Transfixing And Exiting - Xerox Phaser 8400 Service Manual

Transfixing and Exiting

Transfixing and exiting consists of four major functions:
1. Staging the paper for rendezvous with the image on the drum and Transfix Roller
nip
2. Loading the Transfix Roller and engaging the release assembly
3.
Releasing the paper from the drum
4.
Exiting the paper from the printer, or exiting the paper for (2-sided) duplex
printing
Tripping the preheat exit sensor sets up a series of events, which take place on a
predetermined schedule. Paper is transported through the preheater to thermally
prepare it for transfixing. The preheat sensor detects the paper's presence, and
accurately references the leading edge of the paper with the image on the drum. As
the leading edge of the sheet of paper trips the paper preheater exit sensor, the
Transfix Roller is lowered into its loaded position. The Transfix Roller is lifted and
lowered by the Process Drive.
At the point which the Transfix Roller is loaded, but before the drum begins to rotate,
the paper release solenoid is engaged. The paper release assembly is actuated by
energizing the paper release solenoid, which is mounted on the upper inner duplex
guide. The solenoid activates the strip solenoid lever, which in turn rotates the paper
release carriage until it hits the transfix ground pins, which causes the paper release
blade to momentarily drop onto the deadband of the drum, catching the leading edge
of the sheet of paper and guiding the paper to the rotating exit rollers.
After the Transfix Roller is engaged, the drum rotates to advance the paper and
transfix the image. All gears move to rotate the drum transfix camshaft to bring the
Transfix Roller into contact with the drum. The Transfix Roller nip applies the load
necessary to transfer the image to the paper from the drum. Once the image is
transferred, all motion stops and the Transfix Roller is lifted by the Process Drive.
After the leading edge of the paper is beyond the paper release guide, the paper
release solenoid is de-energized. Once the solenoid is de-energized, and the solenoid
return spring provides a force to move the solenoid plunger out of the solenoid coil
and in turn rotate the paper release carriage back to its ready position. The ready
position is established by the stop-spring which is housed inside the strip solenoid
lever. This spring provides a "soft stop". That is, it provides enough of a force to resist
the force of the return spring, but is weak enough to overcome when a customer
rotates the paper release carriage toward the front of the printer for jam clearance.
When the customer releases the carriage after clearing a jam, the carriage rotates back
to a position at which it will automatically be returned to the ready position when the
top cover is closed.
The deskew rollers are not driven during transfixing. The Media Path Drive rotates the
exit rollers in the correct direction to pull the paper out, with the deskew clutch de-
energized. As the Process Drive lifts the Transfix Roller, the exit rollers deposit the
paper into the output tray, ending the print cycle.
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