| 摘要 |
PROBLEM TO BE SOLVED: To provide a fixing device capable of controlling a rotation speed on the basis of torque information, so as to apply an optimal conveyance force to paper.SOLUTION: A fixing device sets a rotation speed of a motor that drives a pressure roller 4 to be lower as a reduction in torque in unit time is larger, on the basis of a torque measurement value obtained by detecting driving torque of the pressure roller 4, and thereby ensures a conveyance force when paper slips to prevent the occurrence of paper jam. When the fixing device determines, with paper jam detection control means, that a reduction in motor rotation torque during paper feed is due to the slip of paper, changes a control amount according to an image area ratio on the paper and a toner input amount to apply an optimal conveyance force to the paper. The fixing device further controls the toner input amount during the slip of paper by controlling a developing bias and/or a charging bias, and thereby controlling a coefficient of friction on the surface of the paper to reduce the slip of paper. |
