| 摘要 |
PURPOSE:To provide a heat-fixing device capable of obtaining an even temperature distribution of a fixing roller in the longitudinal direction and preventing the temperature rise of a non-sheet passing part. CONSTITUTION:A heater 3 of which the initial rise speed is low and a heater 4 of which the initial rise speed is high are arranged in a fixing roller 1, and these are connected in series to an ACDriver 8. The heater 3 is arranged at a position corresponding to a non-sheet passing area the passing of small-sized record material, and the heater 4 is arranged at a position where a sheet is always passed. When the small-sized record material is passed, a continuous current passing time to the heaters is limited, and the heater 3 only is used in the course of rise to suppress heat supply to the non-sheet passing area. When a sheet of ordinary size is passed, current passing time is not limited and both heaters are used after completion of rise to supply heat to the entire area of the roller. |
