| 摘要 |
In a printer, three toner patches are primary-transferred successively to an intermediate transfer belt. Here, after the first toner patch passes through a belt cleaner and before the second toner patch reaches the belt cleaner, and after the second toner patch passes through the belt cleaner and before the third patch reaches the belt cleaner, the belt cleaner is operated to change the state of contact to the intermediate transfer belt to a different state. A density sensor detects density of the toner image on the intermediate transfer belt, and presence/absence of the toner patch is detected. When presence/absence of the first to third patches is detected alternately, it is determined that the belt cleaner is performing the operation described above.
|
