| 摘要 |
PURPOSE:To prevent the wasteful use of sheets and electric power and to obviate the generation of an unnecessary jam by allowing the sheet feeding operation of a feeding means to feed the sheet to be formed with images only when an image forming unit is mounted. CONSTITUTION:A paper feed roller 8 is so energized as not to come into contact with the sheet P and is not subjected to driving while a cartridge 13 is not mounted and, therefore, even if a user erroneously starts a copying operation, the sheet is not fed. On the other hand, sliding bearings 18, 19 are pushed down along arc-shaped holes by the base of the cartridge 13 and a gear 24 is eventually meshed; in addition, the paper feed roller 8 comes into contact with the sheet P to enable the feed operation of the sheet when the cartridge 13 is mounted to the body. The generation of the wasteful use of the sheet and the unnecessary jam and the wasteful consumption of the electric power, etc., are averted in this way. |
