Machine vision inspection system and method for performing high-speed focus height measurement operations

摘要

A machine vision inspection system comprising an illumination source and an imaging system and a method for performing high-speed focus height measurement operations. The method comprises: placing a workpiece in a field of view of the machine vision inspection system; determining a region of interest for focus height measurement operations; operating the illumination source to illuminate the workpiece with strobed illumination; periodically modulating a focus position of the imaging system along a Z-height direction proximate to the workpiece; collecting an image stack, wherein each image of the image stack corresponds to an instance of strobed illumination matched with a phase of the modulated focus position corresponding to an appropriate Z height within the image stack; and determining a Z-height measurement for at least one portion of the region of interest.

主权项

1. A method for performing high-speed focus height measurement operations in a machine vision inspection system comprising an illumination source and an imaging system that comprises a camera system, the method comprising:
placing a workpiece in a field of view of the machine vision inspection system; determining a region of interest for focus height measurement operations; operating the illumination source to illuminate the workpiece with strobed illumination; periodically modulating a focus position of the imaging system over a plurality of positions along a Z-height direction proximate to the workpiece; collecting an image stack comprising respective images focused at respective Z heights, wherein each image of the image stack is exposed using an instance of strobed illumination timed to correspond with a phase of the periodically modulated focus position corresponding to a Z height within the image stack; and determining a Z-height measurement for at least one portion of the region of interest based on analyzing the image stack to determine a Z height corresponding to a best focus position for the at least one portion of the region of interest.