| 摘要 |
<p>The system (10) employs three mirrors (20,22,24) to reflect and propagate beams of electromagnetic energy (16,17,18) from four reflecting surfaces. A convex mirror (20) is the primary mirror/reflector. A concave mirror (22) is both the secondary and quaternary mirror/reflector for the system. A folding mirror (24) which is essentially flat mirror is the tertiary mirror/reflector for the system. The optical axis (36) of the system (10) is normal to the centre of the folding mirror (24). The vertex of the convex mirror (20) and the vertex of the concave mirror (22) lie along the optical axis (36). A distortion corrector (32) and filter (34) are positioned in front of the image plane (30) of the system (10).</p> |
