Electrophotographic photoreceptor including a conductive substrate, an organic photosensitive layer on an outer peripheral surface of the conductive substrate, and an inorganic protective layer on an outer peripheral surface of the organic photosensitive layer, the inorganic protective layer containing gallium and oxygen. A volume resistivity of an inner region of the inorganic protective layer, the inner region extending 0.2 m or about 0.2 m from an inner peripheral surface of the inorganic protective layer in a thickness direction, and a volume resistivity of an outer region of the inorganic protective layer, the outer region extending 0.2 m or about 0.2 m from an outer peripheral surface of the inorganic protective layer in the thickness direction, are both 6.010.sup.7 .Math.cm or more and 4.010.sup.8 .Math.cm or less or about 6.010.sup.7 .Math.cm or more and about 4.010.sup.8 .Math.cm or less.

Provided is an electrophotographic photoreceptor including a conductive support, a photosensitive layer, and a surface protective layer disposed in sequence. The surface protective layer includes a cured product of a composition containing a polymerizable compound, a charge transporting material, and at least two polymerization initiators. The polymerization initiators include an acyl phosphine oxide and an O-acyl oxime.

The invention is to provide an image forming apparatus and an electrophotographic cartridge, which are free from problems of cleaning failure, filming, soiling, residual images (ghosts), fogging, density reduction, noise and the like and which can provide high-definition images even when a toner having a small particle size and having a high degree of circularity is used and even when a photoreceptor having a small outer diameter is used. An image forming apparatus comprising: an electrophotographic photoreceptor containing a conductive support and a photosensitive layer on the conductive support, a charging unit for charging the electrophotographic photoreceptor, an imagewise exposing unit for imagewise exposing the charged electrophotographic photoreceptor to form an electrostatic latent image thereon, a developing unit for developing the electrostatic latent image with a toner, and a transferring unit for transferring the toner from the electrophotographic photoreceptor to a receiving unit, wherein the outer diameter of the electrophotographic photoreceptor is 20 mm or less, the photosensitive layer contains a polyarylate resin, and the toner satisfies the specific requirements (1) and (2).

The invention is to provide an image forming apparatus and an electrophotographic cartridge, which are free from problems of cleaning failure, filming, soiling, residual images (ghosts), fogging, density reduction, noise and the like and which can provide high-definition images even when a toner having a small particle size and having a high degree of circularity is used and even when a photoreceptor having a small outer diameter is used. An image forming apparatus comprising: an electrophotographic photoreceptor containing a conductive support and a photosensitive layer on the conductive support, a charging unit for charging the electrophotographic photoreceptor, an imagewise exposing unit for imagewise exposing the charged electrophotographic photoreceptor to form an electrostatic latent image thereon, a developing unit for developing the electrostatic latent image with a toner, and a transferring unit for transferring the toner from the electrophotographic photoreceptor to a receiving unit, wherein the outer diameter of the electrophotographic photoreceptor is 20 mm or less, the photosensitive layer contains a polyarylate resin, and the toner satisfies the specific requirements (1) and (2).

Disclosed is an electrophotographic photoreceptor including a conductive support, a photosensitive layer on the conductive support and a surface layer on the photosensitive layer. The surface layer includes a cured resin prepared by polymerization of a compound having two or more radically polymerizable functional groups per molecule, the cured resin containing an organic resin fine particle and a metal oxide fine particle, and the organic resin fine particle comprising a resin containing a structural unit derived from at least one of melamine and benzoguanamine, the organic resin fine particle having a number average primary particle size of 0.01 to 3.00 m.

An electrophotographic photosensitive member includes a conductive base; an organic photosensitive layer disposed on the conductive base, the organic photosensitive layer including a layer that constitutes a surface and contains a charge transport material, a binder resin, and silica particles in an amount of about 40% by weight or more; and an inorganic protective layer disposed on the organic photosensitive layer and having a surface roughness Ra of about 5 nm or less.

An electrophotographic photosensitive member that is excellent in the cleaning property and the durability and has a reduced residual potential. The electrophotographic photosensitive member has a surface layer, wherein the surface layer contains a vinyl resin particle, and the vinyl resin particle is surface-treated with a specific compound.

Provided is an electrophotographic photosensitive member including a surface layer, wherein the surface layer contains a fluorine atom-containing resin particle, a binder material, and a polymer having specific structural units.