A printhead module includes a plurality of rows of printhead nozzles, at least some of the rows including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed, wherein the displaced row portions of at least some of the rows are different in length than the displaced row portions of at least some of the other rows.

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.

A liquid ejection head includes a plurality of ejection ports, a plurality of pressure chambers each communicating with each of the ejection ports, a piezoelectric actuator constituting part of walls of the pressure chambers, and a common liquid chamber containing liquid to be supplied to the pressure chambers. The pressure chambers and the common liquid chamber are opposed with an opposing wall interposed therebetween. The opposing wall faces the wall of the pressure chambers constituted by the piezoelectric actuator A reinforcing portion that supports the opposing wall is provided in the common liquid chamber.

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 piezoelectric ceramic contains a main component, Mn as a first auxiliary component, and a second auxiliary component containing at least one element selected from the group consisting of Cu, B, and Si. The main component contains a perovskite metal oxide having the following general formula (1):
(Ba.sub.1-xCa.sub.x).sub.a(Ti.sub.1-yZr.sub.y)O.sub.3(0.100x0.145,0.010y0.039)(1) The amount b (mol) of Mn per mole of the metal oxide is in the range of 0.0048b0.0400, the second auxiliary component content on a metal basis is 0.001 parts by weight or more and 4.000 parts by weight or less per 100 parts by weight of the metal oxide, and the value a of the general formula (1) is in the range of 0.9925+ba1.0025+b.

The present invention aims at providing a piezoelectric substrate that is less susceptible to the influence of adhesive after being subjected to connection, as well as an assembly, a liquid discharge head, and a recording device, each of which uses the piezoelectric substrate. The piezoelectric substrate of the present invention is a flat plate shaped piezoelectric substrate including a piezoelectric ceramic layer, a plurality of first electrodes, a second electrode, and a third electrode. The second electrode includes an outer peripheral part disposed so as to surround the entirety of the first electrodes, and a protrusion extending from the outer peripheral part toward the inside of the outer peripheral part when the piezoelectric substrate is viewed from above. The second electrode and the third electrode are electrically connected to each other at the protrusion. The outer peripheral part is used for an electrical connection with the outside.

An element substrate for a liquid ejecting head includes a substrate, an element forming layer on the substrate, and a discharge port forming member formed of an insulating member on the element forming layer. The element forming layer includes an energy generating element configured to provide energy to a liquid for ejection. The discharge port forming member includes a discharge port forming surface having discharge ports through which the liquid is ejected and an exterior side surface positioned between the discharge port forming surface and the element forming layer. The exterior side surface has a first edge facing the element forming layer. The element substrate further includes a conductive layer disposed between the first edge and the element forming layer and grounded.

An individual electrode formed on an inside surface of a dummy channel, a common electrode formed on an inside surface of a discharge channel, an individual pad formed in a connection groove of an actuator plate, connecting the individual electrodes opposed in an X direction across the discharge channel, and to which an FPC is connected, a shallow groove portion opened toward a rear side on the actuator plate, a common pad formed in the shallow groove portion, and connecting the common electrode and the FPC through the shallow groove portion, and a dividing groove formed in a corner portion made by a surface and a rear-side end surface of the actuator plate, and dividing the common pad from the individual pad.

The present invention aims at providing a piezoelectric substrate that is less susceptible to the influence of adhesive after being subjected to connection, as well as an assembly, a liquid discharge head, and a recording device, each of which uses the piezoelectric substrate. The piezoelectric substrate of the present invention is a flat plate shaped piezoelectric substrate including a piezoelectric ceramic layer, a plurality of first electrodes, a second electrode, and a third electrode. The second electrode includes an outer peripheral part disposed so as to surround the entirety of the first electrodes, and a protrusion extending from the outer peripheral part toward the inside of the outer peripheral part when the piezoelectric substrate is viewed from above. The second electrode and the third electrode are electrically connected to each other at the protrusion. The outer peripheral part is used for an electrical connection with the outside.

A first active region is made of a piezoelectric overlaps a midsection of a pressure chamber when viewed in plan through a pressure applying surface. A second active region is made of a piezoelectric member closer than the first active region to the pressure applying surface. The second active region extends over both a peripheral section of the pressure chamber and an outer region located outside the pressure chamber when viewed in plan through the pressure applying surface. A driver controls intensity of a first electric field applied to the first active region and intensity of a second electric field applied to the second active region such that the time period over which the first active region contracts and the time period over which the second active region contracts overlap or coincide with each other. The first electric field is more intense than the second electric field.