There is provided a method of manufacturing a liquid ejection head. The liquid ejection head includes a recording device substrate, an electric wiring member configured to be connected to the recording device substrate at an electric connection portion, and a support member including a concave portion and a convex portion. The convex portion includes a first surface and a second surface. The method includes applying an adhesive to the surface of the concave portion on which the recording device substrate is to be placed and to the first surface, pressing the applied adhesive after the recording device substrate is placed on the surface of the concave portion on which the recording device substrate is to be placed, to fill, with the adhesive, a gap between the convex portion and the recording device substrate to a position higher than the first surface, and sealing the electric connection portion.

A substrate with an electrical connection section or a substrate for liquid ejection head comprises a wiring layer, a diffusion prevention layer laid on the wiring layer and a connection member laid on the diffusion prevention layer for establishing an electrical connection to an outside. An insulation layer having a wiring-layer-exposing opening is arranged on the wiring layer and the diffusion prevention layer is arranged in the opening, while the connection member is arranged on the diffusion prevention layer so as to cover an outer peripheral edge of the diffusion prevention layer.

A liquid jet device includes a head body configured to jet droplets from a nozzle, a frame at which the head body is positioned, a grounding portion configured to contact a first side surface of the head body in a removal direction from the frame to electrically couple the head body to the frame, and a first pin serving as a pin for positioning the head body with respect to the frame, wherein a contact position between the first side surface and the grounding portion and a position of the first pin overlap in a normal direction of the first side surface.

A liquid discharge head includes a plurality of discharge elements, a plurality of driving elements, a plurality of control circuits, a first ground wiring and a first power supply wiring configured to supply power to the plurality of discharge elements and the plurality of driving elements, and a second ground wiring and a second power supply wiring configured to supply power to the plurality of control circuits. The first ground wiring and the first power supply wiring include, in a first conductive layer of a plurality of conductive layers, a first wiring group extending in a first direction, and in a second conductive layer, a second wiring group extending in a second direction which intersects with the first direction. The second power supply wiring is arranged on one of the first conductive layer and the second conductive layer.

An actuator includes a substrate, a diaphragm on the substrate, a lower electrode on the diaphragm, a piezoelectric body on the lower electrode, and an upper electrode on the piezoelectric body. A ratio of lead (Pb) and zirconium (Zr) in atomic percent (atm %) present at a grain boundary in the piezoelectric body satisfies a relation of Pb/Zr>1.7.

A liquid discharge head includes a flow passage member, a sealing member, and an actuator member. The flow passage member is formed with individual flow passages each including a nozzle and a pressure chamber and the flow passage member has a surface on which the pressure chamber is open. The sealing member is arranged on the surface and seals the pressure chamber. The actuator member has a piezoelectric layer, a driving electrode, and a high electric potential portion. The piezoelectric layer is adhered to a first surface of the sealing member on a side opposite to the flow passage member, via a first adhesive having an insulating property. The driving electrode is arranged on a side opposite to the sealing member with respect to the piezoelectric layer at a position overlapped with the pressure chamber in a first direction orthogonal to the surface.

an adhesive having a first amount exists on a side of the first piezoelectric element line, of a joint of the wiring substrate and the pressure chamber substrate or the vibration plate, an adhesive having a second amount that is larger than the first amount exists on a side of the second piezoelectric element line of the wiring substrate, of the joint, and a first discharging element related to the first piezoelectric element line is different from a second discharging element related to the second piezoelectric element line.

There is provided a piezoelectric actuator, including: a vibration plate; a first piezoelectric body; a second piezoelectric body; a first electrode disposed on a first surface of the first piezoelectric body; a second electrode disposed on a second surface of the second piezoelectric body; an intermediate electrode disposed on an intermediate surface of the first piezoelectric body and overlapping with the first and second electrodes; an intermediate trace connected to the intermediate electrode on the intermediate surface and drawn out to one side in a first direction beyond the first piezoelectric body and the second piezoelectric body; a first trace overlapping with the intermediate trace in the thickness direction and being conducted with the intermediate trace; and a second trace overlapping with the intermediate trace in the thickness direction and being conducted with the intermediate trace.

An inkjet printer includes a support member configured to support a recording medium moving in a first direction, a carriage configured to reciprocate in a second direction orthogonal to the first direction and provided with a first electrical contact and a second electrical contact, a first recording head mounted on the carriage so as to contact the first electrical contact and configured to reciprocate together with the carriage, and an electrical contact protection member mounted on the carriage so as to contact the second electrical contact and configured to reciprocate together with the carriage. A shortest distance between the electrical contact protection member mounted on the carriage and the support member in a third direction is greater than a shortest distance between the first recording head mounted on the carriage and the support member in the third direction, the third direction being orthogonal to the first and second directions.

A liquid ejection head includes a recording element substrate including an energy generating element configured to generate energy for ejecting liquid from an ejection port; an electrical wiring board electrically connected to the recording element substrate to supply an electric signal for driving the energy generating element; a first support member supporting the recording element substrate; and a second support member supporting the first support member and having a greater linear expansion coefficient than the electrical wiring board, wherein the electrical wiring board is bonded to a first surface of the first support member and a second surface of the second support member, and an adhesive that bonds the electrical wiring board to the second surface has a lower elastic modulus than an adhesive that bonds the electrical wiring board to the first surface.