An element substrate of multi-layer structure, comprising an electrothermal transducing element formed in a first layer, a protective film covering the electrothermal transducing element, an anti-cavitation film formed on the protective film, a first electrical wire formed in the same layer as the anti-cavitation film, arranged to be separated from the electrothermal transducing element, and electrically connected to at least one end of the electrothermal transducing element, a second electrical wire on an opposite side, in relation to the electrothermal transducing element, to the protective film, and formed in a second layer, and a first connection member that extends between the first and second layers, and that electrically connects the first and second electrical wires.

An inkjet head includes a head chip and an ink chamber. The head chip has a nozzle substrate provided with nozzles which discharge ink. The ink chamber is located over the head chip. In the ink chamber, the ink to be supplied to the nozzles is stored. The inkjet head is mounted on a mounting member. Between the nozzle substrate and the ink chamber, the inkjet head has a position reference substrate provided with butting parts. The butting parts are butted against the mounting member to position the inkjet head when the inkjet head is mounted on the mounting member.

An element substrate of multi-layer structure, comprising an electrothermal transducing element formed in a first layer, a protective film covering the electrothermal transducing element, an anti-cavitation film formed on the protective film, a first electrical wire formed in the same layer as the anti-cavitation film, arranged to be separated from the electrothermal transducing element, and electrically connected to at least one end of the electrothermal transducing element, a second electrical wire on an opposite side, in relation to the electrothermal transducing element, to the protective film, and formed in a second layer, and a first connection member that extends between the first and second layers, and that electrically connects the first and second electrical wires.

Provided is a liquid ejection head substrate, in which a plurality of units are arranged. Each of the units includes: a pressure generating element formed on a first surface of a support substrate; and a pair of independent liquid chambers, which are formed on both sides of the pressure generating element so as to be opposed to each other, and are opened to the first surface of the support substrate. The liquid ejection head substrate includes, in the support substrate: a first common liquid chamber communicating to a plurality of independent liquid chambers on one side of the pair of independent liquid chambers; a second common liquid chamber communicating to a plurality of independent liquid chambers on another side of the pair of independent liquid chambers; and a partition wall separating the first common liquid chamber and the second common liquid chamber from each other.

The liquid ejection head includes a wall member having formed therein a void for communicating between a first liquid chamber and a second liquid chamber; a first energy generation element to eject the liquid in the first liquid chamber; a second energy generation element to eject the liquid in the second liquid chamber; a first electrode arranged in a vicinity of the first energy generation element in the first liquid chamber; a second electrode for forming, between the first electrode and the second electrode, an electric field in liquid inside the first liquid chamber; and a supply port which supplies liquid to the first energy generation element. The wall member includes a channel wall defining a channel through which the second liquid chamber, the void, and the supply port communicate, and the second electrode is arranged between the second liquid chamber and the supply port in the channel.

Provided is a liquid ejection head substrate, in which a plurality of units are arranged. Each of the units includes: a pressure generating element formed on a first surface of a support substrate; and a pair of independent liquid chambers, which are formed on both sides of the pressure generating element so as to be opposed to each other, and are opened to the first surface of the support substrate. The liquid ejection head substrate includes, in the support substrate: a first common liquid chamber communicating to a plurality of independent liquid chambers on one side of the pair of independent liquid chambers; a second common liquid chamber communicating to a plurality of independent liquid chambers on another side of the pair of independent liquid chambers; and a partition wall separating the first common liquid chamber and the second common liquid chamber from each other.

To make it possible to eject a difference in a change of temperature of liquid accompanying ejection of ink between normal ejection and ejection failure. The liquid ejection apparatus includes: a driving unit configured to drive a heating element; and a detection unit configured to detect an ejection state of the liquid ejection head based on an output from a temperature detection element provided in the liquid ejection head, wherein the liquid ejection head includes, in correspondence to the ejection port: a foaming chamber communicating with the ejection port; a first heating element for ejecting liquid by providing thermal energy to liquid in the foaming chamber; the temperature detection element for detecting temperature in the foaming chamber; and a second heating element generating thermal energy and arranged closer to the temperature detection element than the first heating element.

An inkjet head includes a head chip and an ink chamber. The head chip has a nozzle substrate provided with nozzles which discharge ink. The ink chamber is located over the head chip. In the ink chamber, the ink to be supplied to the nozzles is stored. The inkjet head is mounted on a mounting member. Between the nozzle substrate and the ink chamber, the inkjet head has a position reference substrate provided with butting parts. The butting parts are butted against the mounting member to position the inkjet head when the inkjet head is mounted on the mounting member.

The liquid ejection head includes: a wall member having formed therein a void for communicating between a first liquid chamber and a second liquid chamber; a first energy generation element to eject the liquid in the first liquid chamber; a second energy generation element to eject the liquid in the second liquid chamber; a first electrode is arranged in a vicinity of the first energy generation element in the first liquid chamber; a second electrode for forming, between the first electrode and the second electrode, an electric field in liquid inside the first liquid chamber; and a supply port which supplies liquid to the first energy generation element, wherein the wall member includes a channel wall in which the second liquid chamber, the void, and the supply port communicate, and the second electrode is arranged between the second liquid chamber and the supply port in the channel.

The present disclosure is directed to a microfluidic die that includes a first larger heater and a second smaller heater is a single chamber. The first heater is configured to form a primary bubble that ejects fluid from a nozzle associated with the chamber. The second heater is configured to form a secondary bubble to prevent blow back caused when the primary bubble bursts and ejects fluid from the nozzle. The first and second heater may be coupled to a single input trace and a single ground trace.