Infrared imaging optical system with varying focal length across the field of view
AssigneeRaytheon Company
InventorLacy G. Cook
Life of this patent
Estimating the term…
Abstract
Provided is an infrared imaging optical system with an advantageously varying focal length across the field of view. More specifically, in a particular embodiment, provided is an inverse telephoto lens group having a field of view on the order of at least two radians. The focal length of the lens group is structured and arranged to vary in a pre-determined fashion across the field of view. An IR detector is optically coupled to the inverse telephoto lens group. A pupil is disposed between the IR detector and the inverse telephoto lens group.
Claims23
An infrared imaging optical system comprising:
- an inverse telephoto lens group having a field of view on the order of at least two radians, the focal length varying across the field of view in a pre-determined fashion;
- an IR detector optically coupled to the inverse telephoto lens group;
- and
- a pupil disposed between the IR detector and the inverse telephoto lens group.
An infrared imaging optical system comprising:
- an IR detector focal plane disposed within a cold cavity and oriented towards an optical opening in the cold cavity;
- a pupil proximate to the optical opening;
- an inverse telephoto lens group optically coupled to the pupil, the lens group structured and arranged to receive infrared light from object space in a field of view and map object space angles onto IR detector focal plane locations such that the angular subtense of a first pixel at the focal plane center is greater than the angular subtense of a second pixel at the focal plane edge.
An infrared imaging optical system comprising:
- an inverse telephoto lens group structured and arranged to receive infrared light from a field of view of at least two radians and focus the received light onto a focal plane array detector disposed on the opposite side of a pupil, the telephoto lens group further structured and arranged with a pre-determined varying focal length across the field of view to map object space angles onto focal plane array locations such that an angular subtense of a first detector pixel at the focal plane array center is greater than an angular subtense of a second detector pixel at the focal plane array edge.
Dependencies are inferred from the claim text.