| 摘要 |
<p>An optical apparatus wherethrough light is transmitted to a detecting or measuring device (12, 13 or 14) has an optical path whereby specularly transmitted light passes and impinges on a predetermined area (25) of the detecting or measuring device. Scattered light passes to the device but impinges upon the detecting surface (24, 24a, 24b) thereof over a greater area than the predetermined area (25). To enhance the relative response of the device to scattered light, an attenuating filter (33, 33a, 33b) is placed over the predetermined area (25) of the detecting surface.</p> |
