公开(公告)号：AT222848T

公开(公告)日：2002-09-15

申请号：AT92900076

申请日：1991-10-30

Applicant: 3D SYSTEMS INC

Inventor： SNEAD DAVID E ,  SMALLEY DENIS R ,  COHEN ADAM L ,  ALLISON JOSEPH W ,  VORGITCH THOMAS J ,  CHEN THOMAS P ,  NGUYEN HOP D ,  SCHMIDT KRIS A ,  EVANS HERBERT E ,  FREED RAYMOND S ,  JACOBS PAUL F ,  VINSON WAYNE A

IPC: B29C35/08 ,  B29C67/00 ,  B29K105/24 ,  B29L9/00 ,  G06F17/50

公开(公告)号：CA1339750C

公开(公告)日：1998-03-17

申请号：CA596827

申请日：1989-04-17

Applicant: 3D SYSTEMS INC

Inventor： HULL WILLIAM CHARLES ,  SPENCE STUART T ,  LEWIS CHARLES W ,  VINSON WAYNE A ,  FREED RAYMOND S ,  SMALLEY DENNIS R

IPC: B29C35/08 ,  B29C67/00 ,  B29K105/24 ,  B44B1/00 ,  G03F7/00 ,  G03F7/20 ,  G06F17/50 ,  G06T17/00

Abstract: 94 An improved stereolithography system for generating a three-dimensional object by creating a cross-sectional pattern of the object to be formed at a selected surface of a fluid medium capable of altering its physical state in response to appropriate synergistic stimulation by impinging radiation, particle bombardment or chemical reaction, information defining the object being structurally specified to reduce curl, stress and distortion in the ultimately formed object, the successive adjacent laminae, representing corresponding successive adjacent cross-sections of the object, being automatically formed and integrated together to provide a step-wise laminar buildup of the desired object, whereby a three-dimensional object is formed and drawn from a substantially planar surface of the fluid medium during the forming process. A stereolithographic distortion known as curl is defined, and several techniques to eliminate or reduce curl are described, including dashed line, bent line, secondary structure, rivets, and multi-pass techniques. In addition, a quantitative measurement of curl known as the curl factor, and a test part known as a quarter cylinder are described, which together can be used to measure the effectiveness of the above techniques in reducing curl.

公开(公告)号：CA2095225A1

公开(公告)日：1992-05-14

申请号：CA2095225

申请日：1991-10-30

Applicant: 3D SYSTEMS INC

Inventor： SNEAD DAVID E ,  SMALLEY DENNIS R ,  COHEN ADAM L ,  ALLISON JOSEPH W ,  VORGITCH THOMAS J ,  CHEN THOMAS P ,  NGUYEN HOP D ,  SCHMIDT KRIS A ,  EVANS HERBERT E JR ,  FREED RAYMOND S ,  JACOBS PAUL F ,  VINSON WAYNE A

IPC: B29C35/08 ,  G03F7/20 ,  B29C64/124 ,  B29C67/00 ,  B29K105/24 ,  B29L9/00 ,  G06F17/50 ,  G06F15/72

Abstract: 2095225 9208200 PCTABS00013 A method of and apparatus for slicing a three-dimensional object representation into a plurality of layer representations. The layer representations are subsequently used to form the object layer-by-layer from a solidifiable material by stereolithography (711). If not already provided in the object representation, a plurality of layer boundary representations are first formed, and then the boolean difference (17), of successive layer boundary representations are computed to derive boundaries of up and down-facing regions, enabling different cure parameters to be specified for these different regions. In another method, the depth of the curable material within the objet underlying a selected area element is determined and compared to the depht to the minimum solidification depth of the material. The area element is exposed to solidifying synergistic stimulation only if the depth of the material equals or exceeds the minimum solidification depth. A next layer is created over the first layer without curing the first layer, if the depth is less than the minimum solidification depth. Another method and apparatus (714) eliminates or substantially reduces curling effects in stereolithographically formed objects. Synergistic stimulation is applied to a curable material to form a three-dimensional object through the build up of successive layers.