A liquid discharge apparatus includes a print head discharging a liquid and a control circuit controlling an operation of the print head. the print head includes a connector having a first terminal, a second terminal, a third terminal, and a fourth terminal, a first integrated circuit, a circuit substrate on which the connector and the first integrated circuit are provided and which has first wiring, second wiring, third wiring, fourth wiring, fifth wiring, and sixth wiring, and a first wiring substrate, in which the first wiring electrically couples the first terminal and the first integrated circuit to each other, the fifth wiring electrically couples the first terminal and the first integrated circuit to each other, and the sixth wiring electrically couples the first integrated circuit and the first wiring substrate to each other.

Reduction of the size of the droplet in 1-drop ejection is easily performed. A liquid jet head according to an example of the disclosure includes a nozzle adapted to jet a liquid, a piezoelectric actuator having a pressure chamber communicated with the nozzle and filled with the liquid, and adapted to vary a capacity of the pressure chamber, and a control section adapted to apply a pulse signal to the piezoelectric actuator to thereby expand and contract the capacity of the pressure chamber so as to jet the liquid filling the pressure chamber. The control section applies the pulse signal adapted to expand the capacity in the pressure chamber when jetting 1 drop of the liquid so as to include a first pulse signal having a pulse width one of equal to or shorter than an on-pulse peak, and a second pulse signal disposed with a predetermined time interval from the first pulse signal.

A connection cable electrically connects a head unit and a head unit control circuit. The head unit includes: an ejector, a determination circuit, and an ejection limit circuit. The ejector includes a displaceable piezoelectric element for controlling the liquid ejection. The piezoelectric element is displaced by changing a drive signal potential. The determination circuit determines whether the piezoelectric element has a predetermined electrical storage capability. The ejection limit circuit stops the drive signal to limit the ejection of the liquid based on the determination. The connection cable includes: a first connection supplying a determination instruction signal from the head unit control circuit to the head unit; a second connection supplying the drive signal from the head unit control circuit to the head unit; and a third connection between the first and second connections with a smaller potential change width than the second connection when the ejector ejects the liquid.

An ink-jet recording apparatus, including: a recording head including a first nozzle communicating with a first chamber storing a first ink and a second nozzle communicating with a second chamber storing a second ink whose viscosity change rate differs from the first ink; and a controller configured to determine a drive voltage to be a first voltage and determine voltage application timings for the respective first and second nozzles to be a first timing when estimated viscosity of the first ink is lower than a first viscosity and to determine the drive voltage to be a second voltage higher than the first voltage, determine the voltage application timing for the first nozzle to be the first timing, and determine the voltage application timing for the second nozzle to be a second timing different from the first timing when the estimated viscosity is equal to or higher than the first viscosity.

Thermal inkjet printing wherein a printhead has ink ejection elements which are energizable by electrical pulses of a given energy with fire pulses of an amplitude (V) and a fire pulse width (fp). A printer controller sends commands to the printhead to spit ink drops, one or more temperature sensors coupled to the printhead measure a temperature of the printhead, and a calibration component coupled to the temperature sensor variably adjusts the fire pulse energy provided to the having ink ejection elements of the printhead. The calibration component initiates calibrating the printhead, spitting a number (X) of ink drops at a frequency (Y) by the electrical pulses, reading and storing printhead temperature, varying the fire pulse energy by repeating spitting ink drops and reading and storing printhead temperature, finding minimum temperature from the stored printhead temperatures, and deriving an operational fire pulse (fp.sub.op) from a fire pulse (fp.sub.on) that has produced the minimum temperature, wherein the printer controller uses the operational fire pulse (fp.sub.op) for printing.

A printing apparatus for printing using a printhead including a plurality of nozzles each configured to discharge ink and a plurality of sensors, corresponding to the plurality of nozzles, for detecting a discharge state of ink from the plurality of nozzles, judges a discharge state. More specifically, the apparatus prints, based on print data, an image by driving the printhead under a first drive condition to discharge the ink from the printhead to a first area, discharges ink to a second area different from the first area by driving the printhead, based on inspection data, under a second drive condition different from the first drive condition, and judges a discharge state of each nozzle by monitoring an output from each sensor at a timing of driving the printhead under the second drive condition.

First electronics may determine a count of bubble jet resistors to be fired by a fire pulse group. A fire pulse generator may generate a fire pulse train for bubble jet resistors, the fire pulse train comprising a precursor pulse and a firing pulse separated by a dead time. Second electronics may adjust a width of the fire pulse for the bubble jet resistors of the fire pulse group by maintaining a first edge of the fire pulse relative to the precursor pulse and adjusting a second edge of the fire pulse relative to the precursor pulse based upon the determined count for the fire pulse group.

In an inkjet printer, when an estimated viscosity of a first ink in a first nozzle is less than a threshold value, a power supply generates a first drive voltage, and when the estimated viscosity of the first ink is the threshold value or more, the power supply generates a second drive voltage higher than the first drive voltage. Moreover, at a time of vibrating a meniscus of a second ink in a second nozzle, when the first drive voltage is generated by the power supply, there is output to a drive element a first meniscus vibration signal, and when the second drive voltage is generated, there is output a second meniscus vibration signal by which energy imparted to the second ink by the drive element when applied to the drive element at an identical voltage level will be smaller compared to the first meniscus vibration signal.

A driving circuit includes an amplification circuit that outputs an amplified modulation signal and a level shift circuit. In the level shift circuit, when a reference potential of the amplified modulation signal is shifted to a second potential from a first potential, a second gate driver outputs a third gate signal for controlling a third transistor to be nonconductive and a fourth gate signal for controlling a fourth transistor to be conductive, then outputs the third gate signal for controlling the third transistor to be conductive and the fourth gate signal for controlling the fourth transistor to be nonconductive, and thereafter outputs the third gate signal for controlling the third transistor to be nonconductive and the fourth gate signal for controlling the fourth transistor to be conductive.

An inkjet head includes a pressure chamber in which ink is stored, a nozzle plate including a nozzle which connects with the pressure chamber, an actuator configured to change a volume of the pressure chamber, and a drive circuit. The drive circuit, before a printing is performed, outputs, to the actuator for a first time period, a first signal for changing the volume of the pressure chamber without ejecting ink from the nozzle. A second signal for changing the volume of the pressure chamber is then output to the actuator for a second time period such that ink is ejected from the nozzle. A third signal for changing the volume of the pressure chamber to the extent that the ink is not ejected from the nozzle is then output to the actuator for a third time period.