Abstract: A method for determining a termination time of the step of dispersing a coating composition for a photosensitive layer, containing a binder resin, a powdery charge generating material and a solvent, is disclosed, which comprises (i) providing coating (I) on a substrate by coating the coating composition, following by drying, (ii) providing coating (II) on a substrate by dispersing the coating composition using a dispersion medium to fine the powdery charge generating material, followed by drying, (iii) measuring absorbances of coating (I) at two wavelengths within a short wavelength region and a long wavelength region, respectively, of the spectral absorption wavelength of the charge generating material, (iv) measuring absorbances of coating (II) at the two wavelengthes within the short wavelength region and the long wavelength region, respectively, and (v) calculating spectral absorbance ratios of coatings (I) and (II), respectively, from the following equation: ##EQU1## wherein the dispersing of the coating

Abstract: An electrophotographic photoreceptor comprising a conductive substrate having formed thereon a photosensitive layer containing, as binder resins, (A) a polycarbonate resin comprising a recurring unit represented by formula (I): ##STR1## and (B) a polycarbonate resin comprising a recurring unit represented by formula (II) or (III): ##STR2## wherein X.sub.1 and X.sub.2 each represent a hydrogen atom or an alkyl group, or (B') a copolycarbonate resin comprising a recurring unit represented by formula (II) and a recurring unit represented by formula (IV): ##STR3## said polycarbonate resin (B) or copolycarbonate resin (B') having a lower molecular weight than that of said polycarbonate resin (A). The photoreceptor had high film strength against abrasion and causes no toner filming or adhesion of any other foreign substances and is therefore excellent in electric characteristics and image characteristics.

Abstract: An electrophotographic photoreceptor is disclosed, which comprises an electrically conductive substrate having thereon a charge generating layer and a charge transporting layer, said charge generating layer containing a resin binder and a charge generating material (selenium or an alloy of selenium), and said resin binder being a polyvinyl acetal resin and preferably a partially acetallized polyvinyl butyral resin. The electrophotographic photoreceptor according to the present invention has a photosensitivity which is less dependent on surface voltage.

Abstract: An electrophotographic photoreceptor is disclosed, which comprises an electrically conductive substrate having thereon a photosensitive layer comprising a resin binder in which the following two kinds of charge generating materials are dispersed: (i) selenium or an alloy of selenium and (ii) a phthalocyanine derivative represented by the formula: ##STR1## wherein M represents AlCl, Mg, VO, InCl or H.sub.2. The electrophotographic photoreceptor exhibits a broad spectral sensitivity extending from the visible to the infrared regions of the spectrum and, therefore, can be suited for printers which utilize such light sources as semiconductor lasers, light emitting diodes, etc.

Abstract: An electrophotographic photoreceptor is disclosed, comprising a light-sensitive layer on an electrically conductive substrate, wherein the light-sensitive layer comprises particles of selenium or a selenium alloy as the charge generating material, and at least one compound represented by formula (I), ##STR1## wherein R.sub.1 represents a hydrogen atom, an alkyl group or an alkoxyl group; R.sub.2 and R.sub.3, which may be the same or different, represent each a hydrogen atom, an alkyl group, an alkoxyl group, a halogen atom, an alkoxycarbonyl group or a substituted amino group; and at least one compound represented by formula (II), ##STR2## wherein R.sub.4, R.sub.5 and R.sub.6, which may be the same or different, represent each a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, an alkoxycarbonyl group or a substituted amino group, as the charge transporting materials.