| 摘要 |
PURPOSE:To obtain a developing device which provides high picture quality with both a positive-positive image and a negative-positive image by arranging an atomizing electrode so that an atomized developer passes between an opening part and a developing electrode. CONSTITUTION:When a voltage is applied between a rotary brush 11 and the atomizing electrode 17, insulating toner 7 is atomized, passed between the opening part 16 and developing electrode 18, and recovered to the rotary brush 11. Then, when a minus voltage is applied to the developing electrode 18 by the 2nd high voltage DC power source 20 between the developing electrode 18 and a photosensitive drum 1, the insulating toner 7 which is charged negatively sticks electrostatically only onto a no-charge part on the photosensitive drum 1 which is irradiated with light. The electric field of the charge part of the photosensitive drum 1 is intenser than that an electric produced by applying the voltage between the developing electrode 18 and photosensitive drum 1. Consequently, an image of high picture quality which is superior in the reproducibility of thin lines and gradation is developed. |
