Océ´ Printing Systems Gmbh & Co. Kg

Oce Holding B.v.

Philippe Koerner

Ulrich Stoeckle

Harald Myllek

Florian Hitzlsperger

Werner Zollner

In a method to active print nozzles of an inkjet printer including a print head having print nozzles and respective actuators associated with each of the print nozzles, one or more conveying pulses are generated to eject respective droplets of ink from the respective print nozzle; and the actuator is activated with one or more intermediate pulses having an amplitude and/or a duration that is less than an amplitude and/or a duration of the one or more conveying pulses. The one or more intermediate pulses can be configured such that no ink is ejected from the respective print nozzle with the one or more intermediate pulses.

Printer and method to activate print nozzles

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.

Method to check a print head for application of a fixative in an ink printing apparatus

A method for reducing a locally increased viscosity of ink in an ink print head of an ink printer during printing operation includes: a determination of a printing pause with the aid of a pixel preview; an application of a first sequence of pulses for measurement of the activation current of a piezoelement of the ink print head; and an application of a second sequence of pulses for vibration of the ink meniscus at the exit of a nozzle if the ink print head to intermix the ink having locally increased viscosity with ink having the initial viscosity given a threatened failure of the nozzle.

Method to reduce an increased viscosity in an ink print head of an ink printer

A method for stabilizing a print quality in an inkjet printing system is described. The inkjet printing system can include a nozzle arrangement that may be activated with a number of control signals that can be used to fire ink droplets with corresponding different droplet sizes onto a recording medium. In the method for stabilizing a print quality in an inkjet printing system, a rastered image for an image template can be created. The rastered image can be printable by the inkjet printing system using a subset of the different droplet sizes. Further, the nozzle arrangement can be activated with a control signal for an unused droplet size of the different droplet sizes to induce the nozzle arrangement to generate a prefire pulse.

Method to improve the system stability of inkjet printing systems

Described are a system and a method to activate an actuator for a first nozzle of a plurality of nozzles of an inkjet printing system. The inkjet printer system can be configured to generate triggers with a frequency for printing of a respective line of pixels by the plurality of nozzles. The frequency of the triggers can depend on a print speed of the inkjet printing system, and the print speed can be modifiable. A time period between two successive triggers can correspond to a total duration available to the first nozzle for an ink firing for printing of a pixel of the line. An indicator for a current print speed of the inkjet printing system can be determined. Depending on the indicator for the current print speed, a waveform for activation of an actuator can be defined to produce an ink firing for printing of the pixel of the line on the recording medium by the first nozzle within the total duration available at the current print speed. The waveform can be defined such that, depending on the indicator for the current print speed within the total duration available at the current print speed, the waveform includes: a prefire portion for excitation of a meniscus of the first nozzle without firing the ink droplet, and a fire portion for firing the ink droplet from the first nozzle.

Prefire before pixel in an inspection mode

In a method to control vibration measures and refresh measures in a printing operation of an ink printing system with at least one printing apparatus, the printing apparatus having printing elements that fire ink droplets as print dots at a printing substrate depending on control data determined from print data associated with print images and firing pause information about firing pauses for the printing elements. Prefire data and refresh data derived from the firing pause information and from operating condition information of the printing apparatus are combined with the control data. The vibration measures and refresh measures are executed by the printing elements depending on the firing pause information, the prefire data, and the refresh data, no ink droplets being ejected during the vibration measures and ink droplets being ejected during the refresh measures.

Method to control vibration measures and refresh measures in printing operation of an ink printing system with at least one printing apparatus

In a method to control printing elements of an ink print head for ejection of a respective ink droplet, respective control voltages are applied to activators of the printing elements. The control voltages comprise at least one vibration voltage pulse that induces at least one vibration oscillation in the associated printing element, and an associated print dot voltage pulse that induces an ejection of the respective ink droplet by the associated printing element. The at least one vibration voltage pulse is chronologically arranged before the associated print dot voltage pulse, and an amplitude of the at least one vibration voltage pulse is respectively chosen depending on a size of the respective ink droplet to be subsequently emitted by the respective printing element.

Growing community of inventors

Forstinning, Germany

Philippe Koerner