Apparatus for Three Dimensional Printing Using Imaged Layers

Abstract

A three-dimensional printer adapted to construct three dimensional objects is disclosed. In an exemplary embodiment, the printer includes a first surface adapted to receive a bulk layer of sinterable powder, a polymer such as nylon powder; a radiant energy source, e.g., an incoherent heat source adapted to focus the heat energy to sinter an image from the layer of sinterable powder; and a transfer mechanism adapted to transfer or print the sintered image from the first surface to the object being assembled while fusing the sintered image to the object being assembled. The transfer mechanism is preferably adapted to simultaneously deposit and fuse the sintered image to the object being assembled. The process of generating an image and transferring it to the object being assembled is repeated for each cross section until the assembled object is completed.

1 - 11 . (canceled) 
     
     
         12 . A method of building an object from a plurality of cross sections with a three-dimensional printer (3DP), the method comprising:
 dispensing a layer of sinterable powder;   selectively fusing a portion of a layer of sinterable powder to provide a support structure comprising a substantially rigid portion that is sintered with an energy density substantially the same as an energy density used to fuse the sinterable powder comprising the cross sections of the object;   selectively fusing a portion of a layer of sinterable powder to provide a support structure comprising an interface portion sintered with less energy than the energy density used to fuse the sinterable powder comprising the cross sections of the object; and   selectively fusing a portion of a layer of sinterable powder into a sintered image, the sintered image corresponding to one of said cross sections of the object, wherein the interface portion of the support structure is generally provided between the substantially rigid portion of the support structure and the cross sections of the object.   
     
     
         13 . The method of  claim 12 , wherein the interface portion is selectively fused directly on the substantially rigid portion, and the cross sections of the object are selectively fused directly on the interface portion. 
     
     
         14 . The method of  claim 12 , wherein the interface portion is selectively fused to comprise some unsintered powder. 
     
     
         15 . The method of  claim 12 , wherein the selective fusing is performed with a focused radiant energy source. 
     
     
         16 . The method of  claim 12 , wherein the selective fusing is performed with a steerable mirror and laser. 
     
     
         17 . The method of  claim 12 , further comprising receiving a layer of sinterable powder on a first surface, wherein the selective fusing of at least one of the substantially rigid portion, the interface portion, and the cross sections of the object is performed on the first surface. 
     
     
         18 . The method of  claim 16 , further comprising transferring via a transfer mechanism the selectively fused powder from the first surface to the object being assembled. 
     
     
         19 . The method of  claim 12 , wherein the selectively fusing of the interface portion is performed with less energy per unit area per unit time than the selectively fusing of the layers of sinterable powder corresponding to the cross sections of the object. 
     
     
         20 . The method of  claim 12 , wherein the selectively fusing of the interface portion is performed for a shorter period of time than the selectively fusing of at least one of the substantially rigid portion and the cross sections of the object. 
     
     
         21 . The method of  claim 12 , wherein the selectively fusing provides the interface portion of the support structure between the object and the substantially rigid portion of the support structure. 
     
     
         22 . The method of  claim 12 , wherein selectively fusing the substantially rigid portion and the interface portion of the support structure fully supports all projecting and overhanging portions of the object.