| 摘要 |
PURPOSE:To obtain an inexpensive and high-precision toner concn. control system by supplying the quantity of a toner, which corresponds to an excess over a threshold, from a toner supply device interlocking with a toner supply circuit each time when an integrating counter of black bits exceeds the threshold. CONSTITUTION:The number of black bits in a picture signal is proportional to the black area on the final recorded picture. The supply quantity of the toner corresponding to the number of black bits of a threshold 4 is determined preliminarily; and each time an integrating counter 2 of black bits exceeds the threshold 4, the quantity of the toner corresponding to the excess is supplied into a developing device from the toner supply device interlocking with a toner supply operation circuit 6. Thus, the quantity of the toner corresponding to the consumption is supplied, and the toner concn. in the developing device is ketp constant. Thus, the inexpensive and high-precision toner density control system is obtained. |
