Inkjet printers theory
Inkjet printers technology development starts in the early 1960s. The first inkjet printing device was patented by Siemens in 1951, which led to the introduction of one of the first inkjet chart recorders.
The continuous inkjet printer technology was developed later by IBM in the 1970s. The continuous inkjet technology basis is to deflect and control a continuous inkjet droplet stream direction onto the printed media or into a gutter for recirculation by applying an electric field to previously charged inkjet droplets.
The drop-on-demand inkjet printer technology was led to the market in 1977 when Seimens introduced the PT-80 serial character printer. The drop-on-demand printer ejects ink droplets only when they are needed to print on the media. This method eliminates the complexity of the hardware required for the continuous inkjet printing technology. In these first inkjet printers ink drops are ejected by a pressure wave created by the mechanical motion of the piezoelectric ceramic.
Inkjet printer drop-on-demand technology with piezoelectric actuator
At the same time Canon developed the bubble jet printer technology, a drop-on-demand inkjet printing method where ink drops were ejected from the nozzle by the fast growth of an ink vapor bubble on the top surface of a small heater. Shortly thereafter, Hewlett-Packard independently developed a similar inkjet printing technology and named it thermal inkjet.
Bubble jet printer drop-on-demand technology
The most popular inkjet and bubble-jet printers use serial printing process. Similarly to dot matrix printers, serial inkjet printers use print heads with a number of nozzles arranged in vertical columns. The printing process is the same as in dot matrix printers.
Serial Inkjet printer in action
There are also available inkjet and bubble-jet printers analogous to line dot matrix printers for high speed printing applications. The image printing process is similar to that in LED printers as shown bellow.
Line inkjet printer printing process
The greatest advantages of inkjet printers are, quiet operation, capability to produce color images even with photographic quality and the low printer prices. The down side is that although inkjet printers are generally cheaper to buy than lasers, they are far more expensive to maintain. When it comes to comparing the cost per page, ink jet printers work out many times more expensive than laser printers. There are some exceptions of course for some heavy-duty industrial printers. From Tally claim the T3016 SprintJet prints at only 1/3 of a cent per page.