Xerox Nuvera 100, Service Manual

Page: 61 / 304

General Information 1-61
Print Process in Operation
Once an image has been processed and a printing bitmap created, a
print cycle begins. The printhead and drum are brought up to their
operating temperatures and the ink levels in the ink reservoirs are
checked and ink is added from the ink loader, if necessary. Next, the
printhead is driven horizontally to its home position and the drum is
rotated to its home position.
WARNING
Keep your fingers away from the process gear drive system; it uses
a closed-loop drive system. A closed-loop servo drive system is
inherently dangerous. Since the motor speeds up if it senses the
process gears drive system slowing down, fingers caught in the
process belts and gears can be severely injured.
Printhead Tilt
The printhead is tilted forward into its print position. (Refer to Figure
1-27.) The process motor is activated, which drives the process drive
belt. The belt, in turn, drives a compound gear. Through a follower
gear, the compound gear drives the head tilt cam gear clockwise. A
cam follower, mounted on the lower end of the head tilt arm, follows
the rotating cam gear, which tilts the printhead. The head tilt cam
gear rotates until a set of missing teeth in the cam gear “disengage” it
from the cam drive gear. The cap/wipe/purge assembly, in its standby
position, draws a leaf spring away from a cam lobe located at the back
side of the tilt arm gear. (When the leaf spring pushes against the
cam lobe of the tilt arm gear it forces the gear to mesh with the cam
drive gear.) Pulling the leaf spring away effectively latches the head
tilt cam gear in the printhead forward position. At this point, the
printhead is in its upright print position (home position). (The head
tilt cam gear is principally rotated in a counterclockwise direction to
tilt the printhead forward and back. It only rotates clockwise during
some printhead cleaning operations.)
Tilted forward, the missing teeth of the head tilt cam gear allow the
process motor and gear train to perform other print functions without
affecting the printhead’s tilt position. The cap/wipe/purge assembly is
raised slightly to allow the head tilt cam gear (with a slight spring
assist from the leaf spring pushing against the cam lobe on the back
of the tilt cam gear) to advance forward enough to engage its drive
gear and tilt the printhead back.