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 light beam deflection unit for deflecting a light beam has a carrier seated in rotatable fashion around an optical axis, a reflector arranged at the rotatable carrier, and a reflection face oriented transversely relative to the optical axis. The carrier is connected to a sleeve that laterally surrounds the reflector at least in certain regions, and that rotates with the carrier. The sleeve has a light entry aperture for the incident light beam at an end face facing away from the reflector, and a light exit aperture for the deflected light beam in the generated surface. An achromatic lens that is displaceable in the direction of the optical axis for the purpose of focussing the light beam and that is held by the sleeve is located in the light entry aperture. A wedge-shaped, transparent insert is arranged in the light exit aperture for astigmatism correction.

Abstract: The invention concerns a process and circuit for correcting the light-power output of a laser diode. The circuit comprises a generator (2) for generating a driver current (I.sub.T) which determines the light-power output of the laser diode. The driver current (I.sub.T) is modulated by a modulation signal (B). To correct the light-power output, the circuit includes a linear low-pass filter (5) which is acted on by the modulation signal (B) and which approximately simulates the change with time of the internal temperature of the laser diode (1) as a function of the modulation signal (B). The output signal of the linear low-pass filter (5) acts as a driver current (I.sub.T) correction signal (K), thus compensating for the temperature dependence of the laser-diode light-power output.

Abstract: In a machine for twist tying a bundle of product, the tie ribbon is fed, for looping about the product to a twist head, by a feed roller. The leading end of the tie ribbon is then clamped to the twist head by a first gripper and, rearward of the feed roller, by a staking clamp and the feed roller is allowed to free wheel. The tie ribbon in the path between the feed roller and the staking clamp is then displaced laterally out of the path. The tension in the tie ribbon around the bundle is controlled by regulating the force applied in displacing the tie ribbon. While the tie ribbon is being tightened on the bundle, tie ribbon needed for looping about the next bundle is placed in an accumulator.