| 摘要 |
PURPOSE:To secure an appropriate toner density even in a mimeographic mode by forming a reference latent image for controlling the replenishment of toner at the same density in a normal mode. CONSTITUTION:When the mimeographic mode is set through operating a key on a console panel and when the image part of a photosensitive body 1 reaches a position facing an electrifier 2, a signal from a control CPU switches a switching means 13 to short a varistor 12b. In this state, the grid electrode 11 of the electrifier 2 is grounded through one varistor 12a alone, and the electrostatic potential Vo of a photosensitive drum 1 is set to lower potential VL in absolute value than it applicable to normal copying. Namely, in the mimeographic mode, a reference latent image part and an image part are electrostatically charged to a potential VN and a potential VL, respectively. As a result, the density of the reference toner image for controlling toner density is normally formed to control the toner density appropriately. |
