Method of two-dimensional measurement of the position of an object

摘要

The method involves associating a periodic spatial marking pattern (11) formed by marks placed along a two dimensional grille with rows and columns. The pattern is irradiated with electromagnetic waves. The waves reemitted by the pattern are collected to obtain an image from the spatial distribution. Two timing signals respectively representing the image along the rows and columns are developed. The signals are compared with references representing a reference position to determine the displacement of position of an object along the axes (X, Y) relative to the reference position. An independent claim is also included for a two dimensional pattern for implementing a method for measuring absolute position of an object.