Xerox PHASER 8560MFP, Service Documentation

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10/2006
8-17 Phaser 8510/8560MFP Multifunction Product
Image Output Terminal
Theory of Operation Initial Issue
The tilt cam tilts the head into the basic four positions listed above. The cam has five special
features and associated functions:
1. The cam is combined with a missing tooth gear that allows the cam to be inactive in the
print position. This frees the process drive to perform other system operations.
2. The cam has a latching feature to unlatch and latch the missing tooth gear to engage the
Printhead tilt drive train.
3. The cam profile has a standby dwell (the portion of the cam that has a constant radius).
This holds the Printhead back in the standby position
4. The cam profile has a wipe dwell that holds the Printhead back in the wipe position.
5. The cam profile increases the power consumption at a specific phase of rotation. This
allows the software to identify a power consumption footprint to alert the system when the
head is locked in error.
The Printhead is tilted away from the drum and locked for shipping. When the Printhead is
locked in the shipping position there are three key restraining elements:
1. The Printhead is restrained from rotating from the shipping position by pins extending
from both ends of the Printhead into a pocket. These pockets are defined by dampening
pads that limit motion to the back and polycarbonate locks that pivot into the lock position
and limit forward motion toward the drum. The locks are held in the lock position by the
wiper carriage, and are spring-loaded to normally be unlocked.
2. The Printhead is restrained at the X-Axis shafts by the right and left head restraints that
limit motion at both ends of the Printhead.
3. The Printhead is limited to the nominal motion of 1.7 mm in the X-Axis (left / right side
motion when the Printhead is back and locked) by the right lock and the left home stop on
the left side frame.
Figure 14 Printhead Tilt Drive
In the print position (0 degrees), the Printhead is forward and resting against the right and left
head-to-drum buttons. The head-to-drum buttons define the space between the jet stack and
the drum. When the process drive is activated, it drives the drum maintenance camshaft to
engage the tilt gear train. The tilt cam tilts the Printhead into the print position. The cam is com-
bined with a missing tooth gear that allows the cam to be inactive in the print position, freeing
the process drive to perform other system operations.
The cam has a latching mechanism to unlatch and latch the missing tooth gear to engage the
Printhead tilt drive train. The cam’s latching mechanism also holds the tilt gear in place. A leaf
spring applies constant pressure to engage the gear when the latching mechanism is released.
The arm of the latching mechanism is inside the frame; the rest is visible, outside the frame.
Arrows located on the latching mechanism and on the frame indicate when the Printhead is in
print position. When the arrows on the latching mechanism and frame align, the Printhead is in
the print position and the tilt gear disengages from the process drive. The Head Tilt Solenoid is
actuated and deactuated when the tilt cam gear rotates to the respective engaged and disen-
gaged positions.