Oliff & Berridge
Piezoelectric ink jet print head including common laminar piezoelectric element for two or more ink jetting devices
 A piezoelectric ink jet print head including a common laminar piezoelectric element disposed for activating two or mor ink jetting devices each of which has an ink chamber for ejecting a droplet of ink. The laminar piezoelectric element consists of a plurality of piezoelectric ceramic layers and a plurality of electrode layers which are alternately laminated on each other. Each piezoelectric ceramic layer is polarized in a polarizing direction perpendicular to the direction of lamination of the piezoelectric ceramic and electrode layers. A voltage is applied selectively to the electrode layers for displacing at least one of the piezoelectric ceramic layers in the polarizing direction, so as to change the volume of the ink chamber of a selected one of the ink jetting devices. The electrode layers is formed of a thermistor which has a Curie point lower than that of the piezoelectric ceramic layers and which has a positive temperature coefficient of resistance so that the thermistor is an electrically insulating material at a temperature above the Curie point thereof. 
Brother Kogyo Kabushiki Kaisha
B B B
B41J B41J B41J
inventional additional additional
Yoshikazu Masahiko Makoto
Takahashi Suzuki Takeuchi