| 摘要 |
<p>PROBLEM TO BE SOLVED: To collect data to continuously subject the same to analogue/digital(A/ D) conversion many times to store the obtained digital data in a memory by sampling the data of measuring light and reference light at the same time by two systems to subject the same to A/D conversion. SOLUTION: An interferogram is obtained and the signal thereof is divided into measuring light and reference light by a photocoupler 21 and both lights are respectively detected by photodetectors 25, 27 to be transduced into electric signals which are, in turn, inputted to an A/D converter 30. The interference signal of a monochromatic light source 12 is detected by a photodetector 19 and the electric signal thereof is also inputted to the A/D converter 30. This interference signal is utilized as the sample clock of the A/D converter 30. The output of a displacement sensor 17 is also inputted to the A/D converter 30 as a phase signal. The A/D converter 30 samples measuring light and reference light at the same time to subject the same to A/D conversion and the A/D conversion data are successively stored in a memory. This sampling, the A/D conversion and the storing of data are repeatedly performed two or more times at every sample clock.</p> |
