There are provided a head chip, a liquid jet head, a liquid jet recording device, and a method of manufacturing the head chip each capable of preventing the short circuit of electrodes by ink to maintain an excellent ejection performance over a long period of time. The head chip according to an aspect of the present disclosure includes an actuator plate, a cover plate, and an intermediate plate. In the actuator plate, open apertures which communicate an inside and an outside of a non-ejection channel with each other are formed in both end portions of the non-ejection channel in a Y direction. In the actuator plate, open apertures which communicate an inside and an outside of a non-ejection channel with each other are formed in both end portions of the non-ejection channel in the Y direction.

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: individual channels; a first and second manifold channels; and a bypass channel. Each of the individual channels and the bypass channel are all connected to the first manifold channel on only one of an upper and lower sides of a central portion between upper and lower surfaces of the first manifold channel, and connected to the second manifold channel on only one of upper and lower sides of a central portion between upper and lower surfaces of the second manifold channel. A channel resistance of the bypass channel is smaller than that of the individual channels.

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 ceramic composition is represented by a composition formula A.sub.xBO.sub.3 and includes potassium sodium niobate containing K and Na that account for 80% or more of an amount of A-site elements and containing Nb that accounts for 70% or more of an amount of B-site elements. The piezoelectric ceramic composition contains Ta and Fe at a B-site.

A liquid ejection head includes actuators spaced along a first direction between a first edge and a second edge of a substrate in a second direction. Individual wirings are connected to a first terminal of an actuator and has a terminal portion at the first edge of the substrate. A common wiring has a first portion and a plurality of second portions. Each second portion is branched from the first portion in the second direction and individually connects to a second terminal of an actuator. The first portion extends along the first direction on the substrate and has a first end terminal and a second end terminal spaced from each other. A monitor terminal is at a position between the first and second end terminals. The monitor terminal extends in the second direction from the first edge of the substrate toward the first portion to which it is electrically connected.

In a piezoelectric ceramic composition including potassium sodium niobate, a transition temperature at which a phase transition between an orthorhombic crystal structure and a tetragonal crystal structure occurs lies in a temperature range of −20° C. or higher and 60° C. or lower. In the piezoelectric ceramic composition, αt/αO is 0.72 or more, where αO represents a coefficient of linear expansion determined when a crystal structure is orthorhombic in the temperature range, and αt represents a coefficient of linear expansion determined when a crystal structure is tetragonal in the temperature range.

A method of driving an inkjet head having a nozzle and a pressure generator, a plurality of droplets of the ink discharged in response to a series of the drive signals being caused to hit a recording medium to form a single pixel. The method includes, applying, to the pressure generator, the series of the drive signals including a first one of the drive signals that has a first voltage amplitude and a second one of the drive signals that has a second voltage amplitude larger than the first voltage amplitude. A last drive signal in the series of the drive signals is the second one of the drive signals. The first voltage amplitude and the second voltage amplitude are determined such that a ratio of (first voltage amplitude)/(second voltage amplitude) has a value corresponding to a specific gravity of the ink to be discharged.

According to an embodiment, a liquid ejection head includes a plurality of drive flow paths, a plurality of dummy flow paths, and a plurality of side walls. The drive flow paths connect to liquid ejection nozzles. The dummy flow paths connect to dummy nozzles. The dummy flow paths are adjacent the drive flow paths. The side walls are between the drive flow paths and the dummy flow paths and configured to change volumes of both the drive flow paths and the dummy flow paths in response to drive signals. An acoustic resonance period of liquid in the dummy flow paths is shorter than an acoustic resonance period of the liquid in the drive flow paths.

A modular inkjet printhead includes a plurality of printhead modules arranged end on end in a row. Each printhead module includes: a substrate having a plurality of longitudinal ink supply channels; a plurality of print chips mounted on a first face of the substrate, each print chip receiving ink from a respective ink supply channel; and a plurality of fingers extending longitudinally from opposite ends of each printhead module, each finger having an ink port extending away from a second face of the substrate opposite the first face, each ink port being in fluid communication with a respective ink supply channel Each ink supply channel is connected to a respective pair of ink ports at opposite ends of each printhead module and the fingers of neighboring printhead modules are interdigitated such that the ink ports of neighboring printhead modules overlap.

A printhead module includes: a monolithic substrate having alternate longitudinal slots and longitudinal ink supply channels defined through a thickness of the substrate and extending parallel with each other along a length of the substrate; and a plurality of rows of print chips mounted on a front face of the substrate, each row of print chips receiving ink only from a respective one of the ink supply channels. Each one of the longitudinal slots is configured to supply power and data only to a respective one of the rows of print chips.