There is provided a liquid discharge head including a piezoelectric body having a plurality of individual electrodes and a first common electrode, and a plurality of conductor layers. The plurality of individual electrodes have first to fourth individual electrode arrays, and the first common electrode has first and second extending portions, a plurality of first projecting portions, and a plurality of second projecting portions. Each of the first projecting portions overlaps partially with one of the plurality of individual electrodes forming the second individual electrode array along the stacking direction, and each of the second projecting portions overlaps partially with one of the plurality of individual electrodes forming the third individual electrode array along the stacking direction. The plurality of conductor layers are formed between the plurality of first projecting portions and the plurality of second projecting portions, without contact with the first common electrode and without contact with each other.

S1 is a sum of the areas of a plurality of individual electrodes formed on a first plane of a piezoelectric body of a liquid discharge head, S2 is an area of a first common electrode formed on a second plane, S3 is an area of a second common electrode formed on a third plane, D1 is a distance between a neutral plane and the first plane in a stacking direction, D2 is the distance between the neutral plane and the second plane in the stacking direction, and D3 is the distance between the neutral plane and the third plane in the stacking direction. Then, D1S1+D2S2>D3S3 is satisfied. The liquid discharge head includes a plurality of conductor layers which are formed on the third plane, without contact with the second common electrode and without contact with each other.

An inkjet head including a flow path unit and a plurality of actuator units, each of the plurality of actuator units has a parallelogram shape defined by two sets of opposing sides, which is substantially parallel to a first direction and a second direction intersecting with each other along a plane, the side of the actuator unit parallel to the second direction is substantially parallel to that of an adjacent actuator unit and is shifted from that of the adjacent actuator unit in the second direction, the plurality of actuator units are inclined with respect to two contour lines of a flow path unit, the two contour lines being parallel with each other and extending in a longitudinal direction of the flow path unit, and centers of gravity of contours of the plurality of actuator units are arranged on substantially one straight line which is parallel to the contour lines.

A liquid discharging head includes a discharge port that discharges a liquid, a pressure chamber that communicates with the discharge port, and an energy generating element that is disposed in the pressure chamber. In the liquid discharging head, the discharge port is provided with a plurality of projections that project towards a central portion of the discharge port from an inner peripheral edge of the discharge port, and an interval between the projections at a location where the projections are closest to each other is 5 m or less.

A liquid ejection head includes a first channel member and a plurality of pressurizing parts. The first channel member includes a plurality of ejection holes, a common channel, a damper chamber, and a damper. The first channel member is configured by a plurality of flat plates including a first plate with the plurality of ejection holes and a second plate adjacent to this. The second plate includes a first part sandwiched between the damper chamber and the first plate. A covering layer is unevenly provided on the first surface of the first part.

A head includes the passageway member which is configured by a plurality of plates stacked through the adhesive and in which the ink passageways are configured by communication of the through holes individually formed in the plurality of plates to each other. The plurality of plates includes the resin plate and a plurality of metal plates. The resin plate does not have a relief groove for the adhesive. The plurality of metal plates include the eighth metal plate and/or ninth metal plate which is adhered to the resin plate and includes the relief groove for the adhesive on the resin plate side.

A liquid discharging head includes a discharge port that discharges a liquid, a pressure chamber that communicates with the discharge port, and an energy generating element that is disposed in the pressure chamber. In the liquid discharging head, the discharge port is provided with a plurality of projections that project towards a central portion of the discharge port from an inner peripheral edge of the discharge port, and an interval between the projections at a location where the projections are closest to each other is 5 m or less.

A channel member includes an integrating channel, a plurality of common channels, a plurality of individual channels, and a plurality of ejection ports. The integrating channel extends in a first direction. The plurality of common channels extends in a second direction, is spaced apart from each other in the first direction, and is individually connected to the integrating channel. The plurality of individual channels is connected to the respective plurality of common channels. Each of the plurality of ejection ports is linked with at least one corresponding individual channel. Each of the plurality of common channels includes a first connection region connected to the plurality of individual channels, and a second connection region connected to the integrating channel. Each of the plurality of common channels includes an opening in the second connection region linked with the integrating channel, and a damper in a portion facing the opening.

A liquid discharge head is configured to achieve decrease in temperature difference in the liquid discharge head, and includes a recording device including the liquid discharge head. The liquid discharge head includes a channel member having a plurality of discharge holes, a plurality of pressurization chambers, and a plurality of common channels, and a plurality of pressurizing parts. The plurality of common channels extends in a first direction and configures a common channel group aligned in a second direction crossing the first direction, the common channels are connected with the plurality of pressurization chambers disposed along the common channels among the plurality of pressurization chambers, and the channel member is disposed outside, in the second direction, with respect to the common channel group, and further includes a first end channel extending in the first direction, and the first end channel is lower in channel resistance than the common channels.

An ink-jet recording apparatus includes: a conveyor conveying a sheet; a recording head including first nozzles, second nozzles, first driving elements corresponding to the first nozzles respectively, and second driving elements corresponding to the second nozzles respectively; a controller; and a head driving circuit connected to the controller by first and second signal lines and a third signal line through which a clock signal is transmitted, and connected electrically to the first driving elements and the second driving elements. Each of the first and second driving elements is driven to jet an ink droplet from one of the first and second nozzles when driving voltage is applied from the head driving circuit. The controller repeatedly executes conveyance processing for conveying the sheet with the conveyor and recording processing in which pattern signals indicating patterns of the driving voltage are outputted serially and a jetting instruction signal is outputted serially.