| 摘要 |
PURPOSE:To obtain a developed image which has small edge effect and sufficient solid-black density by providing a means which produces an alternating electric field for transferring toner particles from a layer of toner particles formed on the surface of a developer carrier member to an electrostatic latent image carrier at a development part. CONSTITUTION:A power source 34 applies a voltage to between a photosensitive drum 1 and a sleeve 22 to produce the alternating electric field and toner particles are transferred from a developer on the sleeve 22 to the toner photosensitive drum 1. The development part transfers toner from the surface of the sleeve 22 and surfaces of magnetic particles onto the latent image with the alternating electric field applied to between the photosensitive drum 1 and sleeve 22 to develop the latent image. Toner particles which are not consumed for the development are recovered through the subsequent rotation of the sleeve 22 and applied onto the sleeve 22 again repeatedly by circulation. A repulsive magnetic field is established at the development part, so magnetic particles are agitated and then only toner having sufficient triboelectricity is used for the development, so that sufficient solid-black density is obtained during solid- black development. |
