A liquid discharge head includes: a first pressure chamber group formed by pressure chambers arranged in a first direction; a second pressure chamber group formed by pressure chambers arranged in the first direction, and disposed side by side with the first pressure chamber group in a second direction; a first common channel extending in the first direction and communicating with the pressure chambers composing the first pressure chamber group; a second common channel extending in the first direction and communicating with the pressure chambers composing the second pressure chamber group; a first dummy pressure chamber disposed on one side in the first direction relative to the first pressure chamber group; and a second dummy pressure chamber disposed on the one side in the first direction relative to the second pressure chamber group.

A liquid circulation device includes a liquid chamber that stores a liquid that is to be supplied to a liquid discharge head. A pipeline through which the liquid can be circulated between the liquid chamber and the liquid discharge head is provided. A heater heats the liquid circulating in the pipeline. A first temperature sensor measures the temperature of the heater, and a second temperature sensor measures the temperature of the liquid in the pipeline. A controller controls the heating of the heater based on the liquid temperature measured by the second temperature sensor. The controller also monitors a change in the measured temperature of the heater over time and turns off the heating of the heater when the monitored change satisfies a predetermined stop condition.

The head chip includes an actuator plate having ejection channels and non-ejection channels extending in a Y direction and arranged alternately in an X direction, an intermediate plate overlapped with the actuator plate in a Z direction, and provided with communication holes communicated with the ejection channels and through holes communicated with the non-ejection channels, and a nozzle plate overlapped with the intermediate plate in the Z direction in a state of closing the through holes, and provided with nozzle holes which are communicated with the communication holes, jet liquid contained in the ejection channels, and are formed at positions corresponding to the ejection channels. The non-ejection channels are communicated with an outside of the head chip. The through holes are each disposed at an inner side in the X direction of the inner surfaces extending in the Y direction of the non-ejection channel viewed from the Z direction.

Misalignment of printing positions between print heads associated with thermal expansion is reduced without increasing a data processing load. To this end, printing element substrates in a reference head and an adjustment target head are adjusted to a target temperature, and a liquid is circulated through the print element substrates. After thermal expansion of the reference head and the adjustment target head reaches a steady state, a first printing region being a printing region of the reference head and a second printing region being a printing region of the adjustment target head in a longitudinal direction are obtained from an image printed by using all printing elements. Then, used regions to be used for actual printing are set among the printing elements arranged on the reference head and the adjustment target head based on the first printing region and the second printing region.

A recording apparatus includes: a liquid ejection head including a heating element, a first protection layer that blocks contact between the heating element and liquid, a second protection layer that covers at least a portion of the first protection layer to be heated by the heating element and that functions as a first electrode, a second electrode that is electrically connected to the first electrode through the liquid, an ejection port that ejects the liquid, and a temperature detection element that corresponds to the heating element, and a detection unit configured to detect a feature point in a temperature curve that indicates a relationship between time and temperature, in which a combination of a potential set for the first electrode and a potential set for the second electrode in a case where printing is performed varies from that in a case where the detection unit detects the feature point.

There are provided a method of manufacturing a head chip capable of suppressing the occurrence of the failure in the process of forming the actuator plate to thereby increase the yield ratio, and a method of manufacturing a liquid jet head using the above method of manufacturing a head chip. The method of manufacturing a head chip according to an embodiment of the present disclosure is a method of manufacturing a head chip having an actuator plate adapted to apply pressure to liquid so as to jet the liquid. Forming the actuator plate includes forming a plurality of grooves on a surface of a piezoelectric substrate having one end and the other end so as to extend from the one end side toward the other end side, forming a conductive film on the surface of the piezoelectric substrate provided with the plurality of grooves, forming a laser processing area in the conductive film between the grooves adjacent to each other by performing laser processing from a start point on the one end side of the piezoelectric substrate to an end point on the other end side, and forming a surface removal area in at least a part including the start point and the end point out of the surface of the piezoelectric substrate by performing surface removal processing in a direction crossing the direction in which the laser processing is performed.

A liquid discharging head includes: individual channels aligned in a first direction; and a first common channel and a second common channel extending in the first direction. Each of the individual channels includes a nozzle, a first pressure chamber and second pressure chamber arranged side by side in the first direction, and a connecting channel connecting the nozzle, the first pressure chamber and the second pressure chamber to one another. A first actuator and a second actuator are provided on the first pressure chamber and the second pressure chamber, respectively. The first common channel communicates with the first and second pressure chambers; and the second common channel communicates with the connecting channel.

A liquid ejecting head including: an individual flow path row in which a plurality of individual flow paths communicating with a nozzle that ejects a liquid in a first axis direction are arranged in parallel along a second axis orthogonal to a first axis, and a first common liquid chamber communicating with the plurality of individual flow paths, in which each of the plurality of individual flow paths has a pressure chamber that stores a liquid.

A fluid circulation and ejection system may include a microfluidic die, a single orifice fluid ejector having a drive chamber in the microfluidic die and a pressurized fluid source remote from the microfluidic die to create a pressure gradient across the drive chamber to circulate fluid across the drive chamber.

A liquid ejecting head includes nozzles configured to eject liquid, pressure chambers communicating with the nozzles, the pressure chambers being configured to generate pressure for ejecting the liquid, a first liquid chamber configured to store the liquid to be supplied to the pressure chambers, a second liquid chamber configured to store the liquid that passed through the pressure chambers, first communication paths communicating with the pressure chambers from the first liquid chamber, second communication paths respectively communicating with the second liquid chamber from between the pressure chambers and the nozzles in which flow path resistance in the first communication paths is higher than flow path resistance in the second communication paths.