Image fixing apparatus stably controlling a fixing temperature, and image forming apparatus using the same

An image fixing apparatus, comprising:

• a magnetic flux generator configured to generate a magnetic flux;
• a heat member configured to be heated inductively by the magnetic flux generated by the magnetic flux generator;
• a non-magnetic shield plate configured to reduce the magnetic flux active on the heat member to form a heat reduction area at both ends in a width direction of the heat member;
• and
• a controlling member configured to determine a rotational attitude of the non-magnetic shield plate based on a temperature to rotate the non-magnetic shield plate to change the heat reduction area during a consecutive image forming job on a plurality of recording sheets of a same size.

A method of operating an image forming apparatus, the method comprising:

• forming a toner image on a recording sheet;
• generating a magnetic flux with a magnetic flux generator;
• inductively heating a heat member by the magnetic flux generated in the generating;
• reducing the magnetic flux active on the heat member using a non-magnetic shield plate to form a heat reduction area at both ends in a width direction of the heat member;
• determining a rotational attitude of the non-magnetic shield plate based on a temperature;
• rotating the non-magnetic shield plate to the determined rotational attitude to change the heat reduction area during a consecutive image forming job on a plurality of recording sheets of a same size;
• and
• fixing the toner image onto the recording sheet.

An image forming apparatus, comprising:

• an image forming mechanism configured to form a toner image on a recording sheet;
• and
• an image fixing unit configured to fix the toner image onto the recording sheet, the unit including
• a magnetic flux generator configured to generate a magnetic flux,
• a heat member configured to be heated inductively by the magnetic flux generated by the magnetic flux generator,
• a non-magnetic shield plate configured to reduce the magnetic flux active on the heat member to form a heat reduction area at both ends in a width direction of the heat member, and
• a controller configured to rotate the non-magnetic shield plate based on a temperature to change the heat reduction area.