Toner concentration sensing apparatus.

摘要

An apparatus is provided for sensing toner concentration in a container adapted to retain a quantity of developer material, including varying concentrations of magnetic carrier material and toner material. The sensing apparatus comprises a device (50) for generating a magnetic field within the developer container. The apparatus further comprises a device (172) for controlling the generating device (50) to selectively generate the magnetic field within the developer container, wherein a preselected portion of the developer material is compressed by the magnetic field and a signal is generated across the generating device, the signal across the generating device (50) varying as a function of the concentration of the toner.