| 摘要 |
PROBLEM TO BE SOLVED: To provide an inspection method capable of accurately detecting a defective part such as irregularity or an air bubble included in a side surface section of a cylindrical transparent body, and to provide an inspection method used for it. SOLUTION: In this inspection method, the defective part 20 in the side surface is detected by illuminating the side surface of the cylindrical transparent body 5 from the downside and observing the transmitted light. The illumination is transmitted light through a mask 10 having a stripe pattern where a transparent part 10a and an opaque part 10b are arranged alternately. By arranging the stripe pattern and the center line of the cylindrical transparent body 5 substantially orthogonally, the outline of the defective part 20 is emphasized and detected. COPYRIGHT: (C)2008,JPO&INPIT |
