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:
*Thermal inkjet printers are different from thermal printers. Getting these two types of machines confused would be a very bad thing for business. Thermal inkjet printers are commonly found in small offices and homes whereas thermal printers are specifically designed for printing labels and receipts on special thermal paper.*
Most major manufacturers, including HP, Canon and Brother use the thermal inkjet technology. Epson has patented piezoelectric inkjet technology, which implements the same concept as thermal but ejects ink using vibrations rather than heat. Both technologies are innovative and constantly getting better, providing offices and homes with crisp, professional documents as well as vivid, colorful photos.