There is provided a printing device, which includes a print engine provided with an ejection head configured to eject droplets of ink introduced from a container containing the ink and configured to perform printing using the ink droplets on a recording sheet, and a controller. The controller is configured to automatically set a drive signal pattern defining a signal pattern to drive the ejection head in accordance with contract information concluded for the printing device or for a use by a user of the printing device.

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 (μm), 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.

Printheads and methods of operation. In one embodiment, a printhead includes a plurality of jetting channels comprising first jetting channels configured to jet a first print fluid and second jetting channels configured to jet a second print fluid, and a driver circuit communicatively coupled to actuators of the jetting channels. The driver circuit receives a drive waveform comprising non-jetting pulses and jetting pulses, and gating signals comprising a first active gating signal designated for jetting the first print fluid, and a second active gating signal designated for jetting the second print fluid. The driver circuit selectively applies the non-jetting pulses and the jetting pulses to actuators of the first jetting channels based on the first active gating signal to jet the first print fluid, and selectively applies the jetting pulses to actuators of the second jetting channels based on the second active gating signal to jet the second print fluid.

An actuator drive circuit of a liquid discharge apparatus includes a discharge waveform generating circuit, a sleep waveform generating circuit, and a wake waveform generating circuit. The discharge waveform generating circuit is configured to generate a plurality of drive waveforms to be applied to actuators of the liquid discharge apparatus for liquid discharge. The drive waveforms correspond to gradation values of gradation scale data. The sleep waveform generating circuit is configured to generate a sleep waveform to be applied to the actuators. The sleep waveform causes a voltage of the actuators to transition to a first voltage without liquid discharge. The wake waveform generating circuit is configured to generate a wake waveform to be applied to the actuators. The wake waveform causes the voltage of the actuators to transition to a second voltage higher than the first voltage without liquid discharge.

A liquid discharging apparatus includes: a head having a plurality of nozzles; and a controller. The controller executes: a discharging processing of discharging liquid, from each of the nozzles toward a recording medium, in a liquid droplet amount which is selected for each of pixels from at least three kinds of liquid droplet amounts; and a total discharge amount calculating processing of calculating a total discharge amount of the liquid to be discharged from the nozzles in the discharging processing, based on the liquid droplet amount selected for each of the pixels and a discharge duty which is density of the liquid droplet per a unit area of the recording medium.

A liquid discharging apparatus includes: a channel unit having a nozzle and an individual channel; an actuator applying pressure to liquid in the individual channel to discharge the liquid from the nozzle; a driving circuit electrically connected to the actuator and supplying driving signal to the actuator; and a controller. In a case of determining that a single-sided recording is to be executed, the controller supplies the driving signal corresponding to each of gradation values for each of pixels when discharging the liquid toward one of a first surface and a second surface of a recording medium; in a case of determining that the double-sided recording is to be executed, the controller supplies the driving signal corresponding to each of the gradation values for each of the pixels when discharging the liquid toward the first surface and when discharging the liquid toward the second surface.

A liquid discharge head includes an actuator and a drive circuit. The actuator is configured to expand and contract a pressure chambers. The drive circuit is configured to apply a first drive waveform to cause the actuator to discharge a liquid droplet at a first speed, and then a second drive waveform after the first drive waveform to cause the actuator to discharge a liquid droplet at a second speed slower than the first speed.

There is provided an ink jet recording apparatus including an ink jet head and a drive circuit. The ink jet head forms an image on a recording medium in response to a drive signal applied to multiple piezoelectric elements. The drive signal causes multiple pressure chambers corresponding to the multiple piezoelectric elements to expand or to contract in volume and causes ink in the multiple pressure chambers to be discharged from multiple nozzles. The drive circuit generates a drive signal for discharging multiple liquid droplets to one pixel for combining the multiple liquid droplets together and applies the drive signal to each of the multiple piezoelectric elements of the ink jet head. The drive signal includes multiple discharge pulses which make velocities of tips of respective liquid columns substantially same after a predetermined time from starting of ink discharge from the nozzles.

There is provided a liquid discharge apparatus including: a channel unit having a nozzle surface in which a nozzle is opened; an actuator configured to apply an energy for discharging a liquid from the nozzle; and a controller. Ohnesorge number Oh is in a range from 0.17 to 0.34. The controller is configured to drive the actuator so that a velocity v of the liquid discharged from the nozzle is not more than 8 m/s.

A liquid discharge apparatus includes a head and a switching device. The head includes a piezoelectric element and a pressure chamber configured to discharge liquid. The switching device is configured to select application or non-application of a drive voltage waveform to the piezoelectric element. The drive voltage waveform includes a discharge waveform to pressurize and discharge the liquid in the pressure chamber and a damping waveform to suppress residual vibration in the pressure chamber. The damping waveform is disposed after the discharge waveform in time series. The switching device includes a switch and a diode. The switch is configured to be turned on in a falling waveform element of each of the discharge waveform and the damping waveform. The diode is connected in parallel with the switch in a direction opposite to the falling waveform element of each of the discharge waveform and the damping waveform.