| 摘要 |
PURPOSE:To center and assemble a large-scale machine easily with a high precision, by projecting the laser to a photodetector and locating centers of the machine and the laser. CONSTITUTION:A laser beam 7 is projected to a photodetector 17, and a photo detecting material 12 is rotated to positions at 0 deg., 90 deg., 180 deg., and 270 deg.. A center 28 of the beam 7 is obtained on a basis of curves 26 and 27 of intensity distribution in both directions which intersect for 0 deg. of the photodetector 17. When the photodetector 17 is rotated, a detection center 30 describes a locus 34. The photodetector 17 is divided ino four, and a difference of electromotive force is generated in accordance with the quantity of receiving light. The ouput of the photodetector 17 is detected and is corrected to standard coordinates by an amplifier 21, a filter 22, and a storage device 23, and they are inputted to an operating device 24 while rotating the photo detecting material several times, and the difference between positions of centers 28 and 29 is obtained on a basis of respective corrected values. The result is displayed on a dispaly device 25, and centers 28 and 29 are made coincident with each other so that said difference becomes zero. |
