摘要:
A method for producing a pseudo-stochastic master surface for producing a cover or jacket of a cylinder for contacting printing material, includes providing the master surface with a pseudo-stochastic distribution of microsurfaces. The master surface is produced on the basis of a digital master in a jacket preliminary stage and serves for a preferably galvanic production of a microstructured cover, in which structure elevations correlate with the microsurfaces. The pseudo-stochastic distribution helps to avoid disruptive discernible effects, for example the moiré effect and helps to construct the microstructuring in a targeted manner. A master surface, a method for producing a cylinder cover, a cylinder cover, a machine for processing printing material, a method for producing printed products and a method for microstamping printed products, are also provided.
摘要:
A method for producing a pseudo-stochastic master surface for producing a cover or jacket of a cylinder for contacting printing material, includes providing the master surface with a pseudo-stochastic distribution of microsurfaces. The master surface is produced on the basis of a digital master in a jacket preliminary stage and serves for a preferably galvanic production of a microstructured cover, in which structure elevations correlate with the microsurfaces. The pseudo-stochastic distribution helps to avoid disruptive discernible effects, for example the moiré effect and helps to construct the microstructuring in a targeted manner. A master surface, a method for producing a cylinder cover, a cylinder cover, a machine for processing printing material, a method for producing printed products and a method for microstamping printed products, are also provided.
摘要:
A register control mark for the detection of positional deviations between at least two color separations printed over one another on a printing material in multicolor printing. The control mark has a pattern with parallel lines of a first color separation and, printed in parallel over the pattern, at least two parallel lines of a second color separation.
摘要:
A method for performing a digital multistage screening of a continuous-tone image with a screen having any desired screen resolution and any desired screen angle, in which the screening is carried out by reading out threshold values and comparing the threshold values read out with the color values of the continuous-tone image. Threshold value matrices are used in which the threshold values represent one or more screen dots of a given screen, with which the desired screen resolution and the desired angle are approximated. While the threshold values are being read out, an error between the coordinates of the desired screen and of the given screen is determined, and the error is compensated for by correcting the read address for the threshold value matrix, as soon as the error exceeds a predefined limiting value. Instead of the threshold value matrices, printing-value matrices can also be used.
摘要:
A method for the digital screening of a halftone image by using a first screen having an arbitrary desired screen width and an arbitrary desired screen angle. For the method, the threshold value matrix of a second screen with a different screen angle and width is read out and compared with the color values of a halftone image presented. In order also to approximate screens having a particular irrational tangent and to avoid unpleasant sudden exposed device pixels in clear regions, it is proposed to provide at least one second threshold value matrix having X3Y3 addresses, the X3Y3 addresses of the second threshold value matrix are displaced by a factor 1/B in relation to the X2Y2 addresses of the first threshold value matrix, and to read out the second threshold value matrix as soon as an error D between the first and the second screen exceeds a predefined limiting value.
摘要:
A method for digital imaging of a printing form (10) through application of energy is described, in which a burn-off area (66) is detachably fixed by supporting points (68, 84), supporting points (68, 84) being left in place on the printing form (10) through non-imaging of image spots (112) and in which the burn-off from the burn-off area (66) is detached from the printing form (10) in a cleaning step. A supporting point (68, 84) at a reference point is left in place precisely if the number of image spots (110) to be imaged in a surrounding area (18) of the reference point (12) exceeds a limit value and a boundary area (20) in the surrounding area (18) around the reference point (12) contains only image spots (110) to be imaged. The method may be used in a system for digital imaging of printing forms (10) having an energy source (86), a cleaning unit (70), a control unit (96), and an image processing unit (98) with a computing unit (100), in particular with a raster image processor (RIP) (102) in a printing unit of a printing press.
摘要:
A method for generation and storage of digitized threshold density values for use in creating a half-tone image pattern such as in the form of color separations. The threshold density values in a sub-cell of a multiple reference cell (supercell) are stored as storage words in accordance with a spot function. A sorted sequence is determined tailored in accordance with the spot function and threshold density values are allocated to the words in accordance with position of the words in a sorted sequence. Corrections are made to the threshold density values in order to compensate for different numbers of storage words in the subcells.
摘要:
A register control mark for the detection of positional deviations between at least two color separations printed over one another on a printing material in multicolor printing. The control mark has a pattern with parallel lines of a first color separation and, printed in parallel over the pattern, at least two parallel lines of a second color separation.
摘要:
A method for the digital screening of a halftone image by using a first screen having an arbitrary desired screen width and an arbitrary desired screen angle. For the method, the threshold value matrix of a second screen with a different screen angle and width is read out and compared with the color values of a halftone image presented. In order also to approximate screens having a particular irrational tangent and to avoid unpleasant sudden exposed device pixels in clear regions, it is proposed to provide at least one second threshold value matrix having X3Y3 addresses, the X3Y3 addresses of the second threshold value matrix are displaced by a factor 1/B in relation to the X2Y2 addresses of the first threshold value matrix, and to read out the second threshold value matrix as soon as an error D between the first and the second screen exceeds a predefined limiting value.
摘要:
In a method for digital rastering of a half-tone image with rasters having arbitrary screen widths and screen angles, the rastering occurs by reading out a threshold matrix and comparing the thresholds that are read out to the color values of the half-tone image. For that purpose, a threshold matrix is employed wherein the thresholds represent one or more raster dots of a raster arranged at an angle, the desired screen width and the desired angle being approximated therewith. During the readout of the thresholds, an error between the desired raster and the raster approximated by the threshold matrix is calculated, and the error is compensated by a correction of the readout address for the threshold matrix as soon as the error exceeds a predetermined limit value. Alternatively, stored bit patterns can be employed instead of the threshold matrix, these having been acquired by comparing the tonal values to be reproduced to a threshold matrix.