A liquid discharge apparatus includes: a first discharge section that has a first piezoelectric element and discharges liquid by driving the first piezoelectric element with a driving signal; a driving signal generation section that generates the driving signal; a first selection section that performs a selection operation of selecting whether or not to apply each voltage of a plurality of driving waveforms included in the driving signal to the first piezoelectric element, based on a print data signal; a residual vibration detection section that detects residual vibration of the first discharge section after a voltage of a first driving waveform among the plurality of driving waveforms is applied to the first piezoelectric element; and a control section that generates the print data signal, in which the control section stops the driving signal generation section when causing the residual vibration detection section to detect the residual vibration.

A print head that includes a drive element to be driven when a drive signal is supplied to the drive element and that ejects liquid by the driving of the drive element includes an ejecting module including the drive element and a nozzle from which the liquid is ejected, and a current detecting circuit that detects a drive current generated due to propagation of the drive signal. The current detecting circuit includes a current detector that detects the drive current as a current detection signal, and a processor that controls an operation of the current detecting circuit according to the current detection signal.

A liquid ejecting apparatus includes a first pressure chamber communicating with a first nozzle configured to eject a liquid, a second pressure chamber adjacent to the first pressure chamber and communicating with a second nozzle configured to eject the liquid, and a first driving element corresponding to the first pressure chamber. The liquid ejecting apparatus executes a detection operation of detecting a fluctuation in the pressure of the liquid within the second pressure chamber that occurred when the first driving element was driven to cause the pressure of the liquid within the first pressure chamber to fluctuate.

A liquid ejecting apparatus has: a liquid discharge section configured to change an inner volume of a first pressure chamber communicating with a nozzle by a first piezoelectric element; a pressure vibration section configured to change an inner volume of a second pressure chamber by a second piezoelectric element; a driving signal generation section configured to generate a discharging driving signal for the first piezoelectric element and a detection driving signal for the second piezoelectric element; and a vibration detection section that detects residual vibration of a liquid filled in the second pressure chamber after the supply of the detection driving signal. The viscous resistance of a flow path between the second pressure chamber and the common flow path is lower than the viscous resistance of a flow path between the first pressure chamber and the common flow path.

In a method of controlling a liquid ejecting apparatus, where the liquid ejecting apparatus includes a pressure chamber that communicates with a nozzle that ejects a liquid, a drive element that changes a pressure of the liquid in the pressure chamber, and a drive circuit that supplies the drive element with an ejection pulse that generates a change in the pressure that ejects the liquid from the nozzle, the method includes specifying a viscosity of the liquid in the nozzle and a surface tension of the liquid in the nozzle from a residual vibration when the pressure of the liquid in the pressure chamber is changed, and controlling a waveform of the ejection pulse according to the viscosity and the surface tension.

Example implementations relate to controllers and printers to operate at least one liquid ejection device of a printhead; the liquid ejection device comprising a nozzle and an associated print liquid chamber bearing a transducer to eject print liquid from the nozzle in response to a firing signal; the print chamber being fluidically coupled to a nozzle supply channel; the at least one liquid ejection device comprising a channel coupled to the print liquid chamber and the nozzle supply channel; the channel having a respective actuator to urge print liquid through the print chamber in response to a circulation signal; wherein the controller comprises temperature control circuitry to actuate the respective actuator using a temperature control signal to increase the temperature of print liquid in the print liquid chamber.

A fluidic die including fluid chambers, each including an electrode exposed to an interior of the fluid chamber and each having a corresponding fluid actuator operating at a first voltage level. Monitoring circuitry, operating at a second voltage level lower than the first voltage level, includes a select transistor and a pulldown transistor for each fluid chamber to selectively couple to the electrode, at least the select transistor being a high voltage tolerant transistor to operate at the second voltage in a normal operating condition and having a breakdown voltage level greater than the first voltage level to prevent a fault current from flowing into the select transistor from the electrode in a fault condition if the fluid actuator short-circuits to the electrode.

An infrared permeable ink composition includes an epoxy resin, a curing agent, and a dye, where surface roughness of an optical filter formed by curing the infrared permeable ink composition is equal to or less than about 10 nm.

A liquid ejection head includes a first piezoelectric element that is supplied with a first drive signal, and a second piezoelectric element that is supplied with a second drive signal, wherein the first drive signal transitions from a first potential to a second potential in a first period, maintains the second potential during a second period, and transitions from the second potential to the first potential in a third period, wherein the second drive signal transitions from a third potential to a fourth potential in a fourth period, maintains the fourth potential during a fifth period, and transitions from the fourth potential to the third potential in a sixth period, wherein the first period and the fourth period overlap, wherein the third period and the sixth period overlap, wherein the second potential is higher than the first potential, and wherein the fourth potential is lower than the third potential.

A liquid discharge apparatus includes a diaphragm, a pressure chamber substrate including a partition wall partitioning a pressure chamber communicating with a nozzle discharging liquid, a piezoelectric element including a first active portion that overlaps a center of the pressure chamber and a second active portion that overlaps the pressure chamber at a position closer to an outer edge of the pressure chamber than the first active portion, and a drive signal generation portion that generates a discharge signal for discharging the liquid by being supplied to one of the first active portion and the second active portion and a correction signal that is supplied to the other of the first active portion and the second active portion, in which a potential of the discharge signal changes over time and a potential of the correction signal is constant during a discharge period for discharging the liquid.