A secondary cleaning device has a cleaning brush, collection roller, and
controller. The cleaning brush is driven by a drive mechanism and thereby
rotates in a state that brush fibers thereof are contacting with a
secondary transfer belt to collect toner on the secondary transfer belt.
The collection roller is driven by another drive mechanism and thereby
rotates in a state contacting with the cleaning brush to collect toner
from the cleaning brush. The collection roller rotates in such a manner
that the collection roller and the cleaning brush move in the same
direction with each other at a contact area between the collection roller
and the cleaning brush. The controller controls the drive mechanism such
that the circumferential speed ratio of the collection roller with
respect to the cleaning brush is greater than one and smaller than two.