Patent ID: 6955421

Claim:
A liquid jet head comprising: a piezoelectric vibrator unit having a plurality of piezoelectric vibrators, each piezoelectric vibrator having common internal electrodes and segment internal electrodes laminated alternatively with layers of piezoelectric material interposed therebetween to form an active region in a free end part of the piezoelectric vibrator; and a flow passage unit having a plurality of liquid flow passages that are respectively associated with the piezoelectric vibrators, and that respectively extend from a reservoir through pressure chambers to nozzle openings, wherein: the piezoelectric vibrators unit is attached to the flow passage unit so that the piezoelectric vibrators are respectively contacted with diaphragm parts of the pressure chambers associated with the piezoelectric vibrators; and deformation of the piezoelectric vibrator deforms the associated pressure chamber and changes liquid pressure in the associated pressure chamber to thereby eject liquid from the associated nozzle opening, wherein each of the piezoelectric vibrators have, at least in part, a laminate structure of electrodes, and at least one layer of piezoelectric material, wherein the laminate structure has an external electrode as an outermost electrode in a laminate direction, and an internal electrode that is different in polarity from the external electrode and that is confronted with the external electrode through a layer of the piezoelectric material to form an active region, and wherein a portion of the external electrode, located within the active region, is trimmed away.