| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a fixing device having temperature detecting means that can be switched between a contact mode and a non-contact mode and achieving a long lifetime while maintaining stable fixing quality in either of the modes. <P>SOLUTION: An image forming apparatus includes: a heating rotator heated by heating means; a pressurizing rotator brought into pressure contact with the heating rotator to form a nip between the pressurizing rotator and the heating rotator; temperature detecting means detecting a surface temperature of at least one of the rotators; and feeding means conveying a sheet that carries an unfixed toner image to the nip. The image forming apparatus further includes: driving means which switches the temperature detecting means into either a contact position in contact with the surface of the rotators or a non-contact position separated from the surface of the rotators; and controlling means which controls an energizing state of the heating means in accordance with the detected temperature detected by the temperature detecting means. The controlling means has a first control mode and a second control mode different from the first control mode, and at least when the rotators are warmed up, the controlling means is switched into the first control mode when the temperature detecting means is located at the contact position and is switched into the second control mode when the temperature detecting means is located at the non-contact position. <P>COPYRIGHT: (C)2012,JPO&INPIT |
