A drop-on-demand ink-jet printing head provided with an array of a plurality of piezoelectric elements arranged at regular intervals and fixed at their one ends to a base, the other ends of the respective piezoelectric elements being free ends which are disposed in opposition to nozzle respective apertures,...http://www.google.fr/patents/US5600357?utm_source=gb-gplus-shareBrevet US5600357 - Drop-on-demand ink-jet printing head
