A liquid ejection head having a channel member which includes an ejection hole surface and a pressurization chamber surface opposite thereto. An actuator substrate overlaps the pressurization chamber surface. The channel member includes a plurality of ejection holes opening in the ejection hole surface, a plurality of pressurization chambers individually communicating with the plurality of ejection holes and arranged in plan view of the pressurization chamber surface, and a plurality of dummy pressurization chambers positioned outside of the predetermined region in plan view of the pressurization chamber surface. The actuator substrate includes a plurality of pressurization portions that individually pressurize the pressurization chambers, and a plurality of dummy pressurization portions that individually pressurize the dummy pressurization chambers. The dummy pressurization chambers communicate with each other via a plurality of communication paths. A closed space including the plurality of dummy pressurization chambers and the plurality of communication paths is hermetically closed.

A thin-film piezoelectric material elements are arranged on a thin-film piezoelectric material substrate. The thin-film piezoelectric material substrate includes an insulator on Si substrate including a substrate including silicon and an insulating layer on a surface of the substrate. The thin-film piezoelectric material element includes a thin-film laminated part on a top surface of the insulating layer. The thin-film laminated part includes a YZ seed layer including yttrium and zirconium, and formed on the top surface; a lower electrode film laminated on the YZ seed layer; a piezoelectric material film including lead zirconate titanate, shown by a formula Pb (Zr.sub.xTi.sub.(1-x)) O.sub.3(0≤×≤1), and an upper electrode film laminated on the piezoelectric material film. The thin-film laminated part further includes an upper piezoelectric-material protective-film, laminated on the upper side of the upper electrode film.

A piezoelectric body layer of a first area has (100) plane preferential orientation, and a (100) plane orientation ratio of the piezoelectric body layer of a second area is lower than a (100) plane orientation ratio of the piezoelectric body layer of the first area, when one area far from an end portion of a second electrode is the first area, and one area near the end portion of the second electrode is the second area, of two areas of the second electrode in a second direction intersecting a first direction.

There is provided a liquid ejecting unit that ejects liquid from a plurality of nozzles, in which the planar shape of the ejecting face on which the nozzles are formed is a shape in which a first portion that passes through the center line parallel to the long side of the rectangle of the minimum area including the ejecting face and a second portion that does not pass through the center line are arranged in the direction of the long side.

A liquid discharge head includes: a diaphragm having a nozzle; a substrate including a pressure chamber communicating with the nozzle; a piezoelectric body over the diaphragm, the piezoelectric body configured to deform at least a part of an edge of the nozzle; and a vibration absorbing portion in the diaphragm.

A liquid ejection head includes a plurality of nozzles arranged along a first direction of an ejection surface, a plurality of pressure chambers communicating with the plurality of individual nozzles and provided with actuators configured to apply, to a liquid, pressures for ejecting the liquid from the nozzles, a plurality of discrete flow paths communicating with the plurality of individual pressure chambers, a common flow path communicating with the plurality of individual discrete flow paths via discrete opening portions and extending in the first direction, and a damper mechanism disposed to face the common flow path in a direction crossing the ejection surface to absorb a pressure fluctuation in the liquid in the common flow path. The common flow path is provided with a partition wall disposed between the discrete opening portions adjacent in the first direction to extend in the direction crossing the ejection surface.

A liquid ejecting apparatus includes a supply section configured to selectively supply a first driving signal that drives a piezoelectric element to form an image or a second driving signal that drives the piezoelectric element to determine whether a foreign matter adheres to an inner wall of a nozzle opening, and a determination section that determines whether a foreign matter adheres to the inner wall. The second driving signal includes a first partial signal having its potential changed from a first potential to a second potential, and a second partial signal having its potential changed from the second potential to the first potential. The determination section determines, after the first partial signal is supplied to the piezoelectric element, based on vibration generated in the piezoelectric element due to supply of the second partial signal, whether a foreign matter adheres to the inner wall.

A piezoelectric actuator is provided, including a vibration plate, a piezoelectric layer, a plurality of individual electrodes arranged in two arrays, first and second common electrodes which have first and second facing portions facing parts of the individual electrodes and first and second connecting portions connecting the first and second facing portions respectively, and first and second wiring portions which are arranged on the vibration plate and which are connected to the first and second common electrodes respectively via first and second connecting wirings, wherein one of the first connecting wirings connects the first connecting portion and one of the first wiring portion while striding over the second connecting portion.

A liquid discharge head includes: a piezoelectric body including piezoelectric layers stacked in a stacking direction, the piezoelectric body including a first end and a second end that are separated in a first direction orthogonal to the stacking direction of the piezoelectric layers; individual electrodes positioned in a first plane orthogonal to the stacking direction; a first common electrode formed in a second plane that is orthogonal to the stacking direction and of which position in the stacking direction is different from a position of a neutral plane of the piezoelectric body in the staking direction and a position of the first plane in the staking direction; and a trace positioned in a third plane of which position in the stacking direction is different from a position of the first plane, the position of the second plane, and the position of the neutral plane.

There is provided a head including: a piezoelectric layer; a plurality of individual electrodes located below the piezoelectric layer in an up-down direction; a common electrode located below the piezoelectric layer. The plurality of individual electrodes includes: a first individual electrode array including a plurality of first individual electrodes aligned in a first direction; and a second individual electrode array including a plurality of second individual electrodes aligned in the first direction. The common electrode includes: a plurality of first facing portions which are demarcated to correspond to the plurality of first electrodes, respectively; a plurality of second facing portions which are demarcated to correspond to the plurality of second electrodes, respectively; and a connecting portion located between the plurality of first facing portions and the plurality of second facing portions, and connecting the plurality of first facing portions and the plurality of second facing portions.