Tektronix Phaser 600, Руководство по обслуживанию

Страница: 101 / 286

Service Manual 5-7
Theory of Operation
5
Maintenance station
Like ink-jet printers, the printer requires a maintenance station to keep the
printhead jets working. The printer’s maintenance station performs four basic
functions:
■
Removes air bubbles from within the printhead after power up
■
Removes ink and dust particles from the printhead’s faceplate
■
Maintains meniscus control by preserving the anti-wetting properties
of the printhead’s faceplate; it keeps ink droplets from forming around
the nozzles which causes dot placement errors.
■
Collects waste ink from maintenance cycles: purge and jetting.
To accomplish these tasks, the maintenance station uses the following
components to carry out its tasks:
■
Air pump: vacuum on inlet side, and air knife (pressure) on the output
side.
■
Purge chamber: When pressed against the printhead’s faceplate and a
vacuum is applied, it causes ink to be drawn through the printhead to
clear air-bubbles or remove clogged jets.
■
Cam pin: It controls the air-valve (open or closed) and movement of
the maintenance station (against or away from the printhead).
■
Air-valve: It allows or removes vacuum from the purge chamber.
■
Air knife: Using a stream of air, the bulk of the ink on the faceplate is
moved to the drip plate.
■
Drip plate: It directs hot liquid ink from the maintenance station or
printhead to the waste drawer.
■
Waste bin: It collects waste ink for the user to dispose.
■
Wiper (not shown): The wiper removes the remaining ink or debris
(dirt or dust) from the faceplate.
The wiper is used to remove remaining ink or debris left on the faceplate from an
air knife operation. More importantly, it preserves the anti-wetting properties of
the printhead’s faceplate by keeping ink droplets from forming around the
nozzles which will cause dot placement errors.
The wiper works much like a windshield wiper on a car. Since paper dust or
other debris can build up on the wiper element, it requires cleaning periodically.