| 摘要 |
PROBLEM TO BE SOLVED: To stably secure fixing performance at the time of continuous printing independently of the weight of a recording material and the deflection of input voltage by deciding heating condition in accordance with the rate of change of detected temperature when the recording material is held between nips. SOLUTION: Standby temperature is set equal to or lower than fixing allowable temperature by taking advantage of that the fixing performance of initial printing is secured even at lower temperature than at the time of the continuous printing by the heat capacity of a fixing device. Thus, the rate of change of temperature is measured by providing a certain time required to reach fixing temperature from the standby temperature. In the case that controlled temperature is not maintained in spite of changing the turning-on ratio of a heater when the input voltage is lowered at a high-speed machine, the fixing performance is secured by lowering throughput. As to timing for lowering the throughput; the case that the controlled temperature is not attained after printing a specified number of copies based on a VSYNC (image write-in) signal is set as the timing of changeover. |
