| 摘要 |
The invention relates to high resolution, super wide angle optical assemblies for IR imaging. More particularly, a wide-angle optical assembly for an IR camera is described, comprising a lens system consisting of an object-side lens (2) and an image-side lens (3), and an aperture stop (1) on the object-side of the assembly, wherein: the object-side lens (2) and the image-side lens (3) are positive meniscus lenses; all centers of vertex radii of the lens surfaces are oriented towards the object-side, defining for each lens a concave surface and a convex surface; the thickness (8) of the object-side lens (2) is larger than 0.60 EFL; the thickness (9) of the image-side lens (3) is between 0.30 EFL and 0.70 EFL; 0.95<BFL/EFL<1.2; and, the EFL amounts to between 55% and 75% of the image plan diagonal. This assembly combines a wide field of view with the high spatial resolution needed to fully exploit state of the art 17 mum pixel pitch IR detectors. This is achieved using only two lenses, thus offering a cost advantage over existing many-lenses assemblies.
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