| 摘要 |
PURPOSE:To stabilize process control at the time of reading a black toner patch by operating the process control so that toner patch density may be specified density and keeping the patch density constant in the case of forming a base patch with color toner. CONSTITUTION:A sensor for detecting the toner patch image density faces an intermediate transfer body 10, and the previously decided color toner patch is formed on a photoreceptor 7, and the developed toner patch density is read. The black toner patch is transferred on the color toner patch so as to obtain (base density output) - (black toner patch density output) = (black process control DATA output). Namely, by operating the process control before forming the black toner patch and keeping the density constant, a process control DATA error is eliminated. |
