Heating apparatus and image forming apparatus
AssigneeCanon Kabushiki Kaisha
InventorTakaaki Tsuruya
Life of this patent
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Abstract
There is disclosed a heating apparatus of a magnetic induction heating system. This heating apparatus comprises a control mode for a power source (excitation circuit) for supplying power to magnetic field generating means (exciting coil). The control mode includes a first mode for controlling an ON width by fixing the number of ON times per unit time of a switching element of an inverter circuit of a voltage resonance system when power larger than a predetermined value is supplied, and a second mode for controlling the number of ON times per unit time by fixing the ON width of the switching element to a predetermined ON width.
Claims20
A heating apparatus of a magnetic induction heating system comprising:
- magnetic field generating means for generating a magnetic field;
- a power source circuit for supplying power to said magnetic field generating means, said power source circuit having a switching element;
- and
- control means for controlling the power supplied to said magnetic field generating means, said control means having means for controlling turning ON-OFF of the switching element,
- wherein said control means includes a first mode for controlling the power supplied to said magnetic field generating means by controlling an ON width of the switching element to be variable, and a second mode for controlling the power supplied to said magnetic field generating means by fixing the ON width of the switching element to a predetermined ON width.
An image forming apparatus comprising:
- image forming means for forming and bearing an unfixed toner image on a recording material;
- and
- fixing means for fixing the unfixed toner image on the recording material by heat,
- wherein said fixing means including:
- magnetic field generating means for generating a magnetic field;
- a power source circuit for supplying power to the magnetic field generating means, the power source circuit having a switching element;
- and
- control means for controlling the power supplied to the magnetic field generating means,
- wherein the control means has means for controlling turning ON-OFF of the switching element, and wherein the control means has a first mode for controlling the power supplied to the magnetic field generating means by controlling an ON width of the switching element to be variable, and a second mode for controlling the power supplied to the magnetic field generating means by fixing the ON width of the switching element to a predetermined ON width.
A method for controlling power supplied to magnetic field generating means for generating a magnetic field, comprising steps of:
- deciding power to be supplied to the magnetic field generating means;
- and
- based on the decided output, determining which of a plurality of modes is used to perform power control, the plurality of modes including a first mode for controlling the power supplied to the magnetic field generating means by controlling an ON width of a switching element of a power source circuit for supplying the power to the magnetic field generating means to be variable, and a second mode for controlling the power supplied to the magnetic field generating means by fixing the ON width of the switching element to a predetermined ON width.
Dependencies are inferred from the claim text.