Long-focus color-corrected petzval-type optical objective
AssigneeLockheed Missiles & Space Company, Inc.
InventorRomeo I. Mercado
Life of this patent
Estimating the term…
Abstract
A modified Petzval-type optical objective is provided, whose design form has a long focal length (i.e., 1000 mm) at a large relative aperture (i.e., f/2) over a field of view of 4.2.degree. without vignetting, which is well-corrected for both monochromatic and chromatic aberrations, and which is color-corrected at four wavelengths over a spectral band extending from the visible to the near-infrared regions of the electromagnetic spectrum. The optical objective is made from only two different optical glasses. The design form can be scaled up or down from the 1000 mm focal length by using an appropriate scaling factor.
Claims14
A optical objective of net positive dioptric power, said objective having an image plane at which four discrete wavelength come to a common focus, said optical objective comprising:
- (a) a first lens group consisting of five lens elements,
- (b) a second lens group consisting of four lens elements, and
- (c) a field flattener consisting of one lens element,
- all of said lens elements being disposed along an optic axis, each of said lens elements being rotationally symmetric with respect to said optic axis, said second group of lens elements being separated from said first group of lens elements along said optic axis by an aperture stop, said field flattener being located adjacent said image plane, said lens elements being made from only two different optical glasses, at least one of said lens elements being made from a first one of said optical glasses, at least one other of said lens elements being made from a second one of said optical glasses.
Dependencies are inferred from the claim text.