2-34 Phaser 6121MFP Service Manual
Theory of Operation
Transfer Belt Cleaning
The Transfer Belt Cleaning Blade collects residual toner off the surface of the 
Transfer Belt, and a toner collecting auger transfers waste toner to the Imaging 
Unit reservoir. The prevention seal is affixed to prevent waste toner from leaking 
through a gap above the cleaning blade.
During color printing, an image is formed on the Transfer Belt for each color. The 
cleaning blade uses a retraction mechanism to lift off the belt during the printing 
process. However, no pressure/retraction sensor is used to trigger cleaning blade 
retraction. Instead, the IDC sensor detects a sample image on the Transfer Belt to 
control the pressure/retraction operation. During monochrome printing, no 
retraction sequence is needed. The cleaning blade is normally in contact with the 
Transfer Belt.