A liquid discharge head includes a nozzle from which a liquid is dischargeable in a liquid discharge direction, an individual chamber communicating with the nozzle, a common chamber configured to store the liquid to be supplied to the individual chamber, a pressure generator configured to apply pressure to the liquid in the individual chamber, a holder holding the pressure generator, a first temperature detector adjacent to the common chamber, the first temperature detector configured to detect temperature proximate to the common chamber, and a second temperature detector held by the holder, the second temperature detector configured to detect temperature of the holder.

A method for forming piezoelectric transducers for inkjet printheads includes: forming at least one piezoelectric layer on a substrate; forming at least one electrode pattern by depositing a conductive material on an exposed surface of the at least one piezoelectric layer; and forming a plurality of individual piezoelectric elements from the at least one piezoelectric layer before or after the forming of the at least one electrode pattern.

A liquid discharge head to improve reliability of a dummy pressurization chamber, and a recording device including the liquid discharge head, the liquid discharge head including a channel member having discharge holes, pressurization chambers, a dummy pressurization chamber, and a substrate having pressurizing parts. The channel member includes a pressurization chamber plate, a dummy pressurization chamber plate, and stacked plates. A hole of the pressurization chamber plate has a side surface configuring a side surface of the pressurization chamber, and the hole has an opening configuring an opening of the pressurization chamber. A hole of the dummy pressurization chamber plate has a side surface configuring a side surface of the dummy pressurization chamber, and the hole has an opening configuring an opening of the dummy pressurization chamber. The substrate closes the openings of the pressurization chambers. The pressurization chamber plate closes the opening of the dummy pressurization chamber.

A liquid discharging head includes: a nozzle plate having a plurality of nozzles from which liquid is discharged; a channel member including a plurality of individual liquid chambers that lead to the plurality of nozzles, respectively, and including a plurality of circulation channels that lead to the plurality of individual liquid chambers, respectively; and a common liquid chamber member for forming a common liquid chamber that supplies liquid to the plurality of individual liquid chambers and for forming a circulation common liquid chamber that leads to the plurality of circulation channels.

A liquid circulation device includes a circulation passage, a liquid feeding device, a pressure sensor, and control circuitry. Through the circulation passage, liquid circulates to be supplied to and collected from a circulatory liquid discharge head. The liquid feeding device is configured to circulate the liquid through the circulation passage. The pressure sensor is configured to detect a pressure of the circulation passage. The control circuitry configured to acquire a characteristic indicating a relationship among a drive amount of the liquid feeding device, discharge information of the liquid discharged from the liquid discharge head, and a pressure detection value of the circulation passage; and change, based on the characteristic acquired, at least one of a control parameter and a calculation expression used to control the liquid feeding device.

Actuator device has a main body with base and superstructure bodies, the device having a plurality of actuators formed from a piezoelectric or electrostrictive material and each extend from the base body and form the superstructure body. The actuators each have at least two inner actuating electrodes of which at least one first inner actuating electrode extends, in a positive depthwise direction from the front side up to a distance from the rear side, and of which at least one second inner actuating electrode extends in a negative depthwise direction from the rear side up to a distance from the front side. At least one first inner actuating electrode of each actuator is provided for electrical connection to a first connection pole of an actuating device, a rear-side layer which is formed from electrically conductive material arranged on the rear side of the actuator device.

A liquid discharge head includes a plurality of nozzles, a plurality of individual liquid chambers, a circulation channel, a circulation common liquid chamber, a common liquid chamber, and a vibration damping member. The plurality of nozzles discharges liquid. The plurality of individual liquid chambers is communicated with the plurality of nozzles. The circulation channel is communicated with the plurality of individual liquid chambers. The circulation common liquid chamber is communicated with the circulation channel. The common liquid chamber supplies the liquid to the plurality of individual liquid chambers. The common liquid chamber includes a first portion disposed side by side with the circulation common liquid chamber in an in-plane direction and a second portion having a width greater than a width of the first portion in the in-plane direction. The vibration damping member is recoverably deformable and constitutes a wall surface of the second portion of the common liquid chamber.

According to one embodiment, a liquid discharge head includes a flexible printed circuit (FPC) connected to piezoelectric elements. The FPC has a first end in the first direction. A wiring layer of the FPC has a first region at the first end and a cover layer covering on a second region. The piezoelectric elements are spaced from each other in a second direction and each has a first electrode on a side surface facing towards the FPC. The first side has a joint surface facing the first region of the wiring layer. The first electrode is electrically connected to the wiring layer at the joint surface. The side surface includes a step portion that is recessed from the joint surface. A portion of the cover layer protrudes into a space adjacent to the step portion.

There is provided a liquid discharge head including: a channel unit; a piezoelectric actuator; and a protective member. Pressure chambers form pairs of the pressure chambers arranged in a second direction. Each of the pressure chamber pairs includes a first pressure chamber and a second pressure chamber that communicate with an identical nozzle via a communication channel. The protective member includes first partition walls joined to a surface at a first side in a first direction of the piezoelectric actuator and separating accommodating spaces from each other. Each of the first partition walls is provided between the first pressure chamber and the second pressure chamber, which belong to different pressure chamber pair, in the second direction. Each of the first partition walls is not provided between the first pressure chamber and the second pressure chamber, which belong to an identical pressure chamber pair, in the second direction.

A piezoelectric element includes a first electrode, a piezoelectric layer formed of a first piezoelectric film which is formed on the first electrode and which includes potassium, sodium, and niobium and a plurality of second piezoelectric films which are formed on the first piezoelectric film and which include potassium, sodium, and niobium, and a second electrode formed on the piezoelectric layer, in which the piezoelectric layer is a stack of a plurality of piezoelectric films, the first piezoelectric film has a thickness of 30 nm to 70 nm, a concentration of sodium in each of the piezoelectric films is along a gradient in the film thickness direction with the first electrode side being high and the second electrode side being low.