A liquid discharge head includes a substrate having an element that discharges liquid by generating thermal energy to generate an air bubble in the liquid, and a liquid supply port for supplying the liquid to the element, and a flow path forming assembly including a flow path forming member having a discharge port for discharging the liquid and, between the substrate and the flow path forming member, a pressure chamber including the element disposed adjacent thereto and a flow path causing the pressure chamber and the liquid supply port to communicate with each other. In addition, an interlayer is provided on a joining portion of the substrate and the flow path forming member and provided so as to protrude from between the substrate and the flow path forming member into the flow path, and a protection layer including metal is formed so as to cover the element. The interlayer is not disposed on a boundary portion between the pressure chamber and the flow path, and the protection layer is disposed at least on the boundary portion.

A liquid ejection head having at least one energy generation element for generating heat to be used for ejecting a liquid includes an insulating layer which is provided in contact with a substrate and supports the energy generation element; at least one heat transmitting layer which is composed of a material having a higher thermal conductivity than that of a material of the insulating layer and which is provided, in the insulating layer, between the energy generation element and the substrate; and a heat transmitting member which thermally connects the at least one heat transmitting layer and the substrate, wherein the heat transmitting member is connected to an area, on the heat transmitting layer, excluding an area directly below the energy generation element in a position interposed between the energy generation element and the substrate.

A liquid-discharging-head substrate includes an insulation layer, an electrode, and a heating resistor element, wherein the insulation layer includes a first opening portion including a first opening formed in a surface of the insulation layer, a second opening having a smaller opening area than an opening area of the first opening, and a surface connecting the first opening and the second opening, and a second opening portion extending from the second opening to a back surface of the insulation layer, wherein the electrode is formed in the second opening portion, and a surface of the electrode is exposed from the second opening when viewed from the surface side of the insulation layer, and wherein the heating resistor element is in contact with the surface connecting the first opening and the second opening, and with the surface of the electrode.

In an example, a printhead includes a memristor, in which the memristor may include a first electrode, a second electrode positioned in a crossed relationship with the first electrode to form a junction, and a switching element positioned at the junction between the first electrode and the second electrode, in which the switching layer includes a via formed in the switching element to reduce an area of the switching element.

A reproduction method of a liquid ejecting head including: a process of filling the flow path with an electrolyte solution containing metal, and filling a space between an electrode capable of applying a voltage to between itself and the upper protective film and the upper protective film with the electrolyte solution; and a process of applying a voltage to between the upper protective film and the electrode to make the metal contained in the electrolyte solution deposit on the surface of the upper protective film.

A system and method for selective heating and/or sintering of a material including first and second substrates, an array of one or more resistive heating elements arranged on a planar surface of a substrate and material to be heated located on the other substrate.

A printhead device includes firing chambers, nozzles, and shipping fluid. The shipping fluid includes a shipping fluid density and a shipping fluid viscosity greater than a corresponding ink density and ink viscosity of an ink that will be ejected from the firing chambers and through the nozzles.

A liquid ejection head substrate includes a heating resistor array including a plurality of heating resistors and a protective film covering at least one of the heating resistors. The liquid ejection head substrate further includes a supply opening array and an electrode. The supply opening array is disposed on a side of a surface of the liquid ejection head substrate on which the protective film is provided. The supply opening array includes a plurality of supply openings through which a liquid is supplied arranged in a direction along the heating resistor array. The electrode is disposed on the side of the surface in a space between the supply openings adjacent to each other in a direction along the supply opening array. The electrode is configured such that a voltage is applied between the electrode and the protective film.

Ink is circulated through a circulation flow path between a print head and an ink tank. Detection operation for detecting an ink ejection state in an ejection opening in the print head is performed. The ink circulation and the detection operation are simultaneously performed by performing the detection operation in response to a start of the ink circulation.

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.