Magnetic particles for charging means, and electrophotographic apparatus, process cartridge and image forming method including same

An electrophotographic apparatus, comprising:

• an electrophotographic photosensitive member, and (i) charging means, (ii) imagewise exposure means and (iii) developing means, said (i), (ii) and (iii) disposed in this order opposite to the photosensitive member, wherein
• said charging means includes a charging member comprising magnetic particles and disposed contactable to the photosensitive member so as to charge the photosensitive member based on a voltage received thereby,
• said photosensitive member has a surface layer comprising a charge injection layer,
• said charge injection layer containing lubricant particles and having a volume resistivity of 1×1010 to 5×1012 ohm.cm, and
• the magnetic particles comprise a ferrite component represented by the following formula (1):
• (Fe2O3)X(A)Y(B)Z (1),
• wherein A is MnO, B denotes at least one metal oxide component selected from the group consisting of Na2O, K2O and SrO;
• X, Y and Z denote numbers representing mol ratios and satisfying the following conditions:
• 0.2<X<0.95, 0.01<Y<0.5, X+Y<1, Y>Z and 0.02≦Z≦0.08.