| 摘要 |
PROBLEM TO BE SOLVED: To provide a toner concentration controller capable of measuring toner density stably for a long time without causing any stagnation of a developer existing on the detection surface of a toner concentration sensor and without causing any toner sticking. SOLUTION: This controller is provided with a developer container 51 storing the developer, a detecting means 58 magnetically detecting toner concentration information, a toner replenishing means performing toner replenishment based on the output value of the detecting means, a waveform forming means reducing an output value outputted from the means 58 by periodically scraping the retained developer on the detection surface of the means 58 by a mechanical means 56a, a delaying means by which toner concentration detection is not performed from a specified time when the output value is lowered to a time when the lowered output value is restored to a stable output value; and toner replenishing means can be operated based on a value detected after the delay means is released. |
