Abstract: The invention relates to a process for producing a printing form, in which a covering layer (5) is applied to a first radiation-sensitive layer (4) arranged on a carrier (1), the applied covering layer (5) is structured in accordance with a pattern to be printed, in order to form an irradiation mask (5′), and the radiation-sensitive layer (4) is irradiated and developed. In this way, in the production of printing forms, an irradiation mask (5′) can be applied very precisely in accordance with a pattern to be printed later.

Abstract: In the production of a screen printing stencil, a thin-walled hollow cylinder having a light responsive layer on the outside is rotated about its cylinder axis and exposed by means of a laser beam impinging on it. The laser beam is focused in the region of the light responsive layer. The laser beam is moved in the direction of the cylinder axis, and is switched on and off in agreement with a desired stencil pattern. A radial deviation of the actual position of the wall of the hollow cylinder from its ideal position is determined from at least one measuring position fixed relative to the laser beam for a multiplicity of circumferential positions of the hollow cylinder. A first actuating signal is then derived from at least one of the radial positional deviations obtained at the measuring positions.

Abstract: A device for producing a printing stencil, in particular a screen printing stencil, having a rotatably supported printing cylinder, a laser for generating a laser beam incident on the printing cylinder and capable of being displaced in the longitudinal direction of the printing cylinder, and focusing optics to focus the laser beam onto the surface of the printing cylinder. The focusing optics have at least one deflection mirror with an elastically deformable mirror diaphragm. At least one sensor is provided to measure a distance between itself and the surface of the printing stencil. An actuating signal generator generates an actuating signal as a function of the measured distance. Actuating devices set a curvature of the mirror diaphragm as a function of the actuating signal.

Abstract: A screen printing stencil is produced by irradiating a light responsive layer situated on the surface of a rotating screen printing cylinder in a punctiform fashion by means of a laser beam which impinges at least approximately radially on the screen printing cylinder and is moved in the radial direction thereof. The screen printing cylinder is supported only in the region of its opposite end faces, while it is inflated so strongly over at least one of these end faces by means of a compressed gas that it assumes a circular cross-section. If the circumferential surface of the screen printing cylinder is opened by burning away the light responsive layer, sealing elements can be blown into the screen printing cylinder in order to seal the cylinder in the region of its exposed perforation.

Abstract: In the production of a screen printing stencil, a thin-walled hollow cylinder having a light responsive layer on the outside is rotated about its cylinder axis and exposed by means of a laser beam impinging on it. The laser beam is focused in the region of the light responsive layer. The laser beam is moved in the direction of the cylinder axis, and is switched on and off in agreement with a desired stencil pattern. A radial deviation of the actual position of the wall of the hollow cylinder from its ideal position is determined from at least one measuring position fixed relative to the laser beam for a multiplicity of circumferential positions of the hollow cylinder. A first actuating signal is then derived from at least one of the radial positional deviations obtained at the measuring positions.

Abstract: A device for machining the surface of a thin-walled hollow cylinder using a laser beam. The laser beam is directed essentially radially onto the surface of the hollow cylinder and can be moved in a longitudinal direction along the cylinder's length as the cylinder is rotated, producing a rotary screen. A support bearing can move along with the laser beam for supporting the hollow cylinder around its circumference. The support bearing is stationary in the circumferential direction of the hollow cylinder, that is to say it cannot rotate around the latter, while in addition the laser beam passes through an opening extending radially in the support bearing. As a result, the vibration of the hollow cylinder can be damped in the immediate vicinity of the point of impingement of the laser beam on the hollow cylinder so that very precise master patterns can be generated.

Abstract: A device (1) for programmed spot treatment of a body with a beam of rays, particularly a laser beam (7), using a lens system (4), in which the point of impact of the beam (7) describes a predetermined pattern on the surface of the body particularly a lacquer sealed rotary screen printing stencil 3a, as a result of a relative movement of the body with respect to the device. According to the invention the device (1) has means for maintaining a constant predetermined distance between the center of the lens system (4) and the center of the point of impact of the beam (7) of rays with the surface of the body.

Abstract: Described is a tensioning roller which can expand under the influence of an inflating pressure and which is used for supporting a medium which is to be treated with high-energy radiation.Such a tensioning roller comprises at the outside a thin walled metal cylinder or sleeve which for the purpose of achieving an increased radial expandability according to the invention is provided with axial slots which are evenly distributed around the periphery of the sleeve.The invention also concerns a device for treating a medium with high-energy radiation which comprises a tensioning roller as described.

Abstract: For the production of a screen printing stencil, a foil is perforated in a regular pattern and then coated, so that the openings in the stencil are closed again. According to the desired pattern the coating material is again removed from the openings and for this purpose the foil is stretched and a laser ray is brought to bear upon the pertinent points according to the desired pattern.

Abstract: For the production of a screen printing stencil, a foil is perforated in a regular pattern and then coated, so that the openings in the stencil are closed again. According to the desired pattern the coating material is again removed from the openings and for this purpose the foil is stretched and a laser ray is brought to bear upon the pertinent points according to the desired pattern.

Abstract: A method of making a perforated metal foil, especially for screen printing, comprises applying to a metallic surface a photosensitive layer, exposing the photosensitive layer through a screen pattern, developing the exposed photosensitive layer to remove portions surrounding dots of the photosensitive material, and electrodepositing a metal upon the surface in the region surrounding the dots. Prior to or during a galvanic deposition of the screen metal on the surface, the dots of photosensitive material are swelled so that the tendency of the perforation boundaries to be encrusted with metal is reduced and the perforations resulting in the screen have substantially the same cross sections and sizes as the dots of the photosensitive material.