Balanced focus system and method for achieving optimal focus of

Abstract

A balanced focus system and method achieve optimal focus of different areas of an object that are concurrently imaged and then combined to form a combined image. The balanced focus method is particularly suited for, but not limited to, use with an automatic inspection system for contactlessly measuring at an endface of an optical fiber termination the eccentricity of an optical fiber core relative to a theoretical ideal center of an alignment surface of the termination. The inspection system has an imaging system with a feature imager and one or more boundary segment imagers but preferably four in number, a focus adjustment mechanism (FAM) for adjusting the position of the imagers relative to the imaged object along an optical axis, and a machine vision system for receiving image data from the foregoing imagers and configured to control the FAM. The feature imager is positioned to capture an image of the feature (e.g., fiber core endface), and the one or more boundary segment imagers are positioned to capture an image of a corresponding boundary segment of the object (e.g., termination endface). The machine vision system determines the eccentricity based upon the feature image and the one or more boundary segment images. Significantly, the machine vision system employs the balanced focus system and method to achieve an optimal focus position for the imaging system based upon a series of combined images and a statistic S that is computed for each of the sampling locations.