| 摘要 |
PURPOSE:To carry out trouble detection more precisely and quickly by carrying out abnormality disposing process when the alteration of temperature exceeds an allowable range of target temperature even if the alteration is within the temperature range from the upper limit to the lower limit, regarding temperature adjustment of a fixing apparatus. CONSTITUTION:Following making of power supply or the start of an image forming action, a temperature controlling means keeps the temperature of a fixing apparatus suitable for respective states. However, when a detected temperature is outside a prescribed allowable range, wherein a desired temperature is set to be a reference due to some trouble, abnormality disposing process is carried out. For example, when three kinds of target temperature are set to be 180 deg.C during normal printing process, 160 deg.C during stand-by period and 190 deg.C at the time of making power supply under low temperature condition, an allowable range + or -T deg.C is set for each target temperature. When the temperature exceeds not only the range of the temperature from its upper limit TU to the lower limit TL but also the allowable range, it is determined that a trouble has occurred. |
