Patent Document ID: 4848907
Application ID: 07091278
Patent Status: 1

Claim One:
1. A method of analyzing interference fringes for use in a holographic interferometry process for measuring, by using a computer generated hologram, the shape of an object to be examined, said method comprising: a first step of obtaining a wave surface (xl, yl, zl) of a surface to be measured from measurement interference fringes, on the basis of an interference fringe analyzing method or phase scanning method; a second step of obtaining a coefficient A.sub.k relative to said wave surface (xl, yl, zl) of said surface to be measured, on the basis of the method of least squares or Min-Max method, from a coefficient a.sub.ij of a series of the object wave ##EQU24## which has been obtained based on the hypothesized coordinates on a computer generated hologram at the time when said computer generated hologram is made, and from a coefficient b.sub.ij of a series of the object wave ##EQU25## based on the hypothesized coordinates on said object to be examined, said a coefficient A.sub.k minimizing the square sum or the maximum value of ##EQU26## a third step of obtaining a shape error from the ideal shape of said object by calculating said Formula .circle.3 on the basis of said A.sub.k determined in said second step.