| 摘要 |
PURPOSE:To form a uniform thin layer on the surface of a developer holding member and to prevent a developer from leaking out of a developing device by arranging a magnet which forms a magnetic brush between magnetic members having facing curved surfaces on a developer entrance side. CONSTITUTION:An iron piece 10 as a magnetic member contacts the inside wall part of a container 3 facing the 2nd magnet 7b arranged so that a magnetic pole with the polarity opposite to that of a magnet 7a faces the side of a sleeve 2. A large amount of magnetic particles 5 near the surface of the sleeve 2 while forming the magnetic brush by respectively magnetic poles circulates by a magnetic field and the rotation of the sleeve 2 as shown by an arrow (c). Magnetic particles circulate and are present under the container all the time, and the developer 4 is prevented from flowing below the magnetic brush 8a formed between container 3 and iron piece 10 by the magnet 7b. Further, even when the device is not in operation, the magnetic brush 8a prevents not only the developer, but also the magnetic particles from leaking. Further, the surface of the magnetic member 10 is curved and opposed to the sleeve 2 to prevent abrupt convergence of lines of magnetic force. |
