| 摘要 |
<p>An imaging device (20) includes a refractive imager (26) lying in an optical path (22), and optionally a telescope that directs the optical path (22) to the refractive imager (26). The refractive imager (26) includes a first lens group (40) that forms an intermediate image ( 42) of a scene on the optical path ( 22), wherein the first lens group (40) includes a first-lens-group positive-power lens (44), and a first-lens-group negative-power lens (46). A second lens group (48) relays the intermediate image (42) to a final image surface (50) on the optical path (22), wherein the second lens group (48) includes a second-lens-group positive-power lens (54), and a second-lens-group negative-power lens (52). A third lens group (56) may be selectively inserted into the optical path (22) between the first lens group (40) and the second lens group (48) and selectively removed from the optical path (22). The third lens group (56) includes a third-lens-group positive-power lens (58), and a third-lens-group negative-power lens (60).</p> |
