摘要 |
<p>A method and apparatus are described for marking a moving body of material (26). The method comprises the steps of directing at the moving body (26) a high energy density beam (46,58), concentrating the beam so as to produce an illuminated spot at a location on or within the moving body (26), and moving the spot in accordance with the resultant of two components of movement, the first being equal to the velocity of the moving body (26) and the second being relative to the moving body (26) so as to create a mark of a predetermined shape. In a preferred embodiment the apparatus includes at least one moveable galvanometer mirror (68,70) capable of moving the spot in accordance with the resultant of the two components. <IMAGE></p> |