# US 5,708,932 A · Charging system and electrophotography apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,708,932 A - Document ID: US5708932A - Status: Granted - Kind: A - Application number: 08/779,389 - Filed: 1997-01-07 - Granted: 1998-01-13 - Earliest claimed: 1994-05-19 - Assignees: Canon Kabushiki Kaisha - Inventors: Hideyuki Yano; Akio Maruyama; Yomishi Toshida; Noboru Kashimura; Kazushige Nakamura; Shoji Amamiya; Harumi Ishiyama; Tadashi Furuya - Web page: https://patentgrep.com/patent/US5708932A ## CPC - G03G 5/14708: {comprising organic material} - G03G 5/147: Cover layers - G03G 5/14704: {comprising inorganic material} - G03G 5/14726: {Halogenated polymers} - G03G 5/14734: {Polymers comprising at least one carboxyl radical, e.g. polyacrylic acid, polycrotonic acid, polymaleic acid; Derivatives thereof, e.g. their esters, salts, anhydrides, nitriles, amides} - G03G 5/14791: {Macromolecular compounds characterised by their structure, e.g. block polymers, reticulated polymers, or by their chemical properties, e.g. by molecular weight or acidity} - G03G 13/025: {by contact, friction or induction} - G03G 2215/022: using a magnetic brush - G03G 2215/0497: Exposure from behind the image carrying surface - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract This invention relates to a charging system for charging a body to be electrified, comprising a body to be electrified, and a charging member which can be applied with voltage to brush the surface of said body to be electrified and charge it. Wherein the surface of the body to be electrified exhibits a contact angle of 90.degree. or more for water. ## Claims ### Claim 1 An electrophotographic apparatus comprising: a photosensitive body which includes a surface layer with a volume resistivity of 1.times.10.sup.9 to 1.times.10.sup.14 .OMEGA.cm, and a photosensitive layer disposed inside of the surface layer; and a charging member to which a voltage is applied to charge the photosensitive body, said charging member slidably contacting the surface layer of the photosensitive body, wherein the surface layer of the photosensitive body includes a lubricating material and conductive particles, and has a contacting angle of 90.degree. or more relative to water. ### Claim 2 (depends on 1) An electrophotographic apparatus according to claim 1, wherein a moving direction of said charging member is opposite to a moving direction of the photosensitive body at a contact area between the photosensitive body and the charging member. ### Claim 3 (depends on 1) An electrophotographic apparatus according to claim 1, wherein said charging member comprises a fiber brush which comes into contact with said photosensitive body. ### Claim 4 (depends on 1) An electrophotographic apparatus according to claim 1, wherein said charging member is a magnetic brush having magnetic particles which come into contact with said photosensitive body. ### Claim 5 (depends on 1, 2, 3, 4) An electrophotographic apparatus according to one of claims 1 to 4, wherein the surface layer of said photosensitive body further contains resin. ### Claim 6 (depends on 1) An electrophotographic apparatus according to claim 1, wherein said conductive particles are metal oxide. ### Claim 7 (depends on 1) An electrophotographic apparatus according to claim 1, wherein said lubricating material is selected from the group consisting of fluoro polymer, silicone polymer, fluoro oligomer and silicone oligomer. ### Claim 8 (depends on 1) An electrophotographic apparatus according to claim 1, wherein said lubricating material is a polymer or a copolymer of one or more materials selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, trifluoroethylene, chlorotrifluoroethylene, vinylidene fluoride, vinyl fluoride, and perfluoro alkyl vinyl ether. ### Claim 9 (depends on 1) An electrophotographic apparatus according to claim 1, wherein said surface layer contains 5 to 60 wt % of lubricating material by weight. ### Claim 10 (depends on 1) An electrophotographic apparatus according to claim 1, wherein said lubricating material comprises particles having a mean diameter of 0.005 to 0.3 .mu.m. ### Claim 11 An electrophotography apparatus comprising: a photosensitive body comprising of photosensitive layer and a substrate which supports the photosensitive layers and can transmit light; and a magnetic brush member positioned in contact with the photosensitive body which can be applied with voltage to charge the photosensitive body and perform development, wherein the magnetic brush member has magnetic conductive carrier and toner, and part of the back surface of the photosensitive body corresponding to the contact area with the magnetic brush member is exposed to light, and the fluidity of the carrier is reduced, at least, to a degree indicated by a value of 45 sec/50 g. ### Claim 12 (depends on 11) An electrophotography apparatus according to claim 11, wherein the surface of said photosensitive body exhibits a contact angle of 90.degree. or more for water. ### Claim 13 (depends on 11, 12) An electrophotography apparatus according to claim 11 or 12, wherein said oartier is particles consisting of magnetic cores and coating material covering the surfaces of the magnetic cores. ### Claim 14 (depends on 11) An electrophotography apparatus according to claim 11, or 12, wherein said toner is insulative toner containing wax. ### Claim 15 (depends on 11, 12) An electrophotography apparatus according to claim 11 or 12, wherein said toner is insulative toner with which lubricating fine particles are mixed. ### Claim 16 (depends on 12) An electrophotography apparatus according to claim 12, wherein the surface of said photosensitive body contains lubricating material. ### Claim 17 (depends on 11, 16) An electrophotography apparatus according to claim 11 or 16, wherein the surface of said photosensitive body contains conductive particles and resin. ### Claim 18 (depends on 17) An electrophotography apparatus according to claim 17, wherein said conductive particles are metal oxide. ### Claim 19 (depends on 16) An electrophotography apparatus according to claim 16, wherein said lubricating material is fluoro polymer, silicone polymer, fluoro oligomer or silicone oligomer. ### Claim 20 (depends on 16) An electrophotography apparatus according to claim 16, wherein said lubricating material is polymer or copolymer containing one or more materials selected from tetraluoroethylene, hexafluorepropylene, trifluoroethylene, chlorotrifluoroethylene, vinylidene fluoride, vinyl fluoride and perfluoro olkyl vinyl ether. ### Claim 21 (depends on 11) An electrophotography apparatus according to claim 11, wherein said photosensitive body has a surface layer which contains 5 to 60 wt % of lubricating material in its total weight. ### Claim 22 (depends on 16, 21) An electrophotography apparatus according to claim 16 or 21, wherein said lubricating material is particles having a mean diameter of 0.005 to 0.3 .mu.m. ### Claim 23 (depends on 11) An electrophotography apparatus according to claim 11, wherein said photosensitive body has a surface layer having a resistance of 1.times.10.sup.9 to 1.times.10.sup.14 .OMEGA.m.