Chapter 2
2-18
a) Supplying inks from the ink tanks to the ink supply valve assembly
The ink tanks each contain an ink to feed the printhead.
Head differences allow the inks to flow from the ink tanks to the ink supply valves.
b) Inks flowing from the ink tanks into the subbuffer
As the inks flow from the ink tanks to the subbuffers due to head differences, air infiltrates the ink tanks through
air passages in the subbuffers to keep its internal pressure constant.
When the ink stored in a subbuffer exceeds a predetermined level, it flows into the absorber under the ink tank
through the air passage.
c) Supplying inks from the ink supply valves to the printhead
The ink stored in an ink tank flows to the printhead when the suction pipe is driven with the ink supply valve
opened and the head capped.
As an ink is sucked from the caps, it flows into the waste ink absorber under the maintenance cartridge or purge
unit.
d) Ink supply while printing
The ink supply valves are kept open while printing, so that inks are being constantly fed to the printhead under
the negative pressure of the nozzle assembly caused by discharging inks.
Further, waste inks sucked in a cleaning operation and inks from borderless printing flow into the waste ink
absorber under the maintenance cartridge and into the waste ink box.
When an ink tube filled with ink, opening all whole ink passages (by opening both the ink supply valve and the
printhead fixer lever with an ink tank yet to be installed) could cause the ink in the ink tube to flow backward
due to a head difference, leaking through the hollow needle in the ink tank.
As a precaution, never open all the ink passages at the same time while the ink tubes are filled with inks.
e) Agitating the ink in an ink tank
To prevent the pigment ink stored in a tank from settling, the ink needs to be agitated.
The ink supply valve is continuously opened and closed to cause the ink to flow back into the tank for agitation.
Each ink tank contains an agitating plate to aid in agitating of the ink. (An agitating plate is also installed in the
dye ink tank.)
-Operation timing: Whenever a new tank is installed or 168 hours have expired since the agitation was last
carried out (agitation is carried out regardless of whether printing or cleaning is in progress).
-Ink supply valve open/closed: 30 times (30 seconds)
If 336 hours or more have elapsed, the ink supply valve open/closed count and the time to the next session of
agitation are varied according to the elapsed time.