Xerox Nuvera 100, Service Manual

Page: 63 / 304

General Information 1-63
Drum Preparation
To prepare the drum, a thin, intermediate liquid transfer surface is
applied to the surface of the drum. (Refer to Figure 1-28.) First the
drum is rotated to a speed of 51 cm per second (20 inches per second).
Next, the oil roller and blade of the maintenance drawer are raised
into contact with the drum. To accomplish this, the process motor
rotates clockwise, driving the process drive belt and the compound
gear. Rotating clockwise, the compound gear drives a gear train that
drives the maintenance camshaft’s 3-position electric clutch which, in
turn, engages the maintenance drawer camshaft. The maintenance
drawer camshaft clutch energizes to release the 3-position clutch,
allowing it and the camshaft to rotate about one-half revolution to the
next stop. The cams on the ends of the camshaft push against
followers on each side of the maintenance drawer, forcing the oil roller
and blade against the drum. The de-energized clutch holds the
camshaft in this position.
As the drum nears the end of its rotation, the clutch energizes for a
moment, allowing the camshaft to rotate further; this lowers the oil
roller but leaves the blade in contact with the drum to smooth out the
last of the oil on the drum.
The clutch energizes for a third time to allow the camshaft to rotate
to its home position, and lower the blade. The point at which the blade
ends contact with the drum leaves a bead of oil, called an oil bar. The
oil bar defines the edge of a 40 mm (1.5 in.) swath of the drum which
is not oiled; this swath is called the deadband. No ink will be
deposited on the deadband during the print cycle. Instead, the paper
stripper fingers, which lift the paper off of the drum during printing,
are lowered into contact with the drum in the deadband. This keeps
them from accumulating any oil on their fingertips which would stain
the edge of the print as it is stripped off of the drum.
At this point, the drum starts rotating again at a speed dependent
upon print resolution. As the drum reaches the correct speed, the ink-
jets begin to fire to deposit the image on the oiled portion of the drum.
As the jets fire, the printhead slews in the X-axis to complete the
image on the drum.