A liquid discharge head is provided, the liquid discharge head comprising a plurality of individual channels, a first manifold connected to the plurality of individual channels, a second manifold connected to the plurality of individual channels, and a bypass channel connecting the first manifold and the second manifold and being distinct from the individual channels. A flow channel resistance Rct brought about by the plurality of individual channels, a flow channel resistance Rbp of the bypass channel, a bending loss ΔP provided when the liquid flows from the first manifold via the bypass channel to the second manifold, and a flow rate Q of the liquid flowing through the bypass channel fulfill a relationship of:
0.5<[Rct/(Rbp+(ΔP/Q))]<2.0.

A liquid discharging head includes: a first individual channel array constructed of individual channels aligned in a first direction; and a second individual channel array constructed of individual channels aligned in the first direction. The second individual channel array is arranged side by side to the first individual channel array in a second direction orthogonal to the first direction. Each of the individual channels includes: a nozzle, at least two pressure chambers communicating with the nozzle and arranged in the first direction, and a connecting channel connecting the nozzle and the at least two pressure chambers. The connecting channel has one end in a third direction communicating with the at least two pressure chambers, and the other end in the third direction communicating with the nozzle.

An example recirculation fluid ejection device includes a first unit droplet generator including a first actuator and a first nozzle between a first and a second fluid feed hole, the first fluid feed hole located on a first channel and the second fluid feed hole and a first pump located on a second channel. The example device includes a second unit droplet generator including a second actuator and a second nozzle between a third and a fourth fluid feed hole, the third feed hole located on a third channel and the fourth fluid feed hole and a second pump located on a fourth channel. The first and the second actuators eject fluid at substantially the same backpressure. A first pressure measurable at an inlet of the first channel and the third channel are different from a second pressure measurable at an outlet of the second channel and the fourth channel.

A liquid ejecting device includes a flow path member, an actuator, a pump, and a controller. The flow path member includes a flow path configured to direct flow of a pseudoplastic liquid through the flow path member. The actuator is configured to cause droplets to be ejected. The pump is configured to cause the liquid to flow sequentially through a supply reservoir, a plurality of supply manifolds, a plurality of supply flow paths, and a plurality of pressure chambers. The controller is configured to adjust a flow rate of the liquid to a prescribed target flow rate. The flow path has a flow path shape in which an average viscosity of the liquid in the plurality of supply flow paths is less than or equal to half an average viscosity of the liquid in the plurality of supply manifolds when the flow rate is equal to the target flow rate.

The individual flow path includes a nozzle communicating with an outside, a first flow path, in the middle of which the nozzle is disposed and which extends in a first direction that is an in-plane direction of a nozzle surface of the nozzle plate in which the nozzle opens, a second flow path coupled to the first flow path and extending in a second direction other than the first direction, a third flow path coupled to the second flow path and extending in the third direction other than the second direction, and a pressure chamber which is disposed in the third flow path and in which a pressure change is induced by the energy generating element. A cross-sectional area of the first flow path is smaller than a cross-sectional area of the second flow path.

A liquid discharge head is configured to discharge a liquid, and the liquid discharge head includes an actuator substrate and a holding substrate bonded to the actuator substrate. The actuator substrate includes a pressure generator, and a wiring electrode configured to electrically connect the pressure generator and an exterior of the liquid discharge head. The holding substrate includes an opening configured to expose the wiring electrode to the exterior of the liquid discharge head, and a detection surface adjacent to the opening, the detection surface having a higher reflectance than a surface of the wiring electrode of the actuator substrate.

The interface region may include a region in which first intensity is higher than second intensity and in which the first intensity is higher than third intensity, where a degree of orientation of the (−211) crystal face of the second layer is denoted as the first intensity, the degree of orientation of the (−111) crystal face of the second layer is denoted as the second intensity, and the degree of orientation of the (002) crystal face of the second layer is denoted as the third intensity. The surface-layer region may include a region in which the first intensity is higher than the third intensity and in which the second intensity is higher than the third intensity.

A liquid discharging head includes a stacked body in which plates are adhered to each other by an adhesive. The stacked body is provided with: individual channels including nozzles and pressure chambers, respectively, and aligned in a predetermined aligning direction, the pressure chambers being configured to be pressurized to discharge liquid from the nozzles; a supply manifold being communicated with the individual channels and supplying the liquid to the individual channels; a return manifold being communicating with the individual channels and configured to allow the liquid, which flows in the individual channels and which is not discharged from the nozzles, to flow therethrough; and a dummy channel arranged side by side with the individual channels in the aligning direction. The dummy channel is positioned at outside with respect to an outermost individual channel in the aligning direction.

A liquid discharge head includes a first head tank configured to store a liquid, a first intermediate chamber storing the liquid flowing from the first head tank, a second intermediate chamber storing the liquid flowing from the first intermediate chamber in a flow direction of the liquid, a second head tank storing a liquid flowing from the second intermediate chamber, a first communicating part communicating with the first head tank and the first intermediate chamber, a second communicating part communicating with the second head tank and the second intermediate chamber, and a discharge part configured to discharge a liquid supplied from the first intermediate chamber and the second intermediate chamber.

Provided is a liquid ejection head including plural liquid chambers arranged in rows, each liquid chamber being provided with an orifice configured to eject liquid filling the liquid chamber and an ejection energy generating element, wherein the liquid ejection head includes: a liquid supply path that extends in a direction that the plural liquid chambers are arranged and individually communicates with the plural liquid chambers; a direction change flow path that communicates with the liquid supply path and extends in a direction transverse to the liquid supply path; and a common supply flow path that communicates with the direction change flow path and extends in a direction transverse to the direction change flow path, such that the direction change flow path includes a body portion and at least one grooved flow path, which is narrower than the body portion.