Abstract: The invention is directed to an apparatus and a method for generating separating fissures in a substrate through action of a laser beam having an elliptical beam cross section with a beam spot length in a movement direction along a separating fissure to be generated in the substrate. The apparatus and method are particularly suitable for separating fissures which start or end on the substrate surface. A suitable diaphragm prevents radiation from impinging on the substrate before the start and after the end of the fissure.

Abstract: The invention is directed to an apparatus and a method for generating separating fissures in a substrate through action of a laser beam having an elliptical beam cross section with a beam spot length in a movement direction along a separating fissure to be generated in the substrate. The apparatus and method are particularly suitable for separating fissures which start or end on the substrate surface. A suitable diaphragm prevents radiation from impinging on the substrate before the start and after the end of the fissure.

Abstract: The invention is directed to a method for generating optically perceptible laser-induced cracks in brittle material, wherein a laser beam, followed by a coolant jet, is guided relative to the surface of the brittle material in order to advance a crack trail into the material starting from an initial crack, and wherein a marking agent which penetrates into the crack during the formation of the crack so as to make the latter visible is mixed with the coolant.

Abstract: The invention is directed to a method for generating optically perceptible laser-induced cracks in brittle material, wherein a laser beam, followed by a coolant jet, is guided relative to the surface of the brittle material in order to advance a crack trail into the material starting from an initial crack, and wherein a marking agent which penetrates into the crack during the formation of the crack so as to make the latter visible is mixed with the coolant.

Abstract: A method and apparatus for trimming the edges of a float glass ribbon whose thickness can vary between 0.4 mm and 24 mm in which a specific depth crack is generated for the respective thickness. The depth of the crack is actively influenced by energy introduced by means of a laser which is controlled as a function of the surface temperature of the float glass ribbon and by a subsequent cooling whose acting period is variable. To ensure a permanently reliable process, the severing crack and the thickness of the float glass ribbon are detected in order to initiate a new initial crack immediately in the event that the severing crack should break up and so that a cutting unit comprising the scribing device, the beam-shaping optics and the cooling nozzles is always at a constant vertical distance from the surface of the float glass ribbon. The method and apparatus are distinguished particularly by the fact that only a low laser power is required.

Abstract: Flat workpieces of brittle material be severed in a time-saving manner by an arrangement according to the invention by inducing thermomechanical stresses by laser radiation, particularly along severing lines in the same orientation in alternating directions, in that the arrangement has two coolant nozzles which selectively direct coolant to the workpiece and which, preferably coupled with optical means for shaping the laser beams, are mounted so as to be rotatable around the axis of the laser head.

Abstract: Flat workpieces of brittle material be severed in a time-saving manner by an arrangement according to the invention by inducing thermomechanical stresses by laser radiation particularly along severing lines in the same orientation in alternating directions, in that the arrangement has two coolant nozzles which selectively direct coolant to the workpiece and which, preferably coupled with optical means for shaping the laser beams, are mounted so as to be rotatable around the axis of the laser head.