Providing Ink

(Carriage Illustration ' page 10221)

Print Cartridges

The plotters use two HP DeskJet2type cartridges, each containing 50 nozzles. The cartridges are staggered such that two nozzles on each one are not used.

The main components of a cartridge are the

DPlastic housing

DSpring2bag ink reservoir

DFlex circuit

The spring bag provides a negative pressure inside the ink supply to prevent ink from flowing out through the nozzles. The print head (flex circuit), located on the cartridge, contains the cartridge interface (interconnect) and nozzles.

Drop ￿rowth

Inkjet cartridges invoke a thermal drop2on2demand technology.

Nozzle

12

3

4

1A voltage is applied to a resistive area on the head superheating the bottom layer of the ink droplet and causing nucleation (similar to boiling water).

2The ink boils producing a bubble of water vapor that forces the ink droplet out of the small nozzle orifice.

3As the ink droplet leaves the orifice, the surface tension of the ink draws more ink into the chamber.

4The bubble collapses as the water vapor cools.

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Functional￿Overview 5211￿