| 摘要 |
PURPOSE:To obtain a sharp image having no disorder by repeating the process wherein a latent image is formed on an image carrier and developed by impressing an electric field containing an AC component between the image carrier and a developer conveying body, and increasing the frequency of the AC component successively on every developing operation. CONSTITUTION:The photosensitive drum 1 which is charged electrostatically uniformly by a scorotron electrifier 30 is exposed to a light image from a laser light source through an image forming lens 32 to form an electrostatic latent image. The electrostatic latent image is developed by a developing device 13A. The formed toner image is no transferred to recording paper, and the 2nd electrostatic latent image is formed by the electrostatic charge of the electrifier 30 and image exposure. Then, the 2nd image is developed by a developing device 13B, and development is carried out repeatedly by a developing device 13C. The devices 13A-13C contains toner particles of yellow, magenta, and cyan, and the frequency of the AC component of the electric field impressed during development is set to 1.2, 1.5, and 2.0kHz in the order of development. Thus, a sharp polychromatic image having no disorder is formed. |
