In a case of executing first printing that printing is performed by using a first group, which includes nozzles of a nozzle array whose distances to a detection unit are less than a first predetermined value, and thereafter executing second printing that printing is performed by using a second group, which includes nozzles of the nozzle array whose distances to the detection unit are equal to or less than the first predetermined value and are equal to or more than a second predetermined value, a first driving pulse for the first printing is determined by using a first temperature, which is detected by the detection unit when the first printing is performed. A second driving pulse for the second printing is determined by use of a second temperature, which is derived based on the first temperature and corresponds to a temperature of the nozzles of the second group.

Recording elements are driven by changing a driving pulse applied thereto in accordance with information regarding a total number of times the recording elements have been driven.

In an example, a print head comprises a nozzle to be activated by a delayed fire pulse that is delayed from an initial fire pulse, a sensor to measure an impedance of the nozzle, and a detector to determine a first time instant following the delayed fire pulse for registering a first impedance measurement by the sensor.

A controller adapted for an inkjet printing system is described. The controller can include an analyzer and a prefire inserter. The analyzer can be configured to determine whether a nozzle arrangement should generate a fire pulse in a current line, and whether the last preceding fire pulse was further in the past than an interval value threshold N. The prefire inserter can be configured to insert one or more prefire pulses into the N lines before the current line.

In an example, a method for determining an issue in an inkjet nozzle includes providing an initial fire pulse for firing a nozzle, and receiving the initial fire pulse as a delayed fire pulse at a primitive of the nozzle. The method includes firing the nozzle with the delayed fire pulse, and determining a first time instant following the delayed fire pulse for taking a first impedance measurement across the nozzle.

There is provided a liquid discharge apparatus, including: a drive element configured to apply discharge energy to the liquid to discharge the liquid; signal generators configured to generate a plurality of types of drive signals having mutually different waveforms to drive the drive element; and drive switches electrically located between the signal generators and the drive element to correspond to the plurality of types of drive signals respectively. The drive switches include a first drive switch and a second drive switch which are different in ON-resistance.

Methods and systems are described herein for driving droplet ejection devices with multi-level waveforms. In one embodiment, a method for driving droplet ejection devices includes applying a multi-level waveform to the droplet ejection devices. The multi-level waveform includes a first section having at least one compensating edge and a second section having at least one drive pulse. The compensating edge has a compensating effect on systematic variation in droplet velocity or droplet mass across the droplet ejection devices. In another embodiment, the compensating edge has a compensating effect on cross-talk between the droplet ejection devices.

Methods and systems are described herein for driving droplet ejection devices with multi-level waveforms. In one embodiment, a method for driving droplet ejection devices includes applying a multi-level waveform to the droplet ejection devices. The multi-level waveform includes a first section having at least one compensating edge and a second section having at least one drive pulse. The compensating edge has a compensating effect on systematic variation in droplet velocity or droplet mass across the droplet ejection devices. In another embodiment, the compensating edge has a compensating effect on cross-talk between the droplet ejection devices.

A liquid discharging apparatus includes a driving signal creation section that creates a driving signal, a discharge section provided with a piezoelectric element, and a pressure chamber, and a detection section that is capable of detecting residual vibrations. The driving signal creation section is capable of creating a signal having an inspection waveform of which a potential of a first period is a first potential, a potential of a second period is a second potential, and a potential of a third period is a third potential, as the driving signal. The first potential is a potential that is between the second potential and the third potential, and the internal volume of the pressure chamber in a case in which the driving signal is the second potential is smaller than the internal volume of the pressure chamber in a case in which the driving signal is the third potential.

A controller adapted for an inkjet printing system is described. The controller can include an analyzer and a prefire inserter. The analyzer can be configured to determine whether a nozzle arrangement should generate a fire pulse in a current line, and whether the last preceding fire pulse was further in the past than an interval value threshold N. The prefire inserter can be configured to insert one or more prefire pulses into the N lines before the current line.