An inkjet head drive apparatus comprises a pressure chamber, an actuator, a nozzle and a drive signal output section. The pressure chamber accommodates an ink. The actuator increases or decreases volume of the pressure chamber through an applied a voltage. The nozzle is connected with the pressure chamber to eject the ink through the change in the volume of the pressure chamber. When an ejection pulse for the ejection of the ink from the nozzle is repeated for equal to or greater than three times, the drive signal output section outputs a drive signal having a driving waveform including an initial ejection pulse having a first voltage amplitude and the second ejection pulses and the pulses thereafter having a second voltage amplitude smaller than the first voltage amplitude to the actuator.

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.

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.

A printhead, comprises: a plurality of element substrates that each include a first element substrate adjacent to a second element substrate in a first direction, wherein a first print element array arranged in the first element substrate includes a first print element that is closest to the second element substrate in the first direction, and a second print element array arranged in the second element substrate includes a second print element closest to the first element substrate in the first direction, and an order of arrangement in the second direction of at least the first print element and a first driving circuit corresponding to the first print element is opposite to an order of arrangement in the second direction of the second print element and a second driving circuit corresponding to the second print element.

An ink jet head includes a pressure chamber, a nozzle plate including a nozzle, an actuator configured to cause an ink to be discharged from the pressure chamber via the nozzle, and a drive circuit configured to supply to the actuator an expansion signal, having a pulse width equal to a natural vibration cycle of the ink in the pressure chamber, that expands the pressure chamber to an expanded state from an initial state, a release signal, having a pulse width longer than the natural vibration cycle and shorter than three times the natural vibration cycle, that returns the pressure chamber to the initial state from the expanded state, and a contraction signal, having a pulse width longer than the natural vibration cycle and shorter than three times the natural vibration cycle, that contracts the pressure chamber to a contracted state from the initial state.

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.

The present invention has a problem of suppressing liquid gathering of an interpolation dot which interpolates a discharge defective nozzle and preventing deterioration of image quality, and the problem is solved by the present invention including: an inkjet head configured to separately discharge a large droplet, a medium droplet, and a small droplet from each of a plurality of nozzles; and a control unit which forms an image in a single-pass system by discharging the medium droplets from the plurality of nozzles respectively, and forms an interpolation dot to interpolate a discharge defective nozzle by discharging a droplet from a different nozzle when the discharge defective nozzle is present, the control unit forming the interpolation dot to interpolate the discharge defective nozzle with the use of the large droplet and forming at least one adjacent dot which is in contact with the interpolation dot with the use of the small droplet.

A liquid discharging head includes a channel member which has a plurality of individual channels, each of the plurality of individual channels having a pressure chamber communicating with a nozzle, and a piezoelectric actuator which is configured to make the liquid discharge from the nozzle by causing a change in a pressure on a liquid inside the pressure chamber. The piezoelectric actuator has a thin-film piezoelectric element, and when a Helmholtz natural frequency of the pressure chamber is let to be Fr (kHz) and a diameter of the nozzle is let to be D (?m), a relationship
D<?0.0313?Fr+25.62 (provided that, 100 kHz?Fr)
is satisfied, and a viscosity of the liquid discharged from the nozzle is not higher than 5 mPa.Math.s.

A method for providing a drive waveform for a droplet ejection apparatus. The method includes the steps of receiving a nominal drive waveform including a droplet ejection pulse having a nominal maximum amplitude Vmax(nominal) and for achieving a nominal droplet velocity vel(nominal) and further including a nominal non-ejecting pulse, ahead of the droplet ejection pulse, wherein the nominal non-ejecting pulse is spaced apart from the droplet ejection pulse by a first delay d1; receiving a target droplet velocity vel(target) and/or a target maximum amplitude of the droplet ejection pulse Vmax(target); adjusting one or more waveform parameters on the basis of the received vel(target) and/or Vmax(target) to provide an adjusted drive waveform to achieve at least one of vel(target) and Vmax(target); and outputting the adjusted drive waveform. A method is also provided for operating a droplet ejection apparatus.

A liquid discharge apparatus uses a drive signal including a micro-vibration waveform which causes the piezoelectric element to micro-vibrate such that an ink is not discharged from the nozzle in a case of being applied to the piezoelectric element as the drive signal and a drive waveform which deforms piezoelectric element such that the ink is discharged from the nozzle in a case of being applied to the piezoelectric element as the drive signal. The presentation unit selectably presents the indirect information from which the ink discharge status can be estimated such as the types of ink and the usage status of the ink or the like. The control unit changes the strength of the micro-vibration caused by the micro-vibration waveform based on the indirect information selected on the presentation unit.