A liquid ejection head includes a recording element substrate including an energy generating element configured to generate energy for ejecting liquid from an ejection port; an electrical wiring board electrically connected to the recording element substrate to supply an electric signal for driving the energy generating element; a first support member supporting the recording element substrate; and a second support member supporting the first support member and having a greater linear expansion coefficient than the electrical wiring board, wherein the electrical wiring board is bonded to a first surface of the first support member and a second surface of the second support member, and an adhesive that bonds the electrical wiring board to the second surface has a lower elastic modulus than an adhesive that bonds the electrical wiring board to the first surface.

A multi-chip module (MCM) assembly comprising: a graphite substrate comprising a plurality of silicon chips directly attached to the graphite substrate, and a Printed Wiring Board (PWB) attached to the graphite substrate by means of a solvent-resistant adhesive glue and provided with openings surrounding outer profiles of the silicon chips. A printing bar comprising a plurality of the MCM assemblies is also disclosed.

A method of forming a print head, by forming a heater chip. Via zones having peripheries are defined on a substrate, with heaters formed along the entire peripheries of the via zones. Traces that electrically connect to each of the heaters are formed. In some embodiments, the heater chip is then stored for a period of time. After storing the heater chip, vias are formed in only a selected portion of the via zones, which is a subset of the via zones. A channel layer is formed on the heater chip by forming a first layer on the heater chip. Flow channels are formed in the first layer from the vias to only those heaters on the heater chip that are disposed along the selected portion of the via zones. Bubble chambers are formed in the first layer around only those heaters on the heater chip that are disposed along the selected portion of the via zones. A nozzle plate in formed on the channel layer by forming a second layer on the first layer, and forming nozzles in the second layer above only those heaters on the heater chip that are disposed along the selected portion of the via zones.

An inkjet printing apparatus includes an inkjet head that moves in a main scanning direction at the time of printing; a filter chamber provided on a path for supplying ink to a nozzle hole (nozzle) in the inkjet head; and a spherical body placed on a head filter in the filter chamber. The spherical body has a diameter φ larger than the mesh of the head filter. The spherical body is disposed on the head filter so as to be rollable by the movement of the inkjet head.

A fluid dispensing system with a fluid cartridge having a fluid reservoir and an ejection head. The ejection head has fluid ejectors that are in fluid flow communication with the fluid reservoir. A fluid detection circuit is electrically connected to at least one of the fluid ejectors. The fluid detection circuit is configured to detect and characterize a fluid in the fluid ejector, where the fluid detection circuit characterizes the resistivity of the fluid by adjusting an ejector voltage of the at least one of the fluid ejectors.

One embodiment of the present invention is a liquid ejection apparatus having: a liquid ejection head including a heating element, a first protection layer that blocks contact between the heating element and liquid, a second protection layer that partially covers the first protection layer and functions as a first electrode, a second electrode that is electrically connected to the first electrode through the liquid, and an ejection port that ejects the liquid; and a control unit configured to perform control of setting a potential difference between the first electrode and the second electrode to a predetermined value in each of aging and printing by changing at least one of potentials of the first electrode and the second electrode, wherein ΔVa≠ΔVp is satisfied in the case where the potential difference in the aging is represented by ΔVa and the potential difference in the printing is represented by ΔVp.

In a liquid ejection head in which ejection modules are arrayed on a flow path forming member, each ejection module includes a recording element substrate provided on a support member. The recording element substrate includes a liquid supply channel, a liquid collection channel, and ejection ports. The support member includes supply-side liquid communication ports communicating with the liquid supply channel and collection-side liquid communication ports communicating with the liquid collection channel. The supply-side liquid communication ports and the collection-side liquid communication ports are alternately provided along the direction in which the ejection modules are arrayed. The closest pair of liquid communication ports in the adjacent ends of two adjacent ejection modules are both supply-side or collection-side liquid communication ports.

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 fluid cartridge having a plastic fluid body, a bottom wall having a fluid supply opening therein. A metal insert is adhesively attached to the bottom wall. The metal insert has a fluid supply slot therein corresponding to the fluid supply opening in the bottom wall, a die bond surface adjacent to the fluid supply slot for adhesively attaching an ejection head chip thereto, and a plurality of air vents adjacent to the die bond surface. An ejection head chip is adhesively attached to the die bond surface of the metal insert.

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].