| 摘要 |
PURPOSE:To rub a developer layer on a developing sleeve against the surface of an image carrier during development ad to separate it from the image carrier surface when the development is not carried out by using a magnetic body as a nap cutting plate and rotating and displacing a magnet body to a position where one magnetic pole faces the nap cutting plate when the development is completed. CONSTITUTION:When the developing sleeve 3 rotates as shown by an arrow, the developer in a developer reservoir 6 attracted to the developing sleeve 3 with the magnetic force of magnetic poles 44 and 45 of the magnet body 4 passes through the gap between the nap cutting plate 5 and developing sleeve 3 to nearly the same thickness to form the developer layer, which is raised in a development area with lines of magnetic force from a magnetic pole 41 and rubbed against the surface of the image carrier to develop the latent image. When the development is completed, the magnet body 4 is rotated and displaced so that a magnet pole 46 faces the nap cutting plate 5. Consequently, an intense magnetic field which inhibits a developer from moving owing to the rotation of the developing sleeve 3 is established between the nap cutting plate 5 and magnetic pole 46, and almost no developer layer is formed on the surface of the developing sleeve 3 which passes by the nap cutting plate 5, so that the developer layer on the developing sleeve 3 does not contact the surface of the image carrier 1. |
