Joseph W Allison

US Patent:

53216229, Jun 14, 1994

Filed:

Oct 30, 1990

Appl. No.:

7/606191

Inventors:

David E. Snead - Canyon Country CA
Dennis R. Smalley - Baldwin Park CA
Adam L. Cohen - Los Angeles CA
Joseph W. Allison - Valencia CA
Thomas J. Vorgitch - Simi Valley CA
Thomas P. Chen - Saugus CA

Assignee:

3D Systems, Inc. - Valencia CA

International Classification:

G06F 1546

US Classification:

36447424

Abstract:

A method of and apparatus for slicing a three-dimensional object representation into a plurality of layer representations is described, wherein the layer representations are subsequently used to form the object layer-by-layer according to the principles of stereolithography. If not already provided in the object representation, a plurality of layer boundary representations are first formed, and then the boolean difference 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.

US Patent:

6333741, Dec 25, 2001

Filed:

Dec 18, 1998

Appl. No.:

9/215793

Inventors:

David E. Snead - Canyon Country CA
Dennis R. Smalley - Baldwin Park CA
Adam L. Cohen - Los Angeles CA
Joseph W. Allison - Valencia CA
Thomas J. Vorgitch - Simi Valley CA
Thomas P. Chen - Saugus CA

Assignee:

3D Systems, Inc. - Valencia CA

International Classification:

G06T 1700

US Classification:

345423

Abstract:

A method of and apparatus for slicing a three-dimensional object representation into a plurality of layer representations is described, wherein the layer representations are subsequently used to form the object layer-by-layer according to the principles of stereolithography. If not already provided in the object representation, a plurality of layer boundary representations are first formed, and then the boolean difference 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.

US Patent:

60369116, Mar 14, 2000

Filed:

Jan 27, 1998

Appl. No.:

9/014367

Inventors:

Joseph W. Allison - Valencia CA
Jan Richter - Los Angeles CA
Craig Matthew Childers - Santa Clarita CA
Dennis R. Smalley - Baldwin Park CA
Charles W. Hull - Santa Clarita CA
Paul F. Jacobs - La Crescenta CA

Assignee:

3D Systems, Inc. - Valencia CA

International Classification:

B29C 3508
B29C 4102

US Classification:

264401

Abstract:

An improved method for stereolithographically making an object by alternating the order in which similar sets of vectors are exposed over two or more layers. In another method, a pattern of tightly packed hexagonal tiles are drawn. Each tile is isolated from its neighboring tiles by specifying breaks of unexposed material between the tiles. Using an interrupted scan method, vectors are drawn with periodic breaks along their lengths. In another method, modulator and scanning techniques are used to reduce exposure problems associated with the acceleration and deceleration of the scanning system when jumping between vectors or changing scanning directions.

US Patent:

52386392, Aug 24, 1993

Filed:

Aug 31, 1992

Appl. No.:

7/939549

Inventors:

Wayne A. Vinson - Valencia CA
Joseph W. Allison - Valencia CA
Paul F. Jacobs - La Crescenta CA
Dennis R. Smalley - Baldwin Park CA

Assignee:

3D Systems, Inc. - Valencia CA

International Classification:

B29C 3508
B29C 4102

US Classification:

264 22

Abstract:

A method and apparatus for eliminating or substantially reducing 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. Curling between successive layers is eliminated or substantially reduced by curing a balancing layer in relation to a balanced layer such that reverse curl of the balanced layer caused by the balancing layer offsets or negates normal curl of the balanced layer caused by the balancing layer.

US Patent:

54814707, Jan 2, 1996

Filed:

Jun 13, 1994

Appl. No.:

8/259333

Inventors:

David E. Snead - Canyon Country CA
Dennis R. Smalley - Baldwin Park CA
Adam L. Cohen - Los Angeles CA
Joseph W. Allison - Valencia CA
Thomas J. Vorgitch - Simi Valley CA
Thomas P. Chen - Saugus CA

Assignee:

3D Systems, Inc. - Valencia CA

International Classification:

G06F 1750
G06F 1900

US Classification:

364468

Abstract:

A method of and apparatus for slicing a three-dimensional object representation into a plurality of layer representations is described, wherein the layer representations are subsequently used to form the object layer-by-layer according to the principles of stereolithography. If not already provided in the object representation, a plurality of layer boundary representations are first formed, and then the boolean difference 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.

US Patent:

52563405, Oct 26, 1993

Filed:

Jun 25, 1992

Appl. No.:

7/906207

Inventors:

Joseph W. Allison - Valencia CA
Jan Richter - Los Angeles CA
Craig M. Childers - Santa Clarita CA
Dennis R. Smalley - Baldwin Park CA
Charles W. Hull - Santa Clarita CA
Paul F. Jacobs - La Crescenta CA

Assignee:

3D Systems, Inc. - Valencia CA

International Classification:

B29C 3508
B29C 4102

US Classification:

264 22

Abstract:

An improved method for stereolithographically forming a three-dimensional object wherein ordinarily solidified internal walls of the object remain at least partially unsolidified. Any unsolidified medium within the object can be drained from the internal walls of the object prior to post-curing so that a hollow three-dimensional object is formed. The object is formed on a layer by layer basis with the internal portion of each layer of the object formed as a grid of solidified portions and unsolidified portions wherein the solidified and unsolidified portions are different on each layer. Objects formed in this manner can be used as patterns in investment casting.

US Patent:

58547487, Dec 29, 1998

Filed:

Jun 7, 1995

Appl. No.:

8/475730

Inventors:

David E. Snead - Canyon Country CA
Dennis R. Smalley - Baldwin Park CA
Adam L. Cohen - Los Angeles CA
Joseph W. Allison - Valencia CA
Thomas J. Vorgitch - Simi Valley CA
Thomas P. Chen - Sauqus CA

Assignee:

3D Systems, Inc. - Valencia CA

International Classification:

G06F 1900

US Classification:

36446826

Abstract:

A method of and apparatus for slicing a three-dimensional object representation into a plurality of layer representations is described, wherein the layer representations are subsequently used to form the object layer-by-layer according to the principles of stereolithography. If not already provided in the object representation, a plurality of layer boundary representations are first formed, and then the boolean difference 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.

US Patent:

56098138, Mar 11, 1997

Filed:

Jun 7, 1995

Appl. No.:

8/475714

Inventors:

Joseph W. Allison - Valencia CA
Dennis R. Smalley - Baldwin Park CA
Charles W. Hull - Santa Clarita CA
Paul F. Jacobs - La Crescenta CA

Assignee:

3D Systems, Inc. - Valencia CA

International Classification:

B29C 3508
B29C 4102

US Classification:

264401

Abstract:

An improved method for stereolithographically making an object by alternating the order in which similar sets of vectors are exposed over two or more layers. In another method, a pattern of tightly packed hexagonal tiles are drawn. Each tile is isolated from its neighboring tiles by specifying breaks of unexposed material between the tiles. Using an interrupted scan method, vectors are drawn with periodic breaks along their lengths. In another method, modulator and scanning techniques are used to reduce exposure problems associated with the acceleration and deceleration of the scanning system when jumping between vectors or changing scanning directions.