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 liquid ejection head including a base substrate, an ejection port to eject a liquid, a heating element formed above the base substrate that heats the liquid to eject the liquid from the ejection port, a temperature detection element formed above the base substrate that detects a temperature of the liquid, a wiring layer connected to the heating element, a protective layer formed on the base substrate that protects the heating element and the wiring layer from the liquid, and a liquid supply port that penetrates the base substrate and supplies the liquid to the ejection port. When viewed in a direction perpendicular to the base substrate, the temperature detection element is disposed between the heating element and the liquid supply port, and the temperature detection element is formed on the protective layer.

There is provided a liquid discharge apparatus including: a liquid discharge head having a nozzle; an electrode facing the nozzle; a power supply which generates a potential difference between the liquid discharge head and the electrode; a first output unit which outputs a first signal in accordance with an electric change in a case that the liquid discharge head is caused to perform inspection driving; a low-pass filter; a second output unit; a high-pass filter; a third output unit; and a controller. The controller executes determination as to whether or not the liquid is normally discharged from the nozzle, based on the first signal; and determination as to whether or not a short circuit occurs between the liquid discharge head and the electrode, based on a second signal output from the second output unit and a third signal output from the third output unit.

A liquid discharge apparatus includes an individual flow passage member; and a common flow passage member joined to the individual flow passage member in a first direction. The individual flow passage member has nozzle groups formed on a surface on a side opposite to the common flow passage member and connecting hole groups formed on a surface on a side of the common flow passage member; and the common flow passage member has manifold flow passages corresponding to the connecting hole groups respectively. Each of the nozzle groups includes nozzles aligned in a second direction orthogonal to the first direction; and each of the connecting hole groups includes connecting holes aligned in the second direction and connected to the nozzles respectively. Each of the manifold flow passages extends in the second direction and is connected to the nozzles via the connecting holes.

In a case where air bubbles exist in ink at the time of circulating the ink within a liquid ejection module, the amount circulating ink runs short and stability of ejection is blocked. The liquid ejection module has: a pressure chamber that communicates with an ejection port and which stores a liquid; an energy generation element that produces energy for causing a liquid to be ejected from the ejection port; a supply flow path that supplies a liquid to the pressure chamber; a collecting channel that collects a liquid from the pressure chamber; a liquid sending chamber that connects to the collecting channel; a connection flow path that connects the liquid sending chamber and the supply flow path; and a liquid sending unit configured to circulate a liquid, and the liquid sending chamber has a continuously inclined structure.

A fluid ejection die may include a fluid actuator, a substrate supporting the fluid actuator, a chamber layer supported by the substrate and a bypass passage in the substrate. The substrate may include a closed inlet channel having an inlet opening for connection to an outlet of a fluid source and an outlet channel having an outlet opening of a first size for connection to an inlet of the fluid source. The chamber layer includes a recirculation passage to supply fluid for ejection by the fluid actuator through an ejection orifice and to circulate fluid across the fluid actuator from the closed inlet channel to the outlet channel. The bypass passage is of a second size less than the first size and connects the inlet channel to the inlet of the fluid source while bypassing any fluid actuator provided for ejecting fluid through an ejection orifice.

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 fluid ejection die includes an ejection nozzle and an ejection chamber fluidly connected to the ejection nozzle. The die includes a fluid input hole fluidly connected to the ejection chamber, a fluid output hole, and a fluid output channel fluidly connected to the ejection chamber and the fluid output hole. The die includes a fluid circulation rib positioned between the fluid input hole and the fluid output hole.

There is provided a liquid ejecting head including: first and second nozzle rows extending in a first direction; a first supply flow path; a first filter chamber having a first inlet; and a second filter chamber having a second inlet, in which the first and second nozzle rows are shifted from each other in both the first direction and a second direction orthogonal to the first direction, the first supply flow path has a branch flow path for distributing the liquid between the first filter chamber and the second filter chamber at a branch position, the branch position is disposed between the first filter chamber and the second filter chamber in a plan view, and the first and second inlets are disposed at a part where the first filter chamber and the second filter chamber overlap each other when viewed in the second direction.

A filter is compressed between facing surfaces of a first configuration component and a second configuration component, and a molten resin is poured in such a compressed state. Injection molding of the first configuration component and the second configuration component, joining of the configuration components, and sealing of the circumference of the filter are performed by a pair of metal molds.