# US 7,609,998 B2 · Transfer unit 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 7,609,998 B2 - Document ID: US7609998B2 - Status: Granted - Kind: B2 - Application number: 11/759,657 - Filed: 2007-06-07 - Published: 2007-12-13 - Granted: 2009-10-27 - Earliest claimed: 2006-06-13 - Assignees: Ricoh Company, Ltd. - Inventors: Tsutomu Katoh; Mitsuru Takahashi; Kazuchika Saeki; Nobuto Yokokawa; Kazuosa Kuma; Takeshi Fukao - Web page: https://patentgrep.com/patent/US7609998B2 ## CPC - G03G 21/168: {for the transfer unit} - G03G 15/1615: {relating to the driving mechanism for the intermediate support, e.g. gears, couplings, belt tensioning} - G03G 2215/0119: Linear arrangement adjacent plural transfer points - G03G 2221/1642: for the transfer unit - G03G 2221/1657: transmitting mechanical drive power - G03G 2221/1684: using extractable subframes, e.g. on rails or hinges - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract A transfer belt is driven by a plurality of supporting rollers. A unit frame supports the supporting rollers in a rotatable manner. At least one of the supporting rollers includes a cylindrical member having a substantially same outer diameter over an entire length thereof. Each end portion of the cylindrical member in a longitudinal direction is supported by the unit frame via a bearing in a rotatable manner. ## Claims ### Claim 1 A transfer unit comprising: a plurality of supporting rollers; a transfer belt that is driven by the supporting rollers; a unit frame that supports the supporting rollers in a rotatable manner, wherein at least one of the supporting rollers includes a cylindrical member having a substantially same outer diameter over an entire length thereof, each end portion of the cylindrical member in a longitudinal direction is supported by the unit frame via a bearing in a rotatable manner, and the unit frame includes a through hole communicating with the inside of the cylindrical member. ### Claim 2 (depends on 1) The transfer unit according to claim 1, wherein the cylindrical member includes a driven member that is engaged with a driving member provided on a main body of an image forming apparatus and driven by the driving member in a rotatable manner. ### Claim 3 (depends on 1) The transfer unit according to claim 1, wherein the through hole and the inside of the cylindrical member form an airflow path. ### Claim 4 (depends on 3) The transfer unit according to claim 3, wherein the cylindrical member includes a heat-dissipating member, said heat dissipating member includes a plurality of elongated members fixed to an inside surface of the cylindrical member. ### Claim 5 (depends on 3) The transfer unit according to claim 3, wherein the cylindrical member includes a plurality of arcuate blades that form a fan. ### Claim 6 (depends on 1) The transfer unit according to claim 1, wherein the cylindrical member is made of aluminum. ### Claim 7 A transfer unit comprising: a plurality of supporting rollers; a transfer belt that is driven by the supporting rollers; a unit frame that supports the supporting rollers in a rotatable manner, wherein at least one of the supporting rollers includes a cylindrical member having a substantially same outer diameter over an entire length thereof, each end portion of the cylindrical member in a longitudinal direction is supported by the unit frame via a bearing in a rotatable manner, and the unit frame includes a through hole communicating with the inside of the cylindrical member, wherein a harness extends along the through hole and the inside of the cylindrical member. ### Claim 8 A transfer unit comprising: a plurality of supporting rollers; a transfer belt that is driven by the supporting rollers; a unit frame that supports the supporting rollers in a rotatable manner, wherein at least one of the supporting rollers includes a cylindrical member having a substantially same outer diameter over an entire length thereof, each end portion of the cylindrical member in a longitudinal direction is supported by the unit frame via a bearing in a rotatable manner, wherein the cylindrical member includes a rotation detecting unit that detects number of rotations of the cylindrical member per unit time, and the rotation detection unit includes a photosensor mounted on a bracket projecting from the unit frame. ### Claim 9 An image forming apparatus comprising: a transfer unit that includes a plurality of supporting rollers, a transfer belt that is driven by the supporting rollers, a unit frame that supports the supporting rollers in a rotatable manner, wherein at least one of the supporting rollers includes a cylindrical member having a substantially same outer diameter over an entire length thereof, each end portion of the cylindrical member in a longitudinal direction is supported by the unit frame via a bearing in a rotatable manner, the unit frame includes a through hole communicating with the inside of the cylindrical member; and an image carrier on which a toner image is formed, wherein the toner image formed on the image carrier is transferred onto the transfer belt of the transfer unit for a primary transfer, and the toner image on the transfer belt is transferred onto a recording medium for a secondary transfer to obtain a recorded image. ### Claim 10 An image forming apparatus comprising: a transfer unit that includes a plurality of supporting rollers, a transfer belt that is driven by the supporting rollers, a unit frame that supports the supporting rollers in a rotatable manner, wherein at least one of the supporting rollers includes a cylindrical member having a substantially same outer diameter over an entire length thereof, each end portion of the cylindrical member in a longitudinal direction is supported by the unit frame via a bearing in a rotatable manner, the unit frame includes a through hole communicating with the inside of the cylindrical member; and an image carrier on which a toner image is formed, wherein the toner image formed on the image carrier is transferred onto a recording medium carried by the transfer belt to obtain a recorded image.