Magnetic toner, and developing apparatus and image forming apparatus using it

摘要

A magnetic toner contains, as a magnetic powder, magnetic iron oxide having an octahedral particle shape and an average particle diameter of 0.21 mum or larger and containing 18% or more by weight of FeO. The magnetic toner is so prepared as to have a bulk density A (g/cm3) and a magnetic powder content B (% by weight) that fulfill the formulae 0.8<=A/Bx100<=1.6 and 35<=B<=50. This alleviates the reddishness of images produced with the magnetic toner, and alleviates the disturbance of a thin toner layer on a developing sleeve and thus the fogging resulting therefrom.