Thermal Inkjet Printers
First marketed in 1976, inkjet printers have come a long way in the last few decades. These days, inkjet printers can rival the speed of some laser printers while still creating vibrant, true-to-life images. There are two primary types of drop-on-demand inkjet printers, piezoelectric and thermal, with the latter being far more common.
When a job is sent to a thermal inkjet printer, a resistor within the printhead is immediately heated. This will cause the ink in the hopper to expand into an air bubble within the printhead (which is where the Canon-coined name ‘BubbleJet’ comes from). The ink air bubble is forced through the nozzles (Typically thermal inkjet printers have 300 – 600 nozzles per ink cartridge) and onto the selected media, where it regains liquid form and dries onto the paper. Once that air bubble pops, a vacuum pull is created, which sucks more ink from the cartridge into the printhead for the next bubble.
Here is a quick video as a visual aid: