| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect abnormal temperature appropriately corresponding to the change of conditions even under the condition where the starting temperature raised to a fixing temperaturewith is varied to fluctuate the amount of overshooting. <P>SOLUTION: Judgement of whether the initial rising starting temperature is in a low temperature region with occurrence of overshooting is carried out in an image forming apparatus by a comparator 5 based on temperature signal TEMP of a fixing apparatus with a set value of a setting circuit 6 as reference. A switching means consisting of a D type flop flop 11 and AND gates 12 and 13 is activated according to a judgement result of the comparator 5. The correct detection of the abnormal temperature is made possible according to each state by switching detecting means by actions of the switching means so that when the starting temperature is the low temperature with occurrence of overshooting, the detecting means 7 and 8 are used making the reference value for abnormal temperature to be high temperature and when the temperature is in the temperature range with no occurrence of the overshooting, the detecting means 9 and 10 are used making the reference value for the abnormal temperature to be the low temperature. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
