# US 11,835,876 B2 · Image forming apparatus having removable duct and filter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,835,876 B2 - Document ID: US11835876B2 - Status: Granted - Kind: B2 - Application number: 16/805,221 - Filed: 2020-02-28 - Published: 2020-06-25 - Granted: 2023-12-05 - Earliest claimed: 2017-08-29 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Ryoichi Kawasumi - Web page: https://patentgrep.com/patent/US11835876B2 ## CPC - G03G 21/0052: {using an air flow; Details thereof, e.g. nozzle structure} - G03G 15/657: {Feeding path after the transfer point and up to the fixing point, e.g. guides and feeding means for handling copy material carrying an unfused toner image} - G03G 21/206: {Conducting air through the machine, e.g. for cooling, filtering, removing gases like ozone} - G03G 2215/2093: Release agent handling devices - G03G 2221/0094: Suction - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract In opposition to a sheet feeding path, an ultrafine particle (UFP) collecting filter provided between transfer and fixing is easily exchanged. Therefore, a duct unit kept in a state of holding the UFP collecting filter is removably and easily mounted to a duct. ## Claims ### Claim 1 An image forming apparatus comprising: an image forming portion configured to form a toner image on a sheet at a first position by using toner containing a parting agent; a fixing portion configured to thermally fix, at a second position, the toner image formed on the sheet by said image forming portion; a duct, including a suction port provided opposed to a sheet feeding path between the first position and the second position, configured to discharge air to an outside of said image forming apparatus; a filter, provided at the suction port of said duct, configured to collect particles of a predetermined particle size resulting from the parting agent; a projecting portion projecting from an outer peripheral surface of said duct; and a holder configured to hold said filter, said holder provided with an engaging portion to engage with said projecting portion and being detachable from said duct, wherein said duct includes an edge surface connecting between an inner peripheral surface and the outer peripheral surface, and wherein said filter is compressed by said edge surface and said holder. ### Claim 2 (depends on 1) An image forming apparatus according to claim 1, further comprising a guiding portion configured to guide a back surface of the sheet from the first position to the second position, wherein said suction port is in an opposing positional relationship with said guiding portion through the sheet feeding path. ### Claim 3 (depends on 2) An image forming apparatus according to claim 2, wherein the second position is above the first position with respect to a direction of gravitation. ### Claim 4 (depends on 1) An image forming apparatus according to claim 1, wherein the second position is above the first position with respect to a direction of gravitation. ### Claim 5 (depends on 1) An image forming apparatus according to claim 1, wherein the parting agent is a wax, and the predetermined particle size is 5.6 nm or more and 560 nm or less. ### Claim 6 (depends on 1) An image forming apparatus according to claim 1, further comprising a fan configured to form an air flow in said duct. ### Claim 7 (depends on 6) An image forming apparatus according to claim 6, wherein said fan is provided behind said duct with respect to a front-rear direction of said image forming apparatus. ### Claim 8 (depends on 7) An image forming apparatus according to claim 7, wherein said fixing portion includes a rotatable member capable of nipping and feeding the sheet at the second position, wherein said suction port has an elongated shape with respect to a rotational axis direction of said rotating member, and wherein said holder includes an opening exposing said filter and a pressing portion preventing movement of said filter. ### Claim 9 (depends on 8) An image forming apparatus according to claim 8, wherein said pressing portion is provided in plural in a direction parallel to the rotational axis direction of said rotating member. ### Claim 10 (depends on 8) An image forming apparatus according to claim 8, wherein a length of said suction port with respect to the rotational axis direction of said rotating member is longer than an area where the toner image is formed by said image forming portion with respect to the rotational axis direction of said rotating member. ### Claim 11 (depends on 8) An image forming apparatus according to claim 8, wherein said duct includes a discharge port discharging the air suctioned from said suction port at one end thereof with respect to the rotational axis direction of said rotating member and is closed at the other end thereof, and said suction port is disposed between the one end and the other end of said duct. ### Claim 12 (depends on 8) An image forming apparatus according to claim 8, further comprising a fixing base on which said duct is detachably fixed, wherein said duct includes portions-to-be-engaged disposed at both ends thereof with respect to the rotational axis direction of said rotating member and being engageable with said fixing base. ### Claim 13 (depends on 1) An image forming apparatus according to Claim 1, wherein said engaging portion is an opening into which said projecting portion is inserted.