| 摘要 |
PURPOSE:To form images of nearly constant density by correcting reference toner concentration based on the density of a reference toner image formed actually on a photosensitive body and controlling the toner concentration of a developer to the corrected reference toner concentration. CONSTITUTION:When the reference image density is set in the reference voltage generator III of a toner concentration controller before the start of image forming operation, a reference voltage V2 corresponding to the reference toner concentration (specified toner concentration) corresponding to image reference density is generated. The toner concentration of a developing device 6 is therefore controlled to the reference toner concentration. When the image forming operation is started and the 1st image is formed, on the other hand, a latent image of a patch P is formed and when it passes a position opposite the developing device 6, a patch image P' is formed. The patch image P' passes positions opposite a transfer device 8 and a separator without being transferred to recording paper and reaches a position opposite a photosensor 10, so that its concentration is detected. |
