Fixing device having temperature control means

Abstract

Feature is a fixing device equipped in an image forming device enabling reduction of electronic noise and preventing hot-offset and fixing disorder. The fixing device includes a rotatable fixing roll, a heater for heating the fixing roll, a temperature detector for detecting the surface temperature of the fixing roll, and temperature control circuitry. The temperature control circuitry is for controlling the fixing roll surface to maintain a predetermined temperature by supplying a predetermined electric power to the heater, wherein the temperature of the fixing roll during continuous image forming operation is detected periodically by the temperature detector, and in correspondence to the difference between a fixed reference temperature and the detected temperature, controlling the electric power quantity to be supplied to the heater during a cycle by increasing or decreasing a half-wave unit cycle number of the commercial power source.