With the introduction of the thermal inkjet technology HP has become market leader with this technology. This technology can be characterized by its high print image quality, operating speed, poor maintenance and cost effectiveness.
In this technology, drops are formed by rapidly heating a resistive element in a small chamber containing the ink. The temperature of the resistive element rises to 350 to 400ºC, causing a thin film of ink above the heater to vaporize into a rapidly expanding bubble, causing a pressure pulse that forces a drop of ink through the nozzle. Ejection of the drop leaves a void in the chamber, which is then filled by replacement fluid in preparation for creation of the next drop.
The advantages of thermal inkjet include the potential for very small drop sizes and high nozzle density.