| 摘要 |
<p>PURPOSE:To stabilize a state of a toner image supporting body after discharge, by controlling a surface temperature of a fixing roll in accordance with a variation of a carrying speed of the toner image supporting body, and keeping heat capacity supplied to the toner image supporting body constant. CONSTITUTION:A transfer material P for supporting a toner image T is heated and fixed between a fixing roll 1 containing a heater 2 and a pressure roll 3. In case of a copying magnification variable type copying device, it is necessary to keep heat capacity supplied to the tranfer material almost constant, by changing a moving speed of a photoreceptor or an original. Therefore, 2 kinds of control temperature levels are provided, the heater 2 is controlled by selecting one control temperature level by synchronizing with switching of a moving speed of the photoreceptor, by which a surface temperature of the fixing roll 1 whose temperature is detected by a thermistor 10 is controlled to 2 stages. In this way, heating capacity provided to the transfer material can be kept constant by changing a surface temperature of the fixing roll 1 in accordance with a variation of a carrying speed of the transfer material P, which is caused by a variation of a moving speed of the photoreceptor.</p> |
