MULTI-FOCUS IMAGE USING TUNABLE LENS IN MACHINE VISION INSPECTION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a method that defines an operation for acquiring a multi-exposure image of a workpiece including first and second regions of interest different in a Z height.SOLUTION: A method is configured to: acquire a multi-exposure image by a machine vision inspection system including strobe illumination and a variable focal length lens (for example, a tunable acoustic gradient index of refraction lens) periodically varying a focus position; during a learning mode, determine first and second multi-exposure timing values for instances of the strobe illumination corresponding to first and second phase timings of the periodically varied focus position producing a prescribed degree of focus in the first and second regions of interest; record data indicative of the multi-exposure timing difference; and define operations for acquiring the multi-exposure image of the first and second regions of interest on a current workpiece in operation similar to a representative workpiece, using the data (for example, during an execution mode).SELECTED DRAWING: Figure 1