Purge Unit; Functions Of Purge Unit - Canon iPF700 Series Service Manual

Chapter 2

2.3.2.5 Purge Unit

2.3.2.5.1 Functions of Purge Unit

The purge unit maintains the nozzle assembly of the printhead to maintain print quality.
Functions provided by the purge unit include capping, cleaning and ink supply.
a) Capping function
The capping function presses the caps in the purge unit against the face plate of the nozzle assembly to protect against drying and foreign matter adherence.
Capping takes place at the end of printing, during a suction operation and when the printer stands by in the wake of an error occurrence.
The capping function connects the printhead to the ink passage of the purge unit.
b) Cleaning function
The cleaning function restores the nozzles to facilitate ink discharges through them. It consists of the following three operations:
-Wiping operation
Wipe off paper fibers or residual inks adhering to the face plate of the printhead.
-Pumping operation
Sucks inks from the nozzle assembly and refreshes the inside of the nozzles with new inks.
-Maintenance jet operation
Discharges inks from the nozzle assembly to the caps or to the borderless printing ink jet tray and paper surface to remove bubbles in the nozzles and dust around
the ink discharge ports.
The cleaning function is described below
Cleaning mode Name
Cleaning 1 Normal cleaning
Cleaning 2
Ink level adjustment cleaning
Cleaning 3
Initial filling ink
Cleaning 4 Ink drainage for head replacement
Cleaning 5 Ink drainage for secondary transport
Cleaning 6
Normal (strong) cleaning
Cleaning 7 Aging
Cleaning 8
Flushing
Cleaning 10
Ink filling after secondary transport
Cleaning 15
Dot count suction
Cleaning 16
Precipitated ink agitation
Cleaning 17 Cleaning (weak)
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T-2-3
Description of cleaning
Removes dried ink from nozzles, thick ink accumulated on the face, and paper
particles.
Adjust the ink level in the head by suction, and then performs normal
cleaning.
Fills the empty tube (during initial installation) with ink, and then performs
normal cleaning.
Drains ink to replace the head (drains only the ink in the head).
Drains ink from the head and tube for secondary transport.
Performs suction stronger than when adjusting the ink filling amount in the
head or normal cleaning to unclog nozzles.
Performs idle ejection after replacement of the head.
Performs idle ejection to remove burnt deposits on the surface of the head
heater.
Fills the empty tube (during installation after secondary transport) with ink,
and performs normal cleaning.
Performs suction to remove ink adhered to dried nozzles and thick ink
accumulated on the face when the dot count reaches the prescribed value.
Performs the agitation (ink supply valve open/close) operation to prevent the
ink ingredient from precipitating.
Performs cleaning weaker than normal cleaning to unclog nozzles.
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