The invention relates to a method for detecting a failing ejection unit in an array of ejection units during printing of a digital image with liquid ink in a printer wherein a medium is transported relative to the array. The printed image is captured to density values on print positions of the printed image. The invented method comprises a step of adapting a halftone mask that is used in preparation of the digital image, such that from a variation in the image density around the line shaped defect the exact nozzle number associated with the failing ejection unit can be determined.

In a device for regenerating a print head of an inkjet printing device, a fluid is applied onto the nozzle plate of the print head. The one or more nozzles of the print head can be subsequently operated with one or more no-ejection pulses to produce the effect that fluid is drawn from the nozzle plate into the one or more nozzles and mixes with the ink in the one or more nozzles that the viscosity of the ink in the one or more nozzles is reduced.

There are provided a characteristic table generation system and so on capable of enhancing the convenience of the user. The characteristic table generation system according to an embodiment of the present disclosure is a system for generating a predictive voltage characteristic table for defining a predictive characteristic curve, the system including a data acquisition section configured to obtain a measured viscosity characteristic table defining a measured characteristic curve between viscosity and temperature of the liquid, and a predetermined parameter separately, as input data, a conversion coefficient generation section configured to generate a conversion coefficient used when performing a conversion process from the measured characteristic curve into the predictive characteristic curve based on the predetermined parameter using a first analytical method as a predetermined analytical method which takes the predetermined parameter as an explanatory variable, and which takes the conversion coefficient as an objective variable, and a table generation section configured to perform the conversion process using the measured viscosity characteristic table and the conversion coefficient generated by the conversion coefficient generation section to thereby generate the predictive voltage characteristic table.

A liquid ejecting apparatus includes a first pressure chamber communicating with a first nozzle configured to eject a liquid, a second pressure chamber adjacent to the first pressure chamber and communicating with a second nozzle configured to eject the liquid, and a first driving element corresponding to the first pressure chamber. The liquid ejecting apparatus executes a detection operation of detecting a fluctuation in the pressure of the liquid within the second pressure chamber that occurred when the first driving element was driven to cause the pressure of the liquid within the first pressure chamber to fluctuate.

A liquid ejecting apparatus has: a liquid discharge section configured to change an inner volume of a first pressure chamber communicating with a nozzle by a first piezoelectric element; a pressure vibration section configured to change an inner volume of a second pressure chamber by a second piezoelectric element; a driving signal generation section configured to generate a discharging driving signal for the first piezoelectric element and a detection driving signal for the second piezoelectric element; and a vibration detection section that detects residual vibration of a liquid filled in the second pressure chamber after the supply of the detection driving signal. The viscous resistance of a flow path between the second pressure chamber and the common flow path is lower than the viscous resistance of a flow path between the first pressure chamber and the common flow path.

In a method of controlling a liquid ejecting apparatus, where the liquid ejecting apparatus includes a pressure chamber that communicates with a nozzle that ejects a liquid, a drive element that changes a pressure of the liquid in the pressure chamber, and a drive circuit that supplies the drive element with an ejection pulse that generates a change in the pressure that ejects the liquid from the nozzle, the method includes specifying a viscosity of the liquid in the nozzle and a surface tension of the liquid in the nozzle from a residual vibration when the pressure of the liquid in the pressure chamber is changed, and controlling a waveform of the ejection pulse according to the viscosity and the surface tension.

A liquid discharge apparatus includes a diaphragm, a pressure chamber substrate including a partition wall partitioning a pressure chamber communicating with a nozzle discharging liquid, a piezoelectric element including a first active portion that overlaps a center of the pressure chamber and a second active portion that overlaps the pressure chamber at a position closer to an outer edge of the pressure chamber than the first active portion, and a drive signal generation portion that generates a discharge signal for discharging the liquid by being supplied to one of the first active portion and the second active portion and a correction signal that is supplied to the other of the first active portion and the second active portion, in which a potential of the discharge signal changes over time and a potential of the correction signal is constant during a discharge period for discharging the liquid.

A method for driving a liquid ejecting apparatus according to a thickening state of liquid in a nozzle determined by a thickening determination section. When the thickening state is a first state, a second flushing signal by which liquid is ejected from a nozzle is supplied a first number of times to the driving element without applying a micro vibration signal by which liquid is not ejected from a nozzle. When the thickening state is a second state in which viscosity of the liquid is higher than viscosity of the liquid in the first state, the second flushing signal that is different from a first flushing signal is supplied the first number of times after applying the micro vibration signal, and a first flushing signal by which liquid is ejected from a nozzle is supplied a second number of times to the driving element after applying the second flushing signals.

A liquid jetting device is arranged to eject a droplet of a liquid. The device includes a nozzle, a liquid duct connected to the nozzle, an electro-mechanical transducer arranged to create an acoustic pressure wave in the liquid in the duct, and an electronic control system arranged to apply to the transducer a voltage signal having a waveform configured for ejecting a droplet from the nozzle. The waveform is further configured to quench a residual acoustic pressure wave in the liquid duct and includes a jet pulse, a subsequent first quench pulse having a polarity opposite to that of the jet pulse, and a subsequent second quench pulse having the same polarity as the jet pulse.

A liquid ejecting apparatus is configured to drive a drive element that is driven in accordance with a drive signal for ejecting a plurality of liquid droplets such that the liquid droplets merge together before landing onto a medium. The drive signal includes a plurality of drive waveforms and a first connection waveform that is continuous from a second-to-last drive waveform and continuous to a last drive waveform and along which a potential of the drive signal is kept at a reference level. Pressure changes caused by the contraction waveform of the last drive waveform in a liquid present inside the pressure compartment are larger than pressure changes caused by the contraction waveform of the second-to-last drive waveform in the liquid present inside the pressure compartment. A period of the first connection waveform is 0.8 or more times as long as a natural vibration cycle of the ejecting portion.