An inkjet printhead includes two groups of interleaved nozzles. First and second sets of drop-formation waveforms are associated with the groups of nozzles to selectively cause portions of a liquid jet to break off into drops. A timing delay device time-shifts the second-group waveforms relative to those associated with the first-group waveforms. A charging-electrode waveform having portions with first and second potentials is provided to a charging electrode. The waveform energies of the second-group waveforms is larger than the waveform energies of the corresponding first-group waveforms so that printing drops break off from the liquid jets while the charging-electrode is at the first potential, and non-printing drops break off from the liquid jets while the charging-electrode is at the second potential.

An inkjet printhead includes two groups of interleaved nozzles. First and second sets of drop-formation waveforms are associated with the groups of nozzles to selectively cause portions of a liquid jet to break off into drops. A timing delay device time-shifts the second-group waveforms relative to those associated with the first-group waveforms. A charging-electrode waveform having portions with first and second potentials is provided to a charging electrode. The waveform energies of the second-group waveforms is larger than the waveform energies of the corresponding first-group waveforms so that printing drops break off from the liquid jets while the charging-electrode is at the first potential, and non-printing drops break off from the liquid jets while the charging-electrode is at the second potential.

A liquid discharge apparatus includes a liquid discharge head including a head module provided with a discharge section configured to be driven by a drive signal and discharge a liquid and a supply section configured to supply the drive signal to the discharge section in accordance with a designation signal for designating an operation in the discharge section, and a state signal output section configured to output a state signal, and a wire section including a first wire to which the state signal is supplied, a second wire configured to supply the designation signal, and a third wire configured to supply the drive signal. The first wire includes a first shielding layer containing a conductive material, a second shielding layer containing a conductive material, and a first conductor provided between the first shielding layer and the second shielding layer, the first conductor being configured to transmit the state signal.

A liquid discharge apparatus includes a liquid discharge head including a head module provided with a discharge section configured to be driven by a drive signal and discharge a liquid and a supply section configured to supply the drive signal to the discharge section in accordance with a designation signal for designating an operation in the discharge section, and a state signal output section configured to output a state signal, and a wire section including a first wire to which the state signal is supplied, a second wire configured to supply the designation signal, and a third wire configured to supply the drive signal. The first wire includes a first shielding layer containing a conductive material, a second shielding layer containing a conductive material, and a first conductor provided between the first shielding layer and the second shielding layer, the first conductor being configured to transmit the state signal.

A liquid ejecting apparatus includes a liquid ejecting head including a substrate where a plurality of hollow portions are formed, a flexible plane that delimits a part of the hollow portion, and a piezoelectric element provided corresponding to the hollow portion, an inspection mechanism that inspects ejection of liquid from a nozzle based on an electromotive force of the piezoelectric element, and a signal generation circuit that generates a first drive signal and a second drive signal. The second drive signal maintains a state, where a second vibration portion including the second piezoelectric element and the flexible plane corresponding to the second piezoelectric element is deformed, during a detection period in which the inspection mechanism performs inspection based on vibration caused when a first vibration portion including the first piezoelectric element and the flexible plane corresponding to the first piezoelectric element is driven.

A liquid ejecting apparatus includes a liquid ejecting head including a substrate where a plurality of hollow portions are formed, a flexible plane that delimits a part of the hollow portion, and a piezoelectric element provided corresponding to the hollow portion, an inspection mechanism that inspects ejection of liquid from a nozzle based on an electromotive force of the piezoelectric element, and a signal generation circuit that generates a first drive signal and a second drive signal. The second drive signal maintains a state, where a second vibration portion including the second piezoelectric element and the flexible plane corresponding to the second piezoelectric element is deformed, during a detection period in which the inspection mechanism performs inspection based on vibration caused when a first vibration portion including the first piezoelectric element and the flexible plane corresponding to the first piezoelectric element is driven.

A device for forming and ejecting drops of an ink jet of a CIJ printing machine, this device including: a cavity for containing an ink and including an end provided with a nozzle (10) for ejecting ink drops, actuator means (21, 22, 32, 41, 42), in contact with the cavity, in which device the jet velocity modulation, from the nozzle (10), has a value Vj(f.sub.t) at the operating frequency of the cavity and the actuator, and this jet velocity modulation, at the temperature of 15 C. and at the temperature of 35 C., does not vary, in a frequency range of 5 kHz about the operating frequency f.sub.t, outside the range of between 0.25Vj(f.sub.t) and 4Vj(f.sub.t).

A device for forming and ejecting drops of an ink jet of a CIJ printing machine, this device including: a cavity for containing an ink and including an end provided with a nozzle (10) for ejecting ink drops, actuator means (21, 22, 32, 41, 42), in contact with the cavity, in which device the jet velocity modulation, from the nozzle (10), has a value Vj(f.sub.t) at the operating frequency of the cavity and the actuator, and this jet velocity modulation, at the temperature of 15 C. and at the temperature of 35 C., does not vary, in a frequency range of 5 kHz about the operating frequency f.sub.t, outside the range of between 0.25Vj(f.sub.t) and 4Vj(f.sub.t).

A fluid ejection device is provided with a valving element adapted to reciprocate in the containing chamber to thereby push the fluid out from the ejection port, and then block the ejection port with a tip part. The containing chamber is provided with a communication port for accepting the fluid pressure-fed from a supply section. In the case in which the valving element is located at a predetermined stopping position, a internal space of the containing chamber is divided by a boundary part, which is formed of a part of the valving element and a part of the containing chamber having contact with each other, into a first space including a part of the space between the ejection port and the communication port, and a second space in which the communication port opens.

A fluid ejection device is provided with a valving element adapted to reciprocate in the containing chamber to thereby push the fluid out from the ejection port, and then block the ejection port with a tip part. The containing chamber is provided with a communication port for accepting the fluid pressure-fed from a supply section. In the case in which the valving element is located at a predetermined stopping position, a internal space of the containing chamber is divided by a boundary part, which is formed of a part of the valving element and a part of the containing chamber having contact with each other, into a first space including a part of the space between the ejection port and the communication port, and a second space in which the communication port opens.