Abstract: A device that prints with ink includes an ink reservoir for ink and an arrangement of multiple printing elements, for instance printing heads. The printing elements are identical with one another, they generate ink drops, and they are supplied in parallel with ink from a joint supply line. A further element, which is different from the printing element and which is controllable in terms of its ink flow, for instance a pump, is supplied with ink in parallel with the printing elements by the same supply line. Undesirable hydrostatic pressure changes in the ink are reduced as much as possible, or even eliminated.

Abstract: A device for supplying liquid ink to an ink print head in an ink printing machine includes an ink reservoir, a line for guiding the ink from the reservoir to the print head, a line for guiding the ink from the print head to the reservoir, and a damper for damping pressure fluctuations in the liquid ink. The damper has a movable and/or deformable membrane with a given thickness. In a position of repose, the membrane has a length L and a width W, and the length L is at least twice as long as the width W. The device renders possible in a simple and cost-efficient way to reliably avoid even large pressure fluctuations, in particular high pressure peaks in the liquid ink.

Abstract: A device that prints with ink includes an ink reservoir for ink and an arrangement of multiple printing elements, for instance printing heads. The printing elements are identical with one another, they generate ink drops, and they are supplied in parallel with ink from a joint supply line. A further element, which is different from the printing element and which is controllable in terms of its ink flow, for instance a pump, is supplied with ink in parallel with the printing elements by the same supply line. Undesirable hydrostatic pressure changes in the ink are reduced as much as possible, or even eliminated.

Abstract: A method for printing an image with improved printing quality using liquid ink includes using a pump to pump ink to a print head for printing rows of the image onto a moving printing substrate. A respective value correlated with the amount of ink required to print the rows is calculated for a plurality of individual rows or a plurality of grouped rows of the image. The pump receives a preemptive control signal based on the calculated values.

Abstract: A device for supplying liquid ink to an ink print head in an ink printing machine includes an ink reservoir, a line for guiding the ink from the reservoir to the print head, a line for guiding the ink from the print head to the reservoir, and a damper for damping pressure fluctuations in the liquid ink. The damper has a movable and/or deformable membrane with a given thickness. In a position of repose, the membrane has a length L and a width W, and the length L is at least twice as long as the width W. The device renders possible in a simple and cost-efficient way to reliably avoid even large pressure fluctuations, in particular high pressure peaks in the liquid ink.

Abstract: A method for degassing water-based ink is described. An ink reservoir is connected to a vacuum source via a gas-permeable membrane and a connecting piece to remove the undesired gas. During the degassing process, water vapor is fed to the connecting piece. Thus, the viscosity of the water-based ink in the ink reservoir remains on an essentially constant level. The method may advantageously be implemented continuously in inkjet printing machines.

Abstract: A method for printing an image with improved printing quality using liquid ink includes using a pump to pump ink to a print head for printing rows of the image onto a moving printing substrate. A respective value correlated with the amount of ink required to print the rows is calculated for a plurality of individual rows or a plurality of grouped rows of the image. The pump receives a preemptive control signal based on the calculated values.

Abstract: A device for circulating an ink supply to at least one inkjet print head includes at least two components that are different than the inkjet print head and through which ink flows, such as a pump and a valve for the ink. At least one ink line is connected between the components. At least one section of the ink line is embodied as a channel in a plate. The device advantageously has a compact construction and is easy to clean and service. The device has a high degree of reliability since the number of hose lines is advantageously reduced.

Abstract: A method for damping pressure peaks in an ink line of an inkjet printer includes connecting the line to a chamber divided by a diaphragm into an air-filled first space and an ink-filled second space, connecting the first space to an air-filled buffer, connecting the buffer to an air pump, a) pumping air into the first space until freeing the chamber of ink and the diaphragm rests on a chamber wall or tension in the diaphragm begins rising substantially linearly, then b) pumping air out of the first space until filling the chamber with ink and the diaphragm rests on a chamber wall or tension of the diaphragm begins rising substantially linearly, while determining the number of pump cycles, then c) pumping air into the first space while passing through substantially half of the determined pump cycles. Steps a and b may be reversed.

Abstract: A device for circulating an ink supply to at least one inkjet print head includes at least two components that are different than the inkjet print head and through which ink flows, such as a pump and a valve for the ink. At least one ink line is connected between the components. At least one section of the ink line is embodied as a channel in a plate. The device advantageously has a compact construction and is easy to clean and service. The device has a high degree of reliability since the number of hose lines is advantageously reduced.

Abstract: A method for damping pressure peaks in an ink line of an inkjet printer includes connecting the line to a chamber divided by a diaphragm into an air-filled first space and an ink-filled second space, connecting the first space to an air-filled buffer, connecting the buffer to an air pump, a) pumping air into the first space until freeing the chamber of ink and the diaphragm rests on a chamber wall or tension in the diaphragm begins rising substantially linearly, then b) pumping air out of the first space until filling the chamber with ink and the diaphragm rests on a chamber wall or tension of the diaphragm begins rising substantially linearly, while determining the number of pump cycles, then c) pumping air into the first space while passing through substantially half of the determined pump cycles. Steps a and b may be reversed.

Abstract: A method for creating a printed image with sections on an object using at least two inkjet print heads, includes forming the image of first and second image sections, in a y direction at a fixed angle different than 0° and 180° relative to an object conveying direction, printing print dots of the first and second sections using first and second heads having first and second inkjet nozzles with the sections partially overlapping in a region and potentially forming a light or dark line, defining first and second complementary nozzle fields of the first and second heads to be active for each column of dots in the y direction, and placing a joint between the fields in the overlap region in a light or dark area of the column for each column of dots, avoiding potentially disruptive light or dark lines at the joint and keeping the image without defect.

Abstract: A method for creating a printed image on a rotating, three-dimensional body or bottle eccentrically on a turntable, includes providing an inkjet printing unit having inkjet nozzles along a straight line for printing at a clock rate, rotating the body about a rotation axis parallel to the line using a motor, prescribing a fundamental frequency f0(t) for activating the motor, for example based on a constant angular velocity, activating the motor with the fundamental frequency f0(t), prescribing an average or constant body radius R0, determining a radius change ?R(t) of the body during rotation, calculating a correction value k(t) for the printing unit clock rate, where k(t)=1+?R(t)/R0, and activating the printing unit with a frequency f(t) for the clock rate, where f(t)=f0(t)·k(t), for example permitting printing on eccentrically rotating bottles with a constant print resolution while avoiding image imperfections.

Abstract: A method for creating a printed image with sections on an object using at least two inkjet print heads, includes forming the image of first and second image sections, in a y direction at a fixed angle different than 0° and 180° relative to an object conveying direction, printing print dots of the first and second sections using first and second heads having first and second inkjet nozzles with the sections partially overlapping in a region and potentially forming a light or dark line, defining first and second complementary nozzle fields of the first and second heads to be active for each column of dots in the y direction, and placing a joint between the fields in the overlap region in a light or dark area of the column for each column of dots, avoiding potentially disruptive light or dark lines at the joint and keeping the image without defect.

Abstract: A method for creating a printed image on a rotating, three-dimensional body or bottle eccentrically on a turntable, includes providing an inkjet printing unit having inkjet nozzles along a straight line for printing at a clock rate, rotating the body about a rotation axis parallel to the line using a motor, prescribing a fundamental frequency f0(t) for activating the motor, for example based on a constant angular velocity, activating the motor with the fundamental frequency f0(t), prescribing an average or constant body radius R0, determining a radius change ?R(t) of the body during rotation, calculating a correction value k(t) for the printing unit clock rate, where k(t)=1+?R(t)/R0, and activating the printing unit with a frequency f(t) for the clock rate, where f(t)=f0(t)·k(t), for example permitting printing on eccentrically rotating bottles with a constant print resolution while avoiding image imperfections.

Abstract: The method and apparatus for amplitude modulation of unpolarized light by at least one Bragg modulator on the basis of domain-invertible material, the unpolarized light is modulated by a first Bragg modulator both for defining a polarization plane in the unpolarized light and for modulating a light part to be allocated to the polarization plane. A second Bragg modulator is provided which modulates the light part of the unpolarized light allocated to the polarization plane orthogonal to the polarization plane of the first Bragg modulator. The method and apparatus are particularly useful for recording a product to be printed, such as for manufacturing printing forms.

Abstract: The method and apparatus for amplitude modulation of unpolarized light by at least one Bragg modulator on the basis of domain-invertible material, the unpolarized light is modulated by a first Bragg modulator both for defining a polarization plane in the unpolarized light and for modulating a light part to be allocated to the polarization plane. A second Bragg modulator is provided which modulates the light part of the unpolarized light allocated to the polarization plane orthogonal to the polarization plane of the first Bragg modulator. The method and apparatus are particularly useful for recording a product to be printed, such as for manufacturing printing forms.