Epson AcuLaser M4000N, Service Manual

Page: 36 / 477

EPSON EPL-N3000/AcuLaser M4000N Revision C
Operating Principles Overview 36
Confidential
In the cleaning process, the surface of the Drum is cleared of the remaining toner to get
ready for the next cycle.
The toner is scraped off with the cleaning blade from the surface of the Drum.
C H E C K
P O I N T
„ Toner scraped at the step of cleaning is collected into the used
toner compartment separated from the compartment for
unused toner. The transfer ratio is 90% or more, but varies
with the coverage range of the image and ambient conditions,
such as temperature and humidity. Toner used once cannot be
reused.
„
At the starting point of each printing process, the whole surface
of the drum is scanned with laser beam and the charge from the
previous printing process. If any charge remains on the surface
of the drum from the previous step, it will be removed
completely.
„
At the starting and ending points of continuous printing
process, a negative high voltage is applied to the BTR. If the
toner adheres to the BTR in the previous printing process, the
surface of the BTR will be cleaned by putting the toner back
onto the surface of the drum.