A fluid ejection apparatus includes a plurality of fluid ejectors. Each fluid ejector includes a pumping chamber, and an actuator configured to cause fluid to be ejected from the pumping chamber. The fluid ejection apparatus includes a feed channel fluidically connected to each pumping chamber; and at least one compliant structure formed in a surface of the feed channel. The at least one compliant structure has a lower compliance than the surface of the feed channel.

There is provided liquid discharging head including common liquid chambers each extends along first direction and arranged in second direction orthogonal to the first direction; and individual channels each communicates with one of the common liquid chambers and each has nozzle. The liquid discharging head has first and second ends in the second direction. The common liquid chambers include intermediate common liquid chamber interposed between two of the common liquid chambers and expanded common liquid chamber closest to the first end, length of the expanded common chamber in the second direction being longer than length of the intermediate common chamber in the second direction. The nozzles of the individual channels communicating with the expanded common chamber are positioned on a side of the second end with respect to the expanded common chamber without being positioned on a side of the first end with respect to the expanded common chamber.

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.

A liquid discharge head includes a base plate, a cavity plate located on the base plate and including a cavity, and a piezoelectric actuator substrate located on the cavity plate. The cavity plate includes: a first groove located inside a contact region with the piezoelectric actuator substrate and configured to release an adhesive for bonding the cavity plate and the piezoelectric actuator substrate; and a second groove located in a manner to surround the contact region with the piezoelectric actuator substrate and configured to release the adhesive. The base plate includes a third groove configured to open the first groove to the atmosphere. The third groove is configured to communicate between the first groove and the outside through a first hole communicating with the first groove and a second hole located outside the contact region of the cavity plate and the piezoelectric actuator substrate.

A piezoelectric actuator includes a common electrode on a piezoelectric layer at a first side adjacent to a first surface and extends over a plurality of piezoelectric elements. A plurality of first individual electrodes is on the piezoelectric layer at a second side adjacent to a second surface. Each of the plurality of first individual electrodes is at a piezoelectric element of the plurality of piezoelectric elements, and are not electrically connected together. A first insulating layer is on the common electrode at the first side and extends over the plurality of piezoelectric elements. A plurality of second individual electrodes is on the first insulating layer at the first side. Each of the plurality of second individual electrodes is at a piezoelectric element of the plurality of piezoelectric elements, and overlap centers of the plurality of first individual electrodes. The plurality of second individual electrodes are electrically connected together.

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 droplet deposition apparatus comprising a droplet deposition head, a fluid supply and a controller, wherein: the droplet deposition head comprises one or more fluid chambers each having a nozzle, a fluid inlet path having a fluid inlet into the head, and ending in the one or more nozzles, and a fluid return path starting at the one or more nozzles and ending in a fluid return of the head; each fluid chamber comprises two opposing chamber walls comprising piezoelectric material and deformable upon application of an electric drive signal so as to eject a fluid droplet from the nozzle; the fluid supply is configured to supply a fluid to the fluid inlet at a differential pressure as measured between the fluid inlet and the fluid return; and the controller is configured to apply a drive signal to the piezoelectric chamber walls such that the nozzle or nozzles deposit droplets of a fluid having a viscosity in the range from 45 mPa.Math.s to 130 mPa.Math.s at a jetting temperature between 20° C. and 90° C., and wherein the differential pressure applied by the fluid supply causes a fluid return flow into the fluid return at a rate of between 50 ml/min and 200 ml/min. A method of operating the droplet deposition apparatus, and a control system for carrying out the method, are also provided.

There is provided liquid discharging head having unit heads. Each of the unit heads includes: first piezoelectric layer, driving electrodes arranged on surface of the first piezoelectric layer and to each of which one of first and second potentials is to be applied, and common electrode. The common electrode includes: potential receiving part configured to receive one of the first and second potentials; and extending part extending in extending direction orthogonal to the first direction, so as to overlap with the driving electrodes in the first direction. The unit heads are arranged so that the common electrodes of the plurality of unit heads are adjacent to each other in second direction orthogonal to the first direction. The extending directions of two of the common electrodes adjacent to each other in the second direction are opposite to each other.

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.