In most printers from Mimaki, Mutoh and Roland, the ink is fed from the cartridges via a siphon. For this gravity-fed siphon to work correctly, the print head must be located roughly level with the ink cartridges or bulk ink system. Any imbalance in the level will result in the print heads either starving (not receiving enough ink) or dripping (too much ink pressure).
The Mutoh ValueJet 1604 and larger ValueJet printers have a sub-tank system at the level of the head, but the cartridges are located above the head. Valves control flow into the subtanks, allowing for ink cartridge changes without interrupting printing.
A pump actually pulls ink through the head during filling and cleaning cycles by creating a vacuum between the bottom of the head and the capping station seal. Failure to keep the bottom of the head clean and the seal clean and in good condition will limit the ability to pull ink through the head. This may result in nozzles NOT being cleaned properly and will affect the volume of ink values being writting to the smart cards on carded cartridges.
The smart cart counts the number of pump cycles (and number of nozzle firings) to estimate the amount of ink used. It writes this information to the smart cart to record the amount of ink remaining in the cartridge.
Thanks to Allan at: http://www.ajh-designs.com/ for the graphic.
The image below depicts the ink system for most ValueJet 64" printers.
