# US 7,609,999 B2 · Apparatus for charging an image transfer surface > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,609,999 B2 - Document ID: US7609999B2 - Status: Granted - Kind: B2 - Application number: 11/291,379 - Filed: 2005-12-01 - Published: 2007-06-07 - Granted: 2009-10-27 - Earliest claimed: 2005-12-01 - Assignees: Hewlett-Packard Development Company, L.P. - Inventors: Omer Gila; Michael H. Lee; Seongsik Chang - Web page: https://patentgrep.com/patent/US7609999B2 ## CPC - G03G 15/0233: {Structure, details of the charging member, e.g. chemical composition, surface properties} - G03G 2215/021: by contact, friction or induction - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract An apparatus for charging an image transfer surface in an image transfer device includes a support member and a conductive polymer material surrounding an outer periphery of the support member. An inner portion of the conductive polymer material is loaded with a supplemental conducting agent, and an outer portion of the conductive polymer material is substantially free of the supplemental conducting agent. ## Claims ### Claim 1 An apparatus for contact charging an image transfer surface in an image transfer device, comprising: a support member; and a conductive polymer material surrounding an outer periphery of the support member, wherein an inner portion of the conductive polymer material is loaded with a supplemental conducting agent and an outer portion of the conductive polymer material is substantially free of the supplemental conducting agent, wherein the conductive polymer material includes an ionic conduction agent and the supplemental conducting agent includes an electronic conduction agent such that the inner portion of the conductive polymer material includes the ionic conduction agent and the electronic conduction agent, and the outer portion of the conductive polymer material includes the ionic conduction agent and is substantially free of the electronic conduction agent. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the conductive polymer material comprises an inherently insulative polymer material loaded with a first conducting agent. ### Claim 3 (depends on 2) The apparatus of claim 2, wherein the first conducting agent comprises the ionic conduction agent. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein the ionic conduction agent comprises a salt. ### Claim 5 (depends on 3) The apparatus of claim 3, wherein the electronic conduction agent comprises at least one of carbon black, conductive metal oxide and metal powder. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein a resistivity of the inner portion is approximately the same as a resistivity of the outer portion. ### Claim 7 (depends on 6) The apparatus of claim 6, wherein the inner portion of the conductive polymer is loaded with a first concentration of a first conducting agent and the outer portion of the conductive polymer is loaded with a second concentration of the first conducting agent. ### Claim 8 (depends on 7) The apparatus of claim 7, wherein the first concentration of the first conducting agent in the inner portion of the conducting polymer is less than the second concentration of the first conducting agent in the outer portion of the conducting polymer. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein the supplemental conducting agent is carbon black. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the inner portion of the conductive polymer material comprises in the range of 0.01 to 0.5% by weight carbon black. ### Claim 11 (depends on 1) The apparatus of claim 1, wherein the conductive polymer material has a volume resistivity in the range of about 105 to 108 ohm-centimeters prior to loading the supplemental conducting agent. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein the conductive polymer material loaded with the supplemental conducting agent has a volume resistivity in the range of 104 to 108 ohm-centimeters. ### Claim 13 (depends on 1) The apparatus of claim 1, wherein the outer portion of the conductive polymer material has a thickness in the range of approximately 10 μm to 400 μm. ### Claim 14 (depends on 1) The apparatus of claim 1, wherein the conductive polymer material is comprises ion-conductive material. ### Claim 15 (depends on 14) The apparatus of claim 14, wherein the ion-conductive material comprises polyurethane loaded with lithium salt. ### Claim 16 (depends on 1) The apparatus of claim 1, wherein the support member comprises a metal rod. ### Claim 17 An electrophotographic device comprising: a photoconductor surface for creating an image thereon; and a charge roller for electrically charging the photoconductor surface, the charge roller having an inner conductive layer comprising a conductive polymer material loaded with a supplemental conducting agent and an outer conductive layer comprising the conductive polymer material substantially free of the supplemental conducting agent, wherein the conductive polymer material includes an ionically conductive material and the supplemental conducting agent includes an electronic conduction agent such that the inner conductive layer includes the ionically conductive material and the electronic conduction agent, and the outer conductive layer includes the ionically conductive material and is substantially free of the electronic conduction agent. ### Claim 18 (depends on 17) The electrophotographic device of claim 17, wherein the supplemental conducting agent is carbon black. ### Claim 19 (depends on 17) The electrophotographic device of claim 17, wherein the ionically conductive material is lithium salt. ### Claim 20 (depends on 17) The electrophotographic device of claim 17, wherein the inner conductive layer has a volume resistivity in the range of 104 to 108 ohm-centimeters. ### Claim 21 (depends on 17) The electrophotographic device of claim 17, wherein the outer conductive layer has a volume resistivity in the range of 155 to 108 ohm-centimeters. ### Claim 22 (depends on 17) The electrophotographic device of claim 17, wherein the outer conductive layer has a thickness in the range of approximately 10-400 μm. ### Claim 23 (depends on 17) The electrophotographic device of claim 17, further comprising: an exposure device for forming a latent image on the photoconductor surface; a development device for developing the latent image on the photoconductor surface; and an image transfer apparatus for transferring the image from the photo conductor surface to a printing sheet. ### Claim 24 (depends on 17) The electrophotographic device of claim 17, wherein the photoconductor surface is a continuous surface. ### Claim 25 A method of making a charge roller for charging an image transfer surface in an image transfer device, the method comprising: covering an outer periphery of a support member with a first conductive layer, the first conductive layer comprising a conductive polymer and a supplemental conducting agent mixed in the conductive polymer; and covering an outer periphery of the first conductive layer with a second conductive layer, the second conductive layer comprising the conductive polymer, wherein the conductive polymer includes an ionically conductive material and the supplemental conducting agent includes an electronic conduction agent such that the first conductive layer includes the ionically conductive material and the electronic conduction agent, and the second conductive layer includes the ionically conductive material and is substantially free of the electronic conduction agent. ### Claim 26 (depends on 25) The method of claim 25, wherein covering an outer periphery of the first conducive layer with a second conductive layer comprises spray coating the first conductive layer with the conductive polymer. ### Claim 27 The method of 25, wherein covering an outer periphery of the first conducive layer with a second conductive layer comprises dip coating the first conductive layer with the conductive polymer.