# US 2014/0153981 A1 · Image heating apparatus 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 2014/0153981 A1 - Document ID: US20140153981A1 - Status: Published application - Kind: A1 - Application number: 14/083,994 - Filed: 2013-11-19 - Published: 2014-06-05 - Earliest claimed: 2012-11-30 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Takuya Hasegawa - Web page: https://patentgrep.com/patent/US20140153981A1 ## CPC - G03G 15/2039: {with means for controlling the fixing temperature} - G03G 15/2053: {Structural details of heat elements, e.g. structure of roller or belt, eddy current, induction heating} - G03G 2215/00143: Meandering prevention - G03G 2215/2019: the belt not heating the toner or medium directly, e.g. heating a heating roller - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract An image heating apparatus includes: a rotatable heating member; a belt unit including an endless belt configured to heat the rotatable heating member, and a supporting portion configured to rotatably support an inner surface of the belt; a holding portion configured to rotatably hold the belt unit; a detecting portion configured to detect that the belt is out of a predetermined zone with respect to a widthwise direction of the belt; a tilting portion configured to tilt the belt unit relative to the holding portion in a direction of causing the belt to return into the predetermined zone on the basis of an output of the detecting portion; and a limiting portion configured to limit tilting of the belt unit to an angle exceeding a predetermined angle range wider than an angle range in which the belt unit is capable of being tilted by the tilting portion. ## Claims ### Claim 1 An image heating apparatus comprising: a rotatable heating member configured to heat an image on a sheet; a belt unit including an endless belt configured to heat said rotatable heating member in contact with an outer surface of said rotatable heating member, and a supporting portion configured to rotatably support an inner surface of said endless belt; a holding portion configured to rotatably hold said belt unit; a detecting portion configured to detect that said endless belt is out of a predetermined zone with respect to a widthwise direction of said endless belt; a tilting portion configured to tilt said belt unit relative to said holding portion in a direction of causing said endless belt to return into the predetermined zone on the basis of an output of said detecting portion; and a limiting portion configured to limit tilting of said belt unit to an angle exceeding a predetermined angle range wider than an angle range in which said belt unit is capable of being tilted by said tilting portion. ### Claim 2 (depends on 1) An image heating apparatus according to claim 1, wherein said limiting portion is provided on said holding portion. ### Claim 3 (depends on 1) An image heating apparatus according to claim 1, wherein said supporting portion is a roller in which a heater is incorporated. ### Claim 4 (depends on 1) An image heating apparatus according to claim 1, further comprising a driving mechanism configured to rotationally drive said rotatable heating member, wherein said endless belt is constituted so as to be rotated by rotation of said rotatable heating member. ### Claim 5 (depends on 1) An image heating apparatus according to claim 1, wherein said rotatable heating member is a roller. ### Claim 6 (depends on 1) An image heating apparatus according to claim 1, further comprising a nip forming member configured to form a nip for nipping and conveying the sheet between said nip forming member and said rotatable heating member. ### Claim 7 An image heating apparatus comprising: a rotatable heating member configured to heat a toner image on a sheet; a belt unit including an endless belt configured to heat said rotatable heating member in contact with an outer surface of said rotatable heating member, and a roller configured to rotatably support an inner surface of said endless belt; a detecting portion configured to detect a widthwise position of said endless belt; a tilting portion configured to tilt, on the basis of an output of said detecting portion, said belt unit so that an axis of said roller in a state in which said roller presses said endless belt against said rotatable heating member crosses with a generatrix of said rotatable heating member; and a limiting portion configured to limit tilting of said belt unit to an angle exceeding a predetermined tilt angle range wider than a tilt angle range of said belt unit tilted by said tilting portion. ### Claim 8 (depends on 7) An image heating apparatus according to claim 7, wherein said limiting portion is provided on said holding portion. ### Claim 9 (depends on 7) An image heating apparatus according to claim 7, wherein further comprising a heater, incorporated in said roller, configured to heat said endless belt. ### Claim 10 (depends on 7) An image heating apparatus according to claim 7, further comprising a driving mechanism configured to rotationally drive said rotatable heating member, wherein said endless belt is constituted so as to be rotated by rotation of said rotatable heating member. ### Claim 11 (depends on 7) An image heating apparatus according to claim 7, wherein said rotatable heating member is a roller. ### Claim 12 (depends on 7) An image heating apparatus according to claim 7, further comprising a nip forming member configured to form a nip for nipping and conveying the sheet between said nip forming member and said rotatable heating member. ### Claim 13 An image heating apparatus comprising: a rotatable heating member configured to heat a toner image on a sheet; an endless belt configured to heat said rotatable heating member in contact with an outer surface of said rotatable heating member; two rollers configured to rotatably support an inner surface of said endless belt; a supporting portion configured to support said rollers; a holding portion configured to swingably hold said supporting portion; a detecting portion configured to detect a widthwise position of said endless belt; a swinging portion configured to swing, on the basis of an output of said detecting portion, said supporting portion relative to said holding portion so that said two rollers in a state in which said roller presses said endless belt against said rotatable heating member cross as a unit with said rotatable heating member; and a limiting portion configured to limit swing of said belt unit to an angle exceeding a predetermined angle range wider than an angle range in which said belt unit is capable of being swung by said swinging portion. ### Claim 14 (depends on 13) An image heating apparatus according to claim 13, wherein said swinging portion is provided is an opposite side from said rotatable heating member with respect to said endless belt and has a swinging shaft which is positioned between said two rollers and which is substantially parallel to a direction of normal to a flat surface of said endless belt in a side remote from said rotatable heating member, and wherein said swinging portion swings said holding portion about the swinging shaft on the basis of an output of said detecting portion. ### Claim 15 An image heating apparatus comprising: a rotatable heating member configured to heat an image on a sheet; a belt unit including an endless belt configured to heat said rotatable heating member in contact with an outer surface of said rotatable heating member, and a supporting portion configured to rotatably support an inner surface of said endless belt; a detecting portion configured to detect that said endless belt is out of a predetermined zone with respect to a widthwise direction of said endless belt; a tilting portion configured to tilt said belt unit in a direction of causing said endless belt to return into the predetermined zone on the basis of an output of said detecting portion; and a limiting portion configured to limit tilting of said belt unit. ### Claim 16 (depends on 15) An image heating apparatus according to claim 15, wherein said tilting portion tilts said belt unit within a predetermined angle range about a predetermined tilt center, and wherein said position limits the tilting of said belt unit to an angle exceeding an angle range wider than the predetermined angle range. ### Claim 17 An image forming apparatus comprising: a belt unit including an endless belt and a supporting portion configured to rotatably support an inner surface of said endless belt; a rotatable driving member configured to rotate said endless belt by rotation thereof in contact with an outer surface of said endless belt; a holding portion configured to rotatably hold said belt unit; a detecting portion configured to detect that said endless belt is out of a predetermined zone with respect to a widthwise direction of said endless belt; a tilting portion configured to tilt said belt unit relative to said holding portion in a direction of causing said endless belt to return into the predetermined zone on the basis of an output of said detecting portion; and a limiting portion configured to limit tilting of said belt unit to an angle exceeding a predetermined angle range wider than an angle range in which said belt unit is capable of being tilted by said tilting portion. ### Claim 18 An image forming apparatus comprising: a belt unit including an endless belt and a roller configured to rotatably support an inner surface of said endless belt; a rotatable driving member configured to rotate said endless belt by rotation thereof in contact with an outer surface of said endless belt; a holding portion configured to rotatably hold said belt unit; a detecting portion configured to detect a widthwise position of said endless belt; a tilting portion configured to tilt, on the basis of an output of said detecting portion, said belt unit relative to said holding portion so that an axis of said roller in a state in which said roller presses said endless belt against said rotatable heating member crosses with a generatrix of said rotatable heating member; and a limiting portion configured to limit tilting of said belt unit to an angle exceeding a predetermined angle range wider than an angle range in which said belt unit is capable of being tilted by said tilting portion. ### Claim 19 An image heating apparatus comprising: an endless belt; two rollers configured to rotatably support an inner surface of said endless belt; a rotatable driving member configured to rotate said endless belt by rotation thereof in contact with an outer surface of said endless belt; a supporting portion configured to support said rollers; a holding portion configured to swingably hold said supporting portion; a detecting portion configured to detect a widthwise position of said endless belt; a swinging portion configured to swing, on the basis of an output of said detecting portion, said supporting portion relative to said holding portion so that said two rollers in a state in which said roller presses said endless belt against said rotatable heating member cross as a unit with said rotatable heating member; and a limiting portion configured to limit swing of said belt unit to an angle exceeding a predetermined angle range wider than an angle range in which said belt unit is capable of being swung by said swinging portion. ### Claim 20 (depends on 19) An image heating apparatus according to claim 19, wherein said swinging portion is provided is an opposite side from said rotatable driving member with respect to said endless belt and has a swinging shaft which is positioned between said two rollers and which is substantially parallel to a direction of normal to a flat surface of said endless belt in a side remote from said rotatable driving member, and wherein said swinging portion swings said supporting portion about the swinging shaft on the basis of an output of said detecting portion.