Additive manufacturing with energy delivery system having rotating polygon and second reflective member

Abstract

An additive manufacturing apparatus includes a platform, a dispenser to dispense a plurality of layers of feed material on a top surface of the platform, and an energy delivery assembly. The energy delivery assembly includes a light source to emit one or more light beams, a first reflective member having a plurality of reflective facets, and at least one second reflective member. The first reflective member is rotatable such that sequential facets sweep the light beam sequentially along a path on the uppermost layer. The at least one second reflective member is movable such that the at least one second reflective surface is repositionable to receive at least one of the at least one light beam and redirect the at least one of at least one light beam along a two-dimensional path on the uppermost layer.

What is claimed is: 
     
         1 . An additive manufacturing apparatus comprising:
 a platform;   a dispenser to dispense a plurality of layers of powder a top surface of the platform;   at least one light source to emit a first light beam and a second light beam,   a polygon mirror scanner including a first reflective member positioned in an optical path of the first light beam and not in an optical path of the second light beam to direct the first light beam toward the top surface of the platform to deliver energy to an uppermost layer of the layers of powder, the reflective member having a plurality of reflective facets and rotatable about an axis such that sequential facets sweep a first impingement spot of the first light beam on the uppermost layer sequentially along a predefined path on the uppermost layer,   an actuator to move the predefined path relative to the platform such that a sequence of sweeps by the first impingement spot along the predefined path creates a raster scan by the light beam across the uppermost layer, and   a galvo mirror scanner including at least one reflective surface positioned in the optical path of the second light beam and not in the optical path of the first light beam to direct the second light beam toward the top surface of the platform to deliver energy to the uppermost layer of the layers of powder, the at least one reflective surface tiltable to translate a second impingement spot of the second light beam on the uppermost layer in an adjustable path in a first direction and a second direction substantially perpendicular to the first direction.   
     
     
         2 . The apparatus of  claim 1 , wherein the predefined path is substantially linear. 
     
     
         3 . The apparatus of  claim 1 , comprising a support and the polygon mirror scanner is secured to the support, and the actuator is configured to create relative motion along a horizontal axis between the support and the platform to move the predefined path relative to the platform. 
     
     
         4 . The apparatus of  claim 3 , wherein the actuator is coupled to the support and moves the support. 
     
     
         5 . The apparatus of  claim 3 , wherein the actuator is coupled to the platform and moves the platform. 
     
     
         6 . The apparatus of  claim 3 , wherein the galvo mirror scanner is secured to and moves with the support. 
     
     
         7 . The apparatus of  claim 1 , comprising second galvo mirror scanner positioned in the optical path of the first light beam to move the predefined path relative to the platform and the actuator is coupled to the second mirror galvo mirror scanner. 
     
     
         8 . The apparatus of  claim 1 , wherein the galvo mirror scanner includes a first adjustable reflective surface in the optical path of the second light beam to translate the second impingement spot along the first direction and a second reflective surface in the optical path of the second light beam to translate the second impingement spot along the second direction substantially perpendicular to the first direction. 
     
     
         9 . The apparatus of  claim 1 , wherein the at least one light source comprises a first light source to generate the first light beam and a second light source to generate the second light beam. 
     
     
         10 . The apparatus of  claim 1 , wherein the sequential facets are positioned and oriented relative to the light beam to sweep the first impingement spot of the first light beam sequentially along a linear path. 
     
     
         11 . The apparatus of  claim 1 , comprising a controller configured to store data in a non-transitory computer readable medium, the data defining a region of the uppermost layer to fuse, and the controller is configured to
 cause the polygon mirror scanner to deliver energy toward an interior of the region, and   cause the galvo mirror scanner to deliver energy along a perimeter of the region.   
     
     
         12 . An additive manufacturing apparatus comprising:
 a platform;   a dispenser to dispense a plurality of layers of feed material on a top surface of the platform;   a first energy delivery system comprising
 a first light source to emit a first light beam, and 
 a first reflective member having a plurality of reflective facets, the first reflective member positioned in a path of the first light beam to redirect the first light beam toward a first portion of top surface of the platform to deliver energy to a first region of an uppermost layer of the layers of feed material to fuse the feed material in the first region, wherein the first reflective member is rotatable such that sequential facets sweep the first light beam sequentially along a linear first path on the uppermost layer; and 
   a second energy delivery system comprising
 a second light source to emit a second light beam, and 
 a second reflective member having a plurality of reflective facets, the second reflective member positioned in a path of the second light beam to redirect the second beam toward a second portion of top surface of the platform to deliver energy to a second region of the uppermost layer of the layers of feed material to fuse the feed material in the second region, wherein the second reflective member is rotatable such that sequential facets sweep the second light beam sequentially along a linear second first path on the uppermost layer. 
   
     
     
         13 . The apparatus of  claim 12 , wherein the first energy system and the second energy system are mounted on a support that is movable relative to the platform along a first direction. 
     
     
         14 . The apparatus of  claim 13 , wherein the first direction is at a non-zero angle relative to the linear first path and the linear second path. 
     
     
         15 . The apparatus of  claim 14 , wherein the first linear path and second linear path are parallel. 
     
     
         16 . The apparatus of  claim 15 , wherein the first direction is at a right angle to the linear first path and the linear second path. 
     
     
         17 . The apparatus of  claim 12 , wherein a combination of the first path and the second path span a working area of the platform.