| 摘要 |
PURPOSE:To improve the measuring accuracy of an interval by measuring the variation of an electrostatic capacity between the tip of a laser working head and a metallic material to be worked which is opposed to said tip, through a shield cover holding the same potential as the material to be worked. CONSTITUTION:The laser working head 2 is moved to the metallic material to be worked 1, and an interval between the electrode 3 of its tip and the metallic material to be worked 1 which is opposed to said electrode is varied. In this way, the variation of the electrostatic capacity of a capacitor 6 which is formed between the electrode 3 and the metallic material to be worked 1 is detected by an oscillating device 5. The interval between the laser working head 2 and the material to be worked 1 is controlled so that an oscillation frequency detected by the oscillating device 5 becomes constant. In this way, the interval between the material to be worked and the head can be controlled with the high accuracy. |
