Patent ID: 11886132
Assignee: BROTHER KOGYO KABUSHIKI KAISHA
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 12:
13. An image forming apparatus comprising:
a main body;
a photosensitive drum;
a transfer belt unit including a transfer belt configured to transfer toner on the photosensitive drum onto a sheet conveyed to a portion between the photosensitive drum and the transfer belt;
a cleaning roller configured to make contact with the transfer belt and to clean the transfer belt, the cleaning roller being rotatable at one of a first rotational speed and a second rotational speed faster than the first rotational speed;
a main memory; and
a controller configured to perform:
calculating a deterioration quantity of the transfer belt on a basis of a first rotation time period and a second rotation time period those stored in the main memory, the first rotation time period indicating a total of a period of time that the cleaning roller rotates at the first rotational speed during a cleaning operation added to a previously-stored period of time that the cleaning roller rotated at the first rotational speed, the second rotation time period indicating a total of a period of time that the cleaning roller rotates at the second rotational speed during the cleaning operation added to a previously-stored period of time that the cleaning roller rotated at the second rotational speed.