Image heating device and image forming apparatus using the same

An image forming apparatus comprising:

• a heat-generating member;
• a magnetization coil for heating the heat-generating member through electromagnetic induction, which is arranged in opposition to the heat-generating member;
• an inverter circuit for supplying a high-frequency current to the magnetization coil;
• a control unit for controlling an operation of the inverter circuit;
• and
• a temperature sensor for transmitting a signal for temperature control to the control unit, which is arranged in the heat-generating member at a portion other than a portion that is heated most by the magnetization coil.

An image forming apparatus comprising:

• a fixing belt;
• first and second support rollers for rotatably supporting the fixing belt;
• a magnetization coil for heating at least one of the first support roller and the fixing belt through electromagnetic induction, which is arranged in opposition to the fixing belt at the first support roller;
• an inverter circuit for supplying a high-frequency current to the magnetization coil;
• a control unit for controlling an operation of the inverter circuit;
• and
• a temperature sensor for transmitting a signal for temperature control to the control unit, which is arranged in at least one of the first support roller and the fixing belt at a portion other than a portion that is heated most by the magnetization coil.

An image forming apparatus comprising:

• a heat-generating member, which is at least partially formed of a conductive material;
• a rotatable detecting member;
• a magnetization coil for heating the heat-generating member through electromagnetic induction, which is arranged in opposition to a peripheral surface of the heat-generating member;
• an inverter circuit for supplying a high-frequency current to the magnetization coil;
• a control unit for controlling an operation of the inverter circuit;
• a temperature sensor for transmitting a signal for temperature control to the control unit, which is arranged in the heat-generating member at a portion other than a portion that is heated most by the magnetization coil;
• a rotating means for rotationally driving the rotatable detecting member directly or indirectly;
• and
• a rotation detecting means for detecting rotation of the rotatable detecting member,
• wherein a fixing unit comprising at least the heat-generating member and the rotatable detecting member is freely attachable/detachable to/from an image forming apparatus main body.

An image forming apparatus comprising:

• a fixing belt;
• first and second support rollers for rotatably supporting the fixing belt;
• a magnetization member for heating at least one of the first support roller and the fixing belt through electromagnetic induction, which is arranged in opposition to the fixing belt at the first support roller;
• an inverter circuit for supplying a high-frequency current to the magnetization member;
• a control unit for controlling an operation of the inverter circuit;
• and
• a temperature sensor for detecting a temperature of the first support roller to transmit a signal for temperature control to the control unit, the temperature sensor being arranged inside the fixing belt and inside the first support roller.

An image forming apparatus comprising:

• a fixing belt;
• first and second support rollers for rotatably supporting the fixing belt;
• a magnetization member for heating at least one of the first support roller and the fixing belt through electromagnetic induction, which is arranged in opposition to the fixing belt at the first support roller;
• an inverter circuit for supplying a high-frequency current to the magnetization member;
• a control unit for controlling an operation of the inverter circuit;
• and
• a temperature sensor for detecting a temperature of the first support roller to transmit a signal for temperature control to the control unit, the temperature sensor being arranged inside the fixing belt and outside the first support roller.

An image forming apparatus comprising:

• a fixing belt;
• first and second support rollers for rotatably supporting the fixing belt;
• a magnetization member for heating at least one of the first support roller and the fixing belt through electromagnetic induction, which is arranged in opposition to the fixing belt at the first support roller;
• an inverter circuit for supplying a high-frequency current to the magnetization member;
• a control unit for controlling an operation of the inverter circuit;
• and
• a temperature sensor for detecting a temperature of the fixing belt at a portion on an upstream side, in a rotating direction of the fixing belt, from a portion heated by the magnetization member to transmit a signal for temperature control to the control unit, the temperature sensor being arranged at a portion other than a portion where the magnetization member and the first support roller oppose each other and on an upstream side, in a rotating direction of the fixing belt, from the first support roller.

An image forming apparatus comprising:

• a fixing belt;
• first and second support rollers for rotatably supporting the fixing belt;
• a magnetization member for heating at least one of the first support roller and the fixing belt through electromagnetic induction, which is arranged in opposition to the fixing belt at the first support roller;
• an inverter circuit for supplying a high-frequency current to the magnetization member;
• a control unit for controlling an operation of the inverter circuit;
• and
• a temperature sensor for detecting a temperature of the fixing belt at a portion on a downstream side, in a rotating direction of the fixing belt, from a portion heated by the magnetization member to transmit a signal for temperature control to the control unit, the temperature sensor being arranged at a portion other than a portion where the magnetization member and the first support roller oppose each other and on a downstream side, in a rotating direction of the fixing belt, from the first support roller.

An image forming apparatus comprising:

• a fixing belt;
• first and second support rollers for rotatably supporting the fixing belt;
• a magnetization member for heating at least one of the first support roller and the fixing belt through electromagnetic induction, which is arranged in opposition to the fixing belt at the first support roller;
• an inverter circuit for supplying a high-frequency current to the magnetization member;
• a control unit for controlling an operation of the inverter circuit;
• and
• a temperature sensor for transmitting a signal for temperature control to the control unit, the temperature sensor being arranged inside the fixing belt and at a portion other than a portion where the magnetization member and the first support roller oppose each other.