A liquid ejection apparatus includes a liquid storing unit capable of storing liquid, a liquid ejection unit including an ejection port that is capable of ejecting the liquid, and a pressure control unit that receives the liquid from the liquid storing unit and allows the liquid having a pressure controlled to be within a predetermined pressure range to be supplied to the liquid ejection unit. Additionally, the liquid ejection apparatus includes a first circulation unit that supplies the liquid having the pressure controlled by the pressure control unit to the ejection port while circulating the liquid between the liquid ejection unit and the pressure control unit, and a second circulation unit that circulates the liquid between the liquid storing unit and the pressure control unit.

A liquid discharge head 2 of the present disclosure includes: a flow path member 4 having a plurality of pressurizing chambers 10 connected to respective discharge holes 8, a first common flow path 20 commonly connected to the plurality of pressurizing chambers 10, and a second common flow path 22 commonly connected to the plurality of pressurizing chambers 10; and a plurality of pressurizing units 50 that pressurizes the respective pressurizing chambers 10, in which the first common flow path 20 extends in a first direction and is open to an outside of the flow path member 4 at both end portions, and the second common flow path 22 extends in the first direction and is open to the outside of the flow path member 4 at both end portions.

A liquid discharge head, comprising an insulating member arranged on a substrate, a resistive heating element arranged in the insulating member and configured to generate thermal energy used to discharge a liquid, a bubble chamber provided above the insulating member and configured to generate bubbles of the liquid based on the thermal energy, and a temperature detection element capable of detecting a temperature in the bubble chamber, wherein the temperature detection element is arranged between the resistive heating element and the bubble chamber and in a conductive layer closest to the bubble chamber in a plurality of conductive layers provided with respect to the insulating member.

Provided is a technique that enables voltages to be applied, with high precision, to an electrode layer for inhibition and removal of koge while suppressing increase in the size a substrate. A liquid ejection head substrate includes: electrothermal conversion elements that apply heat to a liquid; an upper electrode part in which a plurality of upper electrodes that protect the electrothermal conversion elements are formed at positions where the upper electrodes come into contact with the liquid; a counter electrode part which is provided to correspond to the upper electrode part and in which a plurality of counter electrodes are formed to be electrically connectable to the upper electrodes via the liquid; and a generation unit that generates a voltage to be applied to at least one of the upper electrode part and the counter electrode part.

A liquid ejection head includes a recording element substrate including an ejection port member including a liquid ejection port, an electrical wiring layer including a pressure generating element that pressurizes the liquid to eject the liquid and an electrically connecting part connected to the pressure generating element to supply power for driving the pressure generating element to the pressure generating element, and a silicon substrate having the ejection port member and the electrical wiring layer. The silicon substrate includes a through-hole passing through the silicon substrate to expose the electrically connecting part. An outer shape of an opening of the through-hole on the back side of the silicon substrate has no side parallel to direction [110] of the silicon substrate or has a side parallel to the direction [110]. The side has a length equal to or less than half an entire length of the through-hole in the direction [110].

A substrate for liquid ejection head comprising, a base material, a heating element including a heating resistor layer for generating thermal energy for discharging a liquid, a wiring layer for supplying electric power to the heating element, and an interlayer insulating film for insulating the heating resistor layer and the wiring layer. A part of a first interlayer insulating film for insulating the heating resistor layer and a first wiring layer adjacent to the heating resistor layer, and a second interlayer insulating film for insulating the first wiring layer and a second wiring layer adjacent to the second interlayer insulating film, includes a material layer represented by Si.sub.wO.sub.xC.sub.yN.sub.z (w+x+y+z=100 (at. %), 37≤w≤60 (at. %), 30≤x≤53 (at. %), 6≤y≤−29 (at. %), 4≤z≤9 (at. %)).

Long-term reliability of a liquid ejection head substrate and a liquid ejection head is improved by suppressing dissolution of an intermediate layer due to anodization. A liquid ejection head substrate including: a flow passage forming member having an ejection orifice and a flow passage; a heating resistance element for ejecting a liquid; an insulating layer covering the heating resistance element; a protecting layer whose surface is exposed to the flow passage; and an intermediate layer provided between the flow passage forming member and the protecting layer, in which the intermediate layer contains a material represented by a following composition formula (I): Si.sub.w1O.sub.x1C.sub.y1 (I), 39≤w1≤62 (at. %), 32≤x1≤55 (at. %), and 6≤y1≤29 (at. %), and w1+x1+y1=100 (at %).

A liquid ejection head circuit board including a substrate, a heat generating resistance element that generates heat energy used for ejection of liquid, an electric wiring layer that is electrically connected to the heat generating resistance element, and an insulating film that insulates the electric wiring layer. The insulating film includes a first insulating film and a second insulating film on the first insulating film, the first insulating film is a first SiOCN film, and the second insulating film is a second SiOCN film containing more carbon than the first SiOCN film or a low-density insulating film with a lower density than the first SiOCN film.

An ejection device is used for an imprint apparatus that presses a mold against an ejection material ejected onto a substrate to form a pattern. The ejection device includes: a housing unit having an ejection head configured to eject the ejection material onto the substrate, and housing configured to accommodate the ejection material; and a control unit configured to control processing of the ejection device. The control unit switches the processing according to a usage status of a consumable part included in the housing unit.

According to examples, an apparatus may include a fluidic chamber, in which fluid is to be temporarily held. The apparatus may also include a heating component to generate heat to form a drive bubble in the fluid held in the fluidic chamber and a cavitation plate may be provided between the fluidic chamber and the heating component. The cavitation plate may be in communication with the fluidic chamber and may physically separate the fluidic chamber from the heating component to protect the heating component. In addition, a controller may determine a condition in the fluidic chamber based on an electrical signal received from the cavitation plate.