DETECTOR FOR CONVERGED POSITION OF CONVERGING OPTICAL SYSTEM IN LASER BEAM MACHINE

PURPOSE:To automatically measure a converged position by detecting the output of a photodetector composing a positional sensor and discriminating the converged position to calculate the deviation of a converged position on an X-Y table. CONSTITUTION:Positional sensors are set to tables 2, 5, the tables 2, 5 are moved to a prescribed position and the positional sensors are irradiated with laser beam so that the coordinate axes in the X, Y direction of X-Y tables 2, 5 on a base 1 coincides with the coordinate axes in the X, Y directions of the positional sensor. The output of each photodetector composing the positional sensor is detected to discriminate which photodetector is irradiated with laser beam. The converged position of the laser beam is calculated by asking for the coordinate position of the positional sensor of the photodetector receiving the laser beam from the origin. In this way, the converged position can be detected in a short time and at a high accuracy.