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: An optical read head contains imaging optics for focusing incident light and light receiving optics arranged concentrically with respect to the imaging optics for receiving the light focused by the imaging optics and reflected from an object. The imaging optics and the light receiving optics are located on the same optical axis, the light receiving optics surrounding the imaging optics. The light receiving optics are also displaced forward in the direction of the incident light with respect to the imaging optics, an input face of the light receiving optics being inclined towards the optical axis. The optical read head is suitable for, among other things, the colour-selective scanning of material webs and other colour patterns and exhibits a high light receiving capability in addition to a high resolution capability.

Abstract: A hollow cylinder, generally a foil, for use in screen printing, is patterned by laser beam machining. The foil is held at its ends and rotated about its axis while a carriage is shiftable along a guide extending on the bed along the cylinder and carrying the laser optics for training a laser beam against the cylinder. Support rollers engage the wall of the hollow cylinder from the exterior on the carriage adjacent the laser impingement location.

Abstract: A hollow cylinder, generally a foil, for use in screen printing, is patterned by laser beam machining. The foil is held at its ends and rotated about its axis while a carriage is shiftable along a guide extending on the bed along the cylinder and carrying the laser optics for training a laser beam against the cylinder. Support rollers engage the wall of the hollow cylinder from the exterior on the carriage adjacent the laser impingement location.

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.