| 摘要 |
PROBLEM TO BE SOLVED: To precisely detect the density of a formed image. SOLUTION: Specially at the time of a test mode, a specified density area is formed on a photoreceptor 2 and toner is attached to it by a developing device 23. Besides, it is transferred on a transfer body 24. The concentration of the toner is detected with respect to the specified density area obtained by attaching the toner with a toner sensor 24b arranged opposedly to the transfer body 24. In such a case, when the concentration is detected, the concentration at an intermediate part except the leading and the trailing edges of the image in the specified density area is detected over plural (n) places. Thus, the concentration is not detected at the front and the back density-unstable parts but it is detected in the stable area of the intermediate part. |
