Fixing device

Abstract

A fixing device for infallibly reduce the heating output without using a control circuit if an excessive temperature rise of a rotary heating member is predicted even if the control circuit fails or runs away. In the fixing device (200), heating of a fixing belt (230) for heat-fixing an unfixed image on a recording medium is controlled by a body-side processor (401). When the fixing belt (230) stops or rotates at a rotational speed of a threshold or less, an oscillation stop circuit (307) stops the oscillation of an inverter circuit (305) to stop the heating independently of the processor (401). To check the operation of a rotation detection circuit (306) for detecting the rotating state of the fixing belt (230) (fixing roller (210)) and the oscillation stop circuit (307), self-diagnosis to ascertain that the fixing belt (230) is not heated by giving an instruction of heating when the condition of not heating fixing belt (230) is satisfied is performed when the power is turned on or performed regularly on standby.

Dependencies are inferred from the claim text.