Method for creating three-dimensional objects by cross-sectional lithography

• US 6,391,245 B1
• Filed: 04/13/1999
• Issued: 05/21/2002
• Est. Priority Date: 04/13/1999
• Status: Active Grant

• Current Assignee: Jeffery M. Smith, Stratasys Incorporated
• Original Assignee: EOM Technologies, LLC
• Inventors: Smith, Jeffrey M.
• Primary Examiner(s): Niebling, John F.
• Assistant Examiner(s): WHITMORE, STACY
• Application Number:
  US09/290,925
• Time in Patent Office: 1,134 Days
• Field of Search: 716/21, 264/401
• US Class Current: 264/401
• CPC Class Codes: B29C 64/129 characterised by the energy source therefor, e.g. by global irradiation combined with a mask
• 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

An improved method for creating a three-dimensional object by generating a cross-sectional pattern of energy of an object to be formed at a selected surface of a medium capable of altering its physical state in response to the energy projected or transmitted onto the selected layer. By impinging radiation, particle bombardment, or chemical reaction by a method controlled by a spatial light modulator, successive adjacent cross-sections of the object are rapidly formed and integrated together to provide a step-wise laminar build-up of the desired object creating a three dimensional manifestation from bitmap images of a series of cross-sections of a computer generated model.

Claims

1. A method of generating a three-dimensional object out of a medium capable of selective solidification upon exposure to synergistic stimulation, comprising the steps of:

providing at least one spatial light modulator array having a plurality of individually controlled pixel elements;

providing a source of said synergistic stimulation;

directing said synergistic stimulation upon said spatial light modulator array(s);

selectively activating a plurality of said pixel elements wherein said activated pixels reflect said synergistic stimulation onto corresponding surface portions of said medium;

maintaining said synergistic stimulation directed at said surface until the surface portions of said medium exposed to said synergistic stimulation solidify to form at least a partial lamina layer;

lowering said lamina layer into said medium by a first distance;

raising said lamina layer by a second distance, wherein the second distance is less than the first distance to form a next surface portion to be exposed; and

repeating the maintaining, lowering and raising steps until the maintaining step forms a final lamina layer, such that adjacent lamina layers are bonded with each other.

2. The method of claim 1 further comprising the step of first translating said spatial light modulator array(s) progressively over the medium after solidification of said partial lamina prior to lowering said lamina layer into said medium in order to solidify an adjacent lamina portion of said medium through said selective synergistic stimulation.

3. The method of claim 1 wherein said spatial light modulator array further comprises a digital micromirror device (DMD).

4. The method of claim 1 wherein said spatial light modulator array further comprises an image light amplifier device (ILA).

5. The method of claim 1 wherein said spatial light modulator array further comprises a direct image light amplifier device (DILA).

6. The method of claim 1 further comprising the step of amplifying said synergistic stimulation reflected from said activated pixel elements of said light modulator array through a lens onto said medium.

7. The method of claim 1 further comprising the step of modulating a portion of said pixel elements to cycle between an activated and deactivated mode, wherein said modulation causes a migration of solidification of said medium corresponding to said modulated pixel elements.

8. The method of claim 1 wherein said synergistic stimulation is rapidly energized and de-energized thereby creating a strobe effect.

9. A method of generating a three-dimensional object layer by layer from a medium, comprising the steps of:

providing at least one energy source;

providing at least one spatial light modulator array having a plurality of individually controlled elements each capable of selectively reflecting or transmitting energy form said energy source(s);

receiving data corresponding to a two-dimensional cross-section of the three-dimensional object;

generating control signals for selectively directing a quantity of said elements in a first direction;

reflecting or transmitting energy from said energy source off or through said spatial light modulator array(s) and onto corresponding surface portions of said medium, whereupon said portions in receipt of said reflected energy are solidified thus forming a replica in the medium of the two-dimensional cross-section;

lowering said two-dimensional cross-section into said medium by a first distance;

raising said two-dimensional cross-section by a second distance, wherein the second distance is less than the first distance to form a next surface portion to be exposed; and

repeating the reflecting, lowering and raising steps incrementally for each two-dimensional cross-section until the entire three-dimensional object is replicated.

10. The method as defined in claim 9 wherein the first direction is that direction in which said energy is directed to reflect form said source off of those elements tilted in the first direction and onto the medium.

11. The method as defined in claim 9 wherein the first direction is that direction in which said energy is directed to reflect from said source off of those elements tilted in the first direction and is further directed away from the medium.

12. The method of claim 9 further comprising the step of translating said reflected energy from said spatial light modulator array(s) progressively over the medium to adjoin a plurality of two-dimensional cross-sections prior to lowering said two-dimensional cross-sections onto said medium.

13. The method of claim 9 further comprising the step of translating said reflected energy from said spatial light modulator array(s) progressively over the medium to create a two-dimensional cross-section larger than the two-dimensional cross-section capable of being reflected off of said spatial light modulator array(s).

14. The method of claim 9 further comprising the step of adjoining a plurality of two-dimensional cross-sections each concurrently solidified in said medium by a dedicated said spatial light modulator array.

15. The method of claim 9 further comprising the step of amplifying said energy reflected from said individual elements through a lens prior to directing said energy onto said medium.

16. The method of claim 9 further comprising the step of modulating at least some of said elements bi-directionally to cyclically reflect and deflect said energy from said medium.

17. The method of claim 9 wherein said energy source comprises a thermal light source.

18. The method of claim 9 wherein said energy source comprises a coherent light source means.

19. The method of claim 9 wherein said energy source comprises a laser.

20. The method of claim 9 wherein said energy source comprises at least one wavelength selected from the electromagnetic spectrum.

21. The method of claim 9 wherein said energy source is rapidly activated and de-activated thereby creating a strobe effect.

22. A method of generating a three-dimensional object out of a medium capable of selective solidification upon exposure to synergistic stimulation, comprising the steps of:

providing a container having the medium therein and a support for the object within the container, wherein a surface of the support is operatively positioned parallel with respect to at least one surface of the medium;

having a gap between a wall of the container and the support such that the medium flows through the gap when the support is displaced relative to the surface of the medium;

providing at least one spatial light modulator array having a plurality of individually controlled pixel elements;

providing a source of said synergistic stimulation;

directing said synergistic stimulation upon said spatial light modulator array(s);

selectively activating a plurality of said pixel elements wherein said activated pixels reflect said synergistic stimulation onto corresponding surface elements of said medium;

maintaining said synergistic stimulation directed at said surface until the surface portions of said medium exposed to said synergistic stimulation solidify to form at least a partial lamina layer;

displacing said support into said medium to form a next surface portion to be exposed; and

repeating the maintaining and lowering steps until the maintaining step forms a final lamina layer, bonding adjacent lamina layers with each other.