Apparatus and method for forming three-dimensional objects using linear solidification with travel axis correction and power control

• US 10,112,345 B2
• Filed: 04/03/2014
• Issued: 10/30/2018
• Est. Priority Date: 04/04/2013
• Status: Active Grant

• Current Assignee: Gulf Filtration Systems Inc. (Desktop Metal, Inc.)
• Original Assignee: Gulf Filtration Systems Inc. (Desktop Metal, Inc.)
• Inventors: El-Siblani, Ali, Shkolnik, Alexandr, Zhou, Chi
• Primary Examiner(s): Schatz, Christopher T
• Application Number:
  US14/243,967
• Publication Number:
  US 20140306380A1
• Time in Patent Office: 1,671 Days
• CPC Class Codes: B29C 64/135 the energy source being concentrated, e.g. scanning lasers or focused light sources
• 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 50/02 for controlling or regulating additive manufacturing processes

Abstract

An apparatus and method for making a three-dimensional object from a solidifiable material using a linear solidification device is shown and described. The apparatus and method compensate for a non-orthogonal angle between the travel axis and scanning axis of a linear scanning device and also provide a substantially constant solidification depth along the scanning axis. In certain examples, a solidification energy control system is also provided to regulate the solidification power supplied to the solidifiable material by modulating the power supplied to the linear solidification device'"'"'s solidification energy source, examples of which include laser diodes.

Claims

1. A method of making a three-dimensional object from a solidifiable material, comprising:

moving a solidification energy source along a first direction;

progressively projecting solidification energy from the solidification energy source onto selected portions of the solidifiable material along a second direction while the solidification energy source moves along the first direction;

modulating the power provided to the solidification energy source to control the solidification power received by the selected portions of the solidifiable material along the second direction, wherein the step of modulating the power provided to the solidification energy source comprises providing a selectively switchable, variable amplitude analog voltage signal to a solidification energy source modulator, and the power of the solidification energy received by the selected portions of the solidifiable material onto which the solidification energy is projected is substantially constant along the second direction.

2. The method of claim 1, wherein the step of modulating the power provided to the solidification energy source comprises varying the amplitude of the selectively switchable, variable amplitude analog voltage signal based on an elapsed time from the receipt of a sensor synchronization signal.

3. The method of claim 2, further comprising providing a power compensation database comprising a plurality of power compensation data entries, wherein each power compensation data entry corresponds to an elapsed time from the receipt of the sensor synchronization signal and defines the amplitude of the selectively switchable, analog voltage signal at the elapsed time.

4. The method of claim 3, further comprising sensing a solidification power received by a solidification energy sensor and adjusting the plurality of power compensation data entries based on the sensed solidification power.

5. The method of claim 4, wherein the step of moving a solidification energy source along a first direction comprises moving the solidification energy source along the first direction across a build envelope, and the step of adjusting the plurality of power compensation data entries based on the sensed solidification power occurs following each traversal of the solidification energy source across the build envelope.

6. The method of claim 3, further comprising the step of generating the power compensation data entries by projecting test solidification energy onto a surface at a plurality of locations along the second direction while maintaining a substantially constant supply power to the solidification energy source and measuring received test solidification power at the plurality of locations.

7. The method of claim 6, further comprising identifying a location among the plurality of locations having the smallest measured received test solidification power, wherein the step of generating the power compensation data entries further comprises adjusting the supply power to the solidification energy source for the plurality of locations until the received solidification power at each location equals the smallest measured received test solidification power.

8. The method of claim 1, further comprising generating a digital signal based on solidification energy source event data corresponding to the three-dimensional object, wherein the digital signal determines whether the analog voltage signal is in electrical communication with the solidification energy source.

9. The method of claim 1, wherein the step of modulating the power provided to the solidification energy source comprises providing a selectively switchable, analog voltage signal to a solidification energy source modulator, the selectively switchable, analog voltage signal has an amplitude that varies to vary the power provided to the solidification energy source, the selectively switchable analog voltage signal is switched based on a digital signal corresponding to solidification energy source event data, and the selectively switchable analog voltage signal and digital signal are synchronized to a common solidification energy sensor signal.

10. The method of claim 1, wherein the solidification energy source is a selectively activatable laser diode.

11. The method of claim 10, wherein the step of progressively projecting solidification energy from the solidification energy source onto selected portions of the solidifiable material along the second direction while the solidification energy source moves along the first direction comprises selectively activating the selectively activatable laser diode as the selectively activatable laser diode moves along the first direction.

12. The method of claim 11, wherein the step of progressively projecting solidification energy from the solidification energy source onto selected portions of the solidifiable material along the second direction while the solidification energy source moves along the first direction further comprises rotating a polygonal mirror in a plane perpendicular to the first direction while selectively activating the selectively activatable laser diode as the selectively activatable laser diode moves along the first direction.

13. The method of claim 1, wherein the solidifiable material is a photopolymer or cross-linkable material.

14. The method of claim 1, wherein the step of moving the solidification energy source along the first direction comprises moving a linear solidification device along the first direction, wherein the linear solidification device comprises a selectively activatable laser diode in optical communication with a rotating polygonal mirror.

15. The method of claim 14, wherein the selectively activatable laser diode is an ultraviolet laser diode.

16. The method of claim 1, wherein the step of progressively projecting solidification energy from the solidification energy source onto selected portions of the solidifiable material along the second direction while the solidification energy source moves along the first direction further comprises projecting the solidification energy through a transparent and/or translucent solidification substrate.

17. The method of claim 16, wherein the step of progressively projecting solidification energy from the solidification energy source onto selected portions of the solidifiable material along the second direction while the solidification energy source moves along the first direction further comprises projecting the solidification energy through a film in contact with the solidifiable material.

18. The method of claim 1, wherein the step of progressively projecting solidification energy from the solidification energy source onto selected portions of the solidifiable material along the second direction while the solidification energy source moves along the first direction further comprises selectively activating the solidification energy source in accordance with data strings, and each data string comprises a plurality of time values.