| 摘要 |
PURPOSE:To detect exactly and stably a remaining quantity of a toner by providing a magnet roller and a blade which is adjacent to said roller, in a toner hopper, and detecting a load variation of a driving device of the roller. CONSTITUTION:A magnet roller 2 having a magnetic outside surface, and a blade 3 which is adjacent to said roller are provided in a toner hopper 1, and the roller 2 is driven by a motor 5 to which a DC constant-voltage power source 6 is connected. In case there is a toner enough, the toner is attracted to the outside circumferential surface of the roller 2, scraped down by the blade 3, and a rotational load in this case increases. When the toner is reduced, it does not increase above a thickness determined by a gap between the blade 3 and the roller 2, and the load is reduced suddenly. This load variation is detected by a potential difference detecting device 8, and a remaining quantity of a toner can be detected exactly and safely. |
