Granted Patent B2

US 12,208,465 · App. 17/091,644 · Granted Jan 28, 2025

Inventors: Darren Beckett (Corrales, NM); Martin S. Piltch (Los Alamos, NM); Scott Betts (Albuquerque, NM); Alberto M. Castro (Santa Fe, NM); Kevin Anderson (Albuquerque, NM); Lars Jacquemetton (Santa Fe, NM); Luis Aguilar (Santa Fe, NM)

Assignee: DIVERGENT TECHNOLOGIES, INC.

B23K26/032B23K26/082B33Y10/00B33Y30/00B33Y50/02G02B5/3025G02B27/281B23K26/342

Abstract

Claims (36)

1. An additive manufacturing system comprising:

a build plane;

an energy source configured to direct energy onto a work region of the build plane;

an optical detector configured to receive one or more optical signals from the work region; and

an optical filter positioned between the work region and the optical detector, the optical filter including a first fixed partially transmissive polarized filter having a first polarization axis and a second fixed partially transmissive polarized filter having a second polarization axis wherein the first polarization axis is rotationally offset 90 degrees from the second polarization axis to attenuate polarized light, and wherein the first and second polarization axes are orthogonal to an optical axis of the first and second polarized filters.

2. The additive manufacturing system of claim 1 wherein:

the first partially transmissive polarized filter allows the optical signals having an electric field not aligned with the first polarization axis to pass through with between 20 percent and 80 percent transmittance; and

the second partially transmissive polarized filter allows the optical signals having an electric field not aligned with the second polarization axis to pass through with between 20 percent and 80 percent transmittance.

3. The additive manufacturing system of claim 1 wherein:

the first partially transmissive polarized filter allows the optical signals having an electric field not aligned with the first polarization axis to pass through with between 45 percent and 55 percent transmittance; and

the second partially transmissive polarized filter allows the optical signals having an electric field not aligned with the second polarization axis to pass through with between 45 percent and 55 percent transmittance.

4. The additive manufacturing system of claim 1 wherein the first and second partially transmissive polarized filters each have a transmittance ratio that is between 1.5 and 2.5.

5. An additive manufacturing method comprising:

scanning an energy source along a first path traversing a layer of powder disposed on a build plane;

receiving one or more optical signals from the build plane during the scanning;

filtering the one or more optical signals sequentially using a first fixed polarized filter having a first polarization axis and a second fixed polarized filter having a second polarization axis wherein the first polarization axis is rotated 90 degrees relative to the second polarization axis, and wherein the first and second polarization axes are orthogonal to an optical axis of the first and second polarized filters; and

analyzing the one or more optical signals after the filtering using an optical sensor.

6. The method of claim 5 wherein the first polarized filter allows between 40 percent and 70 percent of an incident intensity of the one or more optical signals to pass through that have a polarization direction that is not aligned with the first polarization axis.

7. The method of claim 5 wherein the first polarized filter has a transmittance ratio that is between 1.5 and 2.5.

8. The method of claim 5 wherein the second polarized filter allows between 40 percent and 70 percent of an incident intensity of the one or more optical signals to pass through that have a polarization direction that is not aligned with the second polarization axis.

9. The method of claim 5 wherein the second polarized filter has a transmittance ratio that is between 1.5 and 2.5.

10. The method of claim 5 further comprising selectively filtering the one or more optical signals with a bandpass filter before the filtering.

11. An optical system comprising:

a receiving aperture configured to receive one or more optical signals;

an optical filter arranged to filter the one or more optical signals received through the receiving aperture, the optical filter including:

a first fixed polarized filter having a first polarization axis;

a second fixed polarized filter having a second polarization axis;

wherein the first polarization axis is rotationally offset 90 degrees from the second polarization axis;

wherein the first and second polarization axes are orthogonal to an optical axis of the first and second polarized filters; and

wherein the first and the second polarization filters are arranged to sequentially filter the one or more received optical signals; and

an optical sensor configured to generate one or more sensor readings in response to receiving the filtered one or more optical signals.

12. The optical system of claim 11 wherein the first polarized filter allows between 40 percent and 70 percent of an incident intensity of the one or more received optical signals to pass through that have a polarization direction that is not aligned with the first polarization axis.

13. The optical system of claim 11 wherein the first polarized filter has a transmittance ratio that is between 1.5 and 2.5.

14. The optical system of claim 11 wherein the second polarized filter allows between 40 percent and 70 percent of an incident intensity of the one or more received optical signals to pass through that have a polarization direction that is not aligned with the second polarization axis.

15. The optical system of claim 11 wherein the second polarized filter has a transmittance ratio that is between 1.5 and 2.5.

16. The optical system of claim 11 wherein the optical filter further comprises a bandpass filter.

Assignments (4)

Continuity (2)

References Cited (21)