Optics in three-dimensional printing

• US 10,611,092 B2
• Filed: 01/03/2018
• Issued: 04/07/2020
• Est. Priority Date: 01/05/2017
• Status: Active Grant

• Current Assignee: Velo3D, Inc.
• Original Assignee: Velo3D, Inc.
• Inventors: Buller, Benyamin, Milshtein, Erel, Varlakhanov, Alexander, Gunn, Lawrence Arnold, Brudny, Alexander
• Primary Examiner(s): Lee, Thomas C
• Assistant Examiner(s): Tang, Michael
• Application Number:
  US15/861,544
• Publication Number:
  US 20180186067A1
• Time in Patent Office: 825 Days
• CPC Class Codes: B22F 10/28 Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
• CPC Class Codes: B22F 10/31 Calibration of process steps or apparatus settings, e.g. before or during manufacturing
• CPC Class Codes: B22F 10/32 of the atmosphere, e.g. composition or pressure in a building chamber
• CPC Class Codes: B22F 10/36 of energy beam parameters
• CPC Class Codes: B22F 10/366 Scanning parameters, e.g. hatch distance or scanning strategy
• CPC Class Codes: B22F 10/77 of gas
• CPC Class Codes: B22F 12/41 characterised by the type, e.g. laser or electron beam
• CPC Class Codes: B22F 12/44 characterised by the configuration of the radiation means
• CPC Class Codes: B22F 12/45 Two or more
• CPC Class Codes: B22F 12/90 Means for process control, e.g. cameras or sensors
• CPC Class Codes: B22F 2203/03 for feed-back
• CPC Class Codes: B22F 2203/11 temperature, temperature profile
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B23K 26/032 using optical means
• CPC Class Codes: B23K 26/0604 by a combination of beams
• CPC Class Codes: B23K 26/0608 in the same heat affected zone [HAZ] B23K26/0613, B23K26/0619 take precedence
• CPC Class Codes: B23K 26/062 by direct control of the laser beam
• CPC Class Codes: B23K 26/125 of mixed gases
• CPC Class Codes: B23K 26/127 in an enclosure
• CPC Class Codes: B23K 26/34 Laser welding for purposes other than joining
• CPC Class Codes: B23K 26/342 : Build-up welding
• CPC Class Codes: B23K 26/354 : by melting
• CPC Class Codes: B23K 26/703 : Cooling arrangements by using a fluid stream B23K26/14
• CPC Class Codes: B28B 1/001 : Rapid manufacturing of 3D objects by additive depositing, agglomerating or laminating of material selective deposition modelling of metallic powder B22F10/00; rapid manufacturing of 3D objects in general and in particular of plastics B29C64/00
• CPC Class Codes: B28B 17/0081 : Process control
• CPC Class Codes: B29C 64/135 : the energy source being concentrated, e.g. scanning lasers or focused light sources
• CPC Class Codes: B29C 64/153 : using layers of powder being selectively joined, e.g. by selective laser sintering or melting
• CPC Class Codes: B29C 64/268 : using laser beams; using electron beams [EB]
• CPC Class Codes: B29C 64/35 : Cleaning
• CPC Class Codes: B29C 64/393 : for controlling or regulating additive manufacturing processes
• 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
• CPC Class Codes: B33Y 50/02 : for controlling or regulating additive manufacturing processes
• CPC Class Codes: Y02P 10/25 : Process efficiency

Abstract

The present disclosure provides various apparatuses, systems, software, and methods for three-dimensional (3D) printing. The disclosure delineates various optical components of the 3D printing system, their usage, and their optional calibration. The disclosure delineates calibration of one or more components of the 3D printer (e.g., the energy beam).

Claims

1. An apparatus for detecting a three-dimensional object, comprising:

(a) a platform configured to support a material bed, which material bed comprises an exposed surface having (A) an average planarity and (B) an average optical characteristic, which material bed comprises a pre-transformed material that is at least 50 percent diffusive relative to its total reflection, and a transformed material that is at least 80 percent specular relative to its total reflection;

(b) an energy source configured to generate an energy beam, which energy beam is operable to transform a pre-transformed material to the transformed material as part of the three-dimensional object, which three-dimensional object is disposed in the material bed, wherein the three-dimensional object causes at least a portion of the exposed surface to deviate from (I) the average planarity and/or (II) the average optical characteristic, wherein the energy source is disposed adjacent to the platform;

(c) a radiation source configured to generate a structured radiation for projection onto the exposed surface to form a detectable image, wherein the radiation source is disposed adjacent to the energy source; and

(d) a detector configured to detect any deviation using the detectable image, which deviation is indicative of (i) a composition of at least a portion of the three-dimensional object, (ii) a position of the at least the portion of the three-dimensional object, (iii) a shape of the at least the portion of the three-dimensional object, (iv) an average planarity of the exposed surface, or (v) any combination of (i), (ii), (iii) and (iv), wherein the detector is disposed adjacent to the radiation source.

2. The apparatus of claim 1, wherein the radiation source is configured to generate the structured radiation in real time during the printing.

3. The apparatus of claim 1, wherein the detector is configured to detect in real time during the printing.

4. The apparatus of claim 1, further comprising a filter operatively coupled with the radiation source and/or the detector, which filter is configured to alter an intensity of at least a portion of the detectable image received at the detector.

5. The apparatus of claim 4, wherein the filter is operatively coupled with the detector and is configured to alter a focus of the detectable image detected by the detector.

6. The apparatus of claim 5, wherein the filter is configured to lower the resolution of the detectable image detected by the detector.

7. The apparatus of claim 5, wherein the filter is a low pass filter.

8. The apparatus of claim 4, wherein the filter comprises a polarizer.

9. The apparatus of claim 4, wherein the structured radiation comprises a polarized radiation, which structured radiation is projected onto the exposed surface to form the detectable image, wherein the filter is configured to filter out at least part of the polarized radiation.

10. The apparatus of claim 4, wherein the filter has a field of view configured to receive a specular reflection of the structured radiation.

11. The apparatus of claim 10, wherein the specular reflection is polarized, and wherein the filter is configured to at least partially filter out the specular reflection that is polarized.

12. The apparatus of claim 4, wherein the filter is a first filter, wherein the apparatus further comprises a second filter that is configured to generate a polarized radiation of the structured radiation that is projected onto the exposed surface to form the detectable image, and wherein the second filter is operatively coupled to the radiation source.

13. The apparatus of claim 12, wherein the second filter comprises a polarizer.

14. The apparatus of claim 12, wherein the second filter is configured to at least partially cancel out the polarized radiation transmitted by the first filter.

15. The apparatus of claim 14, wherein the polarized radiation comprises a specular reflection from the exposed surface.

16. The apparatus of claim 4, further comprising at least one controller operatively coupled to the energy source and to the detector, which at least one controller is configured to:

(i) direct an evaluation of the deviation using image analysis of a captured image, and (ii) use the evaluation to control at least one characteristic of the energy beam to form the three-dimensional object.

17. The apparatus of claim 16, wherein the evaluation comprises processing the detectable image captured by the detector to eliminate or to average pixels in the detectable image captured by the detector, which pixels are attributed to an edge.

18. The apparatus of claim 17, wherein the edge is in a region from the pre-transformed material to the transformed material.

19. The apparatus of claim 1, wherein the exposed surface (A) comprises a kinematic support, or (B) is operatively coupled to a kinematic support.

20. The apparatus of claim 1, wherein the detector is configured to filter an edge feature in the detectable image.

21. The apparatus of claim 1, further comprising at least one controller operatively coupled to the energy source and to the detector, which at least one controller is configured to (i) direct evaluation of the deviation using the detectable image, which evaluation of the deviation is using image analysis of captured images, and (ii) use the evaluation to control at least one characteristic of the energy beam to form the three-dimensional object.

22. The apparatus of claim 1, wherein the position comprises a vertical position.

23. The apparatus of claim 1, wherein the position comprises a position in the exposed surface.

24. A method for detecting a three-dimensional object, comprising:

(a) directing an energy beam to an exposed surface of a material bed comprising a pre-transformed material that is at least 50 percent diffusive relative to its total reflection, the exposed surface having an average planarity and an average optical characteristic;

(b) transforming the pre-transformed material to a transformed material as part of the three-dimensional object that (I) is disposed in the material bed and (II) causes at least a portion of the exposed surface to deviate from the average planarity and/or the average optical characteristic, which transformed material is at least 80 percent specular relative to its total reflection;

(c) projecting a detectable image on the exposed surface; and

(d) detecting any deviation using the detectable image from the average planarity and/or from the average optical characteristic, which deviation is indicative of (i) a composition of at least a portion of the three-dimensional object, (ii) a position of the at least the portion of the three-dimensional object relative to a platform supporting the material bed, (iii) a shape of the at least the portion of the three-dimensional object, (iv) an average planarity of the exposed surface, or (v) any combination of (i), (ii), (iii), and (iv).

25. The method of claim 24, wherein detecting any deviation comprises capturing an image of the exposed surface and performing an image modification process on the image that is captured, which image modification process comprises identifying a plurality of pixels for modification, wherein identifying is based on a gradient of pixel data values of the image.

26. The method of claim 25, wherein the plurality of pixels is identified by image pixels that have a gradient value at or above a threshold.

27. The method of claim 25, wherein the image modification process comprises filtering.

28. The method of claim 27, wherein filtering comprises edge filtering.

29. The method of claim 25, wherein identifying the plurality of pixels comprises excluding the plurality of pixels from consideration during an image analysis of the image that is captured.

30. The method of claim 25, wherein the identifying the plurality of pixels comprises averaging values of the plurality of pixels with values of a neighboring plurality of pixels during an image analysis of the image that is captured.

31. The method of claim 24, wherein detecting any deviation within the detectable image comprises performing an image analysis of at least a portion of the detectable image comprising determining an image contrast ratio.

32. The method of claim 31, further comprising altering the detectable image considering the image contrast ratio.

33. The method of claim 32, wherein the detectable image comprises (A) a region having a first intensity and a first shape and (B) a region having a second intensity and a second shape, and wherein the first intensity is higher than the second intensity, which higher is detectable, wherein altering comprises modifying the detectable image dynamically.

34. The method of claim 33, wherein modifying comprises altering the first intensity and/or of the second intensity.

35. The method of claim 33, wherein modifying comprises altering the first shape and/or of the second shape.

36. The method of claim 24, further comprising altering an intensity of at least part of the detectable image.

37. The method of claim 36, wherein altering at least part of the detectable image comprises filtering a radiation of the detectable image.

38. The method of claim 37, wherein the filtering comprises altering a polarity of the radiation used in the projection of the detectable image.

39. The method of claim 36, wherein altering at least part of the detectable image comprises filtering a radiation of the detectable image.

40. The method of claim 39, further comprising using a detector to detect any deviation within the detectable image, and wherein filtering comprises lowering a resolution of the detectable image detected by the detector.

41. The method of claim 24, further comprising (A) using a detector to detect any deviation within the detectable image, and (B) altering a focus of the detectable image detected by the detector to filter out an edge feature in the detectable image.

42. The method of claim 24, wherein the position comprises a vertical position.

43. The method of claim 24, wherein the position comprises a position in the exposed surface.

44. The method of claim 43, wherein the process parameter comprises at least one characteristic of the energy beam.

45. The method of claim 24, further comprising controlling a process parameter in real time based at least in part on the deviation using the detectable image detected.