| 摘要 |
PURPOSE:To accurately hold the photosensitive material drum at desired temperature by detecting temperature with two temperature sensors which are brought into contact with a no-image area, and controlling energizing to a heat insulating heater and also making the distribution density of the heat generating body larger at both its end parts than at the center part. CONSTITUTION:The heat insulating heater 10 is arranged in a drum main body 2 so as to be in contact with its inner peripheral surface and the distribution density of its heat generating wire is low at the axial center part of the drum main body 2 and high at both end parts. Then the two temperature sensors 13 and 14 invariably brought into contact with no-image areas 11 and 12 at both ends of the drum main body 2 are provided and a control part 15 controls a power circuit 16 according to the outputs of the temperature sensors 13 and 14 to turn on/off the heat insulating heater 10. Consequently, the whole photosensitive drum 1 is accurately held at the desired temperature. |
