| 摘要 |
PURPOSE:To simplify the control of the replenishment of toner and to reduce the cost of a device in an image forming device where copying for long size is performed by using an electrophotographic copying system. CONSTITUTION:A reference toner image for detecting toner density is formed in an image forming area and out of the image forming area in a direction intersecting with the moving direction of a photosensitive body 101, and the density of the formed reference toner image is detected by P sensors(120 and 121). The control of the replenishment of the toner is basically executed by detecting the density of the reference toner image formed in the image forming area by P sensor 120 in the center. In the case of performing copying for long size, the density of the reference toner image formed out of the image forming area is detected by the P sensor 121 at the end and the copying for long size is executed. |
