In a case where air bubbles exist in ink at the time of circulating the ink within a liquid ejection module, the amount circulating ink runs short and stability of ejection is blocked. The liquid ejection module has: a pressure chamber that communicates with an ejection port and which stores a liquid; an energy generation element that produces energy for causing a liquid to be ejected from the ejection port; a supply flow path that supplies a liquid to the pressure chamber; a collecting channel that collects a liquid from the pressure chamber; a liquid sending chamber that connects to the collecting channel; a connection flow path that connects the liquid sending chamber and the supply flow path; and a liquid sending unit configured to circulate a liquid, and the liquid sending chamber has a continuously inclined structure.

A head module includes: a head including: a nozzle plate having a nozzle from which a liquid is to be discharged; a channel substrate including an individual channel communicating with the nozzle, the nozzle plate bonded to a first bonding surface of the channel substrate; and a cover covering at least one side of a discharge surface of the nozzle plate of the head. The channel substrate has a size larger than the nozzle plate, the cover has a second bonding surface bonded to the first bonding surface of the channel substrate at an outer region of the nozzle plate with an adhesive, the discharge surface of the nozzle plate is liquid-repellent, and the first bonding surfaces of the channel substrate and the second bonding surface of the cover are lyophilic.

In a liquid ejection head, an ejection pressure is applied to a pressure chamber for liquid ejection from a nozzle. A descender extends in a first direction and includes a first end connected to the pressure chamber and a second end. A communication passage is connected to the second end, extends in a second direction crossing the first direction, and has a first dimension in the first direction. The nozzle is positioned at the communication passage such that a shortest distance between an outer periphery thereof and a center of the second end is greater than 0.5 times a second dimension of the second end in the second direction. When viewed in the first direction, the center of the second end and a center of a cross-section defined by the nozzle to be orthogonal to an extending direction of the nozzle intersect an axis of the communication passage.

A liquid discharge head of the present disclosure includes a flow path member having a plurality of discharge holes, a plurality of pressure chambers, a plurality of first common flow paths, a plurality of second common flow paths, and a plurality of pressure sections. The first common flow paths and the second common flow paths are linked through a connection flow path outside a connection range C, the connection range C being linked through the pressure chambers. The flow path member is configured by laminating a plurality of flat plates. The connection flow path includes holes and/or grooves disposed in plates other than the common flow path plates that constitute the first common flow paths and the second common flow paths.

A piezoelectric element includes: a first electrode; an oxide layer formed on the first electrode; a piezoelectric layer formed on the oxide layer and containing potassium, sodium, and niobium; and a second electrode formed on the piezoelectric layer. When a potential difference of 10 V is applied between the first electrode and the second electrode, a current density of a leak current differs by 10,000 times or more between a case in which the first electrode is set at a high potential and a case in which the second electrode is set at a high potential.

A piezoelectric substrate includes: a substrate; a first electrode formed on the substrate; and a piezoelectric layer formed on the first electrode and containing potassium, sodium, and niobium. A full width at half maximum of an X-ray intensity peak on a plane (100) of the piezoelectric layer in a Psi axis-direction scan result of an X-ray diffraction measurement in which a surface of the piezoelectric layer is irradiated with X-rays at an angle of 54.74° from a direction perpendicular to the surface is more than 0° and 1.2° or less.

A liquid ejection head includes a supply manifold, a return manifold, a plurality of individual channels, and a connecting throttle channel. The supply manifold includes a supply port through which liquid is supplied from an exterior. The return manifold includes a return port through which liquid is discharged to the exterior. Each individual channel is connected, at an upstream end thereof, to the supply manifold and, at a downstream end thereof, to the return manifold. Each individual channel communicates with a corresponding one of nozzles and includes an individual throttle channel Through the connecting throttle channel, adjacent ones of the individual throttle channels communicate with each other. The connecting throttle channel has a channel resistance less than or equal to a channel resistance of each individual throttle channel.

Printheads and a method of operating a printhead. In one embodiment, a printhead comprises a plurality of jetting channels, a manifold internal to the printhead that is configured to convey a print fluid from an inlet of the printhead to the jetting channels, and an internal pump disposed at the manifold. The internal pump is configured to draw the print fluid into the manifold through the inlet, and to discharge the print fluid from the manifold to the jetting channels.

In one example, a wedge shaped carriage to carry a printhead back and forth over a print substrate during printing.

There is provide a liquid discharge head including: a supply manifold; a feedback manifold; and a plurality of individual flow channels having: a supply portion, a descender portion, and a feedback portion. The supply manifold has a plurality of supply ports, and the feedback manifold has a plurality of feedback ports. At least part of the supply manifold overlaps with the feedback manifold in the second direction. The plurality of pressure chambers have first pressure chambers forming a first pressure chamber array and second pressure chambers forming a second pressure chamber array. The first pressure chamber array is arranged at one side, of the supply manifold, in a third direction and the second pressure chamber array is arranged at the other side, of the supply manifold, in the third direction. The first pressure chamber array and the second pressure chamber array are connected to the supply manifold.