| 摘要 |
PURPOSE:To make it possible to detect a defect even if the shape of a surface to be measured is not flat and the reflectivity is partially changed by providing light screening characteristics corresponding to the surface to be inspected of a work in a filter, and filtering the passing light which has undergone Fourier transformation through a space. CONSTITUTION:In a memory means (two-dimensional developed memory) 36, the image data of the entire surface to be inspected of a work which is illuminated with a lamp (laser) 30 are inputted through an image input sensor (one- dimensional sensor) 33. An electronic array shutter (diffraction-pattern forming means) 39 forms the diffraction pattern corresponding to the image data of the means 36. When the light is emitted from a lamp 37 on the pattern, the passing light undergoes Fourier transformation 40. Thereafter, the light passes through a space frequency filter 41 and reaches a light-amount sensor 42. The filter 41 is set so that the passing light which has undergone the Fourier transformation 40 is screened from the diffraction pattern formed on the surface to be inspected of the normal work 1. The light does not reach the sensor 42 from the normal work 1. Thus, the presence or absence of the defect is judged with the sensor 42. |
