| 摘要 |
PURPOSE:To obtain a standard potential face in measuring surface potential, by disclosing a metal base on parts of a photoreceptor drum. CONSTITUTION:Standard faces 11 are formed on the circumference of a photoreceptor drum 1 by not providing a photosensitive layer but disclosing a metal base. Alternating voltage is produced on a potential probe 6 with rotation of the drum 1 due to alternately passing of the photosensitive layer charged to a prescribed potential and the faces 11. Charged voltage of the photosensitive layer is obtained from a value Vc by amplifying this signal with an amplifier 5. Output of a corona charger is controlled in accordance with this value. |
