High-speed metrology

• Main Authors: Zengerle, III, Walter H, Weber, Aaron, Matusik, Wojciech, Vidimce, Kiril, Chen, Desai
• Format: Patent
• Language: English
• Published: 10.11.2020
• Subjects: ADDITIVE MANUFACTURING TECHNOLOGY; ADDITIVE MANUFACTURING, i.e. MANUFACTURING OFTHREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVEAGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING,STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; PERFORMING OPERATIONS; PHYSICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TESTING; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

A method and an apparatus are directed to characterizing a continuously moving 3D object via interferometry-based scanning. The method includes repeatedly forming several depth characterizations of the 3D object along respective scan lines of a plurality of scan lines on the surface of the 3D object. During this scanning, the 3D object is undergoing its continuous motion. The method further includes combining the determined depth characterization along the scan lines of the plurality of scan lines to form a depth map representing at least a depth of a portion associated with a location on the surface of the 3D object in the third direction on a grid of locations arranged in the first and second directions. Forming the depth characterizations includes scanning a frequency-dispersed pulsed optical signal in a first direction across the continuously moving 3D object, said 3D object moving in a second direction substantially orthogonal to the first direction. The scanned optical signal forming scan lines on a surface of the 3D object in a third direction substantially orthogonal to the first direction and the second direction.