Image heating apparatus and image forming apparatus

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.

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.

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.

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.

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.

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.