| 摘要 |
PROBLEM TO BE SOLVED: To suppress a temperature rise of a pressure roller and prevent the generation of gloss difference.SOLUTION: A fixation device 20 comprises: a heating roller 1 heated by a heater 8; a fixation roller 2 having an elastic layer on the outer periphery of a core grid; a fixation belt 3 that is stretched between the heating roller 1 and the fixation roller 2 and is endless; and a pressure roller 4 disposed on an outer peripheral side of the fixation belt 3. The fixation device fixes by heating an unfixed toner image on a sheet carrying the image by allowing the sheet to pass a fixation nip part N formed by pressure-contact between the fixation roller 2 and the pressure roller 4 with the fixation belt 3 interposed therebetween. The fixation device 20 includes a pressure mechanism 12 for pressure-contacting and separating the pressure roller 4 with and from the fixation roller 2. The pressure-contact time required from the start of the pressure-contact of the pressure roller 4 by the pressure mechanism 12 to the completion of the pressure-contact is switchable.SELECTED DRAWING: Figure 1 |
