| 摘要 |
PURPOSE:To correct inexpensive residual potential by developing residual potential by setting up a developing bias voltage to 0V or a voltage lower than that of image formation to form a developing pattern and correcting the developing bias voltage by a detecting signal for the density of the developing pattern. CONSTITUTION:Residual potential after destaticization in an area other than an image forming area on a photosensitive body in an image forming cycle is developed by a developing bias voltage to be 0V or lower than that of image formation to form a developing pattern. The density of the developing pattern is detected by an optical detecting means (developing pattern detecting sensor 29) and the developing bias voltage is corrected by the detecting signal. Since the optical detecting means can be used, the correction can be inexpensively attained and the generation of ground dirt can be stably prevented without influence due to external environment. |
