US 6,677,554 B2 · Selective laser sintering with optimized raster scan direction

Abstract

A computer-controlled apparatus and method for fabricating three-dimensional articles in layerwise fashion is disclosed. Upon dispensing a layer of a fusible powder, a laser irradiates selected locations of that layer to fuse the powder into a cross-section of the article to be formed in that layer, such that the fused cross-sections fuse together into the article. The laser is controlled in a raster scan fashion across the selected locations of the powder layer. The raster scan lines are defined, for each cross-section, to achieve an optimal fill scan time. The optimal fill scan time is determined, by the computer estimating the fill scan time by rotating the cross-section over a plurality of rotational angles, and estimating the fill scan time for each of the rotated cross-sections for at least a sample of the fill scans necessary to form the article. The actual fill scan vectors to be used in selective laser sintering of the article are rotated, from a coordinate axis at the target plane, according to the rotation of the cross-section providing the lowest estimated fill scan time.

Claims16

Dependent claims

A method of fabricating at least one three-dimensional article, comprising the steps of:

receiving a computer-readable representation of the at least one article;
for each of a plurality of layers of the at least one article, operating a computer to perform a sequence of operations comprising:
defining the position of at least one cross-section to be formed in the layer;
for each of a plurality of rotational angles, estimating a fill scan time for the raster scanning of the at least one cross-section;
selecting the one of the plurality of rotational angles corresponding to the lowest estimated fill scan time;
deriving fill scan vectors corresponding to the intersection of the at least one cross-section with lines in the coordinate system at an angle, relative to a coordinate axis, corresponding to the selected rotational angle;
and
storing the derived vectors in computer memory;
dispensing a layer of a powder at a target surface;
scanning an energy beam at selected locations of the layer of powder according to the vectors stored in the computer memory;
repeating the dispensing and scanning steps for a plurality of layers of powder to form the article.

8 more elements

Dependencies are inferred from the claim text.

Selective laser sintering with optimized raster scan direction

Life of this patent

Selective laser sintering with optimized raster scan direction

Life of this patent

Abstract

Claims16