Patent ID: 8182074

Claim:
A liquid ejection head, comprising: an ink chamber, which stores ink therein; a nozzle orifice, adapted to eject an ink droplet therefrom; a pressure generating portion, provided in an ink channel communicating the ink chamber and the nozzle orifice, the pressure generating portion comprising a pressure chamber formed in a pressure chamber formation substrate; an elastic plate, which defines a part of the pressure chamber, a piezoelectric vibrator, comprising: a first common electrode, provided on a surface of a vibration plate which is opposite to a surface facing the pressure chamber, and electrically connected to a common potential; a first piezoelectric layer, provided on the first common electrode; a drive electrode, provided on the first piezoelectric layer, and electrically connected to a signal source for supplying a drive signal; a second piezoelectric layer, provided so as to cover the drive electrode; and a second common electrode, provided on the second piezoelectric layer, and electrically connected to the common potential, the piezoelectric vibrator being deformed in accordance with the drive signal supplied to the drive electrode, so that the elastic plate is deformed to vary a volume of the pressure chamber, thereby ejecting the ink droplet from the nozzle orifice; and an ink supply port, arranged between the ink chamber and the pressure generating portion to serve as an orifice, wherein an inertance of the nozzle orifice and an inertance of the ink supply port are greater than an inertance of the pressure generating portion, and wherein a rigidity compliance of the pressure chamber formation substrate is set to be equal to or less than a compliance of the ink.