| 摘要 |
PURPOSE:To freely adjust obtained image density by varying at least one of a electrostatic charging voltage, exposure and developing bias potential at the time of performing a copying operation and a printing operation. CONSTITUTION:Copying density is set by storing the developing bias voltage of a developing device 9, the light quantity of an exposing lamp 15 and the additional quantity of charge to a photosensitive drum 2 by a charge corotron 5 in an NVM(nonvolatile memory) 31 which is base machine. The developing bias voltage, etc., is usually recorded in the NVM 31 so as to attain the adjusted value a3 of the copying density out of the values a1-a5. When it is necessary to change the density, the base machine is changed to get in a self-diagnosis mode so as to change the adjusted values a1-a5. |
