Abstract: A device and a method detect an edge of a recording material, in particular a printing plate, in an exposer for recording printing originals. An exposer has an exposure drum for holding the printing plate, and an exposure head, which is moved axially along the exposure drum and focuses exposure beams onto the printing plate. The position of the edge of the printing plate is determined by a sensing device. To this end, a sensing finger is pivoted into a groove in the surface of the exposure drum and a signal is generated by a sensor when the sensing finger moves when it touches the edge of the recording material. The sensor used is preferably a microswitch. The axial position of the edge of the printing plate is determined by counting the cycles of the feed drive that moves the sensing device.

Abstract: A gripper system for a machine that processes printing material sheets has a gripper with a first clamping surface and a gripper pad, for cooperating with the gripper, with a second clamping surface. One of the two clamping surfaces is formed with a surface relief. The clamping surface which has the surface relief is placed in such a way that, when a narrow printing material sheet is gripped, the clamping surface is covered by the sheet only within a subregion of the clamping surface and, when it grips a broad printing material sheet, it is covered by the latter beyond the subregion. The surface relief is structured differently within the subregion than outside the subregion, in that it is provided within the subregion with an antideformation structure which protects the narrow printing material sheet from excessive clamping deformation.

Abstract: In a method for white balance of an optoelectronic color scanner element of a color scanner device for pixel-by-pixel and line-by-line scanning of a color original rated voltage values are calculated from the optical densities of the white point of the color original and a predetermined white level. Scan light that represents the optical density zero of the color original is simulated with an illumination means and is converted in actual voltage values in a light/voltage transducer means. The gains of the light/voltage transducer unit are set such and held constant for the duration of the following originals' scanning such that the actual voltage values are equal to the calculated rated voltage values, it being thereby achieved that the color signals of the white point correspond to the white level in the later scanning of the original.

Abstract: An apparatus for adjusting the position of a cylindrical image carrier relative to a scanning head is designed to cheaply and easily permit substantially reliable positioning. In the apparatus for adjusting the position of a cylindrical image carrier relative to a scanning head, in which apparatus the image carrier is mounted so as to be rotatable around its longitudinal axis, the image carrier can be swiveled around an axis perpendicular to the longitudinal axis. The invention can be applied to devices that generate images and to devices that reproduce images, in particular for the production of type forms and for the scanning of originals.

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: In an apparatus for point-by-point and line-by-line, opto-electronic scanning of masters chucked on a scanner drum, an illumination unit is provided for generating an illumination spot on the master. A scanner objective, a scanner element and a feed support is provided at which the illumination unit, the scanner objective and the scanner element are arranged. The illumination unit comprises a light conductor that is aligned in the direction of the rotational axis of the scanner drum and has a light exit face for generating a light spot and has optical elements for imaging the light spot onto the master as an illumination spot. At least a sub-section of the light conductor in the region of the light exit face can be inclined by small angles relative to the rotational axis with a Cardanic bearing for fine adjustment of optical beam paths, as a result whereof the illumination spot is displaced on the scanner drum. The slope of the light conductor that has been found to be optimum is then fixed.

Abstract: In a method and an apparatus for point-by-point and line-by-line scanning of a master chucked on a scanner drum, for pixel-by-pixel illumination of the master, a light spot is generated in a light conductor and is imaged onto the master as illumination spot. The light conductor is arranged displaceable with an actuating drive for the purpose of modifying the imaging scale of the illumination spot. For setting the illumination, the luminance of the illumination spot is measured with the opto-electronic scanner element. In a computer, control signals for the actuating drive are generated dependent on the measured luminance. For setting the optimum illumination of the master, the imaging scale of the illumination spot is modified such by displacing the light conductor that the measured luminance of the illumination spot is maximum.

Abstract: In a method and apparatus for point-by-point and line-by-line scanning of masters chucked on a scanner drum, for pixel-by-pixel illumination of the master, a light spot is generated with a light conductor, the light spot being imaged by a matching objective onto the master as an illumination spot. The scan light is focused with a scanner objective and is converted into an image signal in an opto-electronic scanner element. The illumination spot, scanner objective, and scanner element implement a feed motion in the direction of the rotational axis of the scanner drum for planar scanning of the master. Given employment of scanner drums having different diameters, the size of the illumination spot is corrected by a modification of the imaging scale of the light spot. The modification of the imaging scale occurs by displacing the light conductor with an actuating drive relative to the stationary matching objective. A corresponding focus correction occurs with a radial displacement of the scanner objective.

Abstract: In a method for measuring cups given the engraving of printing cylinders in an electronic engraving machine, an engraver of an engraving member engraves cups into a printing cylinder. The geometric dimensions of the cups represent actual hue values. A video image of the cups is picked up. The contour of a cup is determined in the video image and the geometric dimensions of the cup are determined in that the cup contour is measured. For this purpose, the cup contour in the picked up video image is smoothed by a simulation with a spline function or a general polynomial function, and the geometric dimensions of the cup are determined on the basis of the smoothed cup contour. The determined geometric dimensions are the transverse diagonal, the longitudinal diagonal, the through-cut, the web width, the cup surface or the cup volume.

Abstract: In a device for point-by-point and line-by-line scanning of masters chucked on scanner drums having different diameters with an optoelectronic scanner element, which converts the scan light modulated with the content of the master and focused with the scanner objective into an image signal, a scanner element comprising a reflected light illumination is provided for generating an illumination spot on an opaque original. The scanner objective for correction of the focusing of the scan light onto the scanner element given employment of scanner drums having different diameters—is seated displaceable on the optical axis of the scanner element into radial working positions determined by the diameter of the respective scanner drums. The reflected light illumination can be displaced in the direction of the optical axis by the focal intercept change of the scanner objective for the purpose of optimizing the illumination spot given employment of scanner drums of different sizes.

Abstract: A method for producing a frame for a graphic object whose contour is defined by a sequence of Bezier curves is disclosed. To that end, a frame curve that is likewise a Bezier curve and that proceeds approximately parallel to the given Bezier curve is likewise produced for each Bezier curve of the contour. A mid-point PM is formed on the given Bezier curve. Proceeding therefrom at the spacing of the frame width, a mid-point QM for the frame curve to be produced is defined. The checkpoints of the frame curve are defined such that they proceed through the point QM.

Abstract: A device for forming a pile of sheets by means of a pile carrier and a stop. The stop can be swung around a horizontal geometric axis in a first direction away from the pile against a first actuating force of an actuating device and then swung back in the opposite direction by means of the actuating device while simultaneously raising the stop until reaching its alignment position on a second, higher level. So that the stop retains its alignment regardless of the level on which the stop is located, the device is provided with a guide which guide forces the vertical dislocation of the geometric axis, and with an end stop by means of which the stop is kept in the same alignment at any of the elevations assumed by the stop.

Abstract: In a method for seamless engraving of a pattern in an electronic engraving machine, an engraving element engraves a sequence of cups into a rotating engraving cylinder. For planar engraving of the pattern, the engraving element executes an axial feed motion along the printing cylinder. The pattern is seamlessly engraved such that the seam at which the upper edge and lower edge of the pattern meet at the circumference of the printing cylinder is as invisible as possible. For evaluating the engraved seam, a color proof of at least one separation color of the pattern is produced from the engraving data in a proofing unit, the engraved pattern in the color proof being offset in a circumferential direction of the printing cylinder such that the seam lies within the visible area of the color proof. The color proof is printed with a color printer or is displayed on a color monitor. For that purpose, the separation colors of the pattern are converted into printer colors or monitor colors in a color converter.

Abstract: In a method for automatic removal of image errors in digital image data, for example which have arisen due to scratches, hairs, etc., a contour mask is generated with a contour filter and a color mask is additionally generated that covers the image areas having the typical color of an image error. By operating the contour mask and the color mask, an error mask arises that is also automatically corrected and is manually edited as warranted. The remaining contours of the error mask are vectorized. An automatic bleeding retouch is then implemented along the vectorized contours.

Abstract: A method for opto-electronic scanning, by pixel and by line, of screened master photographic images with a sensing device. From the actual scanning, at least one master photographic image area that contains the grid scale is detected in the screened master photographic image. Subsequently, the picture values present in the local area of the detected grid scale area of the master photographic image are transferred by Fourier transformation to the frequency range as a spatial frequency spectrum, and, from the spatial frequency spectrum, the screen ruling and raster angle of the raster of the master photographic image are determined. For the determined raster angle and the determined screen rulings of the grid scale of the master photographic image, the optimal scan frequencies for Moiré-free scanning are determined from the spatial frequency spectrum.

Abstract: In a method and apparatus for conversion of color values of a color negative according to a positive/negative reversal function [Rp, Gp, Bp=f(Rn, Gn, Bn)] color values (Rn, Gn, Bn) for the three color components are acquired by optoelectronic scanning of a color negative in a color scanner. The image luminance value (BLr, BLg, BLb) and the image depth value (BTr, BTg, BTb) of the color negative as well as the corresponding density ranges (&Dgr;Dr, &Dgr;Dg, &Dgr;Db) are determined from the color values (Rn, Gn, Bn) in an image analysis unit for each color component. The positive/negative reversal function is determined in a calculating stage from the density ranges (&Dgr;Dr, &Dgr;Dg, &Dgr;Db) and a defined density range (&Dgr;D′). The positive/negative reversal function is deposited in a table memory as a value table. The color values (Rn, Gn, Bn) of the color negative are then converted into the color values (Rp, Gp, Bp) of the corresponding color positive with the stored value table.

Abstract: An inking unit for a printing machine, which includes at least one ink roller rolling on a plate cylinder of the printing machine, an ink jet printing apparatus with a plurality of ink jets that can be controlled selectively, and an ink transfer device with a rotating mantle surface for transferring printing ink from the ink jet printing apparatus to the at least one ink roller. A compact and stencil-free inking unit for high-quality printing is achieved and the at least one ink roller and the ink transfer device, and have the same outside circumference as the plate cylinder.

Abstract: A printing unit configuration includes an accessory and a connection mechanism moveably fastening the accessory thereto, throwing the accessory thereon into a working position, and removing it therefrom into maintenance positions. A linear guide can be connected to the accessory and disposed perpendicular to a pivot axis, with the mechanism pivoting the accessory away from the unit about the axis and displacing it along the guide. The mechanism can have two pivot axes disposed parallel to the unit rotation axis and can pivot the accessory away from the unit first about the first axis then about the second. The mechanism can pivot the accessory about an axis perpendicular to the unit rotation axis and/or about a single pivot axis disposed below the accessory. The mechanism can connect the accessory to the unit to project into a recess of a side wall of the printing machine at a side opposite an operator side in a maintenance position.

Abstract: Interchangeable scanning drums of drum scanners that are seated at one side for scanning opaque or transparency image originals must be capable of being reliably and quickly connected to the rotatory drive of the scanner unit. Interchangeable drum structures facilitate the attachment of the image originals and allow an economic assembly of scanning drums that, preparatory to the job, can be loaded with image originals simultaneously with the scanning process. According to the Prior Art 874, it was hitherto necessary to design cost-intensive, actively supported work fixtures in order to achieve an adequately stable connection and a dependable, dynamic operation. The present invention avoids this disadvantage with a cost-beneficial design that makes use of centrifugal forces produced by the scanner rotation for the coupling of drum and drive motor flange in combination with toggle lever mechanisms.

Abstract: An apparatus for varying a speed of flat products. The apparatus has a first, higher-speed conveyor arrangement containing conveyor drums and belts, and a second, slower speed conveyor configuration containing belt rollers and belts, in which the flat products are each transported between the belts of the first and second conveyor configurations. A pair of rollers with recesses is provided on the circumference in the conveying path of one of the two conveyor configurations). Rotational bodies move about their respective eccentric axes that in turn are located on crankshafts. The crankshafts rotate on axes with reference to the frame walls, and the rotational bodies and the crankshafts move at a constant angular speed omega.