Heating apparatus for heating a toner image and image forming apparatus including the same
AssigneeCanon Kabushiki Kaisha
InventorsHisae Shimizu, Isao Hayashi, Masaaki Naoi, Hisatoshi Baba
Life of this patent
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Abstract
A non-contact power supply unit including a secondary coil supplies an alternating voltage to multiple heat generation layers provided in a heat generation film. In one of the heat generation layers, a loop is provided as a variable impedance circuit in which the impedance changes according to the frequency. A capacitance element in which the impedance changes according to the frequency is provided in the loop. The heat generation amounts of the heat generation layers are switched by changing the frequency of the alternating voltage generated in the secondary coil according to the size of the recording material that is the heating target.
Claims9
A heating apparatus comprising:
- 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 an 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 heat generation amounts of the plurality of heat generation elements by changing the frequency according to the size of a recording material that is a heating target.
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.
Dependencies are inferred from the claim text.