A liquid discharge head includes a head body configured to discharge a liquid, a head cover on the head body, a head cover covering at least a part of the head body, the head cover disposed outside the head body; a liquid supply port on an upper surface of the head cover, the liquid supply port configured to supply the liquid to the head body, an electrical connection on a side surface of the head cover. The head cover includes a protruding part protruding from the upper surface of the head cover, the protruding part is on a side end of the upper surface of the head cover adjacent to the side surface of the head cover on which the electrical connection is disposed, and the protruding part is higher than another part of the upper surface of the head cover with respect to a lower end surface of the head body.

Breakage of components is suppressed at the time of bonding. A print head with a metal film formed on laminated layers includes an electric wiring layer electrical connection with a metal film, a protective film covering and protecting the electric wiring layer, a groove separating the protective film and the electric wiring layer around the metal film, and a resin film applied to the groove.

The present invention proposes a thermal inkjet printhead, as well as a printing assembly and printing apparatus comprising the same. The thermal inkjet printhead of the present invention comprises: a substrate; a nozzle layer, including a plurality of nozzles formed therethrough; a plurality of ink ejection chambers corresponding to the plurality of nozzles; a plurality of heater resistors formed on the substrate and corresponding to the plurality of ink ejection chambers, each of the heater resistors being located in a different one of the ink ejection chambers so that ink drop ejection through each of the nozzles is caused by heating of one of the heater resistors that is located in the corresponding ink ejection chamber; a plurality of separated cavitation islands formed on and corresponding to the plurality of heater resistors, each of the cavitation islands covering a different one of the heater resistors; and a dielectric layer interposed between the heater resistors and the cavitation islands. Using the present invention can help to enhance and substantially improve the printhead reliability, increasing in turn the yield of the manufacturing process.

An aspect of the present invention is a liquid ejection apparatus including: a liquid ejection head including a heating element, a first protection layer, a second protection layer that functions as a first electrode, a second electrode that is electrically connected to the first electrode, and an ejection port; and a control unit configured to perform control of setting a potential difference between potentials of the first and second electrodes to a predetermined value by changing at least one of the potentials of the first electrode and the second electrode, in which the control unit sets the potential difference to a first value in a case where printing is performed, and the control unit sets the potential difference to a second value different from the first value and feeds power to at least one of a plurality of the heating elements in a case where printing is not performed.

A liquid ejection head includes a recording element substrate and an electric wiring substrate. The recording element substrate includes an ejection port configured to eject liquid, an energy generating element configured to generate energy for ejecting the liquid from the ejection port, and an electrode terminal that is electrically connected to the energy generating element. The electric wiring substrate is electrically connected to the electrode terminal by using wire bonding or the like. The electrode terminal is disposed on a connection surface of the recording element substrate, and a connection region in which electric connection to the electrode terminal is established is arranged at an end portion of the electric wiring substrate. The end portion of the electric wiring substrate is disposed above the surface of the recording element substrate on the connection surface side and is separated from the electrode terminal.

An element substrate of multi-layer structure, comprising an electrothermal transducing element formed in a first layer, a protective film covering the electrothermal transducing element, an anti-cavitation film formed on the protective film, a first electrical wire formed in the same layer as the anti-cavitation film, arranged to be separated from the electrothermal transducing element, and electrically connected to at least one end of the electrothermal transducing element, a second electrical wire on an opposite side, in relation to the electrothermal transducing element, to the protective film, and formed in a second layer, and a first connection member that extends between the first and second layers, and that electrically connects the first and second electrical wires.

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].

A die for a printhead is described herein. The die includes a number of fluid feed holes disposed in a line parallel to a longitudinal axis of the die, wherein the fluid feed holes are formed through a substrate of the die. The die includes a number of fluidic actuators, proximate to the fluid feed holes, to eject fluid received from the fluid feed holes. Circuitry on the die operates the fluidic actuators, wherein traces are provided in layers between adjacent fluid feed holes, connecting circuitry on each side of the fluid feed holes.

An object is to provide a liquid ejection apparatus and a method of controlling a liquid ejection apparatus capable of preventing bubbles generated by kogation removal from interfering with the kogation removal. To this end, in a long liquid ejection head with a liquid circulated therethough, a pressure chamber is pressurized and a voltage is applied to a heat applying portion and an electrode to perform kogation removing cleaning.

A wafer structure is disclosed and includes a chip substrate and a plurality of inkjet chips. The chip substrate is a silicon substrate which is fabricated by a semiconductor process on a wafer of at least 12 inches. The plurality of inkjet chips include at least one first inkjet chip and at least one second inkjet chip. The plurality of inkjet chips are directly formed on the chip substrate by the semiconductor process, respectively, and diced into the at least one first inkjet chip and the at least one second inkjet chip, to be implemented for inkjet printing. Each of the first inkjet chip and the second inkjet chip includes a plurality of ink-drop generators produced by the semiconductor process and formed on the chip substrate.