Toner density control device in an electrophotographic copying apparatus

摘要

A toner density control device comprising a toner density sensor to detect the density of the toner contained in the developer stored in a developing device, toner agitating means to agitate the developer stored in the developing device so as to charge the toner with frictional electricity, control standard value holding means which maintains as the control standard value the toner density that is lower by a specified value than that detected by the toner density sensor under a condition where the developer is agitated for some time by the toner agitating means during the initial stage after the developer is supplied into the developing device, and toner replenishment means which actuates under a condition when the toner density detected by the toner density sensor is lower than the control standard value, thereby controlling the toner density in the developing device in accordance with the control standard value maintained in a manner as stated above.