| 摘要 |
PURPOSE:To control temperature of a small-sized photosensitive body with a high precision by bringing closely a plane heater and a thermistor into contact with the inside face of the photosensitive body and supporting the photosensitive body freely attachably and detachably by a hollow internal cylinder where a temperature control circuit is stored. CONSTITUTION:A heating body 101 of a plane heater 2 brought closely into contact with the inside face of a photosensitive body 1 is divided into two, and a thermistor 108 is attached between divided parts and is connected to a temperature control circuit 5 by a conductor 4. Since the photosensitive body 1 has a small diameter, the temperature control circuit cannot be put in the photosensitive body if a supporting shaft pierces the photosensitive body, and therefore, the photosensitive body 1 is supported freely attachably and detachably by an internal cylinder 14 having a space where the circuit 5 can be stored. The surface temperature of the photosensitive body is uniform in the axial direction because the heating body 101 does not exist in the center part in the axial direction of the photosensitive body. Since the thermistor 108 is brought closely into contact with the surface of the heater 2 and the circuit 5 is stored in the photosensitive body, noise is not inputted to a connection circuit. Thus, the temperature of the small-sized photosensitive body 1 is controlled with a high precision. |
