A head unit includes: a head module having a nozzle surface; a casing; a first connector having a first communication opening; a second connector having a second communication opening; a first liquid-passage tube connected to the first communication opening; first and second branch-liquid-passage tubes connected to the first liquid-passage tube; a first tube joint connecting the first liquid-passage tube to the first and second branch-liquid-passage tubes; a second liquid-passage tube connected to the second communication opening; third and fourth branch-liquid-passage tubes connected to the second liquid-passage tube; and a second tube joint connecting the second liquid-passage tube to the third and fourth branch-liquid-passage tubes. The first tube joint is disposed between the second connector and the second tube joint when viewed in a direction parallel with the nozzle surface.

Printheads for jetting a print fluid. In one embodiment, a printhead includes a main body configured to attach to a stack of plates, where the stack of plates forms a row of jetting channels configured to jet droplets of a print fluid. The main body includes a supply manifold configured to provide a fluid path for the print fluid to the row of jetting channels. The supply manifold comprises a primary manifold duct and a secondary manifold duct that extend in parallel in alignment with the row of jetting channels. The primary manifold duct is fluidly isolated from the secondary manifold duct at end sections of the primary manifold duct, and is fluidly coupled to the secondary manifold duct toward a midsection of a length of the primary manifold duct. The secondary manifold duct is fluidly coupled to the row of jetting channels.

In a circulating system which circulates liquid within a liquid ejecting head, thickening of liquid in the vicinity of an ejection port section can be more securely suppressed. The ejection port section includes a first ejection port disposed at an upstream side with respect to an ejecting direction of ink and a second ejection port disposed at a downstream side with respect to the ejecting direction. The second ejection port includes an enlarged diameter portion whose diameter is enlarged in a radially outward manner from at least a part of an opening edge portion of the first ejection port.

In a state in which a liquid storage body is installed in a liquid ejecting apparatus, at least part of the upper edge of a liquid storage section and at least part of the lower edge of the liquid storage section are in contact with a case and a first inner surface of the liquid storage section and its second inner surface opposite to the first inner surface are separated from each other. The liquid storage section is structured so that as a liquid is supplied, the first inner surface and second inner surface gradually approach each other and, at the same time, come into contact with each other from top to bottom, forming, at the bottom of the interior of the liquid storage section, a liquid flow path through which the liquid flows from the liquid storage section to the liquid supply section.

The liquid ejecting head includes a first individual flow path and a second individual flow path for supplying liquid to a pressure chamber, a first common flow path for supplying liquid to the first individual flow path, and a second common flow path for supplying liquid to the second individual flow path. A first circulation for causing liquid to flow in the order of the first individual flow path, the pressure chamber, and the second individual flow path and a second circulation for causing liquid to flow in the reverse order of the first circulation are switched. A flow path resistance of the first common flow path is designed to be less than a flow path resistance of the second common flow path and a flow path resistance of the first individual flow path is designed to be less than a flow path resistance of the second individual flow path.

An inkjet print head includes an ink supply substrate having an ink supply channel in fluid communication with an ink supply connector channel for receiving ink from an ink reservoir and in fluid communication with an ink return connector channel for supplying ink to the ink reservoir; a droplet forming unit arranged on the ink supply substrate and having an ink inlet surface, in which ink inlet surface an ink inlet port for receiving ink from the ink supply substrate is arranged; a manifold chamber formed over the ink inlet surface of the droplet forming unit; and a filter arranged between the ink supply substrate and droplet forming unit. The filter has a first filter surface at an upstream side and a second filter surface at a downstream side. Filter holes extend from the first filter surface to the second filter surface. The first filter surface forms a wall of the ink supply channel.

A fluid ejection device includes a fluid ejection chamber, a drop ejecting element communicated with the fluid ejection chamber, an orifice communicated with the fluid ejection chamber, a fluid passage between the fluid ejection chamber and the orifice, and a structure in the fluid passage between the fluid ejection chamber and the orifice.

A head unit includes circulation heads disposed at different positions on an XY plane, supply pipes configured to supply liquid to the circulation heads, discharge pipes configured to discharge the liquid from the circulation heads to the outside, and flow path members connecting the circulation heads, the supply pipes, and the discharge pipes. Each circulation head includes a nozzle plate having nozzles. The nozzles include first nozzles on one end side in the X direction and second nozzles on the other end side in the X direction. During circulation, the liquid pressure in the first nozzles is higher than the liquid pressure in the second nozzles, and when the head unit is viewed from the Z direction in plan view, the first nozzles are disposed on both ends in the X direction or the second nozzles are disposed on both ends in the X direction.

There is provided a liquid discharge head including: an individual channel member including individual channel rows; a first common channel member including first common channels and a first partitioning wall, and a damper joined to the first common channel member with adhesive. The damper has first portions that are elastically deformable and overlap with the first common channels and a second portion joined to the first partitioning wall and connected to the first portions. The second portion is thicker than the first portions.

A flow passage structure includes a flow passage member that constitutes a portion of a wall surface of a liquid storage chamber; a flexible film that is laminated on the flow passage member and constitutes a portion of the wall surface of the liquid storage chamber; a sealing body that is laminated on a side opposite to the flow passage member with the flexible film interposed therebetween and forms a space in which the flexible film is exposed; communication passages that are formed in a region around the liquid storage chamber in the sealing body and causes the space to communicate with an atmosphere in a case where the sealing body is seen in a plan view from a direction in which the flow passage member and the flexible film are laminated; and a support portion that supports the flexible film in the communication passage.