A liquid discharge head includes a channel member and an actuator member. A plurality of individual channels each including a nozzle and a pressure chamber communicating with the nozzle, and a communicating channel communicating with the plurality of individual channels are formed in the channel member. The actuator member is arranged on a surface of the channel member and has: a plurality of actuators each overlapping with the pressure chamber of one of the plurality of individual channels in a first direction orthogonal to the surface and having a plurality of individual electrodes, a plurality of branched parts each of which connects individual electrodes, and a trunk part connecting the plurality of branched parts and provided with a contact with respect to an electric power supply part. The communicating channel has an overlapping part overlapping with the trunk part in the first direction.

A piezoelectric actuator includes: a vibration plate: a first piezoelectric body arranged on one side in a thickness direction of the vibration plate; a second piezoelectric body arranged on a side, of the first piezoelectric body, opposite to the vibration plate in the thickness direction; a first electrode arranged between the vibration plate and the first piezoelectric body; a second electrode arranged between the first and second piezoelectric bodies in the thickness direction, and overlapping with the first electrode in the thickness direction; and a third electrode arranged on a side, of the second piezoelectric body, opposite to the first piezoelectric body in the thickness direction, and overlapping with the second electrode in the thickness direction. The second piezoelectric body covers at least a part of a first end surface, of the first piezoelectric body, which is an end surface in a first direction orthogonal to the thickness direction.

A sodium niobate-barium titanate-based coating liquid composition including: (a) a sol-gel raw material containing (i) a niobium component, such as a niobium alkoxide, (ii) a sodium component, such as a sodium alkoxide, (iii) a titanium component, such as a titanium alkoxide, and (iv) a barium component, such as a barium alkoxide; and (b) a compound including at least one kind selected from the group consisting of a β-ketoester compound and a β-diketone compound represented by the following formula (1): ##STR00001## where R.sub.1 represents an alkyl group having 1 or more to 6 or less carbon atoms.

A piezoelectric element includes a piezoelectric layer formed as a stacked structure of first, second, and third piezoelectric films. The first piezoelectric film is formed on a first electrode. The second piezoelectric film is formed on the first piezoelectric film. The third piezoelectric film is formed on the second piezoelectric film. Each of the first, second, and third piezoelectric films includes potassium, sodium, and niobium. A second electrode is formed on the piezoelectric layer. A concentration of sodium in the first piezoelectric film is greater than a concentration of sodium in the second piezoelectric film. The concentration of sodium in the second piezoelectric film is greater than a concentration of sodium in the third piezoelectric film.

A liquid ejecting head includes a diaphragm, a first electrode, a piezoelectric layer, and a second electrode in this order in a first direction, and ejects liquid. The second electrode includes a first portion that is next to the piezoelectric layer in the first direction and is electrically conductive. A length in the first direction is defined as a thickness. One position in a second direction intersecting with the first direction is defined as a first position. Another one position is defined as a second position that is closer to an end of the second electrode in the second direction than the first position is. Given the definition, the thickness of the first portion at the second position is less than the thickness of the first portion at the first position.

A liquid jetting apparatus includes: individual channels; and a manifold commonly provided for the individual channels. Each of the individual channels has: a nozzle; a pressure chamber arranged away from the nozzle in a predetermined direction to extend along a plane orthogonal to the predetermined direction and connected to the manifold, a connecting channel connected to the pressure chamber to form at least a part of a channel communicating the pressure chamber and the nozzle, and a circulation channel connected to the connecting channel to form a part of a channel communicating the connecting channel and the pressure chamber. The connecting channel has a throttle, and the throttle has a smaller diameter along the plane orthogonal to the predetermined direction than a diameter, of a part of the connecting channel except the throttle, along the plane orthogonal to the predetermined direction.

Provided is an inkjet head containing a nozzle plate having at least a substrate, wherein the nozzle plate has a liquid-repellent layer on an outermost surface of the substrate on an ink ejection surface side; a liquid-repellent layer base film is provided between the substrate and the liquid-repellent layer; and the liquid-repellent layer base film contains at least silicon (Si) and carbon (C), and having a maximum peak P of a binding energy of a Si2p orbital of a surface portion measured by X-ray photoeletron spectroscopy is in the range represented by the following Formula (1), Formula (1): 99.6 (eV)≤P≤101.9 (eV).

A piezoelectric device comprises a pressure chamber forming layer, a vibration plate disposed on and connected with the pressure chamber forming layer to form a pressure chamber, and a piezoelectric element disposed on the vibration plate and used for driving the vibration plate to move and thus changing a volume of the pressure chamber, wherein the piezoelectric element is disposed on the vibration plate in such a manner as to cover a portion of the pressure chamber, the piezoelectric element has two opposite ends respectively extending beyond an edge of the pressure chamber and covering the pressure chamber forming layer. The piezoelectric device of the present invention can efficiently actuate the vibration plate, eliminate undesired displacements of the vibration plate in the opposite direction at the edge of the chamber, and provide higher displacement sensitivity to driving voltage.

A liquid jetting apparatus includes: individual channels; and a manifold commonly provided for the individual channels. Each of the individual channels has: a nozzle; a pressure chamber arranged away from the nozzle in a predetermined direction to extend along a plane orthogonal to the predetermined direction and connected to the manifold, a connecting channel connected to the pressure chamber to form at least a part of a channel communicating the pressure chamber and the nozzle, and a circulation channel connected to the connecting channel to form a part of a channel communicating the connecting channel and the pressure chamber. The connecting channel has a throttle, and the throttle has a smaller diameter along the plane orthogonal to the predetermined direction than a diameter, of a part of the connecting channel except the throttle, along the plane orthogonal to the predetermined direction.

Use of a barium titanate based coating liquid composition comprising: (a) a sol-gel source material containing (i) at least a barium component selected from a group consisting of barium alkoxides, hydrolyzates of barium alkoxides and condensates of hydrolyzates of barium alkoxides and (ii) at least a titanium component selected from a group consisting of titanium alkoxides, hydrolyzates of titanium alkoxides and condensates of hydrolyzates of titanium alkoxides; and (b) a β-keto ester compound expressed by general formula (1) shown below: ##STR00001## where R.sub.1 and R.sub.2 independently represent respective alkyl groups having not less than 1 and not more than 6 carbon atoms.