Inkjet

Thermal Inkjet

This technology was first invented by Canon in 1977 and was called bubble-jet. Hewlett Packard independently discovered a similar method which it names thermal-inkjet which is now the preferred name for the technology. In thermal inkjet printers, a heating element is used to heat the ink in the nozzle until it forms a bubble which expands outwards due to the pressure, ultimately bursting and hitting the paper. The ink then cools and collapses, the resulting vacuum draws more ink from the reservoir into the nozzle and the whole sequence can begin again.

A print head might have around 300 such nozzles with each nozzle depositing several micro-liters of ink in every spray. The printing speed is a function of how fast the spraying can be done. Typical printing quality ranges from 300-600 dpi.

picture from: pctechguide.com

picture from: mimech.com