VERFAHREN ZUM STEUERN DER TONERKONZENTRATION FUER ELEKTROFOTOGRAFISCHE KOPIERGERAETE

摘要

An improved method of controlling toner concentration for electrophotographic copying apparatus employing a dual component developing material which is composed of toner particles and magnetic particles. The method is arranged to detect the amount of magnetic particles adhering onto a photosensitive member for controlling the toner replenishing amount according to the amount of the magnetic particles thus detected.