US 12,352,704 B2
Metrology system for measuring edge of circular workpiece
Christopher Richard Hamner, Kirkland, WA (US); and Vahan Senekerimyan, Kirkland, WA (US)
Assigned to Mitutoyo Corporation, Kanagawa-ken (JP)
Filed by Mitutoyo Corporation, Kanagawa-ken (JP)
Filed on Dec. 28, 2022, as Appl. No. 18/147,617.
Prior Publication US 2024/0219316 A1, Jul. 4, 2024
Int. Cl. G01N 21/95 (2006.01); G01N 21/88 (2006.01)
CPC G01N 21/9503 (2013.01) [G01N 21/8806 (2013.01); G01N 2021/8835 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A metrology system, comprising:
an illumination configuration comprising an illumination source;
an objective lens configuration comprising an objective lens and having a lens optical axis; and
an image sensor configuration comprising an image sensor;
wherein:
the illumination configuration, the objective lens configuration and the image sensor configuration form an optical path along which illumination from the illumination configuration travels;
the illumination configuration is configured to provide illumination in an illumination direction toward at least a portion of an edge of a circular workpiece that is along the optical path;
at least part of the illumination configuration is tilted relative to the objective lens configuration such that the illumination direction is at a first tilt angle in relation to the lens optical axis of the objective lens configuration;
the circular workpiece comprises the edge and first and second planar surfaces, for which a first tilt direction corresponding to the first tilt angle is nominally parallel to the first and second planar surfaces; and
the objective lens configuration directs illumination toward the image sensor configuration which is configured to provide an image corresponding to the edge of the circular workpiece.