Abstract: The aim of the invention is to simplify known passivation methods. According to said method, the semi-conductor elements are heated and cleaned in a high vacuum with a gaseous, reactive low-energy medium. A closed, insulating or slightly conductive, transparent protective layer is applied in-situ, said layer being inert in relation to the material on the mirror-type surface and the remaining components of a natural oxide. In a preferred embodiment, the optical semi-conductor elements is a GaAs-based semi-conductor laser, the reactive and low-energy medium is an atomic hydrogen and the protective layer is made of ZnSe.

Abstract: In a device for engraving of cups into a rotating printing cylinder for rotogravure, at least one laser light source with which laser light for formation of the cups is directed onto the rotating printing cylinder. A metal removal element is arranged in a region of an impingement location of the laser light on the printing cylinder to form the cups such that a melt accumulation of material of the printing cylinder which forms a burr at the cups created by the impingement of the laser light is removed substantially continuously and substantially immediately after its creation with the removal element.

Abstract: The aim of the invention is to simplify known passivation methods. According to said method, the semi-conductor elements are heated and cleaned in a high vacuum with a gaseous, reactive low-energy medium. A closed, insulating or slightly conductive, transparent protective layer is applied in-situ, said layer being inert in relation to the material on the mirror-type surface and the remaining components of a natural oxide. In a preferred embodiment, the optical semi-conductor elements is a GaAs— based semi-conductor laser, the reactive and low-energy medium is an atomic hydrogen and the protective layer is made of ZnSe.

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: 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 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.

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: 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 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.

Abstract: A work vehicle, in particular an agricultural or construction tractor, has a cab the lower portion of which lies partially between the vehicle's rear wheels and covers at least part of the power train. To provide adequate access for maintenance, repair, exchange and cleaning of the components beneath the cab without great difficulty and with little expenditure of time, the cab can, after removal of a rear wheel, be tilted laterally about a tilt axis approximately parallel to the longitudinal axis of the vehicle. The tilt angle is approximately 60.degree. to 110.degree., and preferably about 90.degree.. A readily transportable tilting apparatus also is provided which includes a hand-cranked spindle assembly for mounting to the chassis beneath the cab.