Fusing Device, Image Forming Apparatus Having The Fusing Device , And Fusing Method of The Image Forming Apparatus

摘要

A fusing device includes a preheating unit to preheat a developed image on a recording medium, and a heating unit to fuse the preheated developed image onto the recording medium by heating the image without pressing. The preheating unit includes a preheating plate heated by the heating unit and having an airtight interior space, and a phase transition fluid filled in the interior space. The heat generated by the heating unit is stored in the preheating plate using the phase transition fluid, and the temperature of the preheating plate uniform is kept uniform using a non-condensable gas filled in the airtight space of the preheating plate to condense and expand depending on a pressure of the phase transition fluid, and a heat sink arranged corresponding to a charge section of the non-condensable gas to absorb the heat of the preheating plate when the non-condensable gas is contracted.