| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately detect defects on a surface of a hologram. <P>SOLUTION: The apparatus for detecting the defect, which detects the defect on the surface of a thin plate-like hologram 10 to be tested, is provided with a planar light source 11 by which the substantive surface side except the overhead section on the surface of the hologram 10 is irradiated with test light in all directions in relation to the surface of the hologram 10 to be tested, a camera 12 which photographs the surface of the hologram 10 irradiated with the test light as an image viewed directly overhead and obtains image data, and an image data comparing section 32 which judges as to whether the defect is present or not on the surface of the hologram 10 to be tested, on the basis of the image data obtained by the camera 12 and image data of a defect-free hologram having a specification identical to the hologram 10 to be tested and being previously photographed to obtain its image data. <P>COPYRIGHT: (C)2004,JPO |
