Patent ID: 11964435
Assignee: NANYANG TECHNOLOGICAL UNIVERSITY
Field: Measurement (Instruments)
Classification: CPC B  G  Y | IPC B  G

Claim 18:
19. The system according to claim 10, further comprising a second contact image sensor, wherein the at least one processor is further configured to:
obtain a second image of the powder bed layer from scanning the powder bed layer in the first scanning direction using the second contact image sensor, the second contact image sensor being attached to the powder re-coater arm at a same side thereof as the first contact image sensor and at a different distance from the powder bed layer to be scanned compared to the first contact image sensor;
determine a focus level property of the second image; and
determining, for each of one or more regions of the powder bed layer detected as having non-uniformities, whether the region having non-uniformities is a protrusion-type or a depression-type based on the focus level property of the second image at a corresponding region thereof.