Patent ID: 8014427

Claim:
A line-forming optical system for forming a line image for a laser thermal processing system, comprising in order along an optical axis: a laser that generates an input light beam; a first cylindrical lens system that focuses the input light beam to a line focus in a first direction having a central lobe defined by surrounding intensity minima; a first spatial filter located at the line focus and configured to truncate the line image in a second direction within the central lobe, thereby forming a first light beam; a second cylindrical lens system configured to receive and truncate a portion of the first light beam in the second direction to form a second substantially collimated light beam; a knife-edge aperture configured to truncate the second substantially collimated light beam in the second direction to form a third light beam; a third cylindrical lens system having an image plane conjugate with the knife-edge aperture and configured to receive the third light beam and form therefrom a fourth light beam that is focused in the second direction to define a line image length LL at the image plane; and a fourth cylindrical lens system that focuses the fourth light beam in the first direction to define a line image width WL at the image plane.