| 摘要 |
PURPOSE:To shorten the waiting time of image formation at the time of power-on by providing a first heating means on the inside peripheral surface of an image carrier and providing a second heating means in the center part of the image carrier and making the calorific value of the first heating means larger than that of the first heating means. CONSTITUTION:A surface heating body 31 is buried in the inside peripheral surface of a photosensitive drum 4, and a bar-shaped heater 32 is arranged in a drum shaft 5 in the center of the drum 4. The calorific value of the bar- shaped heater 32 is set to a value larger than that of the surface heating body 31. At the time of power-on, power is supplied to the surface heating body 31 and the bar-shaped heater 32 to quickly heat the photosensitive drum 4 to a prescribed temperature, and the bar-shaped heater 32 is turned off, and only the surface heating body 31 is turned on or off to control the temperature. In this case, the bar-shaped heater 32 of large calorific value is arranged in the center of the drum 4 to prevent the damage to a process unit even in case of runaway of the heater 32. Since the surface heating body 31 and the bar- shaped heater 32 are used to heat the drum, the waiting time of image forming is shortened. |
