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 . A method of building an object from a plurality of cross sectional layers with a three-dimensional printer (3DP), the method comprising: 
 sintering at least one first layer of sinterable powder with a first energy density level;    partially sintering at least one second layer of sinterable powder with a second energy density level less than the first energy density level; and    sintering at least one third layer of sinterable powder with a third energy density level greater than the second energy density level to form one or more of the plurality of cross sectional layers.    
   
   
       2 . The method in  claim 1 , wherein the method comprises: 
 generating a substantially rigid support from the at least one first layer;    generating an interface from the at least one second layer; and    generating the object from the at least one third layer.    
   
   
       3 . The method in  claim 2 , wherein the interface is configured to be weaker than both the object and rigid support, thereby permitting the object to be separated from the support.  
   
   
       4 . The method in  claim 3 , wherein: 
 the at least one first layer of sinterable powder is a bulk layer of powder sintered on a first surface;    the at least one second layer of sinterable powder is a bulk layer of sinterable powder sintered on the first surface; and    the at least one third layer of sinterable powder is a bulk layer of powder sintered on the first surface.    
   
   
       5 . The method in  claim 4 , wherein the first surface comprises a drum.  
   
   
       6 . The method in  claim 4 , wherein the sinterable powder of the first layer, second layer, and third layer comprises a sinterable polymer.  
   
   
       7 . The method in  claim 4 , wherein the first layer, second layer, and third layer are sintered with a halogen lamp.  
   
   
       8 . A method of generating an object from a plurality of cross sections with a three-dimensional printer (3DP), the method comprising: 
 generating a plurality of images, each image being sintered from a portion of a bulk layer of sinterable powder on a first surface;    stacking a first set of the plurality of images to form a substantially rigid support;    stacking a second set of the plurality of images on the rigid support to form the object; and    removing unsintered powder after sintering one or more of the plurality of bulk layers and before stacking a next one of the plurality of images.    
   
   
       9 . The method of  claim 8 , further comprising: 
 generating one or more interface images formed from a bulk layer of sinterable powder; and    stacking the one or more interface images directly on the rigid support.    
   
   
       10 . The method of  claim 9 , wherein each of the one or more interface images is partially sintered from a portion of the bulk layer of sinterable powder on the first surface.  
   
   
       11 . The method of  claim 10 , wherein the one or more interface images are partially sintered with a first energy density level, and the second set of images from which the object is formed are sintered with a second energy density level, wherein the second energy density level is greater than the first energy density level.  
   
   
       12 . The method of  claim 11 , wherein the first set of images from which the rigid support is formed are sintered with a third energy density level, wherein the third energy density level is greater than the first energy density level.  
   
   
       13 . A three-dimensional printer (3DP) adapted to generate an object assembled from a plurality of cross sections, comprising: 
 a first surface configured to receive a bulk layer of sinterable powder;    a focused radiant energy source configured to selectively fuse a portion of the layer of sinterable powder on the first surface into a sintered image, the sintered image corresponding to one of said cross sections;    a transfer mechanism adapted to transfer the sintered image from the first surface to the object being assembled; and    a controller configured to transfer one or more sintered images to generate: 
 a) a support structure comprising a substantially rigid portion; and  
 b) the object on the rigid portion.  
   
   
   
       14 . The 3DP of  claim 13 , wherein the controller is further configured to transfer one or more interface layers directly on the rigid support, and generate the object directly on the one or more interface layers.  
   
   
       15 . The 3DP of  claim 13 , wherein the one or more interface layers transferred directly on the rigid support comprise unsintered powder.  
   
   
       16 . The 3DP of  claim 14 , wherein the one or more interface layers are selectively fused with an energy density less than an energy density used to fuse sintered images that form the object.  
   
   
       17 . A method of building an object from a plurality of cross sectional layers with a three-dimensional printer (3DP), the method comprising: 
 generating a rigid support from a first set of one or more sintered images formed from sinterable powder;    generating an interface from a second set of one or more layers of unsintered power transferred to the rigid support; and    generating the object from a third set of one or more sintered images formed from sinterable powder.