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.

A liquid ejection apparatus includes: a liquid ejection head having nozzles; a signal output device; a recovery device configured to perform a first recovery operation or a second recovery operation, to discharge liquid from the nozzles; and a controller configured to: in response to receiving a second signal, activate the signal output device, and drive the liquid ejection head in a check mode for ejecting liquid from the nozzles, the second signal instructing to record a check pattern on a recording medium; in response to receiving a first signal indicating that a first nozzle being one of the nozzles is in failure in liquid ejection when the liquid ejection head in driven in the check mode, activate the recovery device to perform the first recovery operation; and subsequent to the first recovery operation, drive the liquid ejection head to record the check pattern on the recording medium.

A driving device includes a piezoelectric element, a driving electrode, a first switch that performs switching whether to electrically couple the first wire to the driving electrode, a detection circuit that detects, via a second wire, a vibration produced in the piezoelectric element, a second switch that performs switching whether to electrically couple the second wire to the driving electrode, and a determination circuit that determines a state of the piezoelectric element. The second switch remains off during a first period, remains on during a second period subsequent to the first period, remains off during a third period subsequent to the second period, and remains on during a fourth period subsequent to the third period. The determination circuit determines a state of the piezoelectric element, based on a detection result of the detection circuit in at least part of the fourth period.

A printing apparatus includes a print head provided with a discharge port that discharges liquid and a pressure chamber filled with the liquid to be discharged from the discharge port, and configured to perform a printing operation by discharging the liquid from the discharge port based on print data, includes a circulation unit that performs circulation of the liquid in a circulation passage including the pressure chamber in a state where the printing operation is performed, and includes a control unit that controls the circulation unit to continue the circulation for a predetermined time after the printing operation is completed.

A fluid ejection device includes a number of primitives, each receiving a same set of addresses and including a number of ejection chambers, each corresponding to a different address of the set of addresses and including a drive bubble formation mechanism and a drive bubble detect (DBD) mechanism. Input logic receives nozzle column data groups (NCG), each NCG including fire pulse groups (FPG), each FPG including DBD data having an enable value or disable value, and ejection data bits, each ejection data bit corresponding to a different one of the primitives. For each FPG of each NCG, activation logic identifies the FPG as a DBD FPG when the DBD data has the enable value and activates in each primitive the drive bubble formation mechanism and the DBD mechanism identified by the DBD FPG to perform a DBD measurement.

A printing apparatus, which uses a printhead including a circuit configured to inspect an ink discharge status of a selected nozzle using a temperature detection element, causes the printhead to inspect the ink discharge status by changing a threshold value for judging a detection result of the temperature detection element, in order to judge the ink discharge status in a state in which a heater in the selected nozzle is driven by each of a first pulse and a second pulse whose waveform is different from that of the first pulse, obtains first information about a change point where a judgment result obtained by the first pulse changes, and second information about a change point where a judgment result obtained by the second pulse changes, and sets the threshold value, based on the first and second information.

A liquid ejecting apparatus includes a head unit that ejects liquid, in which the head unit includes an integrated circuit and an ejector, the integrated circuit includes a drive signal input terminal that inputs a first drive signal, a first signal input terminal that inputs a first signal, a second signal input terminal that inputs a second signal, a first reference voltage signal input terminal that inputs a first reference voltage signal, a differential signal receiving circuit that converts a pair of first differential signals into a control signal and outputs the control signal, a drive signal selection circuit that outputs a second drive signal based on the control signal and the first drive signal, and a drive signal output terminal that outputs the second drive signal to the ejector, and the first signal input terminal and the first reference voltage signal input terminal are located adjacent to each other.

An liquid ejecting apparatus includes a drive signal output circuit, a control signal output circuit, a differential signal output circuit, a residual vibration signal input circuit, and a head unit, in which the head unit includes an integrated circuit and an ejector, and the integrated circuit includes a drive signal input terminal that inputs a first drive signal, a residual vibration signal output terminal that outputs a residual vibration signal, a differential signal receiving circuit that converts a pair of differential signals into a control signal and outputs the control signal, a drive signal selection circuit that outputs a second drive signal based on the control signal and the first drive signal, a drive signal output terminal that outputs the second drive signal to the ejector, and a residual vibration signal output circuit that outputs a residual vibration signal based on the residual vibration generated by driving the piezoelectric element.

A digital printer and a method of controlling the digital printer having a print head with an array of printing elements and a failure detection system arranged to detect malfunctioning printing elements. When, during printing, a malfunctioning printing element is detected, a switch from the current print strategy to another print strategy is arranged during printing which leaves the number of passes per swatch constant, i.e. the print quality is not affected by the switch.

An inspection apparatus is disclosed. The inspection apparatus includes a laser, an optical sensor, and a controller. In operation, the laser outputs at least one laser beam, the optical sensor measures an intensity of the at least one laser beam passing through a lower region adjacent to the inkjet head, and the controller controls an ink ejection from the inkjet head based on the intensity of the at least one laser beam.