| 摘要 |
PURPOSE:To improve a density control system by measuring the toner image of the detected pattern of a reference density at the same gradation level with a density detecting means. CONSTITUTION:The reference toner image as the reference of the density control of a photosensitive body 41 is formed, the normally reflected light and scattered/ reflected light of the reference toner image are detected by an AIDC sensor 210 provided in the vicinity of the photosensitive drum 41, and a toner sticking quantity is obtained from the difference between both detected signals by a printer control part 201. Then, the grid potential of an electrifying charger 43 and the bias potential of a developing unit 45r are set so as to obtain a constant maximum density according to the detected toner concn. and remove fogging, and a toner concn. is detected in a state where the fogging is removed. Thus, the system of automatic density control is improved. |
