Tonerkonzentrationsermittlung mit Verwendung eines, auf einer Schnecke montierten, Magneten

摘要

A toner concentration sensing system is disclosed for controlling the dispensing of toner into a developer sump. A toner concentration sensor (100) is located in the bottom of the mixing area of the developer sump adjacent one of the mixing augers (44). The toner concentration sensor can be positioned flush with the bottom of the mixing chamber or the sensor can project slightly from the bottom of the chamber. A magnet (120) is positioned on the rotating mixing auger for rotating with the auger past the toner concentration sensor. As the auger rotates, the magnet with developer material adhering thereto, sweeps the top of the toner sensor to improve the accuracy of the toner concentration readings. A toner dispenser is actuated when the detected toner concentration goes below a predetermined limit.