A liquid ejecting head includes a flow path forming substrate in which a pressure generating chamber which communicates with a nozzle which ejects a liquid is formed by a partitioning wall, and a piezoelectric actuator in which a first electrode, a piezoelectric layer, and a second electrode are laminated, in which the piezoelectric layer includes a region which is interposed between the first electrode and the second electrode in a lamination direction, and in which when viewed in plan view from the lamination direction, the region overlaps at least a portion of the edges of each side of an opening of the pressure generating chamber on the piezoelectric actuator side and does not overlap one of the first electrode and the second electrode in at least a portion of the opening.

A liquid ejecting head includes a flow path forming substrate in which a pressure generating chamber which communicates with a nozzle which ejects a liquid is formed by a partitioning wall, and a piezoelectric actuator in which a first electrode, a piezoelectric layer, and a second electrode are laminated, in which the piezoelectric layer includes a region which is interposed between the first electrode and the second electrode in a lamination direction, and in which when viewed in plan view from the lamination direction, the region overlaps at least a portion of the edges of each side of an opening of the pressure generating chamber on the piezoelectric actuator side and does not overlap one of the first electrode and the second electrode in at least a portion of the opening.

A liquid ejection head includes a nozzle, a pressure chamber configured to receive a pressure to eject liquid from the nozzle, a descender, and a communication channel. The descender has a first end and a second end opposite to each other. The first end is connected to the pressure chamber. The communication channel is connected to the second end and extends from a connection with the second end in an X direction. A first direction in which the descender extends from the second end toward the first end is inclined toward the communication channel relative to a Y direction orthogonal to the X direction.

A liquid ejection head includes a supply manifold, a return manifold, and individual channels each connected, at its upstream end, to the supply manifold and, at its downstream end, to the return manifold. Each of the individual channels communicates with a corresponding one of nozzles arranged in an array on a nozzle surface. The supply manifold and the return manifold extend in an extending direction along the nozzle array. The return manifold includes a lower portion located below the supply manifold to overlap the supply manifold in plan view orthogonal to the nozzle surface, and a standing portion located at at least one of opposite ends of the lower portion in the extending direction to be outside the supply manifold in plan view. The standing portion has a height to cover at least a portion of an end of the supply manifold when viewed in the extending direction.

A liquid discharge apparatus includes an individual flow passage member; and a common flow passage member joined to the individual flow passage member in a first direction. The individual flow passage member has nozzle groups formed on a surface on a side opposite to the common flow passage member and connecting hole groups formed on a surface on a side of the common flow passage member; and the common flow passage member has manifold flow passages corresponding to the connecting hole groups respectively. Each of the nozzle groups includes nozzles aligned in a second direction orthogonal to the first direction; and each of the connecting hole groups includes connecting holes aligned in the second direction and connected to the nozzles respectively. Each of the manifold flow passages extends in the second direction and is connected to the nozzles via the connecting holes.

A liquid ejection head includes: individual passages each having a nozzle; supply liquid passages each communicating with an individual inlet of a corresponding one of the individual passages; return liquid passages each communicating with an individual outlet of a corresponding one of the individual passages; a first supply coupling liquid passage coupling the supply liquid passages to each other and communicating with a first inlet of each of the supply liquid passages; and a second supply coupling liquid passage coupling the supply liquid passages to each other and communicating with a second inlet of each of the supply liquid passages. In each of the supply liquid passages, the individual inlet of the corresponding one of the individual passages is located between the first inlet and the second inlet.

A liquid ejection head includes: individual passages each having a nozzle; supply liquid passages each communicating with an individual inlet of a corresponding one of the individual passages; return liquid passages each communicating with an individual outlet of a corresponding one of the individual passages; a first supply coupling liquid passage coupling the supply liquid passages to each other and communicating with a first inlet of each of the supply liquid passages; and a second supply coupling liquid passage coupling the supply liquid passages to each other and communicating with a second inlet of each of the supply liquid passages. In each of the supply liquid passages, the individual inlet of the corresponding one of the individual passages is located between the first inlet and the second inlet.

A liquid discharge head includes: individual channels arranged in a first direction; and first and second common channels each extending in the first direction. An opening of the first common channel and an opening of the second common channel are arranged at the same side with respect to the individual channels in the first direction. Each of the individual channels includes: a first communicating channel and a second communicating channel communicating with the first common channel, and a third communicating channel communicating with the second common channel. A midpoint in the first direction between a first connection position where the first common channel is connected to the first communicating channel and a second connection position where the first common channel is connected to the second communicating channel is positioned in a range of a third connection position where the second common channel is connected to the third communicating channel.

Ejection device for fluid, comprising a solid body including: first semiconductor body including a chamber for containing the fluid, an ejection nozzle in fluid connection with the chamber, and an actuator operatively connected to the chamber to generate, in use, one or more pressure waves in the fluid such as to cause ejection of the fluid from the ejection nozzle; and a second semiconductor body including a channel for feeding the fluid to the chamber, coupled to the first semiconductor body, in such a way that the channel is in fluid connection with the chamber. The second semiconductor body integrates a damping cavity over which extends a damping membrane, the damping cavity and the damping membrane extending laterally to the channel for feeding the fluid.

Ejection device for fluid, comprising a solid body including: first semiconductor body including a chamber for containing the fluid, an ejection nozzle in fluid connection with the chamber, and an actuator operatively connected to the chamber to generate, in use, one or more pressure waves in the fluid such as to cause ejection of the fluid from the ejection nozzle; and a second semiconductor body including a channel for feeding the fluid to the chamber, coupled to the first semiconductor body, in such a way that the channel is in fluid connection with the chamber. The second semiconductor body integrates a damping cavity over which extends a damping membrane, the damping cavity and the damping membrane extending laterally to the channel for feeding the fluid.