Patent ID: 10620408

Abstract:
A compact orthoscopic lens is corrected for monochromatic and chromatic aberrations over wavelengths from 450 to 2450 nm with an angular FOV of 5.56° vertical and 66° horizontal. The 4.36″ effective focal length lens with f-number of 4 is compact measuring 5.2″ from the first optical surface to the image. The lens includes, in order from object to image, a first optical group having a negative optical power; a second optical group having a positive optical power and a third optical group having a negative optical power. The first optical group consists of two elements, the second optical group consists of three elements, one a doublet, and the third optical group consists of two elements. A physical aperture stop is positioned inside the second optical group. Powers of groups and elements, shapes, refractive indices, Abbe numbers and partial dispersions of glasses are selected so the lens is apochromatic and orthoscopic.