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

Claim 8:
9. The method according to claim 1, further comprising:
obtaining a second image of the powder bed layer from scanning the powder bed layer in the first scanning direction using a 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;
determining 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.