A toner cartridge comprises a toner container which contains toner, a driving member which rotationally drives a conveying member, an agitating member which agitates a toner in the toner container while being rotated, a driven member which rotates in association with the driving member which is for rotationally driving the agitating member, and a rotational body which rotates according to rotation of the driven member, has a plurality of slits in rotational circumference for identifying a type of the toner cartridge, and has 1/K or more of the slits when a ratio of a rotational speed R1 (rad/s) of the driving member and a rotational speed R2 (rad/s) of the driven member is K=R2/R1.

Provided is an electrophotographic photosensitive member, which has high abrasion resistance and is resistant to being deeply flawed. Specifically, provided is an electrophotographic photosensitive member comprising a support and a surface layer formed on the support, wherein the surface layer comprises at least inorganic particles having pores in surfaces thereof, wherein at least a resin in the surface layer penetrates the pores, and wherein when vibration having a frequency of 0.5 Hz is applied to the surface layer at 28° C., the loss tangent tan δ of the dynamic viscoelasticity of the surface layer is from 0.005 to 0.05.

Provided is an electrophotographic photosensitive member, which has high abrasion resistance and is resistant to being deeply flawed. Specifically, provided is an electrophotographic photosensitive member comprising a support and a surface layer formed on the support, wherein the surface layer comprises at least inorganic particles having pores in surfaces thereof, wherein at least a resin in the surface layer penetrates the pores, and wherein when vibration having a frequency of 0.5 Hz is applied to the surface layer at 28° C., the loss tangent tan δ of the dynamic viscoelasticity of the surface layer is from 0.005 to 0.05.

An electrophotographic photosensitive member includes, in sequence, a support, a conductive layer, an undercoat layer, a charge generation layer, and a charge transport layer. The conductive layer is a cured film, and the cured film contains titanium oxide particles doped with niobium. The undercoat layer contains a cured product of a composition that contains an electron transport material having a polymerizable functional group and a resin functionalized with a carboxylic acid derivative.

An electrophotographic photosensitive member includes, in sequence, a support, a conductive layer, an undercoat layer, a charge generation layer, and a charge transport layer. The conductive layer is a cured film, and the cured film contains titanium oxide particles doped with niobium. The undercoat layer contains a cured product of a composition that contains an electron transport material having a polymerizable functional group and a resin functionalized with a carboxylic acid derivative.

Provided is a process cartridge detachably attachable to a main body of an electrophotographic apparatus, the process cartridge including: a developing unit including a toner; and an electrophotographic photosensitive member, wherein the toner includes a toner particle, the toner particle has a surface containing a polyvalent acid metal salt particle, and a surface layer of the electrophotographic photosensitive member contains at least one metal oxide particle among an aluminum oxide particle, a silicon dioxide particle, and a tin oxide particle.

Provided is a photoelectric conversion device including: a support; a charge-transporting layer including an organic charge-transporting material or a sensitizing dye electrode layer including an organic sensitizing dye, where the charge-transporting layer or the sensitizing dye electrode layer is disposed on the support; and a ceramic film disposed on the charge-transporting layer or the sensitizing dye electrode layer.

An electrophotographic photoreceptor includes a cylindrical substrate; and a surface layer located on an outer surface of the cylindrical substrate. At least a substrate central portion in a cylindrical axial direction of the outer surface of the cylindrical substrate is formed as a rough surface, and a surface roughness of a surface-layer central portion in the cylindrical axial direction of an outer surface of the surface layer is larger than that of at least one of two surface-layer end portions in the cylindrical axial direction of the outer surface of the surface layer. An image forming apparatus includes the electrophotographic photoreceptor; and a peripheral member capable of contacting a surface of the electrophotographic photoreceptor.

An electrophotographic photoreceptor includes a cylindrical substrate; and a surface layer located on an outer surface of the cylindrical substrate. At least a substrate central portion in a cylindrical axial direction of the outer surface of the cylindrical substrate is formed as a rough surface, and a surface roughness of a surface-layer central portion in the cylindrical axial direction of an outer surface of the surface layer is larger than that of at least one of two surface-layer end portions in the cylindrical axial direction of the outer surface of the surface layer. An image forming apparatus includes the electrophotographic photoreceptor; and a peripheral member capable of contacting a surface of the electrophotographic photoreceptor.

An electrophotographic photosensitive member includes, in sequence, a support, a conductive layer, an undercoat layer, a charge generation layer, and a charge transport layer. The conductive layer is a cured film, and the cured film contains titanium oxide particles doped with niobium. The undercoat layer contains a cured product of a composition that contains an electron transport material having a polymerizable functional group and a resin functionalized with a carboxylic acid derivative.