Patent attributes
A variable aperture assembly for an infrared camera for use with optics having two or more f-numbers. The variable aperture assembly includes a variable iris disposed substantially along an axis of the infrared camera and is thermally connected to a cooling assembly. The variable iris is capable of causing an infrared radiation admitting opening to vary in size. The infrared radiation admitting openings of the variable aperture assembly can be circular or non-circular, including generally rectangular or racetrack shaped openings. The variable aperture assembly provides f-number matching by adjusting the infrared radiation admitting opening to the size necessary to effectively match the numerous f-numbers of the optics, or by adjusting to a size so that a fixed aperture on the radiation shield becomes the effective aperture stop, providing the f-number matching.
