Minute opening survey instrument and minute opening inspection manner

摘要

PROBLEM TO BE SOLVED: To provide a method and an equipment for inspecting a microcgap stably and accurately at high speed through an inexpensive constitution. ;SOLUTION: The microgap inspection equipment comprises means 100 for picking up the image of an optical interference fringe appearing in a ring-like microgap, a first matrix developing means 103 for developing the image data on a coordinate determined by the angle from an arbitrary line extending radially from the center of the ring and the distance from time center of the ring onto a first matrix having rows and columns corresponding, respectively, to the angle and the distance, a second matrix generating means 104 for generating a second matrix having columns of the difference between the adjacent columns in the first matrix, and means 105 for calculating the standard deviation based on each element in the second matrix and making a decision whether a foreign matter is present in the microgap based on the difference between the maximum and minimum values of standard deviation of each column.;COPYRIGHT: (C)1998,JPO