Patent ID: 7654653

Claim:
An ink-jet head comprising: a passage unit having a pressure chamber that communicates with an ink ejection port; a piezoelectric actuator that applies pressure to ink in the pressure chamber, and has an individual electrode formed so as to be opposed to the pressure chamber, a common electrode formed so as to be opposed to the individual electrode, and a piezoelectric layer sandwiched between the individual electrode and the common electrode; a wire member having a substrate, a first wire that is formed on a surface of the substrate and electrically connected to the individual electrode, a second wire that is formed on the surface of the substrate and electrically connected to the common electrode, and a driver IC chip that is mounted on the surface of the substrate, gives a drive potential to the individual electrode through the first wire, and maintains the common electrode at a predetermined reference potential through the second wire; and a heat sink made of a metal material which is in contact with the driver IC chip and dissipates heat generated in the driver IC chip to outside, wherein the second wire is formed along an outer edge of the substrate, and electrically connected and thermally coupled to the heat sink.