| 摘要 |
PURPOSE:To always position a working beam focus on the surface of a work by executing the image pickup of an optical spot formed on an object work by a laser working beam, to a photodetecting lens, and sending out and calculating an electric signal corresponding to said image formed position. CONSTITUTION:When a distance l between a working lens 2 and the surface of a work 8 is varied, a scattered light of an optical spot formed on the work 8 of a laser working beam 1 is varied. Also, an image formed position of the optical spot whose image is formed on a photodetecting surface of an optical position detector (PSD)12 by a photodetecting lens 11 is varied. As a result, currents iA, iB generated across the PSD12 are varied in accordance with the image formed position and inputted to an operation processing circuit 13. In the circuit 13, the distance l between the working lens 2 and the surface of the work 8 is calculated, and by a value of this distance l, a working head body 9 is moved up and down so that a focus of the laser working beam 1 is positioned on the surface of the work 8. |
