Patent ID: 9348120
Filing Date: 2016-05-24
CPC Classification: G02B,H04N

Claim Text:
1. An imaging lens for use with an operational waveband over any subset of 7.5-13.5 μm, the imaging lens comprising: a first optical element of a first high-index material, the first optical element having a front surface and a rear surface; and a second optical element of a second high-index material, the second optical element having a front surface and a rear surface, the front surface of the second optical element facing the rear surface of the first optical element, wherein at least two surfaces of the first and second optical elements are optically powered surfaces, a largest clear aperture of all optically powered surfaces does not exceed a diameter of an image circle of the imaging lens corresponding to a field of view of 55 degrees or greater by more than 30%, sags of optically powered surfaces increase from an object side to an image side, and the first and second high-index materials have