alternating current is flowed from the exciter circuit base on the output signals so that the surface temperature of the fixation belt 13 remains at a preset fixation temperature level target temperature level which is 180 u00b0 c while the fixation belt 13 and pressure roller 14 are rotated and electric current is flowed through the coil 15 c as described above the recording medium p on which the toner image t is present is conveyed through the pre nip n 1 being position so that its surface having the toner image t faces upward the recording medium p is conveyed through the pre nip n 1 while remaining gently pinched between the fixation belt 13 and pressure roller 14 by the resiliency of the fixation belt 13 while the recording medium p is conveyed through the pre nip n 1 it is preheated from both the toner image bearing surface side that is the fixation roller side and the side having no toner image that is the pressure belt side by the pre heated pressure roller 14 and fixation belt 13 respectively referring to fig1 the pre nip n 1 is formed by the simple contact between the fixation belt 13 and pressure roller 14 being therefore advantageous in that the heat which the fixation belt 13 and pressure roller 14 have can be efficiently transmitted to the recording medium p in the pre nip n 1 the recording medium p remains pinched between the peripheral surface of the pressure roller 14 and the outward surface of the fixation belt 13 by the u201c resiliency of the fixation belt 13 u201d as described above therefore the top and bottom surfaces of the recording medium p.