| 摘要 |
PURPOSE:To attain reduction in cost and weight miniaturize a device by directly holding and carrying a developer on a cylindrical magnetic roller having the magnetization of plural magnetic poles. CONSTITUTION:The magnetic roller 9 holds the supplied developer 8 by a magnetic force and a carrying quantity regulating member 11 regulates the developer 8 to a proper quantity and carries it. In other words, the magnetic roller 9 constitutes a magnetic circuit with a cylindrical magnet 12 whose outer periphery has the magnetization of plural poles and a soft magnetic cylindrical yoke 13, The magnetic roller 9 is rotated in a state where the magnetic developer 8 is directly held on the magnetic roller 9 by the leakage magnetic flux of the periphery of the magnet 9, to carry the developer 8. On the other hand, the magnetic roller 9 is a rare earth resin coupling type magnet composed of rare earth magnetic powder consisting of the transition metal consisting essentially of a rare earth element (R) and cobalt, and a thermosetting resin, and has the content of 50 - 80 vol.% of magnetic powder. The device is reduced in cost and weight and miniaturized. |
