Patent ID: 8615179
Filing Date: 2013-12-24
Classification: G03G

Abstract:
1. A fixing device for fixing an unfixed image formed on a recording sheet by causing an electromagnetic heating layer of a first roller to generate heat by using a magnetic flux generated from an electromagnetic induction coil and applying the generated heat to the unfixed image while the recording sheet is passing through a fixing nip formed between the first roller and a second roller pressed against the first roller, the fixing device comprising: an electromagnetic induction heating power source operable to generate high-frequency power by rectifying a commercial-use alternating current and performing high-speed switching on the rectified current by using a switcher, and to output the high-frequency power to the electromagnetic induction coil; a temperature detector operable to detect a surface temperature of the first roller; and an output power determiner operable to determine a desired value of the high-frequency power based on the surface temperature detected by the temperature detector, wherein the electromagnetic induction heating power source includes: a power detector operable to detect information relating to the alternating current based on an instantaneous power value of the alternating current measured only at a time point that is a predetermined period after a zero cross timing of power of the alternating current; and an induction heating power source controller operable to control the switcher based on the information detected by the power detector, such that the high-frequency power has the desired value.