In a case where a direction of ejection of a second liquid is a direction from below to above, the second liquid flows above a first liquid in a pressure chamber. A substrate includes an outflow port located downstream of the pressure chamber in a direction of flow of the first liquid and configured to allow the first liquid to flow out of a liquid flow passage. A wall is located in the liquid flow passage and on a section of the substrate on a side opposite to the pressure chamber across the outflow port, the wall including a portion located higher than a surface of a section of the substrate where the pressure chamber is located on a side opposite to the wall across the outflow port.

A first inflow port allows a first liquid to flow into a liquid flow passage, and a second inflow port allows a second liquid to flow into the liquid flow passage. The first and second liquids flow toward a pressure chamber. There is a portion satisfying L≥W, where L is a length of the first inflow port and W is a length of the liquid flow passage above the first inflow port, in a direction orthogonal to a direction of flow of the first liquid in the pressure chamber and to a direction of ejection of the second liquid from an ejection port. In a case where the second liquid is ejected from bottom to top, the second liquid flows above the first liquid.

A liquid ejection head includes a pressure chamber that allows a first liquid and a second liquid to flow inside, a pressure generation element that applies pressure to the first liquid and an ejection port that ejects the second liquid. The first liquid and the second liquid that flows on a side closer to the ejection port than the first liquid flow in contact with each other in the pressure chamber. The first liquid and the second liquid flowing in the pressure chamber satisfy
0.0<0.44(Q.sub.2/Q.sub.1).sup.−0.322(η.sub.2/η.sub.1).sup.−0.109<1.0,
where η.sub.1 is a viscosity of the first liquid, η.sub.2 is a viscosity of the second liquid, Q.sub.1 is a flow rate of the first liquid, and Q.sub.2 is a flow rate of the second liquid.

A recording apparatus includes a liquid ejection head, where the liquid ejection head includes: an ejection port, a first substrate, and a temperature detection element. The ejection port ejects liquid and includes a protrusion extending toward an ejection port inside. The first substrate includes a heating element that ejects liquid from the ejection port using heat. The temperature detection element detects temperature of the first substrate. Driving of the heating element is controlled based on whether a difference between a voltage value Vp1 measured by the temperature detection element and a preset voltage value Vp01 has a positive value within or outside a predetermined range or a negative value outside the predetermined range. The voltage value Vp1 is measured when a temperature change amount becomes maximum in a temperature falling process of a second substrate located, after the heating element is driven, at a position corresponding to the heating element.

A liquid ejection head includes a liquid channel through which a first liquid and a second liquid flow, a pressure generation element that pressurizes the first liquid and an ejection orifice through which to eject the second liquid in a direction crossing a direction of the flow of the first liquid and the second liquid via the pressurization. A distance in the direction of the flow from a position in the liquid channel at which the first liquid and the second liquid merge to the ejection orifice is greater than an interface stabilization distance in the direction of the flow from a position at which the first liquid and the second liquid contact each other to a position at which a stable interface is obtained between the first liquid and the second liquid.

A highly reliable multilayer structure element substrate according to an embodiment of this present invention comprises: an electrothermal transducer; a temperature detection element formed at a position where the temperature detection element at least partially overlaps the electrothermal transducer in a planar view of the element substrate; and a plurality of wirings connected to the temperature detection element, wherein the temperature detection element can detect temperatures in a plurality of regions when a plurality of different wirings out of the plurality of wirings are selected.

A liquid ejection head includes a flow channel structure, a supply channel structure, and a particular heater. The flow channel structure defines an ejection channel that leads liquid toward a plurality of nozzles arranged in a nozzle row along a first direction. The supply channel structure defines a supply channel configured to allow liquid to flow therefrom to the ejection channel. The particular heater is configured to heat liquid. The flow channel structure is made of inorganic material having a higher thermal conductivity than material used for the supply channel structure. The flow channel structure includes an end portion protruding outward relative to a side surface of the supply channel structure. The particular heater is disposed at the end portion of the flow channel structure.

In some examples, a fluid dispensing device includes storage elements, and a switch assembly comprising switches controllable by control signals responsive to a given fire event that activates a nozzle of the fluid dispensing device to provide a first sense measurement of a first condition of the nozzle to a first storage element of the storage elements, and provide a second sense measurement of a different second condition of the nozzle to a second storage element of the storage elements.

A liquid jetting apparatus includes: individual channels; and a manifold commonly provided for the individual channels. Each of the individual channels has: a nozzle; a pressure chamber arranged away from the nozzle in a predetermined direction to extend along a plane orthogonal to the predetermined direction and connected to the manifold, a connecting channel connected to the pressure chamber to form at least a part of a channel communicating the pressure chamber and the nozzle, and a circulation channel connected to the connecting channel to form a part of a channel communicating the connecting channel and the pressure chamber. The connecting channel has a throttle, and the throttle has a smaller diameter along the plane orthogonal to the predetermined direction than a diameter, of a part of the connecting channel except the throttle, along the plane orthogonal to the predetermined direction.

A liquid jetting apparatus includes: individual channels; and a manifold commonly provided for the individual channels. Each of the individual channels has: a nozzle; a pressure chamber arranged away from the nozzle in a predetermined direction to extend along a plane orthogonal to the predetermined direction and connected to the manifold, a connecting channel connected to the pressure chamber to form at least a part of a channel communicating the pressure chamber and the nozzle, and a circulation channel connected to the connecting channel to form a part of a channel communicating the connecting channel and the pressure chamber. The connecting channel has a throttle, and the throttle has a smaller diameter along the plane orthogonal to the predetermined direction than a diameter, of a part of the connecting channel except the throttle, along the plane orthogonal to the predetermined direction.