LASER WELDING METHOD

摘要

Provided is a laser welding method capable of easily restraining poor welding when spatters adhere to a protective glass of an optical system. The laser welding method includes a decrease-amount calculating step performed before laser welding is performed by irradiating a welding portion of a workpiece with the laser beam having a predetermined power. The decrease-amount calculating step includes irradiating the welding portion with an inspecting laser beam having a power smaller than the predetermined power, receiving a return beam of the inspecting laser beam, measuring the intensity of the return beam, and comparing the intensity of the return beam with a standard intensity to calculate an amount of decrease in power of the inspecting laser beam at the welding portion. The invention refers also to a laser processing device (100) comprising a laser oscillator (10), an optical system (20), a protective glass (20), a controller (40), used in performing said method.