Abstract: In the formation of a multicolor image for generating a color print by repeating operation for transferring on an intermediate transfer member every color after one color toner image is formed on a photoreceptor drum, when an image of each color is written on the photoconductor, the image writing start position of each color is differentiated in a process direction of the photoconductor on the basis of a position reference mark on the intermediate transfer member detected by a sensor. This prevents a defect on the photoconductor from being enlarged and visually conspicuous.

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.