Abstract: An image forming apparatus includes a photoconductor having a surface with a frictional resistance ranging from 45 gram-force to 200 gram-force, a 10-point average roughness RzJIS ranging from 0.1 &mgr;m to 1.5 &mgr;m s or a maximum height Rz of 2.5 &mgr;m. Image formation is performed by the image forming apparatus to allow irregular-shaped toner or spherical toner to be cleaned off efficiently and any background stain on a copied sheet to be prevented. A lubricant is applied to the photoconductor so as to form a nonuniform film thereon, which prevents the frictional resistance from abnormally lowering, thus suppressing image degradation.

Abstract: A plurality of types of engine units which have nonvolatile storage units and which have different performances, respectively, can be attached to an image formation apparatus main body in a replaceable manner. A control unit which controls the performance of an overall apparatus based on information stored in the storage units provided in the engine units, respectively, which are attached to the image formation apparatus main body, is provided in the image formation apparatus main body. Therefore, even if the image formation apparatus main body is common, the performance of the overall apparatus related to recording speed or resolution can be changed only by replacing the engine units different in performance. It is also possible to easily deal with various types of apparatuses.

Abstract: An electrophotographic photoreceptor including an electroconductive substrate; a photosensitive layer located overlying the electroconductive substrate and including a resin; and a surface layer including a filler and a binder resin, wherein the surface layer and the photosensitive layer have a continuous structure, and wherein the surface layer satisfies the following relationship: &sgr;≦D/5, wherein D represents an average of maximum thicknesses of the surface layer in units of micrometers in 20 segments of 5 &mgr;m wide when a portion of a cross section of the photoreceptor of 100 &mgr;m wide is divided into the 20 segments, and &sgr; represents a standard deviation of the 20 maximum thicknesses.

Abstract: An electrophotographic photoreceptor including an electroconductive substrate; a photosensitive layer located overlying the electroconductive substrate and including a resin; and a surface layer including a filler and a binder resin, wherein the surface layer and the photosensitive layer have a continuous structure, and wherein the surface layer satisfies the following relationship: &sgr;≦D/5, wherein D represents an average of maximum thicknesses of the surface layer in units of micrometers in 20 segments of 5 &mgr;m wide when a portion of a cross section of the photoreceptor of 100 &mgr;m wide is divided into the 20 segments, and &sgr; represents a standard deviation of the 20 maximum thicknesses.

Abstract: A plurality of types of engine units which have nonvolatile storage units and which have different performances, respectively, can be attached to an image formation apparatus main body in a replaceable manner. A control unit which controls the performance of an overall apparatus based on information stored in the storage units provided in the engine units, respectively, which are attached to the image formation apparatus main body, is provided in the image formation apparatus main body. Therefore, even if the image formation apparatus main body is common, the performance of the overall apparatus related to recording speed or resolution can be changed only by replacing the engine units different in performance. It is also possible to easily deal with various types of apparatuses.

Abstract: An electrophotographic photoreceptor including an electroconductive substrate; a photosensitive layer located overlying the electroconductive substrate and including a resin; and a surface layer including a filler and a binder resin, wherein the surface layer and the photosensitive layer have a continuous structure, and wherein the surface layer satisfies the following relationship: &sgr;≦D/5, wherein D represents an average of maximum thicknesses of the surface layer in units of micrometers in 20 segments of 5 &mgr;m wide when a portion of a cross section of the photoreceptor of 100 &mgr;m wide is divided into the 20 segments, and &sgr; represents a standard deviation of the 20 maximum thicknesses.

Abstract: An electrophotographic photoreceptor which includes an electroconductive substrate, and a photosensitive layer which is formed overlying the substrate, wherein the photosensitive layer includes a charge generation material, a charge transport polymer material including triarylamine structure and a soft segment in a main chain thereof, and a filler.

Abstract: An electrophotographic photoconductor composed of an electroconductive support and a photoconductive layer formed thereon, which contains as a charge generating material an azo pigment subjected to a salt milling process.

Abstract: An electrophotographic photoconductor includes an electroconductive support and a single-layered photoconductive layer formed thereon, containing a charge transporting material, a binder resin, and a simultaneously pulverized mixture including at least one disazo pigment of formula (1) and at least one trisazo pigment of formula (2), which is obtained by simultaneously pulverizing those azo pigments: ##STR1## wherein R.sup.1 and R.sup.2 each is hydrogen, a halogen atom, trifluoromethyl group, nitro group or cyano group; R.sup.3 is hydrogen, chlorine, fluorine, iodine, bromine, nitro group or cyano group; and Ar.sup.1, Ar.sup.2 and Ar.sup.3 each is a coupler radical, which may be the same or different.

Abstract: An electrophotographic photoconductor is composed of an electroconductive support and a photoconductive layer formed thereon which contains a charge generating material and a charge transporting material. The charge generating material is composed of a particular triasazo compound and a particular disazo compound. A photoconductive composition useful as a photoconductive material is also composed of the trisazo compound and the disazo compound.

Abstract: An electrophotographic copying apparatus is provided with a belt-shaped photoconductor comprising. A magnetic electroconductive support and a photoconductive layer are formed on the photoconduction. A magnetic cleaning member is positioned for cleaning the surface of the belt-shaped photoconductor.

Abstract: An electrophotographic photoconductor is disclosed, which comprises an electroconductive support, an undercoat layer formed on the electroconductive support, comprising at least one metal oxide selected from the group consisting of zirconium oxide, magnesium oxide, calcium oxide, beryllium oxide and lanthanum oxide, and a photoconductive layer comprising a charge generating layer and a charge transporting layer, formed on the undercoat layer.

Abstract: An electrophotographic photoconductor is disclosed, which comprises an electroconductive support and a photoconductive layer comprising (i) a charge generation layer and (ii) a charge transport layer formed on the support, in which the charge generation layer comprises a charge generating material and one component selected from the group consisting of an aliphatic alcohol and a crown ether, or the charge transport layer comprises a charge transporting material and one component selected from the group consisting of an aliphatic alcohol, a polyalkylene glycol, a polyalkylene glycol ester, a polyalkylene glycol ether, and a crown ether.

Abstract: An electrophotographic photoconductor comprising an electroconductive support, an intermediate layer formed thereon, an a photoconductive layer formed on said intermediate layer, which intermediate layer comprises at least one component selected from the group consisting of: (a) monohydric aliphatic alcohol, (b) dihydric aliphatic alcohol, (c) polyethylene glycol, (d) polypropylene glycol, (e) polybutylene glycol, (f) polyethylene glycol monoester and/or polyethylene glycol diester, (g) polyethylene monoether, (h) crown ether, (i) a random or block copolymer having as structure units a hydroxyethylene group and a hydroxypropylene group, and hydroxyl groups at the terminal thereof, and (j) a polymer of a monomer having formula (I) and a copolymer of said monomer and a counterpart monomer: ##STR1## wherein R.sup.1 represents hydrogen or a methyl group; R.sup.2 represents hydrogen, a lower alkyl group or an unsubstituted or substituted aryl group; and n is an integer of 2 to 100.

Abstract: This invention relates to a repeatedly usable photosensitive material for electrophotography, comprising an electroconductive substrate, a photosensitive layer and an intermediate layer located between said electroconductive substrate and said photosensitive layer, characterized in that said intermediate layer comprises an electroconductive polymer and an inorganic white pigment.