| 摘要 |
PURPOSE:To reduce the cost by providing a detecting member which is adjacent to the outside side wall of a developing tank and is moved back and forth between first and second positions and providing an agitating roll which faces the position of the detecting member and is slided on the inside side wall of the developing tank. CONSTITUTION:A detecting member 10 is made of magnet materials, and the attraction is generated between this member 10 and developer in the vicinity of a detecting part by its magnetic force, and meanwhile, the detecting member 10 is attached to a shakably and axially supported arm 9 and can be moved back and forth between first and second positions P1 and P2 and is moved to the first position P1 by the attraction. When the quantity of developer is smaller than a prescribed value, the attraction is weak because magnetic toner of developer does not exist in the vicinity of the detecting member 10, and consequently, the member 10 is moved to the second position P2 by an energizing means, and it is detected by a position detecting means that the detecting member is in the second position P2, and the absence of developer is displayed. |
