Patent ID: 6815636
Filing Date: 2004-11-09
Classification: B29C,B33Y,G05D

Abstract:
A method for forming a three dimensional article by laser sintering comprising the steps of:(a) dispensing a first top layer of powder on a target area; (b) moderating the temperature of said first top layer of powder to a predetermined temperature; (c) directing an energy beam over said target area causing said first top layer of powder to fuse powder in select locations to form an integral layer; (d) dispensing a second top layer of powder over the fused and unfused powder of said first top layer; (e) moderating the temperature of said second top layer of powder to a second predetermined temperature; (f) directing said energy beam over said target area causing said second top layer of powder to form a second integral layer bonded to said first integral layer; and (g) repeating steps (a) to (f) to form additional layers that are integrally bonded to adjacent layers so as to form a three dimensional article, wherein the temperature moderating steps comprise: using a machine vision system to image multiple temperatures of the current top layer of powder and adjusting those temperatures by adjusting the radiant heat output from a zoned radiant heater located above the target area.