- HP All-in-One Printer Manual

Q2431-90912 Chapter 5 Theory of operation 125
Cleaning the transfer charging roller and photosensitive drum
Residual (left over) toner is cleaned off of the transfer charging roller and photosensitive drum so
that subsequent images are crisp and clear. Because not all of the toner is attracted to the media
when the image is transferred from the drum, some toner remains on the drum. Toner may also
remain on the transfer roller if a jam occurs and the transfer of toner to the media operation is not
completed.
A dc negative bias (charge) is applied to the transfer charging roller opposite the photosensitive
drum, which causes the residual toner to be attracted to the drum.
A cleaning blade is in contact with the surface of the drum at all times. As the drum rotates during
printing, excess toner from the transfer charging roller and drum are scraped off and stored in
the waste-toner receptacle.
Figure 56. Cleaning the transfer charging roller and photosensitive drum
Cleaning the transfer charging roller
Cleaning the photosensitive drum
Residual toner
Cleaning blade
Transfer charging roller
Waste toner compartment