| 摘要 |
PURPOSE:To control toner density to a desired value speedily and prevent troubles such as copy fogging by operating a toner recovery and conveyance system associatively with a toner supply mechanism. CONSTITUTION:Residual toner on a photosensitive drum 1 after a transfer stage is recovered by a cleaner part 7. It is returned to a developer part 2 by a toner conveying part 10 and reused. A clutching 9 and a toner dispensing motor 14 operates simultaneously according to the output signal of a toner density detector 15 installed in the developer container 12 at the developer part 2. When the toner density of a developer increases, the conveyance of the recovered toner into the developer container 12 is stopped once the supply of fresh toner by a toner dispensing roll 13 is stopped. Thus, a decrease in toner density is speeded up and the toner density is controlled to the proper value speedily and accurately. |
