In a method for operating an inkjet print head for generating a droplet of a liquid, the inkjet print head comprises a number of ejection units, each ejection unit comprising a piezo-electric actuator having a signal electrode, a common electrode and a piezo-electric layer interposed between the signal electrode and the common electrode. The method comprises providing a non-jetting pulse signal on a common electrode, wherein the non-jetting pulse signal is adapted to generate a pressure wave in the liquid in the corresponding ejection unit without expelling a droplet of the liquid. The method further comprises providing a jetting pulse signal on a signal electrode, wherein the jetting pulse signal is adapted to generate a pressure wave in the liquid in the corresponding ejection unit such that a droplet of the liquid is expelled.

Further, an inkjet print head assembly comprising an inkjet print head and a control circuitry is provided. The inkjet print head assembly is configured for performing the above method.

A printer includes an ink ejecting section that ejects ink from a nozzle, an ink circulation path including an ink flow path through which the ink can be supplied to an ink ejecting section and an ink return path through which the ink supplied to the ink ejecting section is returned, a warming device including a temperature control module provided in the ink circulation path, where the warming device can heat the ink in the temperature control module, and a feed pump that can flow the ink in the ink circulation path, wherein the flow rate of the ink, in the ink circulation path, heated by the warming device is adjusted.

In a method to check a fixative print head for nozzle failures, a reference mark is printed by the nozzles of a colored ink print head and a test mark is printed via overprinting of the colored ink by the nozzles of the colored ink print head and of a fixative by the nozzles of the fixative print head onto a printing substrate web. The test mark and the reference mark are compared with one another. If the reference mark and the test mark correspond to one another (e.g., at least in part), this indicates that nozzles of the fixative print head are operating incorrectly. If operating incorrectly, the nozzles have, for example, failed entirely or eject the fixative at too great an angular deviation.

There is provided a liquid discharge apparatus including a discharge head including nozzles and actuators; a liquid detecting sensor; and a controller. The controller is configured to: cause the actuators to perform a discharge operation; calculate a discharge amount of the liquid discharged from each of the nozzles; determine the discharge amount of the liquid; and cause a first actuator corresponding to a first nozzle, whose discharge amount is less than a first predetermined amount, and a second actuator corresponding to a second nozzle, whose discharge amount is not less than the first predetermined amount and less than a second predetermined amount, to perform a flushing, without causing a third actuator corresponding to a third nozzle, whose discharge amount is not less than the second predetermined amount, to perform the flushing.

A method of compensating for an inoperable inkjet in a printer includes applying a first modification to a first swath of image data that includes a raster corresponding to the inoperable inkjet in image data of a printed image. The method also includes applying a plurality of modifications to a plurality of swaths in the image data to generate a plurality of modified swaths in the image data, where each swath in the plurality of swaths includes a plurality of rasters that do not include the raster corresponding to the inoperable inkjet. The method further includes forming a printed image based on the modified swaths of image data to compensate for an inoperable inkjet in the printer.

Method and respective device for the detection and correction of printing defects of a digital printing device (A) comprising the following steps: —arranging a digital printing device (A) equipped with one or more print heads (H) with a plurality of dispensing nozzles (N); —continuously controlling said plurality of dispensing nozzles (N) to realize a real printing pattern (RPP) on a printing medium (P); —continuously acquiring the real printing pattern (RPP); —detecting at least one printing defect (DF); —elaborating, onboard a control unit of the digital printing device (A), at least one compensation scheme to mask a detected printing defect (DF,); —applying said compensation device during the realization of said real printing pattern (RPP).

A digital printing press includes a printing cylinder configured to transport a sheet, a driving device (41) configured to drive the printing cylinder, an encoder (44) configured to detect the phase of the printing cylinder, and first to fourth inkjet heads (23-26) configured to print the sheet. The digital printing press includes a floating detector (22) facing the printing cylinder and configured to detect an abnormality of the sheet, a display device (8), and a control device (28) configured to control an operation of the driving device (41). The control device (28) includes a function of stopping the driving device (41) when the floating detector (22) detects a floating portion. The control device (28) includes a function of obtaining information specifiable a position of an abnormality occurrence portion based on the phase of the printing cylinder when the floating detector (22) detects the floating portion and the phase of the printing cylinder when the driving device (41) stops after floating detection and displaying the information on the display device (8). It is possible to provide a digital printing press capable of quickly specifying an abnormality occurrence portion detected during printing.

A liquid ejecting apparatus includes a print head, a digital signal output circuit, and a liquid accommodating container, and the print head includes a supply port to which the liquid is supplied from the liquid accommodating container, a nozzle plate having a plurality of nozzles, a substrate that has a first surface and a second surface different from the first surface, a connector to which the digital signal is input, and an integrated circuit to which the digital signal is input via the connector and that outputs an abnormality detection signal indicating presence or absence of an abnormality in the print head, the connector is provided on the first surface, the integrated circuit is provided on the second surface, and a through hole that penetrates the first surface and the second surface is provided in a mounting region on which the integrated circuit is provided in the substrate.

For assessing the functioning of an ejection unit of an inkjet print head, a comparison of a residual pressure wave with a residual pressure wave reference is employed. To enable assessment during printing, multiple residual pressure wave references are provided, each relating to a condition relevant to the residual pressure wave. Such a condition may relate to an actuation status of an adjacent ejection unit which may cause crosstalk, for example. When performing the assessment, the condition during assessment is taken into account, for example for selecting a suitable residual pressure wave reference, such that an appropriate and correct assessment can be performed independent from the conditions during assessment.

A liquid ejection head unit includes a first energy generating element that generates energy that applies pressure to a liquid in the first pressure chamber; a second energy generating element that generates energy that applies pressure to a liquid in the second pressure chamber; a nozzle flow path which communicates the first pressure chamber and the second pressure chamber and in which a nozzle that ejects a liquid is provided; a drive circuit that drives the first energy generating element and the second energy generating element by applying a drive pulse; a detection circuit that detects a parameter related to a physical property of a liquid in the second pressure chamber; wherein a controller drives the first energy generating element by the drive circuit, and performs a first detection operation of detecting the parameter in the second pressure chamber by the detection circuit.