To apply indicia to a surface of a traveling workpiece, particularly of a rapidly moving workpiece, a beam of coherent laser light is split to form two rays, one of which is deflected directly onto the surface whereas the other is indirectly guided onto the surface. The two rays form on the surface two...http://www.google.de/patents/US4307282?utm_source=gb-gplus-sharePatent US4307282 - Method of and arrangement for applying indicia to a surface of a moving workpiece
