| 摘要 |
PURPOSE:To detect pattern periodicity of an object to be inspeced, without error, with no required periodicity measurement and design data on the object to be inspection, relating to a periodic pattern inspecting device. CONSTITUTION:This inspection device is provided with a periodicity detecting part 10 consisting of a picture memory 12 and a host computer 70, and prior to start of inspection operation, the value (picture data) of picture signal SA of an object to be inspected 61 outputted from a picture input part 50 is stored in the picture memory 12. The host computer 70, while the initial phase of reference data is changed for each line with the use of the picture data, calculates temporary auto-correlation function for multiple line data, and adds their calculation results together for each shift amount. With what added as auto-correlation function, the shift amount wherein the n-th peak appears, is obtained, so that 1/n of the shift amount is taken as period to be obtained. Then the period is set as delay amount at a period delay part 62. |
