| 摘要 |
PURPOSE:To make efficient use of natural cooling as much as possible at the time of switching from image formation in a high temperature mode to image formation in a constant temperature mode so as to suppress the waste of power and the generation of 'noise to a minimum by having two set temperature values which are the first set temperature with normal temperature and the second set temperature with higher temperature. CONSTITUTION:A fixing device is provided with a heating roller having a heat source and the first set temperature (T1) of a constant temperature mode and the second set temperature (T2) of a high temperature mode so as to be controlled to either set temperature, a pressure roller positioned in the contactless state away from the heating roller during non-fixing action, an automatic fixing mode switching means for automatically switching to the constant temperature mode after the end of image formation in the high temperature mode, a heating roller force-cooling means for detecting the temperature of the heating roller in the constant temperature mode to be the fixable temperature (T3) or higher and controlling driving so that the pressure roller is rotated in contact with the heating roller, and a means for detecting the temperature of the heating roller to be lower than the fixable temperature (T3) so as to output an image forming action start signal. |
