Laser scribing installation for the superficial treatment of magnetic sheets with spots of elliptic section

摘要

A laser scribing installation for the treatment of grain oriented magnetic sheets, as strip in longitudinal movement, comprising a laser generator for a laser beam, a cylindrical telescopic optical group with varying focal distance for the formation of a laser beam with elliptic section having varying ellipticity as function of the focal distances and a rotating mirror scanner for scanning the laser beam according to a pre-defined angle. The scribing installation further comprises a parabolic reflector extended transversally to the strip for receiving the scanned laser beam and focusing the beam on the strip, as a greatly lengthened elliptic spot, along a treatment path, and wherein the telescopic group is adjustable for modifying the length of one of the axes in the elliptic section of the laser beam incident on the strip.

主权项

1. A laser scribing installation for treatment of grain oriented magnetic sheets, as a strip advancing on a planar surface along a longitudinal direction of movement, said installation comprising a laser generator, a cylindrical telescopic optical group with varying focal distance for formation of an elliptic sectioned laser beam, and a rotating mirror scanner for scanning the laser beam according to a pre-defined angle, wherein said installation further comprises:
a parabolic reflector extended transversally to the strip for receiving the laser beam from the rotating mirror scanner and focusing the beam on the strip, as a lengthened elliptic spot, along a treatment path; a limiting plate arranged between the strip and the parabolic reflector and defining a window for the laser beam directed to the treatment path, and a protection device for generating a gaseous lamina between the limiting plate and the strip, adjacent to the said window; wherein said laser beam defines, in an elliptic section, axes of varying ellipticity as function of said focal distance; wherein said telescopic optical group is adjustable for modifying the length of one of said axes of the laser beam incident on said strip; and wherein said gaseous lamina has function of gaseous barrier tangent to said window for protecting said parabolic reflector from contamination.