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US 4,730,910 AGranted
Wide angle lens system having flare rejection properties
AssigneeHumphrey Instruments, Inc.
InventorWilliam E. Humphrey
Life of this patent
Estimating the term…
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AssigneeHumphrey Instruments, Inc.
InventorWilliam E. Humphrey
Estimating the term…
A wide angle lens system of at least two, and preferably four, similar powered symmetrical component lenses is disclosed; these lenses are from object to image, at least two paired concavo-convex lenses, and preferably two lenses of a concavo-convex or convexo-convex type. The first and last lenses are displaced and rotated usually by rotation about the object (taken as a defining aperture of the optical system, such as a portion of the cornea) or its conjugate, in a first direction to use lens portions between the lens center and one edge; the intermediate lens (preferably the second and third lenses) are displaced and rotated (again usually by rotation about the image conjugate formed by the first lens) in an opposite direction to use the lens portions between the other lens edge and center. Deflected rays in the lens system utilize marginal portions of the lens between the center and one edge only; neither the non-deviating portion of the spherical lenses nor the opposite side of the spherical lenses are used. The lenses are non-concentric. Consequently, the lenses can be further minimally rotated as required for optimum flare rejection.
A flare rejection refracting lens train having two aspherical sequential lens elements wherein each lens element includes at least one surface having an aspheric shape to impart to the lens the object to image optical path length the same for each passing ray, each lens element further including a segment of less than one-half of a symmetrical lens element.
A flare rejection lens train having at least three spherical elements, said lens elements when aligned concentrically forming a lens train having minimal spherical aberration, said lens elements displaced and rotated so that refracted rays through the lens system use lens portions between the center and edge of one-half of the lens and do not use the central portion of the lens and the other half of the lens.
A wide angle lens system comprising in combination:
A wide angle flare rejection lens system including four sequentially, equally-powered spherical component lenses, these lenses comprising at least two, paired concavo-convex lenses each having a near aplanatic surface, and at least two spherical lenses each having at least one convex surface;
Dependencies are inferred from the claim text.