residue includes at least one dihydric phenol residue selected from the group of the specific dihydric phenol residues, and the other specific dihydric phenol residue.

An electrophotographic photosensitive member includes a surface layer containing a charge transporting material and a specific polyester resin having a structure including a specific branched chain.

The present disclosure is drawn to apparatuses and methods that include a coated photoconductive substrate. The coated photoconductive substrate can include a photoconductive substrate with a charge generation layer and a charge transport layer, and can also have a coating adhered to the photoconductive substrate. The coating can have a thickness ranging from 1 nm to 200 nm.

Provided are a process cartridge and an electrophotographic apparatus each of which is reduced in fogging for reducing a toner consumption. Specifically, provided is a process cartridge, which is removably mounted onto a main body of an electrophotographic apparatus, the process cartridge including: a developing unit containing a toner; and an electrophotographic photosensitive member, wherein the toner is a toner including a toner particle, and has a polyvalent acid metal salt on at least part of a surface of the toner particle, wherein the polyvalent acid metal salt includes at least one kind of metal element selected from metal elements belonging to from Group 3 to Group 13, and wherein a surface layer of the electrophotographic photosensitive member contains a resin including a siloxane segment.

An electrophotographic photosensitive member including a surface layer containing a charge generating material and a polyester resin is provided. The polyester resin contains a structure having a 12- or higher-membered cycloalkylene group.

The present invention relates to an electrophotographic photoreceptor, which includes a conductive substrate; an undercoat layer disposed on the conductive substrate and capable of conforming to the contour of the conductive substrate, a photoconductor charge generation layer disposed on the undercoat layer and capable of conforming to the contour of the undercoat layer, and a charge transport layer disposed on the photoconductor charge generation layer. The charge transport layer contains a charge transport material, a binder resin, a fluorine-containing resin, and a plurality of polyhedral oligomeric silsesquioxane (POSS) particles evenly dispersed in the binder resin, and the POSS particles are interconnected with at least one fluorine group and at least two non-fluoridated groups. By adding approximately 1% of the POSS particles and lubricant nanoparticles, a life-time improvement of at least 20% is achieved for an OPC drum.

Providcd is anAn electrophotographic belt having a layered structure with excellent scratch resistance and excellent adhesion of layers to each other. The electrophotographic belt includes a first layer and a second layer directly covering any one of the inner peripheral surface and the outer peripheral surface of the first layer, the first layer containing a first polyester resin, and the second layer containing a second polyester resin and an acrylic resin that contains a carboxy group in its molecule.

Disclosed is a cylindrical electrophotographic photosensitive member having a region A along an outer surface and a region B along the outer surface. In this electrophotographic photosensitive member, the region A is located on an end side in an axial direction of the electrophotographic photosensitive member relative to the region B, the region A has a specific groove provided on the outer surface of the electrophotographic photosensitive member, an area ratio a1 of the groove is 65% to 100%, the region B has specific concave portions provided on the outer surface of the electrophotographic photosensitive member, and an area ratio a2 of the concave portion is 5% to 65%.

An image forming apparatus is provided that includes: an image bearer; a charger; an irradiator; a developing device containing a toner; and a transfer device. The image bearer has a Martens hardness of from 185 to 250 N/m.sup.2. The toner satisfies a relation 0.13≤X/Dn≤0.16, where X [μm] represents an average value of an amount of deformation of the toner by micro-indentation at when a load reaches 3.00×10.sup.−4 N at a loading rate of 3.0×10.sup.−5 N/sec under an environment of 32 degrees C. and 40% RH, and Dn [μm] represents a number average particle diameter of the toner. The toner contains an external additive comprising silica particles and particles composed mainly of strontium titanate. The particles composed mainly of strontium titanate further contain a third element M selected from the group consisting of La, Mg, Ca, Sn, and Si.

Disclosed is a cylindrical electrophotographic photosensitive member having a region A along an outer surface and a region B along the outer surface. In this electrophotographic photosensitive member, the region A is located on an end side in an axial direction of the electrophotographic photosensitive member relative to the region B, the region A has a specific groove provided on the outer surface of the electrophotographic photosensitive member, an area ratio a1 of the groove is 65% to 100%, the region B has specific concave portions provided on the outer surface of the electrophotographic photosensitive member, and an area ratio a2 of the concave portion is 5% to 65%.