| 摘要 |
PROBLEM TO BE SOLVED: To surely detect a residual toner (developer) quantity in a developing cartridge at a low cost, irrespective of the presence or absence of a stirring/conveying member. SOLUTION: The image forming apparatus includes: the developing cartridge having a developer storage part for storing the developer; and a rotary developing unit where a plurality of developing cartridges are attachably/detachably loaded, and also, any one of the loaded developing cartridges is moved to a developing position by rotating the unit with the rotating shaft as a center. The developing cartridge has a light-transmissive window provided in the wall surface of the developing cartridge, and a sweeping unit that is freely rotatably supported by a shaft inside the developing cartridge, and having a sweeping part capable of sweeping the surface of the window while relatively rotating in accordance with the rotation of the developing cartridge. COPYRIGHT: (C)2007,JPO&INPIT |
