Abstract: A controller for a print head of an inkjet printing device is described that is configured to generate a virtual timing signal during a printing pause of the printing device, and to use the virtual timing signal for the generation of pre-ejection pulses in order to produce a reliable regeneration of the nozzles of the print head during the printing pause.

Abstract: Provided is a device for controlling the printing of a print image with a nozzle of an inkjet printing device. The device is configured to—given the presence of a relatively long printing pause of the nozzle insert one or more print image-independent pre-ejection pulse phases, followed by a print image-dependent pre-ejection pulse phase, between the printing of two successive dots, in order to efficiently and reliably increase the print quality of the printing device.

Abstract: Provided is a device for determining an empty ink state of an ink container for an ink printing system. The ink container has a rigid outer container and an inner, flexible fluid pouch. The inner fluid pouch is connected via a fluid conduit to a pump that is configured to convey fluid out of the inner fluid pouch. The pump is configured to output an electrical signal whose periodicity is proportional to a rotational speed of the pump. The device has an evaluation unit that is configured to monitor the frequency of the electrical signal and, upon the frequency falling below a predetermined threshold, to output that the ink container is empty.

Abstract: A method and an arrangement for calibrating a delivery rate of an ink pump of a printing device with the aid of an ink container including a sensor unit for detecting at least a first fill level value. Based on the initial fill level of the ink container below the first fill level value, the ink pump conveys ink from an ink reservoir into the ink container up to a final fill level above the first fill level value, so that at least a predetermined volume between the initial fill level and the first fill level value is filled. Upon conveying the ink into the ink container, an ink pump parameter is determined as of reaching the initial fill level and until the first fill level value is reached. A delivery rate of the ink pump is determined based on the predetermined volume and the ink pump parameter.

Abstract: An arrangement for supplying ink to a print bar with small pressure fluctuations may include an ink reservoir and a damping vessel. The print bar may include at least two print heads and is connected with the ink reservoir via a supply line. Each of the print heads is connected with the damping vessel via at least one damping line. The damping vessel is connected with a discharge line. The end of the damping line ends at a first height in the damping vessel. The end of the discharge line ends at a second height above the first height in the damping vessel. The arrangement may supply ink to the print bar with small gas fraction in the ink.

Abstract: In the print data for a nozzle of a printer, white dots are replaced by pre-ejection pulses. One or more repetitions of the pre-ejection pulses may be inserted into the print data, depending on the actual print speed of the printer, to determine print speed-dependent print data with which the nozzle is activated to print a print image with high print quality.

Abstract: A device may be configured to check, via evaluation of resistance data of a cleaning sensor arranged on a print bar of an inkjet printing device, whether a cleaner for cleaning the one or more print heads of the print bar exhibits a negative effect. The state of a cleaner may be reliably and efficiently monitored via the installation of a cleaning sensor in a print bar.

Abstract: A method and an arrangement for calibrating a delivery rate of an ink pump of a printing device with the aid of an ink container including a sensor unit for detecting at least a first fill level value. Based on the initial fill level of the ink container below the first fill level value, the ink pump conveys ink from an ink reservoir into the ink container up to a final fill level above the first fill level value, so that at least a predetermined volume between the initial fill level and the first fill level value is filled. Upon conveying the ink into the ink container, an ink pump parameter is determined as of reaching the initial fill level and until the first fill level value is reached. A delivery rate of the ink pump is determined based on the predetermined volume and the ink pump parameter.

Abstract: 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.

Abstract: An arrangement for supplying ink to a print bar with small pressure fluctuations may include an ink reservoir and a damping vessel. The print bar may include at least two print heads and is connected with the ink reservoir via a supply line. Each of the print heads is connected with the damping vessel via at least one damping line. The damping vessel is connected with a discharge line. The end of the damping line ends at a first height in the damping vessel. The end of the discharge line ends at a second height above the first height in the damping vessel. The arrangement may supply ink to the print bar with small gas fraction in the ink.

Abstract: A controller for a print head of an inkjet printing device is described that is configured to generate a virtual timing signal during a printing pause of the printing device, and to use the virtual timing signal for the generation of pre-ejection pulses in order to produce a reliable regeneration of the nozzles of the print head during the printing pause.

Abstract: A device may be configured to check, via evaluation of resistance data of a cleaning sensor arranged on a print bar of an inkjet printing device, whether a cleaner for cleaning the one or more print heads of the print bar exhibits a negative effect. The state of a cleaner may be reliably and efficiently monitored via the installation of a cleaning sensor in a print bar.

Abstract: In a method for adjusting a setup for an encoder for printing to a recording medium of unknown thickness with a multi-row inkjet print head in a printing system, a continuous test line is printed onto the recording medium, transversal to a feed direction of said recording medium, a varied width of the test line is measured, and the adjustment of the setup is modified to minimize the width of the test line.

Abstract: An ink supply system for a print bar of an inkjet printing device includes two supply lines that travel along the longitudinal axis of the print bar and direct ink with opposite flow direction. The print heads of the print bar are respectively connected to both supply lines via a connecting line in order to supply ink to said print heads. A uniform mean hydraulic pressure is produced in all print heads via the opposite flow directions in the two supply lines.

Abstract: In order to determine the nip between a print head and a printing substrate in an ink printing apparatus, ink droplets of a first and second size are simultaneously fired toward the printing substrate by different nozzles of a nozzle row of the print head given a predetermined feed velocity of the printing substrate, whereby print dots of a first size are generated on the printing substrate in a first two print dot row and print dots of a second size are generated on the printing substrate in a second two print dot row. The clearance of the first two print dot row from the second two print dot row is subsequently measured, and the size of the nip is determined from the measured clearance.

Abstract: In the print data for a nozzle of a printer, white dots are replaced by pre-ejection pulses. One or more repetitions of the pre-ejection pulses may be inserted into the print data, depending on the actual print speed of the printer, to determine print speed-dependent print data with which the nozzle is activated to print a print image with high print quality.

Abstract: In a method for adjusting a setup for an encoder for printing to a recording medium of unknown thickness with a multi-row inkjet print head in a printing system, a continuous test line is printed onto the recording medium, transversal to a feed direction of said recording medium, a varied width of the test line is measured, and the adjustment of the setup is modified to minimize the width of the test line.

Abstract: A device for automatic adjustment of print heads in a printing machine is presented. The device can include at least one motor and a controller. The motor can drive at least one drive element for at least one retaining element, and drive at least one drive element for at least one adjustment element. The controller can control the at least one motor to: drive the at least one drive element to loosen the at least one retaining element, drive the at least one drive element to position the at least one adjustment element at a predetermined nominal value to position the adjustment element, and drive the at least one drive element to tighten the at least retaining element.

Abstract: 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.

Abstract: An ink supply system for a print bar of an inkjet printing device comprises two supply lines that travel along the longitudinal axis of the print bar and direct ink with opposite flow direction. The print heads of the print bar are respectively connected to both supply lines via a connecting line in order to supply ink to said print heads. A uniform mean hydraulic pressure is produced in all print heads via the opposite flow directions in the two supply lines.