| 摘要 |
<p>A reference face (15) and a face (31) to be measured are irradiated with a white light from a white light source (10) to make an optical path difference. A CPU (20) samples the intensity value of an interference light varying at a specific portion of the face (31) because of the optical path difference, at sampling intervals of a product M•Δ of Δ = (λC2 - λB2)/4λC and a natural number M where λC is the center wavelength of a specific frequency band restricted by a band-pass filter (11) and 2 λB is the band width of the wavelength. In the case of a spectral distribution symmetric with respect to a center wave number kC of the specific frequency band, a characteristic function having a peak position which is identical to the peak position of the interference light is inferred. The irregular shape of the face (31) is measured by determining the height of the peak position of the characteristic function.</p> |
