| 摘要 |
PURPOSE:To prevent occurrence of fog and suppress increase of toner consumption and increase of burden of a cleaning device by forming low density reference density section that changes developing density according to the change of exposure, and changing exposure to form a picture part. CONSTITUTION:During warming up, only a reference density piece 2 is exposed and scanned and the image is formed on the surface of a photosensitive drum 1. The developing density of the image is detected by a developing density detector 14, and correcting voltage to be corrected for reference voltage of an exposure lamp 3 in image formation of the reference density piece 2 at the time of copying made after warming up is stored in a microcomputer. When copying is made, lighting of the exposure lamp 3 is made by voltage corrected for reference voltage by an exposure controller. Thus, occurrence of fog can be prevented. As developing density of the reference density section is low density that can be detected by the developing density detector 14, increase of toner consumption and increase of burden of the cleaning device hardly take place. |
