A fluid ejection device may include fluid actuators and an actuation controller. Each fluid actuator may have an associated address. The actuation controller is to receive an address for a fluid actuator of the device to be actuated and is further to automatically transmit one of different fire pulses based upon the received address.

Systems and methods are provided for printhead waveform adjustment. One embodiment is a system that includes a controller that correlates a series of printhead waveforms input to a printhead with a series of optical density values output by the printhead. The controller determines a single target optical density for the printheads based on an average optical density of the printheads. Also, for each of the printheads, the controller determines a functional relationship between the parameter of the printhead waveforms input to the printhead and the optical density values output by the printhead, and determines a target printhead waveform parameter for the printhead based on the single target optical density input to an inverse of the functional relationship. The controller updates printhead settings to include information of the target printhead waveform parameter determined for each of the printheads for applying to the printheads to output ink at consistent optical density.

An example device in accordance with an aspect of the present disclosure includes modules to generate an input signal, apply the input signal to an ink sample to obtain an ink signal, compare the ink signal to a reference value, and identify whether the ink signal is consistent with an ink signature. A module may be contained on an inkjet printhead die.

A signal generation device includes a first signal generation portion and a second signal generation portion. The first signal generation portion, based on a reference signal that includes a plurality of rectangular single-wave signals, generates an original common signal in which the rise times of the two or more of the single-wave signals are extended so that they are different from each other, and the fall timing of one or more of the single-wave signals is shifted. The second signal generating portion generates a drive signal to be input to a piezoelectric element by extracting a rising edge of any one of the single-wave signals, the rise time of which is extended, from the original common signal amplified by the amplifying portion, maintaining a signal level changed by extracting the rising edge of the single-wave signal, and extracting a falling edge of a single-wave signal after the single-wave signal.

An electronic circuit for driving an inkjet print element in an array of print elements with an electric waveform is provided. The print element includes a piezo transducer for converting the electric waveform in a mechanical displacement. The electric waveform is tunable for an individual print element. The circuit includes a common waveform generator that is connected to the piezo transducer through a first print data dependent switch for providing an electric waveform independent of the print element. The circuit further includes a waveform tuning part, dependent on the print element and the print data, for controlling a second switch that adds electric energy from a voltage source to the electric waveform. The switches are operable in either a saturation state or a blocking state to limit an amount of dissipation in the switches.

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 printer as an example of a liquid discharging apparatus includes a nozzle, a drive signal generation unit that generates a drive signal for driving a piezoelectric element, and a discharge abnormality detection unit that detects a change of an electromotive force of the piezoelectric element, which is caused by residual vibration in a cavity after the drive signal is supplied. The drive signal generation unit generates a first drive signal for checking whether or not a first discharge abnormality caused by a foreign substance adhering to a surface on which the nozzle opens occurs and a second drive signal for checking whether or not a second discharge abnormality caused by a cause other than the foreign substance occurs. A potential of the first drive signal when the discharge abnormality detection unit (example of the residual vibration detection unit) performs checking is different from a potential of the second drive signal when the discharge abnormality detection unit performs checking.

In a method to active print nozzles of an inkjet printer including a print head having print nozzles and respective actuators associated with each of the print nozzles, one or more conveying pulses are generated to eject respective droplets of ink from the respective print nozzle; and the actuator is activated with one or more intermediate pulses having an amplitude and/or a duration that is less than an amplitude and/or a duration of the one or more conveying pulses. The one or more intermediate pulses can be configured such that no ink is ejected from the respective print nozzle with the one or more intermediate pulses.

In at least one embodiment, a number of nozzle rows in a first area on a side of one end of a first substrate closest to one end of a print head is set to be lower than a number of nozzle rows on a central side of the print head relative to the first area, and energy for driving the element on the first substrate is set to be larger than energy for driving the element on a second substrate on the central side of the print head relative to the first substrate to set a dot to be formed on the recording medium by ink discharged from a nozzle in the first area to be larger than a dot to be formed on the recording medium by ink discharged from a nozzle in the second substrate.

A printing system includes a print station for receiving print medium traveling along a transport pathway and an adjustable print head assembly. A medium dispenser transports the print medium on the transport pathway to the print station, and a medium width sensor detects the width of the print medium. A pressure sensor arrangement detects pressure imposed by the print head assembly at points along the width of the transport pathway when an image is printed on the print medium. A monitoring subsystem in communication with the medium width sensor and the pressure sensor arrangement calculates, based upon the detected width and the detected pressure, amounts of pressure imposed by the print head assembly along the width of the print medium.