Driving device of developing units and toner replenishing units for use in image forming apparatus

摘要

A revolution control for a sun and planetary gear system including supporting members for the planetary gears which are revolvable around the same gear and a cam mechanism engaging a portion of the supporting member. The cam mechanism includes a cam shaft carrying a plurality of cams and there is a driving gear engaging the cam shaft. Also, two transmission gear trains present permit the driving gears to operate in either direction while still driving the toner replenishers in the same direction.