In a liquid ejection head, an ejection pressure is applied to a pressure chamber for liquid ejection from a nozzle. A descender extends in a first direction and includes a first end connected to the pressure chamber and a second end. A communication passage is connected to the second end, extends in a second direction crossing the first direction, and has a first dimension in the first direction. The nozzle is positioned at the communication passage such that a shortest distance between an outer periphery thereof and a center of the second end is greater than 0.5 times a second dimension of the second end in the second direction. When viewed in the first direction, the center of the second end and a center of a cross-section defined by the nozzle to be orthogonal to an extending direction of the nozzle intersect an axis of the communication passage.

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.

There is used a liquid ejection head including: a plurality of nozzles for ejecting liquid; a plurality of pressure chambers corresponding to the plurality of nozzles; a plurality of pressure generating elements arranged in the plurality of pressure chambers, and for generating a pressure for ejection; a plurality of first flow passages corresponding to the plurality of pressure chambers; a second flow passage communicating with the plurality of first flow passages, and common to the plurality of pressure chambers; and a damper that is elastically deformed when a pressure of the liquid is increased by the pressure generating element. The liquid is supplied to each of the plurality of pressure chambers from the common second flow passage via the plurality of first flow passages, and a Young's modulus of the second flow passage member configuring the second flow passage is 65 GPa or less.

A liquid ejection head includes an individual channel, a first manifold, a filter, a second manifold, and a bypass path. The individual channel has a nozzle. The first manifold is in fluid communication with the individual channel. The filter is disposed in the first manifold. The second manifold is in fluid communication with the individual channel. The bypass path is positioned across the filter from the individual channel with respect to a direction perpendicular to a surface extending direction of the filter. The bypass path provides fluid communication between the first manifold and the second manifold not via the individual channel.

A liquid discharge head 2 of the present disclosure includes: a flow path member 4 having a plurality of pressurizing chambers 10 connected to respective discharge holes 8, a first common flow path 20 commonly connected to the plurality of pressurizing chambers 10, and a second common flow path 22 commonly connected to the plurality of pressurizing chambers 10; and a plurality of pressurizing units 50 that pressurizes the respective pressurizing chambers 10, in which the first common flow path 20 extends in a first direction and is open to an outside of the flow path member 4 at both end portions, and the second common flow path 22 extends in the first direction and is open to the outside of the flow path member 4 at both end portions.

A liquid discharge head includes a flow channel member including a first surface and a second surface opposite to the first surface, and a pressing unit on the first surface. The flow channel member includes a first discharge hole and a second discharge hole in the second surface, a first individual flow channel connected to the first discharge hole, a first pressurizing chamber on an upstream side of the first discharge hole in the first individual flow channel, a second individual flow channel connected to the second discharge hole, a second pressurizing chamber on an upstream side of the second discharge hole in the second individual flow channel, and a manifold commonly connected to an upstream side of first individual flow channel and an upstream side of the second individual flow channel. The first individual flow channel and the second individual flow channel have an overlapping portion in plan view.

A liquid discharge head according to an embodiment includes: a flow channel member including a first surface and a second surface located opposite to the first surface, a pressing unit located on the first surface, and a supply member connected to the flow channel member. The flow channel member includes a plurality of discharge holes located in the second surface. The supply member includes, in this order from an upstream side, a first supply flow channel, a first connection flow channel connected to the first supply flow channel, and a reservoir connected to the first connection flow channel, the first connection flow channel being connected to the second surface side of the reservoir.

A liquid ejection head includes ejection orifices for ejecting liquid, common liquid chambers connected to the ejection orifices, common flow passages, and pitch conversion flow passages that connects the common flow passages and liquid chambers to each other. The pitch conversion flow passages includes a periphery formed with resin. In a case where a number of pitch conversion flow passages in a group is minimum on a condition that one or more of the pitch conversion flow passages are respectively included in the group, the pitch conversion flow passages have a repeating pattern in which the group is repeatedly arranged. At least one of two pitch conversion flow passages adjoining an m-th pitch conversion flow passage (m is all integers from 1 to n−2, where n is an integer of 3 or more) is one of first to (m+1)-th pitch conversion flow passages.

A liquid ejection head having a channel member which includes an ejection hole surface and a pressurization chamber surface opposite thereto. An actuator substrate overlaps the pressurization chamber surface. The channel member includes a plurality of ejection holes opening in the ejection hole surface, a plurality of pressurization chambers individually communicating with the plurality of ejection holes and arranged in plan view of the pressurization chamber surface, and a plurality of dummy pressurization chambers positioned outside of the predetermined region in plan view of the pressurization chamber surface. The actuator substrate includes a plurality of pressurization portions that individually pressurize the pressurization chambers, and a plurality of dummy pressurization portions that individually pressurize the dummy pressurization chambers. The dummy pressurization chambers communicate with each other via a plurality of communication paths. A closed space including the plurality of dummy pressurization chambers and the plurality of communication paths is hermetically closed.

A liquid ejection head includes a flow channel structure, a supply channel structure, a piezoelectric element, a sealing substrate, and a heater. The flow channel structure defines an ejection channel including an individual channel and a manifold. The individual channel has a nozzle and a pressure chamber in which pressure is applied to liquid for causing the liquid to be ejected from the nozzle. The supply channel structure defines a supply channel configured to allow the liquid to flow therethrough to the ejection channel. The piezoelectric element is positioned on an upper surface of the flow channel structure and facing the pressure chamber via a vibration plate. The sealing substrate is made of a material having a higher thermal conductivity than the supply channel structure. The sealing substrate surrounds the piezoelectric element on the flow channel structure to seal the piezoelectric element. The heater is disposed at the sealing substrate.