Abstract: A multibeam scanning device for scanning a photosensitive material with a multi-spot array includes a plurality of fiber exits, which are in each case detachably inserted into a holder of a mount of the multibeam scanning device. The fiber exits are aligned in order to generate a precise multi-spot array. A method for correcting the position of image points of a multi-spot array is also provided. The fiber exits are inserted into the holder such that they have a defined rotational angle in relation to their axis and such that all image points have substantially the same angular alignment in relation to their desired position. Then the distances of the individual image points from their desired positions are reduced by deflecting the laser beams and/or by delaying the time of incidence of the laser beams on the photosensitive material.

Abstract: A method and a multibeam scanning device for ablation of a surface on a rotating drum by laser engraving with a multi-spot array includes simultaneously emitting laser beams from fiber exits disposed beside one another, dividing up each of the beams, after emerging from the exit in an AOM array having a number of AOMs corresponding to the number of exits, into two or more partial beams modulated independently of one another, imaging the exits with an optical system on the surface, and moving the exits, the AOM array, and the optical system together in a drum axial direction while the surface is scanned by the multi-spot array in a drum circumferential direction to make possible, without increasing the number of fiber lasers, an increase in the number of scanning points of the multi-spot array and a reduction of the space required by the scanning device.

Abstract: A laser diode in a recorder is thermally stabilized. The laser diode is used to produce a light beam, which is modulated by superimposing a basic current and a modulation current derived from an image signal, and exposes a recording material point by point and line by line. Between the exposure periods, wherein in each case one line is exposed, there are return periods, wherein the light beam is guided to the start of the next line, and wherein the laser diode is modulated for the purpose of thermal stabilization. In the return period, the laser diode is modulated with the basic current during a stabilization period, the sum of the modulation times during the exposure period and during the stabilization period being constant. In addition, during the return period, the laser diode can be modulated with a modulation current, which is derived from the inverted image signal from the preceding or the following line.

Abstract: A multi-beam scanning apparatus is provided for use with a recording medium that is located on an at least partially cylindrical inner bearing face of a recording device, in which the bearing face has a cylinder axis. The scanning apparatus includes a scanner unit for scanning the recording medium with at least one exposure beam. The scanner unit includes an acousto-optical element that is either an acousto-optical deflector or an acousto-optical modulator. The scanner unit includes a deflection element that is axially displaceable and rotatable relative to the cylinder axis of the bearing face. The acousto-optical element is mounted to rotate together with the deflection element about the cylinder axis.

Abstract: The printing plate has a carrier layer, a photopolymer layer and a laser-sensitive layer, in particular, a flexographic printing plate for direct laser exposure. The laser-sensitive layer is firstly selectively removed in a laser exposure unit with a laser beam that is moved relative to the printing plate, and the printing plate is subsequently irradiated with UV light at least on the side of the selectively removed laser-sensitive layer. This prevents washing out of the photopolymer layer under the removed regions of the laser-sensitive layer during subsequent developing of the printing plate. Time required for the partial removal of the laser-sensitive layer and the irradiation with UV light and to lower the space requirement and investment costs, different regions of the plate are irradiated with laser beam and with the UV light simultaneously in the laser exposure unit.

Abstract: In a method and device for removing light by absorption, undesired light is guided by a light entrance aperture into a hollow body having a light-absorbing inner surface. The light which is directed into the hollow body falls onto the reflection surface of a reflector. The reflection surface is configured and positioned in such a way that the light which is reflected back from the reflection surface is not reflected in itself, that only a minor amount of said light does not reach the outside as scattered light via the light entrance aperture and that a substantial amount of the light reaches the inside of the hollow body where it is absorbed. The invention finds particular use in an electronic recording device for point and line elimination of a recording material with a laser beam, wherein an undesired secondary beam is absorbed according to the inventive method in order to avoid disturbing retroreflections.

Abstract: A method and apparatus is provided for exposing the recording material. A light beam is generated by a light source. The light beam passes through an optical isolator, through a light modulator, and then exposes recording material point-by-point and line-by-line. The modulator is activated during exposing of each line in an exposing time span, the modulator being deactivated at least at times within a return time span for each line. The optical isolator is enabled during the exposing time span. To compensate for heating of the optical isolator, the optical isolator is also activated for at least a portion of the return time span. A sum of time extents of the exposing time span and the compensation time span are approximately a constant for each line. Activation of the isolator during the compensation time span compensates for thermal effects which occur in the optical isolator as a result of activation and de-activation thereof.