| 摘要 |
PURPOSE:To grasp developer concentration in a developing means so that proper amount of developer can be supplied even though consecutive copying is performed by instructing the starting of concentration control on every switching timing of an original image. CONSTITUTION:A controller part 51 controls image forming process and patch detection ATR execution on each image forming station Pm, Pc, Py, or Pk. A toner concentration detecting means controls the turning-on timing of an LED 11M radiating near infrared light on each photosensitive drum, etc., processes concentration data from a photodiode 12M, etc., and controls the driving of the toner carrying screw of a toner hopper. The controller part 51 detects the switching timing of the original image carried by an RDF 13, and instructs to start the concentration control by every switching timing as scheduled so that the developer concentration in the developing devices 4M, 4C, 4Y, and 4K can be grasped; therefore, proper amount of the developer can be supplied even when the consecutive copying is performed. |
