Abstract: 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.

Abstract: In a method for print tuning of a printer or copier, at least one first region of a first printing element to be printed is selected. Further, at least one third region of a second printing element to be printed is selected. The second printing element can be different from the first printing element. Additionally, the first and the third region can be repeatedly printed on a same proof sheet to print tune the printer or copier. The at least one printing parameter can be varied from region to region in the repeated printing of the first region, and from region to region in the repeated printing of the third region.

Abstract: Methods and devices for digital printing to a recording medium are described. The printing can use a liquid print ink that includes a flammable carrier. Print control data can be generated from print data and the print control data can activate one or more print groups to print to the recording medium. An areal coverage can be determined based on the print control data. The areal coverage corresponds to a quantity of color applied onto the recording medium. The determined areal coverage can be limited to a predetermined maximum average areal coverage within a predetermined averaging area. The predetermined maximum average areal coverage can be less than a maximum theoretical areal coverage. The recording medium can be heated in, for example, a heating chamber. The predetermined averaging area can be smaller than an area of the recording medium located within the heating chamber.

Abstract: In a method to damp an oscillation of a roller driven via a drive in a printing system, a printing substrate web is directed across the roller, the roller and the printing substrate web forming a system capable of vibrating. With the drive the roller is driven with a predetermined nominal moment. With a sensor, a real value is determined of a variable representative of a velocity with which the printing substrate web is transported by the roller. In aid of a predetermined calculation rule, a correction moment is calculated from the determined real value such that a damping of the vibration-capable system results like a mechanical viscous damper. The correction moment is added to the predetermined nominal moment upon activation of the drive.

Abstract: In a printing apparatus a print bar assembly is provided with multiple print bars, a designed space being present between the print bars and a recording medium. A climate control has a feed channel running parallel to a length of the recording medium. Openings lead from the feed channel to the print bars to introduce a conditioned gas flow of predetermined temperature and moisture to the print bars such that a laminar gas flow is generated in the designed space between nozzle plates of the print bars and the recording medium. A barrier is arranged at an intake of the print bar assembly which blocks an air boundary layer entrained with the moving recording medium before the print bar assembly.

Abstract: A method and a controller operable to adjust the field strength of an electrical field for the toner transfer in an electrographic printing process. Current values of framework parameters can be determined and a control loop configured to adjust the electrical field is adapted based on current values of the framework parameters. An electrical reference variable of the control loop can be adapted to the current values of the framework parameters. The electrical reference variable can include, for example, a current and/or a voltage for the toner transfer.

Abstract: In a method to improve the transfer of charged toner particles onto a recording medium in an electrographic printing process, the recording medium can be heated before the transfer of the charged toner particles to reduce an electrical resistance of the recording medium. A voltage can be applied between a transfer electrode and a counter-electrode to generate an electrical field at a transfer point between the transfer electrode and the counter-electrode, wherein the transfer electrode includes the charged toner particles. The recording medium can be guided to the transfer point to transition the charged toner particles from the transfer electrode to the recording medium at the transfer point under an effect of the electrical field; A current can be detected that flows between the transfer electrode and the counter-electrode across the recording medium. The voltage can be adapted based on the current.

Abstract: A device adapted to clean a photoconductor. The device can include a blade and an absorbent element. The absorbent element can be made from an absorbent material. The absorbent element can be arranged in front of the blade as viewed in the movement direction.

Abstract: In a method to adjust print quality of print images in an electrophoretic digital printer with at least one print group, the print group generates charge images of the print images. The charge images are developed with a developer station into toner images using liquid developer having carrier fluid and toner. The toner images are transfer-printed onto a carrier medium in a transfer station. A first control marking is generated on the recording medium with elements of the first control marking being aligned transverse to a printing direction. A shape of the elements of the first control marking is measured to generate a first measurement signal. The first measurement signal is compared with a predetermined nominal value, and given a difference, an adjustment signal is generated via which an amount of the carrier fluid in the liquid developer is modified so that the first measurement signal approaches the predetermined nominal value.

Abstract: A method and device for digital printing to a recording medium with liquid print color is described. In a method for digital printing, a print image defined by print data is printed onto the recording medium via application of the liquid print color. After the application of the liquid print color onto the recording medium, the recording medium can be heated to vaporize the carrier fluid. Upon heating, air is supplied that mixes with the vapor to form a combustible gas. The combustible gas can be supplied to a combustion chamber and converted into waste gas. In a method for digital printing, an areal coverage can be determined. The areal coverage describes a quantity of color applied onto the recording medium by the carrier fluid. Further, the air supply can be proportionally controlled to the determined areal coverage.

Abstract: A print group for a digital printer can include a transfer station and a wetting system. The transfer station can be configured to transfer a toner image onto a first side of a recording medium at a transfer point in response to an electrical field, the transfer station being configured to apply the electrical field between a transfer electrode on the first side of the recording medium and a counter-electrode on a second side of the recording medium, wherein the recording medium is directed between the transfer electrode and the counter-electrode. The wetting system can be configure to apply a conductive fluid onto a surface of the second side of the recording medium at the transfer point, the conductive fluid at least partially forming a conductive connecting layer between the surface of the second side of the recording medium and a surface of the counter-electrode at the transfer point.

Abstract: A printing system can include an energizer, a condition group, a print group, a sensor, and a controller. The energizer can be configured to treat a surface of a recording medium to increase an energy of the surface. The conditioning group can be configured to provide a coating substance on the surface having been treated by the energizer to provide a pre-treated recording medium having a coated surface. The print group can be configured to print a toner-based print image onto the coated surface of the pre-treated recording medium using electrophoresis. The sensor can be configured to detect resistance data indicative of a resistance of the pre-treated recording medium orthogonal to the coated surface of the pre-treated recording medium. The controller can be configured to control the energizer to adapt a dimension of the increase of the energy of the surface of the recording medium based the resistance data.

Abstract: A method and a developer station are described. The method and developer station being operable to adapt the inking of an image substrate. The method including applying a voltage across a developer layer on the developer element of the developer station. The application of the voltage causing a current to flow through the developer layer, where the current can be measured. The an indicator of a thickness of the developer layer and/or of the toner quantity in the developer layer is generated based on the voltage and/or the current. The indicator can be used to adjust the inking of the image substrate. For example, the current can be compared to a characteristic curve to generate the indicator.

Abstract: In a method or system to control a temperature of a substrate to be printed to and which exhibits said temperature during a traversal of a printing system, specifically selecting or controlling a fluid temperature of a liquid fluid to be applied onto the substrate to specifically influence the substrate temperature, the fluid being applied onto the substrate before the substrate is printed to. At least one of the fluid temperature and a quantity of the fluid applied onto the substrate per time unit at least depending on at least one of a first measurement value for a temperature of the substrate before the application of the fluid and a second measurement value for a surface temperature of the substrate after the application of the fluid.

Abstract: In a method to administer, via a print job administrator, print jobs to be printed at a printing system, a plurality of print jobs are determined. A print job can indicate a specification of one or more print features. Different specifications of a print feature may require different configurations of the printing system. Change-over expenditures for the printing of at least two print jobs of the plurality of print jobs by the printing system can be determined based on the specification of the one or more print features of the plurality of print jobs. An order for the printing of the plurality of print jobs can be determined based on the change-over expenditures. The order of the plurality of print jobs can be indicated.

Abstract: In a method for visually reviewing a print data stream present in a print data language, the print data stream is rastered using a rastering device of a printing system. The rastered print data is cached in a print data memory at the printing system. A section of the cached rastered print data can be read out using a collection process executable at the printing system. The collection process can receive and execute a request to read out a specific section of the rastered print data. The readout rastered print data can be transmitted to a display device using a real time-capable communication connection. The rastered print data can be presented at the display device.

Abstract: Methods to exchange printing substrate rolls in a printer are described. In an exchange method, ink is printed to a first printing substrate web being unwound from a first printing substrate roll. The first printing substrate web is exchanged with a second printing substrate web being unwound from a second printing substrate roll. A transition region of the first and the second printing substrate webs is printed to during the exchange of the first and the second printing substrate webs. The transition region can be formed by gluing the second and the first printing substrate webs atop one another. A predetermined pattern can be printed onto the transition region during the exchange of the printing substrate rolls. The predetermined pattern can be chosen such that all nozzles of at least one print head are used for printing.

Abstract: In a method to control a color printer or color copier, a color separation of a first color and a color separation of a second color are applied to a printing substrate to generate a print image. Also, with aid of a printing unit, at least a first control field is printed on the printing substrate. The first control field has a predetermined pattern that includes at least the first color and the second color and is designed such that a color value of the first control field changes depending on a registration error between the first and the second color separations. A reference field is also printed on the printing substrate, a pattern of the reference field being predetermined such that it has a same color value independent of the registration error. The color value of the first control field is measured with a color value sensor. The color value of the reference field is also measured with the color value sensor and a desired color value is determined depending on the color value of the reference field.

Abstract: A roller for transferring a print image or a toner layer onto another element in a printer or copier is provided. The roller can include a base body, a first elastic layer applied onto the base body and a second elastic layer applied onto the first elastic layer, wherein the ratio of the moduli of elasticity of the elastic layers and/or the ratio of the thicknesses of the elastic layers are matched to one another so that the average surface velocity difference between the roller and the other element is reduced and/or minimized.

Abstract: 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.