# US 7,608,372 B2 · Electrophotographic photoreceptor, electrophotographic image forming method, electrophotographic image forming apparatus, and processing cartridge > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,372 B2 - Document ID: US7608372B2 - Status: Granted - Kind: B2 - Application number: 11/259,243 - Filed: 2005-10-26 - Published: 2006-06-15 - Granted: 2009-10-27 - Earliest claimed: 2004-12-13 - Assignees: Konica Minolta Business Technologies, Inc. - Inventors: Takeshi Ishida; Kimiyuki Itou; Fumitaka Mochizuki; Shinichi Yabuki - Web page: https://patentgrep.com/patent/US7608372B2 ## CPC - G03G 5/102: {consisting of or comprising metals} - G03G 5/047: characterised by the charge-generation layers or charge transport layers {(G03G5/0433 and G03G5/0436 take precedence)} - G03G 5/056: {Polyesters} - G03G 5/104: {comprising inorganic material other than metals, e.g. salts, oxides, carbon} - G03G 5/142: {Inert intermediate layers} - G03G 5/144: {comprising inorganic material} - G03G 5/14704: {comprising inorganic material} - G03G 5/14752: {Polyesters} - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract Provided are a photoreceptor, an image forming method, an image forming apparatus and a processing cartridge exhibiting an excellent effect on high quality toner images with no image defect caused by occurrence of fog, lowered image density and sharpness, or generation of black spots. Disclosed also is an electrophotographic photoreceptor including an electrically conductive support containing aluminum, an uppermost layer, and at least an intermediate layer containing inorganic particles and binder, the intermediate layer being provided between the support and the uppermost layer, wherein the support has on a surface of the support crystallizing material particles having a diameter of 0.3-10 μm in an amount of being 0.5-20 per (20 μm)2, the inorganic particles have a number average primary particle diameter of 5-300 nm, the intermediate layer is an insulating layer and covered by the uppermost layer. ## Claims ### Claim 1 An electrophotographic photoreceptor comprising an electrically conductive support containing aluminum, an a photosensitive layer, and at least an intermediate layer containing inorganic particles and binder, the intermediate layer being provided between the support and the photosensitive layer, wherein the support has on a surface of the support crystallizing material particles having a diameter of 0.3-10 μm in an amount of being 0.5-20 per (20 μm)2, the inorganic particles have a number average primary particle diameter of 5-300 nm, the intermediate layer is an insulating layer the entire intermediate layer including at least one end of the intermediate layer is substantially covered by the photosensitive layer, and wherein the photosensitive layer directly adheres to the support. ### Claim 2 (depends on 1) The electrophotographic photoreceptor of claim 1, wherein the photosensitive layer contains a polyarylate resin or a polyarylate copolymer resin. ### Claim 3 (depends on 1) The electrophotographic photoreceptor of claim 1, wherein the inorganic particles are N-type semiconductive particles. ### Claim 4 (depends on 1) The electrophotographic photoreceptor of claim 1, wherein the inorganic particles comprise inorganic oxides. ### Claim 5 (depends on 1) The electrophotographic photoreceptor of claim 1, wherein the inorganic particles comprise titanium oxides. ### Claim 6 (depends on 1) The electrophotographic photoreceptor of claim 1, wherein the inorganic particles are subjected to surface treatment. ### Claim 7 (depends on 1) The electrophotographic photoreceptor of claim 1, wherein the intermediate layer has a thickness of 0.2-40μm. ### Claim 8 (depends on 1) The electrophotographic photoreceptor of claim 1, wherein the binder comprises polyamide resin. ### Claim 9 (depends on 1) The electrophotographic photoreceptor of claim 1, wherein the photosensitive layer has at least a charge generation layer and a charge transfer layer provided on the intermediate layer in this order. ### Claim 10 (depends on 1) The electrophotographic photoreceptor of claim 1, wherein a protective layer is provided on the photosensitive layer. ### Claim 11 (depends on 1) An electrophotographic image forming method comprising the steps of: (a) charging an electrophotographic photoreceptor as defined in claim 1, (b) exposing the charged electrophotographic photoreceptor to form an electrostatic latent image, (c) developing the electrostatic latent image with a developer containing a toner to form a toner image, and (d) transferring the toner image to a recording material. ### Claim 12 (depends on 11) The electrophotographic image forming method of claim 11, wherein the photosensitive layer contains a polyarylate resin or a polyarylate copolymer resin. ### Claim 13 (depends on 11) The electrophotographic image forming method of claim 11, wherein a charging member is brought into contact with the electrophotographic photoreceptor to be charged in the charging step. ### Claim 14 (depends on 13) The electrophotographic image forming method of claim 13, wherein the charging member is a charging roller. ### Claim 15 (depends on 13) The electrophotographic image forming method of claim 13, wherein the charging member is a magnetic brush. ### Claim 16 (depends on 1) An electrophotographic image forming apparatus comprising the electrophotographic photoreceptor of claim 1. ### Claim 17 (depends on 1) A processing cartridge capable of being mounted on and dismounted from an electrophotographic image forming apparatus, comprising the electrophotographic photoreceptor of claim 1 and at least one of a charging device, an exposure device, a development device, a transfer device and a cleaning device. ### Claim 18 (depends on 13) The electrophotographic photoreceptor of claim 13, wherein the protective layer contains a polyarylate resin or a polyacrylate copolymer resin. ### Claim 19 (depends on 10, 11) The electrophotographic image forming method of claim 11, wherein the electrophotographic photoreceptor is defined by claim 10 and the protective layer contains a polyarylare resin or a polyarylate copolymer resin.