Abstract: A cylindrical developer carrier capable of fully charging a toner compound on a developing sleeve via frictional force even after being used repeatedly. The cylindrical developer carrier includes an electrically conductive substrate having an evenly roughened surface, and an alumite layer formed on the roughened surface, wherein the alumite layer has a uniform distribution of minute holes that reach the substrate surface. A method for manufacturing the cylindrical developer carrier includes roughening the electrically conductive substrate surface by blasting it with spherical fine particles, forming the alumite layer on the roughened surface by an anodizing method, and blasting the surface of the alumite-layer with amorphous fine particles that a diameter greater than that of the spherical fine particles.

Abstract: A direct heating type toner fixing roller for electrophotographic apparatuses is composed of a cylindrical tube made of a resin into which are mixed electrically conductive additives, preferably carbon fiber and carbon black powder. The resin is injection molded under defined conditions so that a reverse crown profile is formed. The roller of the invention is held in place at the toner fixing position by shafts, and the shafts themselves are supported by flanges. Electric power is supplied to the cylindrical tube to heat the tube to a predetermined thermal toner-fixing temperature through power supply terminals in contact with electrically conductive flanges. Alternately, the power supply terminals may make direct contact with peripheral parts of the cylindrical tube to heat the tube.

Abstract: An electrophotographic photoconductor include an conductive substrate; an undercoat layer provided on the conductive substrate; and a photosensitive layer having charge-generation and charge-transport functions provided on the undercoat layer. The undercoat layer includes a polyamide resin and methylhydrogenpolysiloxane-treated titanium dioxide and preferably styrene-maleic acid half-ester copolymer. The photoconductor can be produced by the steps of: dispersing a polyamide resin and methylhydrogenpolysiloxane-treated titanium dioxide and preferably styrene-maleic acid half-ester copolymer in a mixture solvent of an alcohol-type solvent and a halogenated hydrocarbon-type solvent, thereby preparing a coating liquid for an undercoat layer; applying the coating liquid onto a conductive substrate, thereby providing an undercoat layer on the substrate; and forming a photosensitive layer on the undercoat layer.

Abstract: An organic photosensitive member for electrophotography is provided which comprises a photosensitive layer 3 formed on an electroconductive substrate 1 via an undercoating layer 2, the photosensitive layer 3 comprising a charge generating layer 4 and a charge transporting layer 5, wherein the undercoating layer 2 consists essentially of 12/6/66 copolymeric polyamide expressed by the general formula (I) ##STR1## and a styrene/maleic acid half ester copolymer. By providing such an undercoating layer, it becomes possible to obtain a photosensitive member having excellent electrophotographic characteristics, involving minimal changes in these characteristics during repeated use, and giving a high quality image stably.