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 handheld printer may include an array of fluid ejectors, a sensor to output speed variation signals indicative of variations in speeds of movement amongst the array of fluid ejectors as the handheld printer is moved across a print target;and a controller to output control signals adjusting a relative timing of fluid ejection by the fluid ejectors based on the speed variation signals.

A fluid ejector includes a fluid ejection module having a substrate and a layer separate from the substrate. The substrate includes a plurality of fluid ejection elements arranged in a matrix, each fluid ejection element configured to cause a fluid to be ejected from a nozzle. The layer separate from the substrate includes a plurality of electrical connections, each electrical connection adjacent to a corresponding fluid ejection element.

A liquid ejection head includes an ejection opening; a passage in which an energy generation element is disposed; an ejection opening portion that allows communication between the ejection opening and the passage; a supply passage for allowing the liquid to flow into the passage; and an outflow passage for allowing the liquid to flow out to the outside. An expression of H.sup.−0.34×P.sup.−0.66×W>1.7 is satisfied when a height of the passage is set to H [μm], a length of the ejection opening portion is set to P [μm], and a length of the ejection opening portion is set to W [μm].

The fluid ejection device includes a plurality of nozzles and a plurality of ejection chambers that includes a respective ejection chamber fluidically coupled to a respective nozzle. A plurality of inlet passages are fluidically coupled to the ejection chambers and input fluid to the ejection chambers at a first pressure. A plurality of outlet passages are fluidically coupled to the ejection chambers and output fluid from the ejection chambers at a second pressure that is less than the first pressure. Fluid circulates through the ejection chambers based on the pressure difference between the first and second pressure. The fluid ejection device also includes at least one micropump fluidically coupled to at least one ejection chamber to pump fluid through the at least one ejection chamber.

A liquid ejecting head includes first and second individual flow paths arranged side by side along a first direction; a first nozzle communicating with the first individual flow path; a second nozzle communicating with the second individual flow path; and a common liquid chamber coupled to the first and second individual flow paths. The first and second nozzles have openings in a nozzle surface having a second direction as a normal direction. The first individual flow path has a first upstream communication path extending between the first nozzle and the common liquid chamber along the second direction. The second individual flow path has a second upstream communication path extending between the second nozzle and the common liquid chamber along the second direction. The first upstream communication path and the second upstream communication path have parts which do not overlap each other when seen along the first direction.

A wafer structure is disclosed and includes a chip substrate and a plurality of inkjet chips. The chip substrate is a silicon substrate fabricated by a semiconductor process. At least one inkjet chip is directly formed on the chip substrate by the semiconductor process and diced into the at least one inkjet chip for inkjet printing. Each of the inkjet chip includes a plurality of ink-drop generators produced by a semiconductor process and formed on the chip substrate. Each of the ink-drop generators includes a thermal-barrier layer, a resistance heating layer, a conductive layer, a protective layer, a barrier layer, an ink-supply chamber and a nozzle.

An inkjet printhead includes a head body in which a first fine channel that is connected to an ink inlet and thus guides an inflow of ink, a second fine channel that is disposed below the first fine channel, communicated with the first fine channel through a connection via hole, and guides an outflow of the ink by being connected to an ink outlet, and a nozzle that is opened downward from the second fine channel are defined, and a micro heater that is disposed closer to the connection via hole in an upper portion of the first fine channel than to an end of the first fine channel where the first fine channel is connected to the ink inlet or an end of the second fine channel where the second fine channel is connected to the ink outlet.

Provided is a liquid ejection apparatus, liquid ejection method, dispensing apparatus, and compound introduction apparatus capable of inhibiting contamination of a liquid after being ejected. The liquid ejection apparatus has an ejection unit having an ejection part and an ejection energy generation element that ejects a liquid from the ejection part by using a principle of inkjet ejection into an internal space in a storage part capable of storing the ejected liquid. When ejecting the liquid, the ejection unit covers an opening portion of the storage part to thereby screen the internal space in the storage part from an external space.

An element substrate used in a liquid discharge head that discharges liquid to a recording material includes a substrate, an energy generating element that generates energy used to discharge the liquid, circuit wiring that has an electrode portion for external electrical connection and that drives the energy generating element, and that is implemented on the substrate, a first protective film layer that has an opening portion for exposing the electrode portion and that covers the circuit wiring, an electroplating ground layer formed on the electrode portion, and an electroplated bump layer made of a metal material formed on the electroplating ground layer. A bent portion is formed in the first protective film layer by the first protective film layer covering a protruding portion that the circuit wiring has. A second protective film layer is formed on the first protective film layer and covers the bent portion.