| 摘要 |
PURPOSE:To effectively correct image quality and to provide a copy image with stable image quality. CONSTITUTION:A toner patch is formed on a photosensitive drum 1 and the amount of toner sticking to the photosensitive drum 1 is detected by an optical sensor 3. Based on the detection value, the concentration of the toner of developer is controlled by a toner concentration controller 4a to correct image density. When the correction of the toner concentration reaches its limit, the main electrification output of the main electrifier 2 is controlled by the main electrification controller 2a to carry out image quality correction by the surface potential of the photosensitive drum 1. |
