A print head includes: an integrated circuit apparatus that switches whether or not to supply drive signals to a plurality of piezoelectric elements, and includes a first circuit block that switches whether or not to supply the drive signal, a second circuit block that switches whether or not to supply the drive signal, a third circuit block that switches whether or not to supply the drive signal, a fourth circuit block, and a first buffer area, a second buffer area, and a third buffer area in which no circuit element is located, in which the first buffer area is located between the first circuit block and the fourth circuit block, the second buffer area is located between the second circuit block and the fourth circuit block, and the third buffer area is located between the third circuit block and the fourth circuit block.

A flow path structure including a first-flow path includes a first-flow path member that including a first-resin member made of a resin and a first-film member having a film, a second-flow path member laminated on the first-flow path member and adhered to the first-flow path member, in which the first-resin member includes a first-front surface that is a surface facing the second-flow path member and that is provided with a first-recessed portion, the first-film member includes a first-surface and a second-surface that is opposite from the first-surface, at least a portion of the first-surface is in close contact with a front surface of the first-resin member inside the first-recessed portion, and the second-surface and the second-flow path member define at least a portion of the first-flow path in a region overlapping the first-recessed portion in a laminating direction of the first-flow path member and the second-flow path member.

A method of bonding two components includes plating a first of the components with a first silver layer, a tin layer, and a second silver layer, plating a second of the components with silver, inserting the first and second components into a pre-heated press, and applying pressure to the components causing the components to bond. A stack of layers has a first component layer, a first silver layer, a tin layer, a second silver layer, a second component silver layer, and a second component layer.

A head chip, a liquid jet head, and a liquid jet recording device each capable of achieving a reduction in size and an increase in nozzle density are provided. The head chip according to an aspect of the present disclosure includes a flow channel member having a flow channel formation area including a flow channel through which liquid flows, and a pressure chamber which is communicated with the flow channel, and in which the liquid is contained, an actuator plate which is stacked on the flow channel member in a state of being opposed to the pressure chamber in a first direction, a drive electrode which is formed on a surface facing to the first direction in the actuator plate, and which is configured to deform the actuator plate in the first direction so as to change a volume of the pressure chamber, and a pad which is formed on a pad formation surface, and which is coupled to the drive electrode, and on which external wiring is mounted, wherein the pad formation surface is an area overlapping the flow channel formation area when viewed from the first direction, and the pad formation surface is disposed so as to face to an opposite side in the first direction to the flow channel member.

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.

A piezoelectric actuator array includes a substrate plate with a number of signal leads and at least one common lead, and a number of piezoelectric bodies arranged in a row on one surface of the substrate plate and formed by dividing a common piezoelectric block. The piezoelectric bodies include a number of active bodies each of which has, on a first side of the row, a signal electrode in contact with one of the signal leads and, on an opposite second side of the row, a common electrode in contact with the common lead. The substrate plate has at least one connector lead disposed on the first side of the row and electrically connected to the common lead on the second side of the row. At least one piezoelectric body has a conductive outer surface layer that establishes an electrically conductive path from the connector lead to the common lead.

There is provided a method for producing a liquid transport apparatus includes: a pressure chamber plate partially defining a pressure chamber that communicates with a nozzle for ejecting liquid; an insulating ceramics layer located on a surface of the pressure chamber plate to cover the pressure chamber; a piezoelectric layer located on the insulating ceramics layer; and a first electrode located on the piezoelectric layer. The method includes: forming the insulating ceramics layer on the pressure chamber plate by heating an insulating ceramic material; forming the piezoelectric layer and the first electrode on the insulating ceramics layer; forming the piezoelectric layer including annealing the piezoelectric layer at the annealing temperature; and forming the pressure chamber by removing a part of the pressure chamber plate so that a part of the insulating ceramics layer is exposed on the pressure chamber.

A piezoelectric device includes a diaphragm, a piezoelectric actuator, and an orientation layer between the diaphragm and the piezoelectric layer. The piezoelectric actuator has a first electrode, a piezoelectric layer, and a second electrode, with the first electrode, a piezoelectric layer, and a second electrode on the diaphragm. The orientation layer is a stack of two or more tiers.

A liquid ejection head includes a first substrate having a first surface and a second surface opposite the first surface, the first surface having a structure, a second substrate having a second surface facing the first surface of the first substrate, and a third substrate having a first surface facing the second surface of the first substrate. The first, second, and third substrates are joined together by an adhesive. The second surface of the first substrate has an opening located in a region on a rear side of the structure and having corners each having a curvature radius R2. The second surface of the second substrate has an opening in a region facing the structure and having corners each having a curvature radius R1. The curvature radii R1 and R2 satisfy R1<R2.

A liquid circulation device includes a circulation passage, a liquid feeding device, a pressure sensor, and control circuitry. Through the circulation passage, liquid circulates to be supplied to and collected from a circulatory liquid discharge head. The liquid feeding device is configured to circulate the liquid through the circulation passage. The pressure sensor is configured to detect a pressure of the circulation passage. The control circuitry configured to acquire a characteristic indicating a relationship among a drive amount of the liquid feeding device, discharge information of the liquid discharged from the liquid discharge head, and a pressure detection value of the circulation passage; and change, based on the characteristic acquired, at least one of a control parameter and a calculation expression used to control the liquid feeding device.