# US 9,519,249 B2 · Fixing device and image forming apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,519,249 B2 - Document ID: US9519249B2 - Status: Granted - Kind: B2 - Application number: 14/968,512 - Filed: 2015-12-14 - Published: 2016-06-16 - Granted: 2016-12-13 - Earliest claimed: 2014-12-12 - Assignees: Ricoh Company, Ltd. - Applicants: Fumihiro Hirose; Masami Okamoto; Kenji Nozawa; Yuuki Kikushima; Kensuke Yamaji; Keisuke Kubota; Shuutaroh Yuasa; Kaori Hemmi - Inventors: Fumihiro Hirose; Masami Okamoto; Kenji Nozawa; Yuuki Kikushima; Kensuke Yamaji; Keisuke Kubota; Shuutaroh Yuasa; Kaori Hemmi - Web page: https://patentgrep.com/patent/US9519249B2 ## CPC - G03G 15/2053: {Structural details of heat elements, e.g. structure of roller or belt, eddy current, induction heating} - G03G 15/2017: {Structural details of the fixing unit in general, e.g. cooling means, heat shielding means (G03G15/2053 takes precedence)} - G03G 2215/2032: the belt further entrained around additional rotating belt support members - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract A fixing device includes a cylindrical heat roller; a plurality of heaters disposed inside the heat roller, extending along a longitudinal axis of the heat roller; and a heat adjuster, disposed among the plurality of heaters, to adjust heat from one to another of the plurality of heaters. An image forming apparatus includes an image forming section to form an image on a recording medium; and the fixing device as described above, to fix the image onto the recording medium. ## Claims ### Claim 1 A fixing device comprising: a cylindrical heat roller; a plurality of heaters including at least three heaters disposed inside the heat roller, extending along a longitudinal axis of the heat roller; and a heat adjuster, disposed among the plurality of heaters, to absorb heat from one to another of the plurality of heaters, the heat adjuster including a curved surface facing at least some of said heaters. ### Claim 2 (depends on 1) The fixing device as claimed in claim 1, wherein the heat adjuster is disposed equidistant from each of the plurality of heaters. ### Claim 3 (depends on 1) The fixing device as claimed in claim 1, wherein the plurality of heaters is disposed equidistantly around an inner circumference of the heat roller, and the heat adjuster is disposed at an internal central portion of the heat roller. ### Claim 4 (depends on 1) The fixing device as claimed in claim 1, wherein the heat adjuster is formed of glass. ### Claim 5 (depends on 4) The fixing device as claimed in claim 4, wherein the heat adjuster is formed of quartz glass. ### Claim 6 (depends on 1) The fixing device as claimed in claim 1, wherein the heat adjuster reflects heat from the plurality of heaters. ### Claim 7 (depends on 1) The fixing device as claimed in claim 1, wherein the heat adjuster comprises a reflection layer around a circumference thereof. ### Claim 8 (depends on 1) The fixing device as claimed in claim 1, comprising: a fixing roller; a belt rotatably stretched around the heat roller and the fixing roller; and a pressure roller to press against the fixing roller via the belt, wherein the pressure roller, and the belt pressed by the pressure roller form a nip portion. ### Claim 9 (depends on 1) The fixing device as claimed in claim 1, further comprising a pressure roller to press against the heat roller, wherein the pressure roller and the heat roller form a nip portion. ### Claim 10 (depends on 1) The fixing device as claimed in claim 1, wherein a total rated power of the plurality of heaters sums up to 5,000 watts or greater. ### Claim 11 (depends on 1) An image forming apparatus comprising the fixing device as claimed in claim 1. ### Claim 12 (depends on 1) An image forming apparatus comprising: an image forming section to form an image on a recording medium; and the fixing device as claimed in claim 1, to fix the image onto the recording medium. ### Claim 13 (depends on 1) The fixing device as claimed in claim 1, further comprising a pressure roller to press against the heat roller and wherein the heat adjuster is cylindrical, wherein the pressure roller and the heat roller form a nip portion. ### Claim 14 A fixing device comprising: a cylindrical heat roller; a plurality of heaters disposed inside the heat roller, extending along a longitudinal axis of the heat roller; and a heat adjuster, disposed among the plurality of heaters, to adjust heat from one to another of the plurality of heaters, the heat adjuster comprising glass. ### Claim 15 (depends on 14) The fixing device as claimed in claim 14, wherein the heat adjuster comprises quartz glass. ### Claim 16 (depends on 14) The fixing device as claimed in claim 14, wherein the heat adjuster reflects heat from the plurality of heaters. ### Claim 17 (depends on 14) The fixing device as claimed in claim 14, wherein the heat adjuster comprises a reflection layer around a circumference thereof. ### Claim 18 (depends on 14) The fixing device as claimed in claim 14, comprising: a fixing roller; a belt rotatably stretched around the heat roller and the fixing roller; and a pressure roller to press against the fixing roller via the belt, wherein the pressure roller, and the belt pressed by the pressure roller form a nip portion. ### Claim 19 (depends on 14) An image forming apparatus comprising: an image forming section to form an image on a recording medium; and the fixing device as claimed in claim 14, to fix the image onto the recording medium. ### Claim 20 A fixing device comprising: a cylindrical heat roller; a plurality of heaters including at least three heaters disposed inside the heat roller, extending along a longitudinal axis of the heat roller; and a heat adjuster, disposed among the plurality of heaters, to absorb heat from one to another of the plurality of heaters, the heat adjuster having a polygonal shape bounded by five or more line segments.