Patent ID: 8735768
Filing Date: 2014-05-27
Classification: B23K,G01B

Abstract:
1. A laser welding apparatus for welding by a laser beam, comprising: a laser light source that emits the laser beam; a first optical element that coaxially emits, to a welded part, the laser beam and an object beam having a different wavelength from the laser beam; a second optical element that causes a spot diameter of the object beam to be larger than a spot diameter of the laser beam on the welded part; an optical interferometer that emits the object beam to the first optical element, detects through the first optical element the object beam reflected on the welded part, and generates an electric signal; a measuring unit that measures a penetration depth of the welded part based on the electric signal; and an evaluating unit that evaluates the welded part based on the penetration depth of the welded part, wherein the optical interferometer generates a coherent beam from the object beam and a reference beam, and generates the electric signal based on the coherent beam according to a difference in optical path length between the object beam and the reference beam, wherein the optical interferometer comprises: wherein the measuring unit measures the penetration depth of the welded part based on the differential component.