Inkjet printers spray the printing ink onto the print medium through the finest nozzles as the smallest pixels. Like other color printers, the inkjet color printer works on the basis of the CMYK color model with subtractive color mixing by spraying the color inks of the three primary colorscyan (C), magenta (M) and yellow (Y) as well as the depth (K) onto the print medium as adjacent pixels.
The colored inks are in closed printer cartridges, which, in the case of various manufacturers, also contain the electronics for the print head. There are printer cartridges for black and for the primary colors cyan, magenta and yellow.
The print head is made using microsystems technology( MEMS) and can have several hundred or even over a thousand nozzles per color, from which tiny droplets of ink are sprayed. The droplet size is crucial for the quality of the printout and is only a few picoliters (pl), or trillionths of a liter. Top-of-the- line devices range from 1 pl to 5 pl. The ink droplets can be sprayed at a rate of over 10,000 drops/ second, depending on the printer. Droplet velocity is 10 m/s and above. The resolution of inkjet printers is in the range of 300 dpi to 1,200 dpi, and in devices for professional use it reaches values of up to 10,000 dpi. The ink dot itself has a size of only 20 µm at a resolution of 1,000 dpi, and only 4 µm at 5,000 dpi.
Inkjet printers can spray ink onto the paper continuously, using the drop-on-demand method, or using the continuous-drop method such as the Continuous Ink Jet( CIJ). In the drop-on-demand method, the control of the nozzle technology for droplet formation can be based on the piezoelectric method used in piezo printers or by means of a heating element as in the bubble jet. They can print the individual color dots with different intensity and create color tones by color mixing or screening. In addition, some devices can vary the size of the ink droplets within certain limits.
The inkjet printer is widely used and is available as a black-and-white and color printer.