An inkjet head including a flow path unit and a plurality of actuator units, each of the plurality of actuator units has a parallelogram shape defined by two sets of opposing sides, which is substantially parallel to a first direction and a second direction intersecting with each other along a plane, the side of the actuator unit parallel to the second direction is substantially parallel to that of an adjacent actuator unit and is shifted from that of the adjacent actuator unit in the second direction, the plurality of actuator units are inclined with respect to two contour lines of a flow path unit, the two contour lines being parallel with each other and extending in a longitudinal direction of the flow path unit, and centers of gravity of contours of the plurality of actuator units are arranged on substantially one straight line which is parallel to the contour lines.

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.

There is provided a liquid discharge apparatus configured to discharge a liquid, including a channel member for the liquid. The channel member is formed to include: a pressure chamber configured to contain the liquid; a nozzle configured to discharge the liquid; a connection channel connecting the pressure chamber and the nozzle; and a discharge channel which is connected to the connection channel so as to discharge the liquid in the connection channel or connected to the pressure chamber so as to discharge the liquid in the pressure chamber. An intersection line between an orthogonal plane orthogonal to an extending direction of the discharge channel and an upper surface of the discharge channel defining an upper portion of the discharge channel has an arc-like shape protruding upwardly.

A channel member of a liquid ejection head includes an ejection surface, an outer peripheral surface that is connected to an outer edge of the ejection surface and that faces outside of the ejection surface in a direction along the ejection surface, and a plurality of ejection holes that open in the ejection surface. The channel member includes a plurality of concave portions in the outer edge of the ejection surface, the plurality of concave portions being recessed in the ejection surface and being recessed in the outer peripheral surface. With the configuration, it is possible to collect, in the concave portions, a liquid (such as ink mist) that has leaked out from the ejection holes.

A piezoelectric actuator includes a first piezoelectric layer and a first electrode layer disposed on a surface of the first piezoelectric layer. The first electrode layer includes a trunk portion and a plurality of brunch portions branched from the trunk portion. The trunk portion includes a plurality of junction points from each of which a corresponding branch portion of the plurality of branch portions is branched, an end spaced from the plurality of junction points, and a first through hole positioned between the plurality of junction points and the end of the trunk portion. A first mark is positioned inside the first through hole.

A liquid discharge head includes: a channel member having a nozzle surface and a back surface disposed separately from the nozzle surface, the channel member formed having nozzles arranged in the nozzle surface, individual channels connected to the nozzles, first and second common channels connected to the individual channels, a first opening that is opened in the back surface and communicates with an end of the first common channel, and a second opening that is opened in the back surface and communicates with an end of the second common channel, and a filter member disposed on the back surface and having a filter that covers the first opening. The second opening is not covered with the filter, and an area of the first opening is larger than an area of the second opening.

There is provided a liquid discharge head including: first and second common channels extending in a first direction; and a plurality of individual channels each including: a supplying part, a descender part, and a returning part. The returning part includes: a throttle part and a wide part. Each of a plurality of nozzles is located at a position at which each of the plurality of nozzles overlaps with the wide part in a second direction. At a throttle-starting position which is a boundary between the throttle part and the wide part, a length in the second direction of the throttle part and a length in the second direction of the wide part are same.

An inkjet head including a flow path unit and a plurality of actuator units, each of the plurality of actuator units has a parallelogram shape defined by two sets of opposing sides, which is substantially parallel to a first direction and a second direction intersecting with each other along a plane, the side of the actuator unit parallel to the second direction is substantially parallel to that of an adjacent actuator unit and is shifted from that of the adjacent actuator unit in the second direction, the plurality of actuator units are inclined with respect to two contour lines of a flow path unit, the two contour lines being parallel with each other and extending in a longitudinal direction of the flow path unit, and centers of gravity of contours of the plurality of actuator units are arranged on substantially one straight line which is parallel to the contour lines.

A first channel member of a fluid discharge head includes a plurality of discharge holes, a plurality of pressurization chambers individually linked to the discharge holes, and first and second shared channels linked to the pressurization chambers. The first shared channel opens at a plurality of first openings linked to the pressurization chambers, includes a first connection region that is a range of distribution of the plurality of first openings in the channel direction of the first shared channel. The second shared channel opens at a plurality of second openings linked to the plurality of pressurization chambers. The second shared includes a second connection region that is a range of distribution of the plurality of second openings in the channel direction of the second shared channel. The first channel member further includes a bypass channel linked to the first and second connection regions in parallel with the pressurization chambers.

There is provided a liquid discharge head including a channel unit that includes plates stacked on top of each other in a first direction and is formed having individual channels, a first common channel, and a second common channel. The first and second common channels communicate with the individual channels. Each individual channel includes a nozzle, a pressure chamber, a descender, a first throttle channel, and a second throttle channel. The plates include a nozzle plate, a pressure chamber plate, and a first plate formed having a first through hole that constitutes part of the descender. A center portion of the nozzle is positioned at a side opposite to the second throttle channel in the second direction with respect to a center portion of the descender. The descender has a protruding channel portion that is formed in the first plate, is positioned at an end at the side opposite to the second throttle channel in the second direction, and protrudes toward the side opposite to the second throttle channel beyond any other portion of the descender.