Patent ID: 8450639

Claim:
Laser machining head having an integrated sensor device for focus position monitoring, said laser machining head comprises means for monitoring said focus position including a focusing lens having an optical axis and a focal length and a downstream protective glass in order to focus a machining beam that strikes said focusing lens as a parallel beam into a resultant focal point of said focusing lens with a downstream protective glass, in which focal point a workpiece is arranged, a beam splitter for dividing a laser beam arranged upstream of the focusing lens in the parallel beam path, a sensor connected to an evaluation unit, wherein said beam splitter divides said laser beam, which is coupled into the laser machining head, into the machining beam and a measuring beam, and a mirror arranged downstream of the beam splitter in such a manner that it reflects the measuring beam at an angle α to said optical axis of the focusing lens onto the focusing lens in order to image it onto a receiving surface of the sensor in an image point conjugate with the focal point.