Fixing device, image forming apparatus having the same and image forming method
First Claim
1. A fixing device, comprising:
- a fixing member having an outer peripheral face with which a sheet to be transported is brought into pressure contact;
an exciting coil placed along the outer peripheral face of the fixing member to form an elongated shape with respect to a width direction of the sheet to be transported for induction heating of a heat generating layer of the fixing member;
an RF power supply circuit for applying a voltage of a certain drive frequency to the exciting coil so as to make the heat generating layer of the fixing member generate heat through the exciting coil;
a degaussing coil placed in a small size sheet non-passing region corresponding to a part of the outer peripheral face of the fixing member with respect to the width direction of the sheet along the exciting coil;
a changeover switch for opening or closing the degaussing coil in accordance with a size of the sheet to be transported; and
a control section for changing and setting a drive frequency of the RF power supply circuit along with opening or closing of the degaussing coil.
1 Assignment
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Accused Products
Abstract
A fixing device, an image forming apparatus having the same include a fixing member having an outer peripheral face with which a sheet to be transported is brought into pressure contact, an exciting coil for induction heating of a heat generating layer of the fixing member, and an RF power supply circuit for applying a voltage of a certain drive frequency to the exciting coil. A degaussing coil is placed in small size sheet non-passing regions corresponding to end sections of the outer peripheral face of the fixing member with respect to the width direction of the sheet. A changeover switch opens or closes the degaussing coil in accordance with the size of the sheet to be transported. A control section is provided for changing and setting a drive frequency of the RF power supply circuit along with opening or closing of the degaussing coil.
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Citations
14 Claims
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1. A fixing device, comprising:
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a fixing member having an outer peripheral face with which a sheet to be transported is brought into pressure contact; an exciting coil placed along the outer peripheral face of the fixing member to form an elongated shape with respect to a width direction of the sheet to be transported for induction heating of a heat generating layer of the fixing member; an RF power supply circuit for applying a voltage of a certain drive frequency to the exciting coil so as to make the heat generating layer of the fixing member generate heat through the exciting coil; a degaussing coil placed in a small size sheet non-passing region corresponding to a part of the outer peripheral face of the fixing member with respect to the width direction of the sheet along the exciting coil; a changeover switch for opening or closing the degaussing coil in accordance with a size of the sheet to be transported; and a control section for changing and setting a drive frequency of the RF power supply circuit along with opening or closing of the degaussing coil. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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Specification