| 摘要 |
<p>1533265 Optical positioning of workpiece GENERAL ELECTRIC CO 15 Dec 1975 [19 Dec 1974] 51259/75 Heading G1A To position the surface of a workpiece 10 with respect to a given point and so determine the extent of a machining operation light from source 14 reflected by the surface is focused on to a photo-sensitive detector 24, the displacement of the focused light spot from reference point 32 on the detector surface corresponding to movement of the workpiece surface from the optical axis intersection 28. The source may be a helium/neon gas laser. The axis intersection may be initially positioned within the workpiece and a grinding wheel (44) Fig. 5 (not shown) applied until the reflected light spot is incident on point 32. Alternatively the light source may be directed along the same axis as a drilling laser beam by a movable mirror or fixed beam-splitter (62) Fig. 6 (not shown). The size of the drilled holes, which is dependent on the position of the workpiece with respect to the laser focusing lens (58), may be monitored by an image scanner (82) Figs. 7 and 8 (not shown) and any necessary corrections to the drilling laser intensity or focus offset made for subsequent holes in the workpiece. A filter (88) for ambient light rejection may be provided on the reflected light axis.</p> |
