The printing apparatus includes: a time-division driving unit configured to divide a plurality of printing elements into a plurality of blocks, and between a target reference signal and the next reference signal, drive the plurality of printing elements at a time interval for each of the blocks on a basis of the target reference signal to thereby perform one column of printing, wherein the time-division driving unit drives, in a case where in a first column, a time after the target reference signal is acquired and until the next reference signal is acquired is shorter than a time required for one column of printing, the plurality of printing elements so that a time required for printing the second column in which the next printing is performed becomes shorter than a time required for one column of printing in the first column.

An inkjet head driving method includes applying a voltage signal having a combined drive waveform that includes unit drive waveforms to a pressure generator and causing a nozzle to jet ink droplets such that the droplets land on a medium as one droplet. Each unit drive waveform includes a first pulse waveform for jetting a droplet and a second pulse waveform for pulling back the jetted droplet. The first and second pulse waveforms each include an expansion part for expanding a pressure chamber and a following contraction part for contracting the chamber. The combined drive waveform includes a first unit drive waveform and a following second unit drive waveform. A voltage amplitude of the contraction part of the second pulse waveform in the second unit waveform is greater than that of the contraction part of the second pulse waveform in the first unit drive waveform.

A liquid ejection device includes a head having a nozzle, an element causing the nozzle to eject liquid, a reservoir configured to store the liquid to be supplied to the nozzle, and a controller. The controller is configured to change a drive signal to drive the element based on a quantity of the liquid stored in the reservoir.

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 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.

A first output section outputs a first parameter calculated for each nozzle in a group obtained by dividing the nozzles into groups for each certain number so that density unevenness of ink ejected from each nozzle in the group is corrected. A second output section outputs a second parameter calculated for each group so that change rate of the density unevenness between groups is corrected. A first register circuit divides first parameters for each nozzle in the group and stores the first parameters. A second register circuit divides second parameters for each group and stores the second parameters. A multiplication section sequentially multiplies the first parameters by the second parameters. A conversion section converts a multiplication value to correction data of each nozzle. A setting section sets the correction data in a memory.

In accordance with an embodiment, an inkjet head comprises an ejection section and a driving section. The ejection section ejects ink according to the operations of an actuator. In order to make the ejection section eject different amount of ink for different drops, the driving section applies voltage to the actuator of the ejection section such that the ejection section ejects ink continuously based on the printing data indicating the times the ejection section ejects ink and a position flag designating a drop frame number where ink starting to be ejected.

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.

A driving pulse to be applied is changed when an overlapped level of invert timing of driving pulse is large.

An inkjet printing system includes at least one drop ejector array module having an array of drop ejectors disposed on a substrate. A primary temperature sensor is located near a first set of drop ejectors. At least one secondary temperature sensor is located near a second set of drop ejectors. Temperature comparison circuitry on the substrate is configured to compare signals from the primary temperature sensor and the at least one secondary temperature sensor. Pulse modification circuitry on the substrate is electrically connected to the temperature comparison circuitry and is configured to modify an input pulse waveform. The inkjet printing system also includes a controller that is electrically connected to the primary temperature sensor via a temperature output pad and to the pulse modification circuitry via a pulse waveform input pad.