| 摘要 |
PURPOSE:To satisfy two image quality characteristics of a flat image density and a thin line simultaneously by using two or more parameters for changing developing conditions. CONSTITUTION:A copying machine is provided with a means 12 detecting the parameter related to a toner concentration in a developer, a means 26 detecting the parameter related to the difference between the size of the thin line expected to be formed on the developing device 10 and that of the thin line actually formed. Further, the copying machine is provided with means 13 - 20 which change two or more parameters among the relative rotational speed of a developing roller 11 and an electrostatic drum 21, their distance, the surface potential of the electrostatic drum 21, the position of a magnetic pole in the developing roller 11, a bias potential or the exposure of the electrostatic drum 21 when a latent image is formed, and a developer adhering quantity on the developing roller 11, based on the above mentioned both parameters, to change the developing condition. Thus, the image quality characteristics of an image density and a thin line is simultaneously improved. |
