Patent ID: 8184368
Filing Date: 2012-05-22
Classification: G02B,H04N

Abstract:
1. An optical system adapted to operate in either a narrow field of view mode or a wide field of view mode to image an object, the optical system comprising: a first entrance aperture; a second entrance aperture; a reflective beam expander comprising a first side, a second side, a third side, and a fourth side, where the first side is opposite the second side, and the third side is opposite the fourth side; a reflective imager comprising a first side, a second side, a third side, and a fourth side, where the first side is opposite the second side, and the third side is opposite the fourth side; a moveable field of view changing mirror; and an imaging detector; where in the narrow field of view mode: where in the wide field of view mode: where the moveable field of view changing mirror is positioned between the first entrance aperture and at least a portion of the first side of the reflective imager so as to block the optical beam path between the first entrance aperture and the at least a portion of the first side of the reflective imager when in the wide field of view mode; where the moveable field of view changing mirror is positioned next to the third side of the reflective beam expander so as to receive the second optical beam from the reflective beam expander and to reflect the second optical beam to the first side of the reflective imager; where the moveable field of view changing mirror is positioned a predetermined distance away from the third side of the reflective beam expander so the moveable field of view changing mirror is located out of the optical beam path between the first entrance aperture and the at least a portion of the first side of the reflective imager when in the narrow field of view mode.