Patent ID: 8648279
Filing Date: 2014-02-11
Classification: B23K,G02B

Abstract:
1. A process control apparatus that controls a focus position of a laser beam, while a laser processing apparatus converges the laser beam into a predetermined focus position by using a processing lens and performs a laser processing on a workpiece, the process control apparatus comprising: a calculator that, based on a magnitude of an output of the laser beam that changes during the laser processing, calculates a change amount of a positional deviation of the focus position in an optical axis direction that changes during the laser processing at a laser beam radiation position; and a focus position control unit that, based on the change amount of the positional deviation that has been calculated by the calculator, controls the focus position of the laser beam during the laser processing so as to resolve the positional deviation of the focus position wherein the calculator calculates a beam intensity of the laser beam per unit area by using the magnitude of the output of the laser beam and a diameter of the laser beam, and the calculator calculates the change amount of the positional deviation by using the beam intensity per unit area that has been calculated and a heat absorption factor of the processing lens that is input from an external source.