| 摘要 |
PROBLEM TO BE SOLVED: To make compatible both the speedy switching of adjustment of temperature and appropriate temperature distribution of a fixing roller, by shortening the state in which an image heating member is in a usage-disabled state for image heating operation when the adjustment temperature is switched. SOLUTION: A fixation roller is made up of two heaters a main heater and a subordinate heater. The center portion of the main heater of the fixation roller is greater in the amount of heat generation than the lengthwise end portions of the fixation roller. When the temperature of the fixing roller makes transition from the adjusted temperature on the high-temperature side to adjusted temperature on the low-temperature side, the fixing roller is cooled by the cooling fan. After the fixing roller has been cooled to a preliminary temperature lower than the adjusted temperature on the low-temperature side, cooling fan is stopped, and then the fixing roller is heated to a predetermined adjusted temperature by the subordinate heater. COPYRIGHT: (C)2007,JPO&INPIT
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