Stereolithographic method and apparatus for production of three dimensional objects using recoating parameters for groups of layers

• US 6,103,176 A
• Filed: 02/08/1999
• Issued: 08/15/2000
• Est. Priority Date: 08/29/1997
• Status: Expired due to Term

• Current Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Original Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Inventors: Manners, Chris R., Nguyen, Hop D.
• Primary Examiner(s): Tentoni, Leo B.
• Application Number:
  US09/248,351
• Time in Patent Office: 554 Days
• Field of Search: 264/308, 264/401, 425/174.4, 425/375, 700/120
• US Class Current: 264/401
• CPC Class Codes: B29C 41/12 Spreading-out the material on a substrate , e.g. on the surface of a liquid
• CPC Class Codes: B29C 41/36 Feeding the material on to the mould, core or other substrate
• CPC Class Codes: B29C 64/124 using layers of liquid which are selectively solidified
• CPC Class Codes: B29C 64/40 Structures for supporting 3D objects during manufacture and intended to be sacrificed after completion thereof
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor

Abstract

A rapid prototyping and manufacturing (e.g. stereolithography) method and apparatus for making three-dimensional objects with enhanced control of coating parameters used when forming layers of liquid or other fluid-like material in preparation for forming laminae of the object. The each lamina of the object is treated as either a primary laminae or secondary laminae. Only minority portions of the secondary layers are solidified when their associated layers are formed. Primary laminae are solidified in majority portions, along with previously unsolidified portions of secondary lamina, when their associated layers are formed. Recoating parameters are supplied for groups of primary layers and secondary layers such that coating formation may be controlled differently for primary layers and for secondary layers. Coating control for secondary layers may be based on the position of individual secondary layers, or sets of secondary layers, relative to the primary layers. The enhanced control leads to (1) more accurate layer formation, and/or (2) faster layer formation times for groups of successive layers.

Claims

1. A method of forming a three-dimensional object from a plurality of adhered laminae, comprising:

forming successive layers of material adjacent to any last formed layers of material in preparation for forming subsequent laminae of the object, some of the successive layers being primary layers spaced one from the other by one or more secondary layers positioned intermediate thereto;

defining at least first and second groups of layers, wherein the first group comprises a plurality of primary layers and the second group comprises one or more secondary layers located between the pair of successive primary layers in the first group;

selectively exposing the primary layers to form at least majority portions of primary laminae in association therewith and to form at least portions of the secondary laminae; and

selectively exposing the secondary layers to form at least minority portions of the secondary laminae in association therewith;

wherein the exposure of the primary layers and secondary layers results in adhesion of laminae to previously formed laminae so as to form the object from a plurality of adhered laminae;

wherein the formation of the first group of layers is controlled by a first set of recoating parameters and the formation of the second group of layers is controlled by a second set of recoating parameters that is different from the first set.

2. The method of claim 1 wherein at least a third group of layers comprises one or more secondary layers that are not in the second group but which are located intermediate to the primary layers in the first group, and wherein at least a third set of recoating parameters is applied during formation of the layers included in the at least third group.

3. The method of claim 2 wherein the at least third group comprises at least a third group and a fourth group wherein the third set of recoating parameters is used in forming the layers in the third group and a fourth set of recoating parameters is used in forming the layers of the fourth group.

4. The method of claim 2 wherein the at least third group comprises at least a third group, a fourth group, and a fifth group and wherein the third set of recoating parameters is used in forming the layers in the third group, a fourth set of recoating parameters is used in forming the layers of the fourth group, and a fifth set of recoating parameters is used in forming the layers of the fifth group.

5. The method of claim 1 wherein the same number of secondary layers exist between each pair of successive primary layers.

6. The method of claim 1 wherein a different number of secondary layers exist between a first pair of successive primary layers and a second pair of successive primary layers.

7. The method of claim 2 wherein the second group of layers includes a single secondary layer located between each pair of successive primary layers and wherein at least one additional secondary layer exists between at least some of the successive primary layers.

8. The method of claim 2 wherein the second group of layers includes two or more consecutive secondary layers located between each pair of successive primary layers.

9. The method of claim 2 wherein the at least third group of layers includes a single secondary layer that is located between two successive primary layers.

10. The method of claim 2 wherein the at least third group of layers includes two or more consecutive secondary layers located between each pair of successive primary layers.

11. The method of claim 2 wherein the at least third set of recoating parameters is different from the first and second sets of recoating parameters.

12. The method of claim 1 additionally comprising sweeping a recoating device over at least some laminae during formation of at least some layers wherein the recoating parameters include one or more of (1) number of times the recoating device is to sweep, (2) speed for at least one sweep, (3) clearance between an upper surface of a last formed lamina and a bottom edge of the recoating device during sweeping, (4) a Z-wait between completion of sweeping and beginning exposure of the layer, and (5) a predip delay.

13. The method of claim 1 wherein a minimum number N of secondary layers exist between successive primary layers and the number of layers in the second group located between each pair of primary layers is specified by a number S, wherein is less than N, wherein layers in the second group immediately precede a primary layer.

14. A method of forming a three-dimensional object from a plurality of adhered laminae, comprising:

defining a number S of successive layers as a set;

defining a plurality of set of layers;

defining a plurality of groups of layers, wherein the groups contain one or more layers from each of the plurality of sets;

associating recoating parameters with each of the defined groups;

forming successive layers of material adjacent to any last formed layers of material in preparation for forming subsequent laminae of the object, wherein the recoating parameters utilized for forming a particular layer are dictated by recoating parameters specified for the group that contains the specific layer;

selectively exposing the layers to form at least portions of the lamina associated therewith to form the object from a plurality of adhered laminae.

15. An apparatus for forming a three-dimensional object from a plurality of adhered laminae, comprising:

means for forming successive layers of material adjacent to any previously formed layers of material in preparation for forming subsequent laminae of the object, some of the successive layers being primary layers spaced one from the other by one or more secondary layers positioned intermediate thereto;

means for defining at least first and second groups of layers, wherein the first group comprises a plurality of primary layers and the second group comprises one or more secondary layers located between successive pairs of primary layers;

means for selectively exposing the primary layers to form at least majority portions of primary laminae in association therewith and to form at least portions of the secondary laminae; and

means for selectively exposing the secondary layers to form at least minority portions of the secondary laminae in association therewith;

wherein the exposure of the primary layers and secondary layers results in adhesion of laminae to previously formed laminae so as to form the object from a plurality of adhered laminae;

wherein the means for forming forms the first group of layers under the control of a first set of recoating parameters and forms the second group of layers under the control of a second set of recoating parameters that is different from the first set.

16. An apparatus for forming a three-dimensional object from a plurality of adhered laminae, comprising:

a coating system for forming successive layers of material adjacent to any previously formed layers of material in preparation for forming subsequent laminae of the object, some of the successive layers being primary layers spaced one from the other by one or more secondary layers positioned intermediate thereto;

a computer programmed to define at least first and second groups of layers, wherein the first group comprises a plurality of primary layers and the second group comprises one or more secondary layers located between pairs of successive primary layers;

an exposure system for selectively exposing the layers of material including exposing (1) the primary layers to form at least majority portions of primary laminae in association therewith and to form at least portions of the secondary laminae, and (2) the secondary layers to form at least minority portions of the secondary laminae in association therewith;

wherein the exposure of the primary layers and secondary layers results in adhesion of laminae to previously formed laminae so as to form the object from a plurality of adhered laminae;

wherein the coating system forms the first group of layers under the control of a first set of recoating parameters and forms the second group of layers under the control of a second set of recoating parameters that is different from the first set.

17. An apparatus for forming a three-dimensional object from a plurality of adhered laminae, comprising:

means for defining a number S of successive layers as a set;

means for defining a plurality of set of layers;

means for defining a plurality of groups of layers, wherein the groups contain one or more layers from each of the plurality of sets;

means for associating recoating parameters with each of the defined groups;

means for forming successive layers of material adjacent to any last formed layers of material in preparation for forming subsequent laminae of the object, wherein the recoating parameters utilized for forming a particular layer are dictated by recoating parameters specified for the group that contains the specific layer; and

means for selectively exposing the layers to form at least portions of the lamina associated therewith to form the object from a plurality of adhered laminae.