# US 8,541,089 B2 · Fixing belt, base element for fixing belt, fixing device, image forming apparatus and method for producing base element > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,541,089 B2 - Document ID: US8541089B2 - Status: Granted - Kind: B2 - Application number: 11/828,645 - Filed: 2007-07-26 - Published: 2008-01-31 - Granted: 2013-09-24 - Earliest claimed: 2006-07-26 - Assignees: Ricoh Company, Ltd. - Applicants: Hiroshi Katabami; Minoru Matsuo; Shigenobu Fukui - Inventors: Hiroshi Katabami; Minoru Matsuo; Shigenobu Fukui - Web page: https://patentgrep.com/patent/US8541089B2 ## CPC - B29D 29/00: Producing belts or bands - G03G 15/2057: {relating to the chemical composition of the heat element and layers thereof} - G03G 2215/2016: Heating belt - Y10T 428/19: Sheets or webs edge spliced or joined - Y10T 428/192: Sheets or webs coplanar - Y10T 428/265: 1 mil or less - B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00) - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A base element for a fixing belt are provided. The base element includes a sheet which is made of a heat resistant resin and has opposite end portions joined in an endless state. A conductive film layer of a thickness of 3 to 15 μm is provided over two third or more area of an inner surface of the endless belt. ## Claims ### Claim 1 A base element for a fixing belt, comprising a sheet comprising a heat-resistant resin, wherein the sheet has opposite end portions that are joined in an endless state, a conductive film layer of a thickness of 3 to 15 μm comprises striped application parts covering at least two thirds but not the entirety of an inner surface of the sheet having opposite end portions joined in an endless state, the striped application parts comprise a conductive material sprayed on the sheet, the striped application parts of the conductive film layer are inclined to a rotation direction of the belt, and the conductive film layer satisfies a following relationship: ⅔≦X/(X+Y)<1, where X represents a total area of the striped application parts of the conductive film layer, and Y represents a total area of intervals between the striped application parts of the conductive film layer. ### Claim 2 (depends on 1) The base element according to claim 1, wherein the heat-resistant resin is a polyimide resin. ### Claim 3 (depends on 1) The base element according to claim 1, wherein the conductive film layer comprises a polyimide, a polyphenylene sulfide, and a conductive carbon. ### Claim 4 (depends on 1) The base element according to claim 1, wherein the opposite end portions of the sheet are joined with a silicon adhesive. ### Claim 5 (depends on 1) The base element according to claim 1, wherein a thinned portion is formed on each of the opposite end portions of the sheet. ### Claim 6 (depends on 5) The base element according to claim 5, wherein each of the thinned portions is formed in a stepped shape. ### Claim 7 (depends on 5) The base element according to claim 5, wherein each of the thinned portions is formed in a tapered shape. ### Claim 8 (depends on 1) The base element of claim 1, wherein the conductive film layer has a thickness of 3 μm. ### Claim 9 (depends on 1) A fixing belt comprising the base element of claim 1, an elastic layer, and a separation layer. ### Claim 10 (depends on 9) A fixing device comprising the fixing belt of claim 9. ### Claim 11 (depends on 10) An image-forming apparatus comprising the fixing device of claim 10. ### Claim 12 (depends on 1) A method for producing the base element according to claim 1, the method comprising: joining opposite end portions of the sheet to form an endless belt; and applying a conductive film-material to an inner surface of the endless belt to form the conductive film layer while rotating the endless belt. ### Claim 13 (depends on 12) The method according to claim 12, wherein the sheet comprises a heat-resistant resin that is a polyimide resin. ### Claim 14 (depends on 12) The method according to claim 12, further comprising forming thinned portions on opposite sides of the opposite end portions of the sheet before joining the opposite end portions of the sheet to form the endless belt. ### Claim 15 (depends on 12) The method according to claim 12, further comprising forming areas on opposite sides of the opposite end portions of the sheet before joining the opposite end portions of the sheet to form the endless belt. ### Claim 16 (depends on 14) The method according to claim 14, wherein each of the thinned portions is formed in a stepped shape. ### Claim 17 (depends on 14) The method according to claim 14, wherein each of the thinned portions is formed in a tapered shape. ### Claim 18 (depends on 1) A method for producing the base element of claim 1, the method comprising: applying a conductive film-material to a surface of the sheet; and joining opposite end portions of the sheet to form an endless belt so that the surface provided with the conductive film-material is disposed on an inner side of the endless belt. ### Claim 19 (depends on 18) The method according to claim 18, wherein the sheet comprises a heat-resistant resin that is a polyimide resin. ### Claim 20 (depends on 18) The method according to claim 18, further comprising, before the joining opposite end portions of the sheet to form an endless belt, forming thinned portions on opposite sides of the opposite end portions of the sheet.