| 摘要 |
PURPOSE:To provide an image forming device which faithfully reproduces a multi-gradation original without causing a decrease in highest density, a decrease in resolution resulting from way of half tone dot, and prevents character reproducibility from decreasing. CONSTITUTION:The image forming device is equipped with: a photosensitive drum 10 which holds an image; a contact electrifier 1 which electrifies the photosensitive drum 10 in contact with the drum 10; and a bias application means 3 which applies a voltage in which a DC voltage and an AC voltage overlap to the contact electrifier 1. The bias application means 3 switches the frequency of the AC voltage which is applied to the contact electrifier 1, when image formation in character mode is carried out and when image formation in photographic mode is carried out. |
