| 摘要 |
PROBLEM TO BE SOLVED: To provide an apparatus for detecting defects capable of occurately detecting defects, such as flaws, cracks and the like formed on a spherical surface of an object to be inspected, even when their sizes are small. SOLUTION: The apparatus for detecting defects comprises a Fourier transform lens 25 applying Fourier transformation to the light reflected from a workpiece WK; and a spatial filter 26 for blocking specular light DR and extracting a diffused light SL which are the portions of the reflected light, after the Fourier transformation. The spatial filter 26 is disposed on the Fourier transform surface of the Fourier transform lens 25 and equipped with a light-blocking part 26b, whose size corresponds to the beam diameter of the specular light DR being condensed. The reflected light which is emitted from a laser light source 21 and reflected by the workpiece WK, is subjected to Fourier transformation by the Fourier transform lens 25 and is led to the spatial filter 26. The spatial filter 26 blocks the specular light DR at the light-blocking part 26b and leads the diffuse light SL to a CCD camera 29. COPYRIGHT: (C)2008,JPO&INPIT
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