| 摘要 |
PURPOSE:To achieve discrimination of flaws easily and accurately, by running a transparent or translucent material between polarizing plates arranged to be orthogonal to each other to detect flaws by light transmitted therethrough. CONSTITUTION:Transparent or translucent substrate 5 runs between polarizing plates 1 and 2 arranged orthogonally to each other and is irradiated with light from a light source 3 arranged therebelow to detect a transmission light with a light receiving section 4. When a flaw is present on the substrate 5, the scattered light thereof is incident on the light receiving section 4, thereby enabling discrimination of the presence of flaws easily and accurately. |
