Patent ID: 7627259

Claim:
A method for controlling a fuser cooling fan, the method comprising: sensing at least one of an ambient temperature and ambient humidity around an image forming apparatus; determining at least one of a temperature range and a humidity range; detecting a number of sheets printed by the image forming apparatus; comparing the sensed at least one of ambient temperature and ambient humidity to the at least one of a temperature range and a humidity range; and varying operation of the cooling fan based on the comparison and the number of sheets printed to cool a fixing unit of the image forming apparatus, wherein, if the at least one of temperature and humidity is below a reference temperature comprising 32° C. and a reference humidity comprising 80%, respectively, the operation of the cooling fan is delayed, and wherein, if the ambient temperature is between 10° C. and 32° C., the cooling fan operates after 1-2 sheets of paper are printed, and if the ambient temperature is below 10° C., the cooling fan operates after 3-5 sheets of paper are printed.