| 摘要 |
PURPOSE:To clearly photograph only an abnormal projection on a surface to be image-picked up by reflecting parallel light from an illumination light source irregularly by the stain-finished surface of a reflecting mirror and lighting the surface to be image-picked up, and observing its reflected light. CONSTITUTION:The parallel light (a) from illumination lamps 1 arranged at four equal intervals of a circumference is reflected irregularly by the surface of a stain-finished film 10 adhered to the surface of a conical reflecting mirror 8 on the internal surface of an opening part 5 and a reflecting mirror surface 9 to illuminate the surface 12 of a body to be image-picked up through the opening part 5. When the surface 12 is smooth, its reflected light (b) is incident on neither a lens 6 nor a camera 5, but if there is a projection 13 on the surface, it can be observed as reflected light b'. Therefore, only the abnormal projection on the surface to be image-picked up can be photographed clearly. |
