| 摘要 |
PURPOSE:To minimize the deterioration of a transfer material holding body and to obtain an excellent image by making the extent of cleaning higher at the part of the transfer material holder corresponding to a toner image than at other parts. CONSTITUTION:A transfer drum 27 is cleaned after a specified number of copies are taken. Then only the concentration of black toner is detected by using the reflection density of a toner image on a photosensitive drum 19 and different cleaning operation is performed only when black development is performed. When the black development is carried out, a transfer drum cleaner 200 is so controlled that the coupling part 1033 of the drum 27 is cleaned twice. The cleaning operation is carried out by putting electrostatic discharging high voltages 23 and 24 in operation, operating a transfer drum cleaner backup 201, and operating a transfer cleaning motor and operating a cleaner 200 which is moved away from the drum 27 normally. Further, when the black development is not performed, the outer periphery of the drum 27 is cleaned by one turn. |
