# US 2014/0153947 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 2014/0153947 A1 - Document ID: US20140153947A1 - Status: Published application - Kind: A1 - Application number: 14/091,669 - Filed: 2013-11-27 - 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/US20140153947A1 ## CPC - G03G 15/2014: {using contact heat} - G03G 15/2053: {Structural details of heat elements, e.g. structure of roller or belt, eddy current, induction heating} - 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 endless belt; a contact portion configured to contact a widthwise edge of the endless belt; an urging portion configured to urge the contact portion toward the widthwise edge of the endless belt; a detecting portion configured to detect, that the endless belt is out of a predetermined zone, depending on a position of the contact portion; a tilting portion configured to tilt the belt unit in a direction of causing the endless belt to return into the predetermined zone on the basis of an output of the detecting portion; and a retracting portion configured to retract the contact portion from the endless belt against an urging force of the urging 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 contact portion configured to contact a widthwise edge of said endless belt; an urging portion configured to urge said contact portion toward the widthwise edge of said endless belt; a detecting portion configured to detect, that said endless belt is out of a predetermined zone, depending on a position of said contact portion; 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 retracting portion configured to retract said contact portion from said endless belt against an urging force of said urging portion. ### Claim 2 (depends on 1) An image heating apparatus according to claim 1, further comprising a pressing mechanism configured to press said toward said rotatable heating member, wherein said retracting portion retracts said contact portion from said endless belt with a demounting operation of said pressing mechanism from said image heating apparatus. ### Claim 3 (depends on 2) An image heating apparatus according to claim 2, wherein said demounting portion permits contact of said contact portion with the widthwise edge of said endless belt with a mounting operation of said pressing mechanism into said image heating apparatus. ### Claim 4 (depends on 1) An image heating apparatus according to claim 1, wherein said retracting portion retracts said contact portion from said endless belt with a demounting operation of said belt unit from said image heating apparatus. ### Claim 5 (depends on 4) An image heating apparatus according to claim 4, wherein said retracting portion permits contact of said contact portion with the widthwise edge of said end portion with a mounting operation of said belt unit into said image heating apparatus. ### Claim 6 (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 7 (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 8 (depends on 1) An image heating apparatus according to claim 1, wherein said rotatable heating member is a roller. ### Claim 9 (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 10 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 supporting roller configured to rotatably support an inner surface of said endless belt; a contact portion configured to contact a widthwise edge of said endless belt; an urging portion configured to urge said contact portion toward the widthwise edge of said endless belt; a detecting portion configured to detect a widthwise position of said endless belt depending on a position of said contact portion; 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 supporting roller placed in a state in which said supporting roller presses said endless belt against said rotatable heating member crosses with a generatrix of said rotatable heating member; and a retracting portion configured to retract said contact portion from said endless belt against an urging force of said urging portion. ### Claim 11 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 supporting rollers configured to rotatably support an inner surface of said endless belt; a holding portion configured to hold said endless belt and said two supporting rollers; a contact portion configured to contact a widthwise edge of said endless belt; an urging portion configured to urge said contact portion toward the widthwise edge of said endless belt; a detecting portion configured to detect a widthwise position of said endless belt depending on a position of said contact portion; and a swinging portion configured to swing, on the basis of an output of said detecting portion, said holding portion so that said two supporting rollers placed in a state in which said two supporting rollers press said endless belt against said rotatable heating member cross as a unit with said rotatable heating member. ### Claim 12 (depends on 11) An image heating apparatus according to claim 11, 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 supporting 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 13 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 contact portion configured to contact a widthwise edge of said endless belt; an urging portion configured to urge said contact portion toward the widthwise edge of said endless belt; a detecting portion configured to detect, that said endless belt is out of a predetermined zone, depending on a position of said contact portion; 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 retracting portion configured to retract said contact portion from said endless belt against an urging force of said urging portion. ### Claim 14 An image forming apparatus comprising: a belt unit including an endless belt and a supporting 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 contact portion configured to contact a widthwise edge of said endless belt; an urging portion configured to urge said contact portion toward the widthwise edge of said endless belt; a detecting portion configured to detect a widthwise position of said endless belt depending on a position of said contact portion; 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 supporting roller placed in a state in which said supporting roller presses said endless belt against said rotatable heating member crosses with a generatrix of said rotatable heating member; and a retracting portion configured to retract said contact portion from said endless belt against an urging force of said urging portion. ### Claim 15 An image forming apparatus comprising: an endless belt: two supporting rollers configured to rotatably support an inner surface of said endless belt; a rotatable heating 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 hold said endless belt and said two supporting rollers; a contact portion configured to contact a widthwise edge of said endless belt; an urging portion configured to urge said contact portion toward the widthwise edge of said endless belt; a detecting portion configured to detect a widthwise position of said endless belt depending on a position of said contact portion; and a swinging portion configured to swing, on the basis of an output of said detecting portion, said holding portion so that said two supporting rollers placed in a state in which said two supporting rollers press said endless belt against said rotatable heating member cross as a unit with said rotatable heating member. ### Claim 16 (depends on 15) An image forming apparatus according to claim 15, 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 supporting 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 holding portion about the swinging shaft on the basis of an output of said detecting portion.