Abstract: In a method or machine for engraving printing cylinders for packaging, pattern, or wallpaper printing and equipped with at least two engraving members, each engraving member engraving elements to be printed into the printing cylinder and, for an areal engraving, executes a feed movement parallel to a longitudinal axis of the printing cylinder. To shorten engraving time, a print image or layout for the printing cylinder is subdivided into at least two circumferential engraving strips, one engraving member being associated with each engraving strip. At least one strip boundary is automatically placed between said engraving strips in at least one white space remaining unengraved between at least some of the elements to be printed.

Abstract: In a method and apparatus for engraving printing cylinders in an electronic engraving machine, an engraving control signal is formed from an image signal, which represents the tonal values of the cups to be engraved, and from a raster signal for generating a printing raster. An engraving stylus of an engraving element controlled by the engraving control signal engraves a printing form engraving line by engraving line in the form of cups arranged in the printing raster in a rotating printing cylinder. Functionability of the engraving stylus is continuously checked during engraving of the printing cylinder by a digital filtering of the engraving control signal in an engraving stylus monitoring device. When damage is found, a control signal is generated that aborts the engraving, or acoustically or optically signals the identified damage to the engraving stylus.

Abstract: In a method and apparatus for engraving printing cylinders in an electronic engraving machine, an engraving control signal is formed from an image signal that represents tonal values of cups to be engraved and from a periodic raster signal for generating a printing raster. An engraving stylus of an engraving element controlled by the engraving control signal engraves a printing form in the form of cups arranged in the printing raster in a rotating printing cylinder. For checking of the functionability of the engraving stylus, test cups are engraved simultaneously when engraving the printing form. A respective measurement interval is defined for selected test cups. The raster signal is respectively eliminated from the engraving control signal for the duration of the measurement interval, and the remaining engraving control signal is investigated for harmonics characteristic of damage to the engraving stylus.

Abstract: In a method for engraving printing cylinders in an electronic engraving machine, printing densities are matched in individual engraving lanes by engraving cups in the printing lanes with which the prescribed characteristic rated printing densities are to be achieved. The actual printing densities are identified by measurement after the printing. A corrected lane calibration is derived for the respective engraving lane from deviations between the rated printing densities and the actual printing densities. The allocated corrected lane calibration is applied in the engraving lanes.

Abstract: An idle distance of an engraving stylus for engraving a rotogravure printing cylinder is set from the cylinder surface of the rotogravure printing cylinder by use of a sliding element that is provided for the guidance of the engraving stylus connected to the sliding element along the cylinder surface during engraving. The setting of the idle distance is undertaken relative to a reference surface that is indicative of the cylinder surface.

Abstract: In a method for calibrating an engraving amplifier in an electronic engraving machine, whereby a vibration signal is used to control the engraving of an engraving element by using engraving tone values representing desired tone values ranging from “light” to “dark”, small cup shapes are engraved. The dimensions of the cup shapes define the real tone values. Transmission functions are initially determined, reproducing correlations between signal values that are adjusted in the engraving amplifier and the resulting changes in the real dimensions of the cup shapes. Sample cup shapes are engraved for predetermined desired tone values using the adjusted signal values for at least one of the parameters such as “vibration”, “light”, “dark” or “mid tone”. Differential values are obtained from real measured dimensions and the predetermined desired dimensions of the sample cup shapes, taking into account the transmission functions, whereby the differential values are used to correct the adjusted signal values.

Abstract: In a method for making and evaluating a sample cut in an engraving machine, an engraving control signal for guiding a stylus is formed from engraving data. The stylus cuts a series of cups. During a trial engraving trial cups are engraved and a video image is made. In accordance with screen parameters, measuring points are fixed in the video image as distances to a selected reference point. Geometric parameters of the trail cups are measured in the video image and are compared to corresponding geometric parameters of the cups representing predetermined tone values. Adjustment values are deduced from this comparison which are used to calibrate the engraving control signal.

Abstract: In a method for making and evaluating a sample engraving in an electronic engraving machine for engraving printing cylinders for rotogravure, during a sample engraving, trial cups are engraved for predetermined tone values by an engraving element. After the sample engraving, a video camera is positioned at a predetermined axial measuring position, and a video image of the trial cups is recorded. The deviations of position of a measuring point of a selected trial cup are determined from a reference point as position errors ?xM, ?yM. The position errors ?xM, ?yM are then corrected by axially displacing the video camera to a new measuring position and/or by rotating the printing cylinder. Afterwards, the geometric values of the trial cup are measured and are compared with the geometric values of the predetermined tone values.

Abstract: An engraving element of an electronic engraving machine for engraving printing forms is formed of a shaft oscillating around a longitudinal axis with small rotational angles. A drive system is provided for the shaft with a lever attached to one end of the shaft. An engraving stylus is provided for engraving the printing form, along with a restoring element for the shaft, a bearing for the shaft, and a damping mechanism for the shaft having a damping element secured to the shaft and a stationary damping chamber. The damping element comprises at least one damping disk that is designed circularly at least in regions and extends perpendicular to the shaft. The damping chamber is designed at least as a hollow-cylindrical segment around the shaft into which the damping disk projects and extends at least over the circular region of the damping disk. The damping chamber is filled with a ferro-fluidic fluid as a damping agent.

Abstract: A system and method for selectively process material on a processing surface of a printing form to create a fine structure or pattern for images or text. At least one fiber laser comprising a pump source and a laser fiber is provided. A laser gun is mounted adjacent the printing form and has at least a focusing optics. The fiber laser outputs a laser beam which is diffraction-limited to permit the focusing optics to focus the laser beam onto the processing surface of the printing form as a spot having a spot size sufficiently small to process the processing surface to create the fine structure or pattern images or text.

Abstract: In a method to produce a printing form for rotogravure, in particular for heliorotogravure, a surface of the formis provided with a wear-resistant layer and the surface is provided with cups. Furthermore, a printing form is provided whereby the surface of the printing form comprises a wear-resistant layer in which the cups, with regard to their depth, are at least partially provided therein. The printing form may be used in a printing device for heliorotogravure.

Abstract: In a cooling device and method for cooling an engraving system of an engraving device given engraving devices for engraving printing form surfaces, the cooling device comprises a plurality of cooling units wherein each cooling unit is allocated to respectively cool one engraving head.

Abstract: In a method for changing the size of line elements on a printed page, first the nature of the size change is determined and a positive/negative identifier identifying the nature (positive/negative) of the line elements is determined for each pixel of the printed page. A copy window whose expanse determines the desired size change is defined around a substitution field. Copy window and substitution field are displaced across the printed page, and the density values of the copy window are compared to the density value of the substitution field in each window position.

Abstract: In a method for processing signals in an electronic engraving machine for engraving printing forms, in particular printing cylinders used for rotogravure, an engraving control signal is obtained by superimposing engraving data, representing tone values between “white” and “black” which are to be engraved, with a periodic screen signal for generating a gravure screen. The engraving control signal guides the lifting movement of the stylus of an engraving element. As a result of the lifting movement of the stylus, a series of cups arranged in the gravure screen is engraved on the printing form. To compensate an incorrect lifting movement of the stylus (rebound effect, lag effect), the engraving data undergo digital filtering before superposition of the gravure screen.

Abstract: In a method for engraving a printing cylinder using an engraving member in an electronic engraving machine, an engraving tool of an engraving member controlled by an engraving signal engraves a sequence of grooves arranged in a printing screen in a rotating printing cylinder. The engraving signal is formed by superimposing an image signal representing the shade values of light and dark of the grooves to be engraved and a periodic screen signal for generating the printing screen. In order to compensate for disruptive influences on the shade values of the engraved grooves resulting from operating temperatures in the engraving member, the operating temperature in the engraving member is measured at at least one measurement point. Depending on at least one measuring temperature, the electrical control of the engraving member is corrected and/or the temperature of at least one component of the engraving member and/or the air circulating around the engraving member is modified.

Abstract: In a method for operating an engraving member in an electronic engraving machine to engrave printing forms, especially printing cylinders for intaglio printing, a stylus of the engraving member is controlled by an engraving signal and engraves a sequence of cups arranged in a gravure screen in the rotating printing cylinder. The engraving signal is formed by superimposing the image signal representing the tone gradations to be engraved. In order to obtain good quality engraving, the engraving member is heated to a temperature that is close to operating temperature before engraving starts and/or during an interruption of engraving. For this purpose, the engraving member is driven with a periodic signal whose frequency is preferably located inside the ultrasonic range in order to avoid noise disturbances.

Abstract: In an engraver of an electrical engraving machine for engraving pressure cylinders, the engraver comprises a rotating system which oscillates around small angles. The engraver further comprises a drive system for the rotating system and of an engraving element that is arranged at the rotating system. The engraving element is used to grave cup-shapes in the pressure cylinder by carrying out a lifting movement directed at the pressure cylinder. The clearance angle of the engraver is arranged in a tilt in the direction of the engraving of the cup-shapes in relation to a line of reference which extends vertically to the generated surface of the pressure cylinder. The clearance angle is thus enlarged. Especially buckled cup-shapes can be engraved in the correct tone value using the tilted arrangement of the engraving element.

Abstract: In a method for processing signals in an electronic engraving machine for engraving printing forms, engraving control signals for guiding the stylus of an engraving element are obtained from engraving data representing predetermined tone values between “light” (white) and “dark” (black). The stylus engraves a series of cups in the printing form. The cup depths determine the tone values actually engraved. Before engraving, the engraving control signals corresponding to “light” and “dark” are calibrated by adjustment variables so that the engraved “light” and “dark” tone values correspond to the predetermined “light” and “dark” tone values. So that the “light” engraved tone value remains constant when the “dark” tone value changes, the difference between the old “dark” adjustment variable and a new “dark” adjustment variable is formed before engraving.

Abstract: An engraving element of an electronic engraving machine for engraving printing cylinders as a shaft oscillating with small rotational angles around the longitudinal axis, a restoring element, a shaft bearing, a damping mechanism, a drive for the shaft, a lever-shaped stylus holder attached to the shaft, and an engraving stylus as a cutting tool. For engraving cups, the engraving stylus executes a stroke motion in the direction of a rotating printing cylinder. The engraving element is arranged with respect to the printing cylinder rotating around the rotational axis such that the shaft of the engraving element proceeds substantially parallel to the rotational axis of the printing cylinder, and the stroke motion of the engraving stylus occurs in a plane oriented perpendicular to the rotational axis of the printing cylinder. As a result, a better geometry of the cups is achieved in the engraving.

Abstract: In a method for multi-beam exposure of a printing form, preferably with laser beams, a computer transmits printing form data to a distributor via a data line as a sequence of recording lines and the distributor cyclically distributes the recording lines onto the input stages of an optics head where N parallel laser beams are generated and modulated with the printing form data of the recording lines. The laser beams are subdivided into active and inactive laser beams, recording lines of the printing form are transmitted via the data line for the active laser beams, and empty lines are inserted into the transmitted sequence of the recording lines for the inactive laser beams. The empty lines contain data values with which the inactive laser beams are driven dark.