An output device that creates the desired image by emitting ink from an array of orifices or nozzles. The array of nozzles shuttles across the page, printing one character at a time, or serially. This category includes the following types of device:

Piezo electric inkjet — Print heads in which ink is ejected by electrically actuating a special crystalline or ceramic component to compress the ink and force it out of the nozzle.

Thermal inkjet — Heat is used to generate vapor bubbles, which are ejected through nozzles that project droplets onto a surface to form text or images. Thermal inkjet’s advantages include small and highly controlled droplets and high system reliability. Thermal inkjet print heads are used in a wide range of serial and line inkjets. Originally developed for desktop printers, thermal inkjet printing has spread to specialty applications, such as direct-mail addressing, wide-format printing and package coding operations.