| 摘要 |
PURPOSE:To always ensure stable laser processing with second position reproducibility, by adding a position compensating mechanism to an optical scanning part using a galvanometer. CONSTITUTION:Laser light 26 supplied from a light source 11 is turned by an angle theta0 proportional to a designated coordinate data by means of a galvanometer type scanning mechanism 12. Thus the light 26 is turned into the output light 27 having a theta0 angle to the optical axis of an f.Q lens 13. The light 27 is condensed on the focal plane at a position distant away by f.Q(f: focal distance) through the lens 13. The laser light transmitted partially through a mirror 14 forms spots 21-23 with respect to condensed spots 31-33. An L-shaped shielding plate is put on the focal plane, and the transmitted light is led to a photodetector 18 via a lens 17. The laser light is scanned through the spots 31- 33, and an output signal 41 is turned into a pulse-converted output signal 43 though a differentiating circuit 19. This signal 43 is usd to a latch pulse of a latch circuit 34. Then the value of a coordinate counter is read by a control circuit such as a CPU, etc. at a time point when the laser light passes through a position 22 or 24, i.e., when the signal 43 is delivered. |
