| 摘要 |
PURPOSE:To obtain a copy of stable picture quality regardless of copy mode by perform forcible supplementation and controlling the forcible supplementation according to the quantity of copies. CONSTITUTION:When a copy button is pressed, copying operation is started after a photosensitive drum idles, and the signal of image density obtained by a detecting means PS is inputted to a comparator 12 on every copying operation and compared with a reference potential to perform normal toner supplementation on the basis of the result; and recovered toner is always supplemented again throughout the rotation of the photosensitive drum. When the quantity of copies on a cumulative counter attains to ten, a forcible supplementation timer is set to fixed quantity in intermittent copy mode and toner is supplemented forcibly until the counting operation ends. On the other hand, when the cumulative counting attains to ten in continuous copy mode, in next discrimination, it is checked whether the output of the comparator is lower in level than the standard or not, so that the forcible supplementation is not performed when not. When the output level is low, the forcible supplementation timer is set to a decrease mode and the toner is supplemented forcibly until the counting ends. |
