The control portion controls (i) a discharging operation of discharging the liquid from the plurality of nozzles by driving the plurality of energy generation elements and (ii) a pressurization operation of pressurizing the liquid from the individual flow path side in a state in which the plurality of nozzles are sealed by the sealing portion.

According to one embodiment, a liquid discharge head includes a pressure chamber and a nozzle. The pressure chamber extends in a first direction from a first end to a second end and forms a flow path for a fluid to be ejected from the nozzle. The nozzle is for ejecting liquid from the pressure chamber in a second direction intersecting the first direction. The nozzle is at a position offset from a midpoint of the pressure chamber in the first direction towards one of the first or second ends of the pressure chamber.

A liquid discharge head includes an individual channel which includes: a nozzle; a pressure chamber; a descender of which one end in the first direction is nearer to the nozzle than the other end; and a second connecting channel connecting a second common channel and the one end of the descender. A central axis of the nozzle is positioned between the second common channel and a central axis of the descender in the second direction. The descender includes a first portion including the one end and a second portion positioned between the pressure chamber and the first portion in the first direction. In an end, of the descender, opposite to the second connecting channel in the second direction, an inner wall defining the one end of the first portion protrudes toward the second connecting channel in the second direction beyond an inner wall defining the second portion.

A liquid discharge head includes: a first pressure chamber group formed by pressure chambers arranged in a first direction; a second pressure chamber group formed by pressure chambers arranged in the first direction, and disposed side by side with the first pressure chamber group in a second direction; a first common channel extending in the first direction and communicating with the pressure chambers composing the first pressure chamber group; a second common channel extending in the first direction and communicating with the pressure chambers composing the second pressure chamber group; a first dummy pressure chamber disposed on one side in the first direction relative to the first pressure chamber group; and a second dummy pressure chamber disposed on the one side in the first direction relative to the second pressure chamber group.

A liquid ejecting head that has an ejection surface configured to eject a liquid includes a plurality of head chips that are long in a first direction. The plurality of head chips are arranged inside a virtual parallelogram including a first virtual side and a second virtual side that are in contact with at least one of the plurality of head chips and that extend in the first direction, and a third virtual side and a fourth virtual side that are in contact with at least one of the plurality of head chips and that extend in a second direction intersecting the first direction, and the ejection surface is not overlapped with an acute-angled portion of the virtual parallelogram when the ejection surface is viewed in a normal direction of the ejection surface.

A liquid discharge head that includes piezoelectric elements, a pressure chamber plate defining pressure chambers corresponding to the piezoelectric elements, and a vibrating plate disposed between the piezoelectric elements and the pressure chamber plate is provided. In the liquid discharge head, the vibrating plate has, in a first position and a second position, a first portion and a second portion that is away from the end of the pressure chamber than the first portion in a first direction and has a thickness different from a thickness of the first portion. In the first position, a width of the second portion in the first direction is a first width, and in the second position, a width of the second portion in the first direction is a second width that is less than the first width.

Systems and methods are provided for cover plates for printheads. One embodiment is an apparatus that includes a cover plate for a printhead. The cover plate includes multiple layers of electrically conductive material, a layer of nonconductive ferrite that is sandwiched between the multiple layers, and at least one connector that penetrates through the multiple layers and the layer of nonconductive ferrite to form a conductive pathway for electric current between the multiple layers through the layer of nonconductive ferrite. The cover plate also includes at least one opening that penetrates through the multiple layers and the layer of nonconductive ferrite, and that is configured to align with nozzles of the printhead.

An inkjet print head includes a plurality of droplet jetting devices. The plurality of droplet jetting devices is formed of a nozzle layer defining, for each of the plurality of droplet jetting devices, a nozzle, a membrane layer carrying, on a membrane, a restrictor layer and an actuator for generating pressure waves in a liquid in a pressure chamber that is connected to the nozzle. The actuator is positioned in an actuator chamber in the restrictor layer, and a distribution layer defining a supply line for supplying the liquid to the pressure chamber. The restrictor layer includes an inlet restrictor having a cross-section and an outlet restrictor positioned on opposites sides of the actuator and having a cross-section that is different from the cross-section of the inlet restrictor.

A liquid discharge head includes a plurality of nozzle arrays arranged in a first direction. The plurality of nozzle arrays each includes nozzles from which a liquid is discharged, the nozzles arranged in a second direction intersecting the first direction, and one of two nozzle arrays of the plurality of nozzle arrays adjacent to each other in the first direction include at least two nozzles arranged at different nozzle intervals from corresponding nozzles of another of the two nozzle arrays in the first direction.

A liquid discharging head includes: individual channels; a first common channel; and a second common channel Each of the plurality of individual channels includes: a pressure chamber, a nozzle, a connecting channel, a first communicating channel, and two second communicating channels. A first vector of the first communicating channel has an orientation from one end to the other end of the first communicating channel. Respective second vectors of the two second communicating channels have orientations, each of the orientations being from one end to the other end of one of the two second communicating channels along an extending direction of the two second communicating channels. The first communicating channel is arranged, with respect to the nozzle, on one side in a second direction orthogonal to the first direction, and the two second communicating channels are arranged, with respect to the nozzle, on the other side in the second direction. Each of the orientation of the first vector and the orientation of the second vector includes an orientation component from the one side toward the other side in the second direction.