Patent ID: 7285744

Claim:
A method for simultaneously heating materials having an arbitrary, substantially flat shape of a heating contour by means of laser radiation, comprising the steps of: coupling a laser beam to an optical arrangement for annularly reshaping the laser beam and focusing said annular laser beam towards an entrance side of a tube having a wall that is transparent to IR radiation; coupling the laser beam in a longitudinal direction into the wall of the tube at the entrance side having one closed annularly formed entering surface; guiding the IR radiation through the wall of the tube from the entrance side to an exit side having one closed with respect to the entrance side differently shaped emerging surface being arbitrarily formed in accordance with a desired heating contour; reshaping the laser beam during passing from the tube from the entrance side towards the exit side from its annular shape to the shape of the heating contour; and imaging an emerging laser beam onto a heating plane by means of a converging lens to heat materials to be welded.