IMAGE FORMING DEVICE

PROBLEM TO BE SOLVED: To thermally insulate a photoreceptor drum uniformly in the rotating direction without being accompanied by a waste power consumption, and inexpensively prevent a trouble such as image flow or a dew condensation. SOLUTION: This device has an endless air circulating line 26 for forcedly circulating air, which is provided extending over the vicinity part of the heat roller 24 of a heat fixing device 14 and the rotating center part of a photoreceptor drum 5, a heat absorbing part A and a radiation part B are formed in the heat roller vicinity part of the air circulating pipeline 26 and in the rotating center part of the photoreceptor drum 5, respectively. This device also has a temperature detecting means 29 for detecting the surface temperature of the photoreceptor 5, and a control means 36 for keeping the surface temperature of the photoreceptor drum 5 within a prescribed temperature range on the basis of the temperature detection information from the temperature detecting means 29.