| 摘要 |
PURPOSE:To prevent generation of wrinkles on a sheet due to warp of the sheet caused by a fixation processing, by providing a pressure adjusting means for adjusting a sheet pressing force, and adjusting automatically the sheet pressing force in accordance with a paper passing mode of the sheet. CONSTITUTION:A pressure roller 12b of a fixing device 12 is movable in the upper and lower directions, supported so as to be pushed up by a pressure cam 12f placed in its lower part, and a pressure adjusting mechanism 50 is placed in the tip part. When a supporting member 52 ascends, the pressure cam 12f turns clockwise direction and pushes up the pressure roller 12b, therefore, a pressing force applied to a sheet passing through between a fixing roller 12a and the pressure roller 12b increases, and on the contrary, when the supporting member 52 descends, the pressing force applied to the sheet decreases. When a copy processing is started after setting to a paper passing mode, in case of processing the first face of the sheet, the sheet pressing force of the fixing device is set automatically smaller than usual. In such a way, wrinkles are not generated on the sheet. |
