Heating apparatus for heating a toner image and image forming apparatus including the same

An image forming apparatus comprising:

• an image forming unit configured to form a toner image on a recording material;
• and
• a fixing unit configured to fix the toner image to the recording material by heating the toner image and the recording material,
• wherein the fixing unit includes:
• a plurality of heat generation elements provided on a heat generation film;
• a non-contact power supply unit configured to supply power in a contactless manner to the plurality of heat generation elements;
• a variable impedance circuit electrically connected to at least one of the plurality of heat generation elements, and in which impedance changes according to the frequency of an alternating voltage supplied by the non-contact power supply unit;
• and
• a frequency change unit configured to switch the heat generation amounts of the plurality of heat generation elements by changing the frequency according to the size of the recording material.