| 摘要 |
PROBLEM TO BE SOLVED: To perform a proper density processing control to the change of developing equipment characteristic, and save the wasteful use of time and toner related to the density processing. SOLUTION: Each developing equipment 4a-4d has a nonvolatile memory 50 loaded thereon to store the printing number of sheets. A CPU part 60 judges the initial period, stable period and performance deteriorating period of the developing equipments 4a-4d by the printing number of sheets stored in the memories 50 to change the number of image forming conditions such as developing bias, exposure quantity and photosensitive drum potential for executing a density processing control including the density measurement of a patch image formed on an intermediate transfer body 5. |
