In recent years, office printing machines have been required to provide both energy-saving performance and such convenience as less start-up time (warm-up time) -the time it takes until a machine becomes ready for operation after power-on -and less recovery time from power save mode. The fuser, which melts toner and fuses it on paper in multifunction devices incorporating xerography technology (electrophotography technology) generally consumes about 70 % of total power consumption. Moreover, about 70 % of the power consumed by the fuser is used for preheating during standby time, which means that reducing fuser preheating (power consumption) can significantly contribute to energy-saving performance. However, reducing the warm-up time and recovery time from power save mode entails preheating the fusing part so that it can reach the toner-melting temperature relatively quickly. Consequently, achieving both energy-saving performance and such convenience poses a big challenge.
Fuji Xerox therefore developed an IH (induction heating) fuser that provides multifunction devices with both energy-saving performance and high-level convenience.
Fig. 1 shows the basic configuration of the IH fuser. This unique configuration consists of an IH belt (containing a nonmagnetic metal heating layer several μm thick) and an IH coil that generates an alternating magnetic field. Both the belt and coil are sandwiched between inner and outer magnetic materials. This structure strengthens the magnetic coupling, creates the desired magnetic flux path, and increases heating efficiency through electromagnetic induction, which rapidly heats the IH belt.
Optimizing the thickness of each layer and the materials used in the IH belt (which contains a nonmagnetic metal heating layer several μm thick) not only ensures belt durability but also minimizes the belt's heat capacity to 1/6 to 1/4 of that for heat rolls with aluminum or iron base material. Moreover, as the fuser warms up, the latch mechanism withdraws the pressure roll from the IH belt. This prevents heat conduction to the pressure roll and enables efficient heating of the IH belt at minimum heat capacity.
Fig. 1: Basic Configuration of IH Fuser
In order to reduce the warm-up time and recovery time from power save mode, the fusing part that melts toner and fixes it on paper must be heated quickly to the desired temperature from room temperature or from low-to- medium temperature when in power save or standby mode. As indicated in Fig. 2, a fuser (at room temperature) using IH fusing technology needs only three seconds of warm-up time before fusing can be performed. Since Fuji Xerox's IH fusing technology enables extremely rapid heating, there is no need for preheating during standby time or in power save mode. Fig. 3 shows that a considerable amount of energy can be saved.
Fig. 2: Comparison of Warm-up Time of Fuser in Same Speed-Class Products
Fig. 3: Comparison of TEC valueNote1 in Same Speed-Class Products
Also, by combining this technology with our SmartWelcomEyes Technology and Smart Energy Management Technology, we have enabled "zero waiting time experience," thereby realizing our "RealGreen"Note2 concept.
Fig. 4: Three Technologies that Enable "RealGreen"