To prevent toner from adhering to a temperature detecting element and to prevent the damage of a rotating body and the soiling of an image due to the toner by providing a 1st temperature detecting element detecting surface temperature while abutting on a paper non-passing area and a 2nd temperature detecting element abutting on a paper passing area on another rotating body.
A thermistor 5a on an upper roller 1 side is arranged at the end of the roller being a paper non-passing part, and a thermistor 5b on a lower roller 2 side is arranged in the center of the roller so that the paper passing area may be obtained whatever size paper passes. The temperature control of the rollers 1 and 2 is respectively and independently performed by both thermistors 5a and 5b in a standby state where the rollers 1 and 2 are not rotated. In a printing state, the temperature control is performed by utilizing only the temperature detected by the thermistor 5b on the roller 2 side and making the turn-on timing of upper and lower heaters the same. Namely, the duty ratio of the turn-on time of the upper and the lower heaters is made the same. Therefore, the thickness of a core bar is adjusted so that the heat capacity of the rollers 1 and 2 may be equal.
| JP6494306 | Image forming device |
| JP7352853 | Fixing device and image forming device |
KUME TAKAO
KAMIYA YUKIO
YOSHIZAWA RYUICHI
