Patent ID: 9500781
Filing Date: 2016-11-22
CPC Classification: B23K,G02B,H01S

Claim Text:
1. An optical system comprising: a laser oscillator that generates laser light and emits the laser light toward the optical system; a first lens that focuses the laser light which is used for processing a workpiece; a second lens that is disposed on the same optical axis as the laser light that passes through the first lens and through which the laser light focused by the first lens passes; and a drive portion that moves the second lens out of the optical path of the laser light when cutting the workpiece and places the second lens in the optical path of the laser light when welding the workpiece, wherein the second lens has a first region that is positioned on the optical axis and does not have lens properties, as well as a second region that surrounds the first region and diverges the laser light, wherein the laser light that passes through the second lens is radiated directly to the workpiece, wherein the first lens and the second lens are disposed so that a focal point of the laser light that has passed through the first region of the second lens is set at a processing point of the workpiece or in a vicinity of the processing point, and wherein the first region is a plate-like member in which a surface from which the laser light enters and a surface from which the laser light is emitted are parallel to each other.