Patent ID: 6868239

Claim:
A remaining amount detection mechanism, comprising: a rotating shaft that is inserted into a through hole provided in a developer tank of a developing unit used in a printer; a stirring member, provided on the rotating shaft, that rotates in the developer tank in combination with the rotating shaft while receiving resistance exerted by developer stored in the developer tank; and a sensor section that detects an amount of the developer remaining in the developer tank in accordance with a rotational condition of the rotating shaft, wherein: a flange face is provided on an internal portion of the rotating shaft so as to be positioned inside the developer tank, and a sealing member made of elastic material is disposed between (a) a pierced wall surface of the developer tank through which the through hole is provided and (b) the flange face of the rotating shaft, so as to surround the rotating shaft, and the sealing member closely contacts both the pierced wall surface and the flange face.