| 摘要 |
PURPOSE:To provide a variable speed driving device which does not cause speed fluctuations, has no need to provide costly electromagnetic clutches at every change step, and adapts itself to specification changes such as increase in changing-over through partial modification. CONSTITUTION:The electrophotographic copier is driven by the 1st driving chain 71 driving a photosensitive drum A, a cleaning device G and a slit exposure optical system H and the 2nd driving chain 72 in charge of other structural parts. Namely, the 1st driving chain 71 of the drive motor 70 is put on the tension sprocket 74 maintaining a tense state, the 1st unit sprocket 75 of the 1st unit M driving the photosensitive drum and the cleaning device A, and the sprockets 79, 80, 81 provided to the return driving shaft 76, and the 1st, 2nd input shafts 77, 78 of the 2nd unit N driving the slit exposure optical system H. Since such changer is chageable by an inexpensive electromagnetic solenoid, the cost of production is low. |
