| 摘要 |
PROBLEM TO BE SOLVED: To perform sure feed of toner by satisfying toner feeding ability and life of a powder screw pump by making the number of drive rotations of the powder screw pump variable and raising the number of rotations only when it is necessary according to a degraded state of recovered toner assumed from temperature rise in a machine and a use condition. SOLUTION: In this image forming apparatus having a recovered toner transfer means to return the recovered toner recovered from a cleaning means 6 to a developing means 4 and an intermittent driving means to intermittently drive the recovered toner transfer means and in which at least a screw pump and an air pump are used as the recovered toner transfer means, the number of drive rotations of the recovered toner transfer means is made variable. |
