An electrical circuit for measuring the shape of a voltage waveform in a print head of a printer includes an integrated circuit for generating one or more voltage amplitude waveforms. The electrical circuit includes an inkjet drop forming unit including a plurality of inkjet chambers, wherein each of the plurality of inkjet chambers includes a piezoelectric actuator and an ink nozzle, and a connecting circuit between the integrated circuit and the inkjet drop forming unit suitable for applying one of the one or more voltage amplitude waveforms generated by the integrated circuit to the piezoelectric actuator in one of the plurality of inkjet chambers. In order to measure the shape of the one or more generated voltage amplitude waveforms via capacitive crosstalk, the electrical circuit also includes a conductor in physical proximity to the connecting circuit.

A liquid discharge head includes an actuator base, a case member, and a nozzle plate. The actuator base includes a plurality of grooves space from each other in a first direction. Each of the grooves extends in a second direction. The actuator base is formed of a piezoelectric ceramic material. The case member includes a frame portion spaced from the actuator base in the second direction. The frame portion has an end surface in the third direction that is level with an end surface of the actuator base in the third direction. The frame portion is formed of a ceramic material having aluminum titanate as a main component. The nozzle plate is contacting the end surface of the frame portion and the end surface of the actuator base.

In order to provide a liquid ejection device capable of ejecting a minute liquid droplet with stability, an end surface of a first partition portion is fixed to a plate with a first adhesive layer, an end surface of a second partition portion is fixed to the plate with a second adhesive layer, and an elastic coefficient of the first adhesive layer is smaller than an elastic coefficient of the second adhesive layer.

Provided is a lead-free piezoelectric material having satisfactory piezoelectric constant and mechanical quality factor in a device driving temperature range (−30° C. to 50° C.) The piezoelectric material includes a main component containing a perovskite-type metal oxide represented by Formula 1, a first auxiliary component composed of Mn, and a second auxiliary component composed of Bi or Bi and Li. The content of Mn is 0.040 parts by weight or more and 0.500 parts by weight or less based on 100 parts by weight of the metal oxide on a metal basis. The content of Bi is 0.042 parts by weight or more and 0.850 parts by weight or less and the content of Li is 0.028 parts by weight or less (including 0 parts by weight) based on 100 parts by weight of the metal oxide on a metal basis. (Ba.sub.1-xCa.sub.x).sub.a(Ti.sub.1-yZr.sub.y)O.sub.3 . . . (1), wherein, 0.030≦x<0.090, 0.030≦y≦0.080, and 0.9860≦a≦1.0200.

A liquid discharge head may reduce possibility that pressure from a discharge unit reaches a third channel and a fourth channel. The liquid discharge head includes a plurality of discharge units each including a discharge hole, a pressurization chamber communicating with the discharge hole, a first channel for liquid supply to the pressurization chamber, and a second channel for liquid collection from the pressurization chamber, a pressurizing part configured to pressurize the pressurization chamber, a third channel connected commonly to the first channels of the plurality of discharge units, the third channel for liquid supply to the discharge units, a fourth channel connected commonly to the second channels of the plurality of discharge units, the fourth channel for liquid collection from the discharge units, and a fifth channel connecting the discharge units and having channel resistance larger than channel resistance of the first channel and the second channel.

A liquid ejection head has a base plate with an actuator on an upper surface. Pressure chambers are formed in the actuator. A first common chamber connects to a first side of the pressure chambers, and a second common chamber connects to a second side. A nozzle plate is on an upper surface side of the actuator and has nozzles at positions corresponding to the pressure chambers. A supply hole is in the base plate and connected to the first common chamber. A discharge hole is in the base plate and connected to the second common chamber. A manifold is on a lower surface of the base plate. The manifold has a supply flow path for supplying liquid to the supply hole, a discharge flow path for receiving liquid from the discharge hole, and a temperature control flow path through which a temperature control liquid can flow.

An inkjet head manufacturing method for an inkjet head that includes a head chip including: a nozzle ejecting ink; and a flow path substrate including an ink flow path which communicates with the nozzle and through which the ink flows, the method including: composite substrate manufacturing that is manufacturing a composite substrate including a plurality of regions which forms flow path substrates by being split; first protective film forming that is forming a first protective film on a surface of the composite substrate and an inner wall surface of the ink flow path; splitting that is splitting the composite substrate into the flow path substrates; and second protective film forming that is forming a second protective film on at least an exposed face in a split face of the flow path substrate generated in the splitting, the exposed face being exposed in a surface of the head chip.

According to an embodiment, a liquid ejection head includes a plurality of drive flow paths, a plurality of dummy flow paths, and a plurality of side walls. The drive flow paths connect to liquid ejection nozzles. The dummy flow paths connect to dummy nozzles. The dummy flow paths are adjacent the drive flow paths. The side walls are between the drive flow paths and the dummy flow paths and configured to change volumes of both the drive flow paths and the dummy flow paths in response to drive signals. An acoustic resonance period of liquid in the dummy flow paths is shorter than an acoustic resonance period of the liquid in the drive flow paths.

In a liquid ejection head, an ejection pressure is applied to a pressure chamber for liquid ejection from a nozzle. A descender extends in a first direction and includes a first end connected to the pressure chamber and a second end. A communication passage is connected to the second end, extends in a second direction crossing the first direction, and has a first dimension in the first direction. The nozzle is positioned at the communication passage such that a shortest distance between an outer periphery thereof and a center of the second end is greater than 0.5 times a second dimension of the second end in the second direction. When viewed in the first direction, the center of the second end and a center of a cross-section defined by the nozzle to be orthogonal to an extending direction of the nozzle intersect an axis of the communication passage.

A stress caused in an actuator member with respect to input or output of heat is reduced. There is provided a liquid jet head including an actuator member having a pressure chamber, a low rigidity support part which is disposed at one side with respect to the actuator member, and is coupled to the actuator member, and a high rigidity support part which is disposed at the other side opposite to the one side with respect to the actuator member, and is coupled to the actuator member. The high rigidity support part has a high rigidity part which includes a head constituent member of the liquid jet head higher in linear expansion coefficient and Young's modulus than the actuator member, and which reduces a thermal deformation of the high rigidity support part in a direction of extension or contraction of the actuator member with respect to input or output of heat to or from the liquid jet head to be smaller than a thermal deformation exhibited in the direction of the extension or the contraction by the head constituent member with respect to the input or the output of the heat. The low rigidity support part is lower in rigidity in the direction of the extension or the contraction than the actuator member.