Method for calibrating at least one scanning system of an SLS or SLM installation

Patent metadata

Field	Value
Publication number	US-11014196-B2
Application number	US-201716083840-A
Country	US
Kind code	B2
Filing date	Feb 2, 2017
Priority date	Apr 7, 2016
Publication date	May 25, 2021
Grant date	May 25, 2021

Abstract

A procedure for calibration of at least one scanning system of a laser sinter or laser melt facility can be carried out in a short time, can take place automatically, and thereby can be carried out before each individual construction process. The procedure may include generation of at least one line pattern through at least one scanning system on a surface at the level of a construction field.

First claim

The invention claimed is:

1. A method of calibrating at least one scanning system of a laser sinter or laser melt facility, the at least one scanning system comprising at least one laser beam source directed onto a construction field in order by a construction process to melt or fuse a construction material capable of sintering or melting and thus through its cooling selectively to solidify such construction material, the method comprising:
generating through the at least one scanning system, at least one line pattern on a surface at the level of the construction field, wherein generating the at least one line pattern comprises:
projecting, by the at least one scanning system, the at least one line pattern on an upper surface of a calibration plate provided with a specified line pattern permanently applied thereto;
recording with a camera disposed over a construction field and reading into a memory, a deviation of the at least one line pattern produced by at least one scanning system from the specified line pattern;
executing, by a processor, a field correction of the at least one line pattern by calculation of correction data regarding the at least one scanning system, the correction data containing information for correction of any distortions of the at least one line pattern; and
measuring and correcting, by the processor, the deviation of the at least one line pattern visible on the surface of the calibration plate and recordable with the camera over the construction field so that the at least line pattern produced by the scanning system coincides with the specified line pattern permanently applied to the calibration plate.

2. The method according to claim 1 , comprising:
illuminating the construction field with the camera, the camera having been calibrated by the field correction of the at least one line pattern for correction of the distortion of the at least one line pattern; and
recording with the camera and reading into the memory, line patterns, which are already corrected as regards distortions;
calculating, by the processor, further correction data regarding rotation, offset, scaling, and/or displacement regarding a plurality of scanning system relative to each other in such a way that by use of further correction data on the plurality of scanning systems and mutual alignment and accommodation of the plurality of scanning systems and the line patterns produced by them is achieved.

3. The method according to claim 1 , comprising calculating, by the processor, further correction data for a plurality of scanning systems.

4. The method according to claim 3 , wherein calculation data determined, by the processor, for a plurality of scanning systems is aggregated into a combined correction data set.

5. The method according to claim 2 , comprising calculating, by the processor, further correction data for the outer limits of the construction field.

6. The method according to claim 2 , wherein the line patterns corresponding to adjacent scanning systems intersect one another.

7. The method according to claim 2 , wherein line patterns of adjacent scanning systems are configured separately next to each other.

8. The method according to claim 2 , comprising showing on a display a deviation from adjacent line patterns or line patterns that overlap in areas due to mutual rotation, mutual offset, mutual scaling, or numerical displacement.

9. The method according to claim 1 , wherein the surface unit is illuminated so that a laser beam of a scanning system produces a constantly visible line pattern detectable by the camera.

10. The method according to claim 1 , wherein with provision of the at least one scanning system the ascertained correction values concerning rotation, scaling, and displacement relate to the position of the line pattern in the construction chamber or related to at least one edge of the construction chamber.

Assignees

• Cl Schutzrechtsverwaltungs Gmbh
• Concept Laser Gmbh

Inventors

• Herzog Frank
• Bechmann Florian
• Zeulner Fabian

Classifications

• B23K26/34 Primary

  Laser welding for purposes other than joining · CPC title

• B22F12/90

  Means for process control, e.g. cameras or sensors · CPC title

• B22F12/44

  characterised by the configuration of the radiation means · CPC title

• B22F10/31

  Calibration of process steps or apparatus settings, e.g. before or during manufacturing · CPC title

• B22F10/28

  Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] · CPC title