| 摘要 |
The invention relates to an infrared objective (IR objective) with a lens arrangement for the production of an infrared image on a detector element of infrared detector equipment. In this respect it may be a question of a focal plane array (FPA) within a Dewar vessel with an internal cold shield for substantially preventing access of thermal radiation from the surroundings (spurious light fractions). The internal cold shield is placed behind an external uncooled cold shield comprising several staggered external cold diaphragms. In this respect the external cold shield is partly arranged in front of and/or partly within the lens arrangement, the external cold shield with the lens arrangement being so designed and so arranged in relation to the internal cold shield that each optical ray, which comes from the lens element and is outside the optical pupil, is reflected back via the external cold shield and the lens arrangement into the or, respectively, on the internal cold shield, one of the cold diaphragms constituting the aperture diaphragm. The infrared objective may be designed telecentrically. The infrared objective may be a component of a complex infrared optical system (for instance as a front afocal).
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