| 摘要 |
<p>Method and apparatus for maintaining the focal point of a laser beam used for laser machining relative to a workpiece, including an optical distance measuring sensor having a measurement beam, a mirror for combining the measurement and laser beams into a predetermined optical path having a common axis for both beams, and a focusing element which may be in the form of a refractive lens or a reflective parabolic mirror located in the optical path, and a control means for controlling the location of the focal point of the laser beam based on the distance sensed by measurement beam. In drilling, once the hole breaks through the workpiece, the application of the laser beam can be stopped by observing a departure from the incremental distance measurement change.</p> |
