The apparatus is of the type wherein a piezoelectric transducer (19) is selectively operated to produce a pressure wave in the ink in a duct (16, 22), which causes a droplet of ink to be expelled from the nozzle (18). In order to absorb the energy of the pressure wave which is directed towards the ink...http://www.google.fr/patents/US4630072?utm_source=gb-gplus-shareBrevet US4630072 - Jet printing apparatus
