High speed optical inspection system with adaptive focusing

摘要

An optical inspection system for inspecting a substrate is provided. The system includes an array of cameras configured to acquire a plurality of sets of images as the substrate and the array undergo relative motion with respect to each other. At least one focus actuator is operably coupled to each camera of the array of cameras to cause displacement of at least a portion of each camera that affects focus. A substrate range calculator is configured to receive at least portions of images from the array and to calculate range between the array of cameras and the substrate. A controller is coupled to the array of cameras and to the range calculator. The controller is configured to provide a control signal to each of the at least one focus actuator to adaptively focus each camera of the array during the relative motion.