LASER BEAM MACHINING DEVICE

摘要

PROBLEM TO BE SOLVED: To measure laser beam output with good accuracy by receiving part of the laser beam with a thermally responsive output measuring element provided with a cover for thermally isolating the element from the ambient environment and measuring the generated heat. SOLUTION: Part of the laser beam is reflected by a half mirror and a photodetecting part 30 is irradiated with the laser beam through windows 34a and 36a. The photodetecting plate 30a of the photodetecting part 30 is heated by the laser beam and the temperature of the photodetecting plate 30a is measured by the thermocouple element 30b. The photodetecting part 30 is thermally isolated from the ambient environment by the double cover 32 and the result of the measurement of the thermocouple element 30b depends only on the heat quantity generated in the photodetecting part 30 by the laser beam. The double cover 32 is composed of an inner cover 34 and an outer cover 36. The outer cover 36 is composed of an isolating member 38 and a thermally insulating material 40. The output of the laser beam is determined by the result of the measurement of the thermocouple element 30b and an attenuator is so regulated that the output of the laser beam attains optimum energy.