| 摘要 |
<p>A developing apparatus is provided in which the toner concentration of a developing agent for electrostatic duplicator is detected with high precision by positively magnetizing the developing agent present in the detection region in a toner concentration detecting container. The developing agent within the detecting container is magnetized within a range of a magnetic flux density under which the permeability is not so changed with the change of magnetic field, even if a change of the magnetic flux of a magnetic roll or the like is produced.</p> |
