Catadioptric lens system
AssigneeQuestar Corporation
InventorsEdward K. Kaprelian, William E. Mimmack
Life of this patent
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Abstract
The invention provides a highly corrected catadioptric telephoto lens comprising in succession, from the long conjugate end, an aspherized negative meniscus corrector plate, a Mangin type primary mirror which directs light to a secondary mirror comprising the central portion of the second surface of the corrector lens, a first positive meniscus corrector lens and a second biconcave corrector lens. The relative aperture is f/8 and the overall length of the system from first vertex to image plane is less than 0.4 focal length.
Claims9
A catadioptric objective comprising an aspheric negative meniscus corrector plate concave to the long conjugate, a primary mirror of the Mangin type spaced from said corrector plate and receiving light transmitted therethrough, a secondary mirror comprising a reflective area at the center of the second surface of said corrector plate and receiving light reflected from said primary mirror, and a spaced apart pair of corrector lenses located between said primary and secondary mirror for receiving light from the latter, said pair of corrector lenses comprising a positive meniscus lens convex to received light and a biconcave lens.
A catadioptric objective lens comprising a negative meniscus lens (.sup.L 1) having its concave surfaces facing the long conjugate and having an aspherized second surface, a primary mirror (.sup.M 1) of the Mangin type with a central portion cut away to allow the unaltered passage of light and having a rear surface of shorter radius than the front surface, a secondary mirror comprising a reflective central portion of the second surface of the corrector plate, a first corrector lens (.sup.L 2) between said primary and secondary mirrors comprising a positive meniscus lens, and a second corrector lens (.sup.L 3) between said primary and secondary mirrors and spaced from said first corrector lens, said second corrector lens comprising a biconcave lens of greater absolute power than said meniscus corrector lens.
Dependencies are inferred from the claim text.