A fluid circulation and ejection system may include a microfluidic die, a single orifice fluid ejector having a drive chamber in the microfluidic die and a pressurized fluid source remote from the microfluidic die to create a pressure gradient across the drive chamber to circulate fluid across the drive chamber.

A liquid ejection head that includes ejection orifices and is configured by bonding a silicon substrate and a support substrate, flow passages which penetrate a bonding surface between the silicon substrate and the support substrate and through which different types of liquids flow. An in-partition wall space that is open to the bonding surface between the silicon substrate and the support substrate is formed in a partition wall for separating the flow passages. The internal pressure of the in-partition wall space is set to be lower than pressure of the liquid on each of the flow passages.

In some examples, a print bar fabrication method comprises placing printhead dies face down on a carrier, placing a printed circuit board on the carrier, wire bonding each printhead die of the printhead dies to the printed circuit board, and overmolding the printhead dies and the printed circuit board on the carrier, including fully encapsulating the wire bonds.

A deposition device including an injection block and a print die is provided, which allows for vertical movement of the injection block while still maintaining connection between the print die and external gas sources. Also disclosed is an injection block suitable for such devices, which provides improved vertical range of motion and thermal consistency compared to conventional injection block devices.

A liquid ejection head includes a recording element substrate having a substrate provided with a plurality of flow paths for liquid to be ejected on a recording material by a recording element and a cover member that is provided with a plurality of communication holes in communication with the plurality of flow paths and that is joined to the substrate, a liquid supply member supplying the liquid to the plurality of flow paths through the plurality of communication holes of the cover member, and an adhesive member adhering the cover member and the liquid supply member. At least a part of an abutment region of the cover member in abutment against the substrate and apart from a region provided with the plurality of communication holes has a cover member opening for contacting the adhesive member and the substrate to each other.

An example printhead includes a circulation channel having an inlet for receiving a fluid and an outlet for expelling the fluid, a first nozzle fluidically coupled to the circulation channel, the first nozzle being operable at a first absolute pressure, and a second nozzle fluidically coupled to the circulation channel, the second nozzle being operable at a second absolute pressure, the absolute second pressure being lower than the first absolute pressure. The absolute pressure in the circulation channel decreases as the fluid flows from the inlet to the outlet, and the first nozzle is positioned closer to the inlet of the circulation channel than the second nozzle.

An example printhead includes a set of circulation channels for flowing a fluid therethrough, the set of nozzles including higher-pressure channels and lower-pressure channels; a first nozzle array having a first nozzle; a second nozzle array having a second nozzle, the first nozzle and the second nozzle forming a row region; a first inter-channel passage fluidically coupling the first nozzle to a first pair of adjacent circulation channels, the first pair including a higher-pressure channel on a first side of a lower-pressure channel; and a second inter-channel passage fluidically coupling the second nozzle to a second pair of adjacent circulation channels, the second pair including a higher-pressure channel on a second side of a lower-pressure channel, the second side being opposite the first side.

Fluid is continuously recirculated through a thermal fluid-ejection printhead. Prior to firing a thermal resistor of the printhead to thermally eject a drop of the fluid through a nozzle of the printhead, the fluid is recirculated on-demand through a chamber of the printhead between the nozzle and the thermal resistor. The thermal resistor is fired to thermally eject the drop of the fluid through the nozzle. The fluid has a concentration of solids greater than 12% by volume.

A flow path member includes a first substrate having a first surface that has a flow path, and includes a second substrate having a second surface opposing the first surface. In the flow path member in which the first and second substrates are joined together with adhesive provided between the first and second surfaces, a groove is formed in at least one of the first and second surfaces. When the first substrate is viewed from a direction orthogonal to the first surface, the flow path is disposed on a groove inner side. The groove has a first portion having a first depth and a second portion having a second depth shallower than the first depth. The second portion is that portion of the groove existing inside a region surrounded by an outer edge of the first surface and extension lines of two sides that form a flow path corner.

A liquid ejection head has at least a structure including an ejection orifice forming member having an ejection orifice for ejecting a liquid and a flow path communicating with the ejection orifice and a flow path forming substrate having a liquid introduction flow path communicating with the flow path and supplying the liquid, and includes: a first titanium oxide film with a pure water contact angle of 40° or less; and a second titanium oxide film with a pure water contact angle of 70° or more, wherein the first titanium oxide film covers the structure including inner walls of the flow path and the liquid introduction flow path and is exposed in the flow path and the liquid introduction flow path, and the second titanium oxide film has a portion covering the first titanium oxide film in a vicinity of an opening end.