| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing device in which scratching of a development sleeve at magnetically sealed parts is prevented, in a developing device in which outflow of toner at both ends of a developer carrier using a magnetic one-component developer is prevented by magnetic seal. SOLUTION: The developing device 10 in an image forming apparatus comprises the development sleeve 11 which is rotatably disposed oppositely to a photoreceptor 30 and in which magnets 19 are arranged to develop a latent image, and sealing members 16 which are disposed near both ends of the development sleeve 11 while keeping a predetermined distance from the outer peripheral face of the sleeve 11 and which form magnetic ear to prevent outflow of a magnetic one-component developer to the outside of a development area, wherein the magnetic one-component developer is toner in which magnetic particles are dispersed in a binder resin. The magnetic particles are based on an octahedron which is a convex polyhedron defined by eight triangles, each vertex and edge of the octahedron are curved, and each magnetic particle has a portion considered to be a straight line at the outer peripheral portion of its projected image. COPYRIGHT: (C)2008,JPO&INPIT |
