| 摘要 |
PURPOSE:To make it possible to easily detect a flaw only by a density value by extracting the density levels of a normal part and a flaw part in a largely different form, by utilizing the reflective characteristics of the mirror surface of an object to be inspected and a light source corresponding to a rotary surface. CONSTITUTION:For example, in detecting the flaw of the mirror reflective surface 1-1 of cone shaped matter to be inspected, a circumferential shape irradiation light source 2 such as a circular lamp is used and a TV camera 3 is arranged above said light source 2. When the light source 2 is present at the position of a drawing (a), the image data 1' inputted to the TV camera 3 consists of a ring shaped bright part 1-1-0, a dark part 1-1, and a circular dark part 1-2'. In this state, the light source is downwardly moved to the position shown by a drawing (c) to gradually change the distance between the light source 2 and the matter 1 and data from the ring shaped image data 1-1-0 present at the uppermost position of an inclined surface to the ring shaped image data 1-1-n present at the lowermost position of said inclined surface are successively obtained. In a flaw A is present on the surface of the matter 1, image data, wherein a dark part A' is present on a part of a ring shaped bright part 1-1-m, is obtained. |
