Patent ID: 9122039
Filing Date: 2015-09-01
Classification: G02B,H04N

Abstract:
1. An optical system comprising: an exit aperture; an active imaging sub-system optically coupled to the exit aperture and configured to transmit a beam via the output aperture and to receive a reflection of the beam via the exit aperture; and a field of view switching mechanism positioned between the exit aperture and the active imaging sub-system, the field of view switching mechanism configured as a pupil relay having non-unity magnification to switch a field of view of the active imaging sub-system between a wide field of view and a narrow field of view while maintaining a constant size of the exit aperture, wherein the field of view switching mechanism includes a pair of Cassegrain telescopes disposed on either side of a flat fold mirror and is configured to relay the beam between first and second pupils located opposite one another on either side of the field of view switching mechanism, and wherein the flat fold mirror and the pair of Cassegrain telescopes are movable about an axis equidistant between the first and second pupils to switch between the wide field of view and the narrow field of view.