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 print head includes a substrate having a hole, a circuit on the substrate, the circuit having traces and a hole corresponding to the hole in the substrate, the hole forming a fluid path, and a raised structure on the substrate around the fluid path, the raised structure positioned to seal the circuit from the fluid path.

A method for manufacturing a liquid ejection head including the steps of preparing a substrate including, on a surface of the substrate, a layer having a plurality of openings in which opening portions of supply portions are located and which are arrayed in an array direction and another opening which is different from the plurality of openings and is located beyond the array end portion in the array direction, and attaching a dry film for forming flow passages to the substrate and the layer.

An ink-jet recording head includes a plurality of recording element substrates each having an ejection pressure generating element configured to generate pressure for ejecting ink from an ink discharge port. The plurality of recording element substrates each include a first surface on which the corresponding ejection pressure generating element is disposed and a second surface, serving as an end surface intersecting with the first surface, being at least partially formed by etching.

A droplet generator for a continuous stream ink jet printhead includes an elongate cavity for containing ink and nozzle orifices in fluid communication with the cavity for passing the ink from the cavity to form jets. The nozzle orifices extend along a length of the cavity. A mounting plate provides a wall of the cavity opposite the nozzle orifices. A plurality of actuators is disposed in the cavity to vibrate the ink in the cavity such that each jet breaks up into ink droplets at substantially a same predetermined distance from the wall. Each of the plurality of actuators is integrally connected to the mounting plate by a membrane.

In a substrate, a first flow channel opened in a first surface of a silicon base material having a crystal orientation of <110>, and a second flow channel opened in a second surface of the silicon base material opposite the first surface are formed to communicate with each other. The second flow channel has an opening width narrower than an opening width of the first flow channel, and a groove portion shallower than a depth of the second flow channel is formed close to the opening of the second flow channel in a region that is inside the opening of the first flow channel and outside the opening of the second flow channel in the second surface.

A liquid ejection head has at least a structure including an ejection orifice forming member having an ejection orifice for ejecting a liquid and a flow path communicating with the ejection orifice and a flow path forming substrate having a liquid introduction flow path communicating with the flow path and supplying the liquid, and includes: a first titanium oxide film with a pure water contact angle of 40° or less; and a second titanium oxide film with a pure water contact angle of 70° or more, wherein the first titanium oxide film covers the structure including inner walls of the flow path and the liquid introduction flow path and is exposed in the flow path and the liquid introduction flow path, and the second titanium oxide film has a portion covering the first titanium oxide film in a vicinity of an opening end.

Provided is a liquid ejection device capable of ejecting a minute liquid droplet with stability, in which a capacity of a pressure chamber facing a second partition portion increases, and a capacity of the pressure chamber facing a first partition portion decreases, at a time when a voltage is applied so that a potential of a first electrode becomes lower than a potential of a second electrode, compared to a time when a voltage is applied so that the potential of the first electrode becomes the same as the potential of the second electrode, the first electrode and the second electrode being included in an electrode formed on each of both side surfaces of partitions.

A method is provided for manufacturing a piezoelectric device including a piezoelectric element that is disposed above a diaphragm and that has a multilayer structure including a first electrode disposed above the diaphragm, a piezoelectric layer disposed on the first electrode, and a second electrode disposed on the piezoelectric layer. The method includes forming the multilayer structure including the first electrode, the piezoelectric layer, and the second electrode above the diaphragm, forming a voltage application electrode extending outwardly from an end of the second electrode to cover a region located above the piezoelectric layer in an inactive section having no second electrode, applying a voltage between the first electrode and the second electrode, and removing the voltage application electrode.

Provided are a vibrating plate, a first electrode provided over the vibrating plate, a piezoelectric layer provided over the first electrode, and a second electrode provided over the piezoelectric layer are provided. The piezoelectric layer is interposed between the first electrode and the second electrode. The piezoelectric layer includes an active portion of which at least one end portion is defined by the first electrode, and a non-active portion provided on an outside of the end portion of the first electrode for defining the active portion. The vibrating plate includes a first vibration portion under the non-active portion and a second vibration portion on an outside of the first vibration portion. The second vibration portion includes a taper part having the thickness which is increased toward the first vibration portion.