| 摘要 |
<p>An optical system for distinguishing features of a target. A light source (1) is located at a source position for generating a plurality of light rays emanating from the source position. A lens (2) is positioned in front of the light source position. The lens has a first surface for receiving light rays emanating from the source position and a second surface, opposite the first surface, for outputting the received light rays. The first and second surfaces are separated by a thickness. The second surface has a first clear area for passing a first group of light rays through the lens. The second surface further includes a treated area (23) that is separate from the first clear area.</p> |
