| 摘要 |
<p>PURPOSE:To enable easy and highly accurate measurement to find on which surface a foreign matter exists by one scanning, by providing a plurality of detection means with respect to a plurality of surfaces to be measured. CONSTITUTION:This apparatus is made up of a luminous flux 1, a substrate 2, pellicle protective films 3 and 4, optical members 5a-5d, view stops 6a-6d, light guides 7a-7d and light receivers 8a-8d. The member 5a, the stop 6a, the guide 7a and the light receiver 8a composes a part of one detection means (A). Other means 5b-5d, the stops 6b-6d, the guides 7b-7d and light receivers 8b-8d also compose a part of detection means (B), (C), and (D) simultaneously. Here, supposing that a foreign matter exists on a surface 2b to be measured, the luminous flux 1 hits a foreign matter and scattered lights are generated isotropically from the foreign matter. At this point, as the means (B) has a focus adjusted to the surface to be measured, the member 5b focus the scattered luminous fluxes efficiently. On the other hand, as the other means (A) or the like is defocused on the surface 2b being measured, light is intercepted by the stop 6a provided near the position where the member 5 is in conjugation with the surface to be measured.</p> |
