A piezoelectric device including a flow path forming substrate in which pressure chambers are formed, a diaphragm, and piezoelectric actuators. Active portions, each having a piezoelectric layer interposed between a first electrode and a second electrode, are each, in plan view, provided from an edge portion opposing the pressure chamber to a portion outside the pressure chamber, and a ratio of a film thickness of the piezoelectric layer to a film thickness of the diaphragm is 4.7 or less.

A liquid ejection head includes a plate with a plurality of nozzles arranged along a first direction through which liquid is ejected. A substrate is on the plate and includes a hole extending along the first direction by which the liquid is supplied. An actuator is on the substrate along the hole, The actuator has a plurality of pressure chambers, from which the liquid from the hole is ejected by the nozzles, and a plurality of air chambers. Each air chamber is between two of the pressure chambers that are adjacent to each other. A plurality of individual electrodes is formed on the substrate and each is connected to a corresponding one of the pressure chambers. A common electrode is formed on the substrate and an inner peripheral surface of the hole.

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.

A liquid ejection apparatus is configured to control a supply of a drive signal to a drive element by a controller so that a target period is either an ejection period or a non-ejection period based on print data. The drive signal includes an ejection pulse and a non-ejection pulse. The controller: does not supply the non-ejection pulse to the drive element when the target period is the non-ejection period and an elapsed time length from the last ejection period is less than the predetermined time length, and supplies the non-ejection pulse to the drive element when the target period is the non-ejection period and the elapsed time length is equal to or longer than the predetermined time length. The predetermined time length is an integral multiple or more of ½ of a natural vibration cycle of a meniscus of a liquid in the nozzle.

A liquid ejection module includes a pressure chamber, a supply flow channel that supplies a liquid to the pressure chamber, a collection flow channel that collects the liquid from the pressure chamber, a liquid feeding chamber connected to one of the supply flow channel and the collection flow channel, and a connection flow channel connecting the liquid feeding chamber to the other of the supply flow channel and the collection flow channel. The liquid feeding chamber includes a liquid feeding mechanism that circulates the liquid in the supply flow channel, the pressure chamber, the collection flow channel, the liquid feeding chamber, and the connection flow channel. A ratio of a sum of flow channel resistance of the supply flow channel, the pressure chamber, and the collection flow channel relative to flow channel resistance of the connection flow channel is equal to or above 0.5.

There is provided a piezoelectric element including: a substrate; a first electrode formed at a first substrate surface of the substrate in a first direction; a first piezoelectric layer that is formed at the first electrode and that includes a flat surface portion along the first substrate surface and an inclined surface portion inclined with respect to the flat surface portion; a second piezoelectric layer that is formed at the inclined surface portion 170a and whose thickness is smaller than a thickness of the flat surface portion of the first piezoelectric layer; and a second electrode formed at at least the flat surface portion.

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.

There is provided a liquid discharging head including: supply manifolds; a supply integration channel which extends linearly along an arrangement direction crossing a longitudinal direction of the supply manifolds; return manifolds; and a return integration channel which extends linearly along the arrangement direction. The supply integration channel has a supply port arranged apart from the supply manifolds, being configured to supply liquid to the supply integration channel via the supply port, and at least a part of the supply port being overlapped, in a plan view, with a pressure chamber-arranging area in which pressure chambers communicating with nozzles are arranged. The return integration channel has a return port arranged apart from the return manifolds, being configured to drain the liquid from the return integration channel via the return port, and at least a part of the return port being overlapped, in the plan view, with the pressure chamber-arranging area.

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.

A head unit includes a recording head, a head-side frame, a unit frame, a first head mounting member, a second head mounting member, a head angle adjustment mechanism, and an urging member. The unit frame is configured to hold the recording head on both side surfaces of a main frame standing along a width direction orthogonal to a conveyance direction of a recording medium. The urging member is arranged on a side opposite to an opposing surface of the first head mounting member and the second head mounting member with respect to the main frame, and is configured to urge the head-side frame in a direction of separating away from the main frame, A counteraction of a pressing force that acts on the head-side frame from the urging member acts on the first head mounting member and the second head mounting member from the head-side frame.