| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface shape measuring method capable of long-range measurement by improving measurement accuracy in two-wavelength phase-shifting interferometry and only slightly improving a conventional phase-shift optical system. SOLUTION: In the surface shape measuring method, an error distribution contained in fringe order computation is estimated in the determination of fringe order of each position in two-wavelength phase-shifting interferometry (Step S21-S24), and the fringe order is determined by subtracting specified errors from the error distribution (Step S25 and S26). As enlarging a measuring range by two-wavelength phase-shifting interferometry, it is therefore possible to reduce the effects of errors due to fringe order errors in its arithmetic processes and maintain original high accuracy in phase-shift interferometry. As a result, it is possible to accurately measure the surface shape of an object to be measured at a long range. COPYRIGHT: (C)2006,JPO&NCIPI
|
