| 摘要 |
PURPOSE:To stabilize a developing condition, and to make the density of a developed image constant by providing a magnet on the position for exerting no influence on a line of magnetic force of a magnetic roller, in the vicinity of a tracking roller for keeping the interval of a photosensitive cylinder and the magnetic roller constant. CONSTITUTION:A magnetic brush developing device is constituted so that a housing 2 and a photosensitive drum 1 are adjacent to each other. A magnetic roller 4 is dormed by absorbing and sticking a developer to the surface, and a tracking roller 3 for keeping the interval to the photosensitive drum 1 constant is placed coaxially with the magnetic roller 4. Also, the developer which is scattered at the time of a development is collected and caught by a magnetic shield 5 in the housing. Moreover, a magnet 6 is provided on both end parts of the magnetic roller 4 at the position for exerting no influence on the line of magnetic force from the magnetic roller 4, in the vicinity of the tracking roller 3. Even in case of using an endless belt-shaped photosensitive body which is not shown in the figure, the magnet is provided in the same way. In such a way, a developing condition is stabilized, and the density of a developed image is equalized. |
