Lens assembly and optical imaging using same
A lens assembly includes, in order from an object side to an image side: a first lens; a first meniscus lens in optical communication with the first lens; a second meniscus lens in optical communication with the first meniscus lens; an aperture stop in optical communication with the second meniscus lens; a fourth lens in optical communication with the aperture stop; and a bi-convex lens in optical communication with the fourth lens. The lens assembly is a four group, five element, lens assembly that is constructed so that at least one of the lenses may be replaced without also requiring the other lenses in the assembly to be significantly changed, resulting in a “flexible” construction. The lens assembly may be adapted to provide a field of view of approximately 15 degrees; approximately 0% vignetting within the field of view; and a distortion of the image of less than approximately 1%. Multiple lens assemblies and detectors may be provided in a single housing.
1. A lens assembly comprising:
a plurality of lenses for producing an image of an object, the plurality of lenses adapted to provide:
a field of view of approximately 15 degrees;
approximately 0% vignetting within the field of view;
a distortion of the image of less than approximately 1%;
wherein the plurality of lenses includes five lenses, wherein the five lenses include, in order from an object side to an image side:
a first lens;
a first meniscus lens;
a second meniscus lens;
a fourth lens; and
a bi-convex lens.
2. The lens assembly of claim 1 , wherein the plurality of lenses are configured to define a focal length, and wherein a length of the plurality of lenses is approximately equal to the focal length.
3. The lens assembly of claim 1 , further comprising:
an aperture stop in optical communication with the plurality of lenses.
4. The lens assembly of claim 3 , wherein the plurality of lenses is non-symmetrical about the aperture stop.
5. The lens assembly of claim 1 , further comprising:
at least one planar plate in optical communication with the plurality of lenses.
6. The lens assembly of claim 5 , wherein the plurality of lenses is further adapted to provide:
offsetting aberrations to compensate for aberrations introduce by the at least one planar plate.
7. The lens assembly of claim 1 , wherein the first lens is a plano-convex lens.
8. The lens assembly of claim 1 , wherein the first lens is a meniscus lens.
9. The lens assembly of claim 1 , wherein the fourth lens is a meniscus lens.
10. The lens assembly of claim 1 , wherein the fourth lens is a bi-concave lens.