Patent ID: 8988777
Filing Date: 2015-03-24
Classification: B23K

Abstract:
1. A cutting processing device, comprising: a light source that emits a laser beam; and an irradiation optical system which has a plurality of lenses, and is provided for light-guiding and light-converging the laser beam emitted from the light source to a board formed from a hard and brittle material; wherein the irradiation optical system comprises a beam expander having a first lens that is a concave lens or a convex lens, and a second lens that is a convex lens, in order along a laser-beam travel direction, the beam expander being configured so as to make an interval between the first lens and the second lens variable, the irradiation optical system further comprising a light converging lens, disposed at a last position along the laser-beam travel direction, configured to form a groove on a surface of the board by irradiating the board with the laser beam; and wherein a birefringent material that splits the laser beam into an ordinary light beam and an extraordinary light beam is used as a material entity of at least one of the first lens and the second lens to form two beam waists, wherein an interval between the beam waists along an optical axis direction of the irradiation optical system is altered depending on the interval between the first lens and the second lens.