Innovation Gallery

HP ThinkJet, 1984

This small, rugged printer, dubbed ThinkJet for thermal inkjet, was introduced in 1984. Just as the HP-35 calculator replaced the manual slide rule forever, inkjet technology spelled the end for the noisy dot-matrix printer. Thermal inkjet technology developed at HP was introduced in a high-quality, low-price personal printer.

The invention came about when an engineer working on developing thin-film technology for integrated circuit applications was testing the response of a thin silicon-based film to electrical stimulation. The electricity superheated the medium, and droplets of fluid lying under the film were expelled. An idea was born. What if you could finely control these jets of fluid? Large, industrial inkjet marking devices already existed, but up to this point only crude printing of quite large characters for industrial purposes was practical. Suddenly it looked like this marking technology could be miniaturized - and it had the advantages of requiring very little power to print and being inherently inexpensive to manufacture.

Inkjet technology offered HP the opportunity to replace the least expensive printer in the market - serial dot-matrix printers - with products that were superior in every way. Inkjet had the potential for better print quality, greater font and graphics capabilities, quieter operation, extremely low power consumption and, eventually, high-quality, low-cost color.

Additional information:

Model for the Grit Wheel Plotter.

The HP ThinkJet was the first mass-marketed personal inkjet printer. Inkjet technology spelled the end for the noisy dot-matrix printer.