Method of identifying workpieces which are in a hot state

摘要

Method of identifying workpieces of glass, ceramic or porcelain which are in a hot state. According to the new method, workpieces which are still in a very hot state can be reliably identified without a thermal or mechanical stress being applied to part of the workpiece. A thin carrier layer about 50 to 1000 nanometers thick, serving as an identification field and consisting of a material which condenses and solidifies on the hot workpiece, especially metal or graphite, is vapour-deposited on the hot workpiece under an inert gas atmosphere and the symbols serving for identification, such as numbers, letters, bars or similar codings, are generated by partial removal of the carrier layer by means of laser beams. The method is particularly suitable for identifying picture tubes, optical glasses and other workpieces of glass, ceramic or porcelain.