| 摘要 |
<p>A laser device for perforating the wrappers (32) of cigarettes provides two parallel laser beams (29,30) from a single beam (26). The device comprises two focusing means (15,16) for focusing respective beams of the two parallel beams (29,30), the focusing means (15,16) being relatively movable so as to vary the spacing of the two parallel beams (29,30). <IMAGE></p> |
