Abstract: The geometry of the cast part is provided as a digital pattern and an inverse pattern for the lost casting mold including any core is generated from the digital pattern. A layer of a particulate molding material is provided. The molding material is made of a first material and a second material. The first material is chemically inert when irradiated by electromagnetic radiation. The second material is curable by a chemical curing process that is initiated by electromagnetic radiation. The layer is scanned by irradiating electromagnetic radiation on places of the layer corresponding to the inverse pattern for the lost casting mold including any core. The irradiation is controlled to initiate the chemical curing process in the second material.

Abstract: In a method for producing a three-dimensional object wherein the object is generated by successive solidification of individual layers of the object from a liquid or powdery material by action of electromagnetic radiation, the problem arises that the object is either distorted due to shrinkage of the material or that the quality of the surface of the object is poor when using a corresponding shrinkage reducing construction. For the solution of this problem, each layer is separated in an inner core region (2) and an outer shell region (3) and the action of the radiation is controlled in the core region and in the shell region for generating different properties of both regions.

Abstract: In a method for producing a three-dimensional object (6) wherein the object is produced by successive solidification of individual layers (6a, 6b, 6c, 6d, 64) of a liquid or powderous material (3) by action of electromagnetic radiation (8, 10) and a supporting structure (20, 21) for supporting the object (6) is co-solidified together with the object (6), the supporting structure (20, 21) is decomposed in a three-dimensional fashion into an inner core region (22) an an outer envelope region (23) and the irradiation is varied for producing different characteristics of both regions.

Abstract: In a method for calibrating the deflection control of a laser beam a light-sensitive medium (5) is exposed to a laser beam (2) at predetermined positions for generating a test pattern (20), thereafter digitized partial pictures of pattern portions (21) of the test pattern (20) are produced and the digitized partial pictures are composed to a digitized overall picture of the test pattern (20). The correction data for the control (4) for deflecting the laser beam (2) are calculated on the basis of a comparison of actual positions of the laser beam (2) on the digitized overall picture with predetermined desired coordinates.

Abstract: A three-dimensional object is modelled by solidifying superposed layers in such a manner that on an already solidified layer a following layer of initially liquid or powdery material is solidified by light action or the like in correspondence with the form of the object.

Abstract: In the process according to our invention authenticating (code) marks are provided on paper, particularly a security or other financial instrument, by contacting laser radiation from a laser light source on the paper to form the authenticating marks. The objects of our invention are attained with an apparatus equipped with a pivotable mirror device which allows the laser radiation to be directed on sheets of paper arranged transverse to the transport direction on a paper sheet. A preservative medium can be used to coat and protect the marks particularly from mechanical abrasion.