| 摘要 |
<p>A system for scanning a laser beam 1 over an area of a workpiece 7, includes first and second scanning mirrors 4, 5 arranged to direct a laser beam at an area 6 of a workpiece 7 to be treated, means for oscillating each of the said mirrors about an axis 4<1>, 5<1> so as to cause the laser beam to scan the area 6 of the workpiece 7 with a phase difference of ninety degrees between the oscillations of the two mirrors and means 2 for causing the laser beam to be incident alternately on each mirror only during that part of its motion when its angular velocity is substantially constant. <IMAGE></p> |
