| 摘要 |
PURPOSE:To enable stable surface inspection by converting the density levels of respective split image data using a conversion table, and making the average level of image data for the whole subject to be inspected uniform. CONSTITUTION:Masked split image data of a subject to be inspected are stored in an image memory 9, and respective average density levels in the parts other than the masked part are calculated by an average level calculating circuit 13, and the values thereof are supplied to a conversion table generating circuit 14. The circuit 14 generates a conversion table for making the average density level of the whole wafer uniform and stores it in a conversion table memory 15. When the respective divided image data are stored in a memory 9 in the surface inspection of a wafer 2, a data converting circuit 16 reads successively the respective split image data from the memory 9 and converts density levels thereof respectively to make the average density level of image data of the whole wafer 2 uniform. Thus, stable surface inspection can be carried out without being influence by the video signals from subjects other than the subject to be inspected. |
