Continuous Ink Jet Printing Theory

Inkjet technology has been in existence since the 1950s and has been used commercially since the 1970s. Nowadays, continuous inkjet technology has become synonymous with inexpensive, fast and reliable printing in the home and elsewhere.

Principle

The principle behind continuous inkjet printing is essentially very simple. A pump directs ink from a reservoir to a print head containing a series of tiny nozzles, which eject droplets of ink onto paper or some other material.

Piezo Crystal

The ejection of ink droplets is controlled by a vibrating quartz crystal, known as a piezoelectric, or piezo, crystal. The piezo crystal has a natural vibration frequency, typically between 50,000 and 175,000 vibrations per second, or 50 an d175 kilohertz (kHz), depending upon its thickness.

Deflection

Ink droplets are exposed initially to static electricity, so that each of them acquires an electrical charge. They then pass through a deflection field and the degree of deflection determines exactly when each drop lands on the finished printed page. Any unprinted drops are collected and returned to the reservoir for reuse.

References

• World Scientific: Inkjet Printing Technologies
• enotes: Quartz