A liquid discharge head includes a substrate, a pressure chamber through which a first liquid and a second liquid flow while being in contact with each other, a pressure generating element configured to pressurize the first liquid, and a discharge port configured to discharge the second liquid. The substrate has a first channel and a second channel that each extend through the substrate. The first channel is used to supply the first liquid to the pressure chamber. The second channel is used to supply the second liquid to the pressure chamber. A viscosity of the second liquid is greater than a viscosity of the first liquid. An average cross-section area of the second channel is greater than an average cross-section area of the first channel.

In this liquid ejecting head, the pressure chamber extends in a second direction crossing a first direction, the first direction being a direction from the pressure chamber to the nozzle. The pressure chamber and the absorbing chamber are disposed at a same position in the first direction and next to each other in the second direction. The actuator is disposed on an opposite side in the first direction with respect to the pressure chamber. The absorption member is disposed on the opposite side in the first direction with respect to the absorbing chamber, the absorption member including at least part of members constituting the actuator.

A liquid supply device includes a collection sub tank and a collection flow path. The collection sub tank collects liquid from a liquid discharge head. The collection flow path connects the liquid discharge head and the collection sub tank. The collection sub tank includes a first inflow port connected with the collection flow path and a first inner wall portion on an extension line extending from the first inflow port in a direction in which the liquid flows into the collection sub tank from the collection flow path. The first inner wall portion has one of an inclined surface inclined with respect to the extension line, an arc-shaped surface, and a curved surface.

A fluid ejection apparatus includes a plurality of fluid ejectors. Each fluid ejector includes a pumping chamber, and an actuator configured to cause fluid to be ejected from the pumping chamber. The fluid ejection apparatus includes a feed channel fluidically connected to each pumping chamber; and at least one compliant structure formed in a surface of the feed channel. The at least one compliant structure has a lower compliance than the surface of the feed channel.

A liquid ejection head and liquid ejection apparatus capable of suppressing deterioration in image quality without adding a member for heat radiation is to be provided. Therefore, in the liquid ejection head that ejects a circulating liquid, the second engagement part formed on the discharge port side has an elongated hole shape extending in the arrow B direction so as to support the liquid ejection unit support member in such a manner capable of allowing the thermal deformation.

When a pressure of the liquid inside the common supply flow path is higher than a pressure of the liquid inside the pressure chamber, the adjustment portion changes the cross-sectional area to be a first cross-sectional area when a pressure difference, which is a difference between the pressure of the liquid inside the common supply flow path and the pressure of the liquid inside the pressure chamber, is a first pressure difference, and changes the cross-sectional area to be a second cross-sectional area larger than the first cross-sectional area when the pressure difference is a second pressure difference larger than the first pressure difference.

The control portion controls (i) a discharging operation of discharging the liquid from the plurality of nozzles by driving the plurality of energy generation elements and (ii) a pressurization operation of pressurizing the liquid from the individual flow path side in a state in which the plurality of nozzles are sealed by the sealing portion.

A liquid ejecting head includes a liquid flow channel including nozzles constituting a nozzle row configured to eject a liquid, a dummy flow channel including dummy nozzles constituting a dummy nozzle row not configured to eject liquid, and a closing section formed by an adhesive and closing the dummy flow channel.

A liquid discharge head includes an individual channel which includes: a nozzle; a pressure chamber; a descender of which one end in the first direction is nearer to the nozzle than the other end; and a second connecting channel connecting a second common channel and the one end of the descender. A central axis of the nozzle is positioned between the second common channel and a central axis of the descender in the second direction. The descender includes a first portion including the one end and a second portion positioned between the pressure chamber and the first portion in the first direction. In an end, of the descender, opposite to the second connecting channel in the second direction, an inner wall defining the one end of the first portion protrudes toward the second connecting channel in the second direction beyond an inner wall defining the second portion.

A printing apparatus includes: a tank configured to contain ink; a print head configured to eject ink supplied from the tank; a supply flow path through which liquid is supplied from the tank to the print head; a collection flow path through which liquid is collected from the print head to the tank; a circulation unit configured to circulate ink inside a circulation flow path including the tank, the supply flow path, the print head, and the collection flow path; and a cooling unit configured to cool the tank by blowing.