| 摘要 |
PURPOSE:To obtain a low-cost fixing device which secures proper electrostatic discharging effect by discharging or charging at least one of a couple of rollers for fixation electrostatically and performing sequence control over at least one of the driving polarity, driving time, and driving current and voltage of a corona discharger according to the quantity of sheets processed by one image forming device or continuous running time. CONSTITUTION:A control circuit 19 discharge a fixing roller 9 electrostatically by driving the corona discharger by a high-voltage power source 17 for a specific time at every time from the point of time when the quantity of continuously copied sheets immediately before (or currently) reaches predetermined n1, n2, n3.... In this case, the control circuit 19 decides that (n) is <=5, 5>= and <=10, >=10 and <=20, or >=20 and finds driving times y1-y4 of the corona discharger 15 from y1=K1n<0.5>, y2=K2n<0.5>, y3=K3n<0.5>, and y4=K1n<0.5>, where, k1-k4 are such constants that k1>k2>k3>k4. |
