Method of controlling replenishment of toners

摘要

A toner replenishment control method for a developing material including two kinds of toners triboelectrically chargeable to polarities opposite to each other, which includes the steps of causing the respective toners contained in the developing material to separately adhere to each of first and second surface areas of a detecting member having predetermined potentials, obtaining first and second detecting signals substantially proportional to amounts of the respective toners which have adhered to the first and second surface areas, the first and second detected signals being set to become equal to each other when a mixing ratio of the respective toners in the developing material is set at a standard mixing ratio, relatively comparing the first and second detected signals, and in the presence of a difference therebetween, replenishing either one of the respective toners to the developing material for eliminating the difference.