Patent ID: 7677709
Filing Date: 2010-03-16
Classification: B41J

Abstract:
1. A liquid ejection head, comprising: a nozzle through which liquid is ejected; a pressure chamber which is connected to the nozzle; a diaphragm which pressurizes the pressure chamber; and a laminated piezoelectric element which causes the diaphragm to deform and is bonded to a section of the diaphragm by means of a thin film forming technique, wherein: an effective surface area of the diaphragm forming one inner surface of the pressure chamber is greater than a surface area of the bonding section between the diaphragm and the laminated piezoelectric element; a surface area of an active section of the laminated piezoelectric element is greater than the effective surface area of the diaphragm; a width of the bonding section between the diaphragm and the laminated piezoelectric element through which the laminated piezoelectric element directly presses is ⅓an effective width of the diaphragm; and the laminated piezoelectric element has a projection on a lower section which corresponds with the bonded section between the diaphragm and the laminated piezoelectric element, the projection being in contact with the diaphragm, and cross-sectional areas extending on planes parallel to the diaphragm, and the larger a distance from the diaphragm to the plane is, the smaller the cross-sectional area of the laminated piezoelectric element extending on the plane becomes.