A method for setting a drop shape in a printing process, including the steps of controlling (S101) a piezo element of a printing nozzle by a first voltage profile; detecting (S102) an electric current value averaged over the first voltage profile or a sound amplitude averaged over the first voltage profile; controlling (S103) the piezo element of the printing nozzle by a second voltage profile; detecting (S104) an electric current value averaged over the second voltage profile or a sound amplitude averaged over the second voltage profile; and selecting (S105) the voltage profile with the lower detected current value or the lower detected sound amplitude.

A method for analyzing a print head (103), including the steps of driving (S101) a piezo element within the print head with a sequence of voltage profiles; and detecting (S102) a sound level, a current flow, a resistance, an impedance, and/or a temperature of the print head during the driving.

A method for delivering a predetermined amount of fluid from a fluid ejection head. The method includes measuring one or more parameters selected from fluid flow parameters and electrical parameters for the fluid ejection head to provide one or more measured parameters; calculating a fluid ejection offset value from the one or more measured parameters; storing the fluid ejection offset value in a memory location on the fluid ejection head; accessing the fluid ejection offset value by an ejection head controller; and adjusting an amount of fluid ejected from the fluid ejection head during a fluid ejection step using the fluid ejection offset value to provide the predetermined amount of fluid from the fluid ejection head.

According to one embodiment, a driving device for liquid ejection heads includes a control unit configured to apply a multi-droplet waveform to a liquid ejecting element. The multi-droplet waveform is one of a plurality of preset patterns in which each droplet waveform in the multi-droplet waveform is one of a reference ejection waveform or a minute adjustment waveform. The reference ejection waveform causes a droplet of a nominal reference volume to be ejected by the liquid ejecting element. The minute adjustment waveform causes a droplet of less than the nominal reference volume to be ejected by the liquid ejecting element in variable volume increments.

There is provided a printing apparatus including: a head having a discharge surface in which a nozzle configured to discharge a liquid droplet in a first direction is opened; a light-emitter configured to emit light; a light-receiver configured to receive the light; a gradient adding member configured to add a gradient to a light intensity of an optical path of the light in each of second and third directions, the second and third directions intersecting the first direction, the second and third directions intersecting with each other; and a controller. The optical path intersects a flying area in which the liquid droplet from the nozzle flies at a position between the gradient adding member and the light-receiver. The controller is configured to detect a deviation of a flying direction of the liquid droplet based on an amount of the light received by the light-receiver.

A liquid discharge apparatus includes a liquid discharge head configured to discharge a liquid, and a drive waveform generator configured to generate a drive waveform to be applied to the liquid discharge head, the drive waveform including a first discharge pulse to cause the liquid discharge head to discharge the liquid, a second discharge pulse after the first discharge pulse, the second discharge pulse to cause the liquid discharge head to discharge the liquid, and a pulse interval between the first discharge pulse and the second discharge pulse, the pulse interval being equal to a time period in which the liquid is discharged by the second discharge pulse in a damping state in which the second discharge pulse is damped by a meniscus vibration generated by the first discharge pulse.

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.

Systems and method of maintaining a uniform temperature distribution in an inkjet head. The inkjet head includes a plurality of ink channels that jet droplets of a liquid material onto a medium using piezoelectric actuators. A temperature controller includes a non-jetting pulse generator that provides non-jetting pulses to one or more of the piezoelectric actuators to generate heat. The non-jetting pulses cause the piezoelectric actuators to actuate without jetting a droplet from its corresponding ink channel.

A driving circuit for driving a capacitive load includes a signal modulation section that causes an original drive signal to be pulse-modulated to generate a modulation signal, a signal amplification section that amplifies the modulation signal to generate an amplification modulation signal, and a coil that smooths the amplification modulation signal to generate a drive signal.

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.