| 摘要 |
PURPOSE:To avoid the uneven density for a developed picture, by providing a magnetic pole at the upperstream side of the developing main magnetic pole and at a position approximate to the main magnetic pole and forming an auxiliary tuft near another tuft formed to said main magnetic pole. CONSTITUTION:A magnet 32 that forms an auxiliary magnetic pole is provided at the upperstream side of a developing main magnetic pole and adjacently to a magnet 31 that forms the main magnetic pole. Tufts 34A and 34B are formed on a rotary sleeve 33. If the distance (l) is set at about <=15mm. between the tufts 34A and 34B, a number of fine magnetic brushes are formed to the tuft 34A. Thus a picture free from an uneven density can be developed by using such tuft 34A, while the tuft 34B produces some unevenness of density. The distance (l) can be reduced by cutting a part of the magnet. The auxiliary magnet can be used in >=2 units. In case when the auxiliary and main magnets are adjacent to each other and in the same polarity, a magnetic substance such as an iron piece or the like is put between both magnets. |
