PURPOSE: To obtain a device which smoothly controls the temperature of a fixing roller even in the case of turning on/off a fixing heater, especially, in the case of warming up, and prevents the temperature from excessively rising when abnormality occurs in the fixing device by judging the occurrence of the abnormality of the fixing device based on the ratio of change of the resistance by temperature of the fixing heater before and after the fixing heater is turned off.
CONSTITUTION: A sequence control part 7 controls the sequence of an entire image forming device and forcibly turns off the fixing heater 3 in the case of detecting the abnormality of the fixing device based on information from a temperature control part 8. When the fixing heater 3 is turned off by attaining the set temperature in the case of turning on/off the fixing heater 3, especially, in the case of warming up that the follow of the temperature is bad, the ratio of change of the resistance by temperature per unit time of a fixing thermistor 4 before it is turned off by the control part 8 and the ratio of change of the resistance by temperature after it is turned off are compared. In the case that the compared result is deviated from previously set change characteristic, that the abnormality occurs in the fixing device is judged.
| JPH11232887 | ELECTRONIC DEVICE |
MORI GORO
SENMA TOSHITAKA
YAMAMOTO MASAHIRO
TAKAHASHI MASARU
HAYASHI TAKAMASA
MIYAJIMA MASAMI
ISOBE TAKAHITO
SASAMOTO TETSURO
