| 摘要 |
PURPOSE:To adjust a toner density without a drop in copying speed even if an original exceeds the normal size by comparing the reflection density of the toner adhering part of a pattern for detecting which is formed in the prescribed area of a non-image part on an image carrier with a reference density, and controlling the toner density. CONSTITUTION:In the original D exceeding the normal size, the uniformly electrified, prescribed area of the non-image part on the image carrier 1 is developed by a prescribed developing bias and the pattern for detecting is formed. The reflection density of the area where the toner adheres of the pattern for detecting is detected by a detector 8, a detection signal is compared with a voltage corresponding to the reference density set in advance and the toner density is controlled. Thus, even if the original D exceeds a normal size, a toner density is easily controlled without a drop in copying speed. |
