| 摘要 |
PURPOSE:To performing printing of constant density regardless of the varying amounts of printing by adding the amount of developing powder consumption corresponding to the amount of printing and the amount of the developing powder consumed in correspondence to the number of revolutions of a developing roller thereby controlling the replenishing amount. CONSTITUTION:A printing signal indicating the amount of printing is inputted from the upper device 9 of a central processing unit or the like to a counter 10. On the other hand, the count value corresponding to the number of revolutions of the developing roller is inputted to a counter 14 via an encoder 15 connected to a develoing roller driving source 16. In an adder 11, the count values of both counters 10, 14 are added and the output thereof is inputted to a developing powder hopper driving part 12 which in turn controls a developing powder feed roller, thereby replenishing the required amount of the developing powder. Since the developing powder consumed in correspondence to the number of revolutions of the developing roller other than the amount of printing is replenished by this, the density of printing does not lower even in case when the amount of printing is small, thus good printing of always constant quality is accomplished. |
