Abstract: A system that provides a head-up display for an operator of a vehicle includes a collection device that can collect infrared energy and an image source coupled to the collection device. The image source can generate a visual image based on the collected infrared energy. The system also includes a lens through which the visual image passes before presentation to the operator of the vehicle and a reflector that can reflect the visual image before presentation to the operator of the vehicle.

Abstract: An offset reverse telephoto projection lens that is telecentric in modulator space and has an air equivalent back focal distance of at least 3.3 inches and preferably at least 4.0 inches. The lens comprising, from the image side, a first objective lens group 408 having a negative power and a second telecentric lens group having a positive power. The second telecentric lens group 410 is telecentric in object space such that the image of the aperture is focused at infinity and light converges on the object plane perpendicular to the axis of the lens. Embodiments of the lens have a back focal distance to effective focal length ratio of at least 0.86:1, preferably at least 1.2:1, more preferably at least 1.3:1, still more preferably at least 4.08:1, and most preferably 5.0:1. The embodiments described have a field of view between 14 degrees and 73 degrees, have throw ratios of 1.2:1 to 7:1, and an overall length ranging from less than 5 inches to 12.5 inches.

Abstract: A polymeric infrared window (10) is described which comprises a sheet of polymeric material (14). Sheet 14 further may comprise a layer of molecular weave polymer material (34) fixed to a electromagnetic interference shield (32). In addition, a polymeric sheet (42) may be embossed with a binary defractive pattern (40) to create a polymeric defractive lens (38).

Abstract: A chopper, in an infrared imaging system, is used to scatter infrared radiation from a viewed scene. This scattered radiation is detected with an infrared detector and used to produce a reference signal, which represents the uniform average radiance of the scene. This reference signal may be substracted from a signal representing the unscattered radiation emitted by the scene, to produce a signal that represents only radiance differences and that is an optimal signal for amplification.

Abstract: The present invention teaches infrared chalcogenide glass compositions having very low dispersion in the eight to twelve micron range, which are formed as III-V-VI-VII compositions, e.g. 14% (atomic) gallium plus 25% antimony plus 40% selenium plus 21% bromine. The introduction of a group VII component into a chalcogenide glass provides low dispersion, and the group III component compensates for the strong devitrification tendencies of the group VII component and maintains the mechanical properties of the glass.

Abstract: An improved radiation energy detecting system is disclosed. The system comprises a rotating scanning mirror reflecting energy radiating from objects in the field of view through a novel image derotating prism, providing optimum transmission modulation transfer and minimal dimension for packaging, and focusing optics onto a radiant energy detecting array. The detector converts the radiant energy to electrical signals representative of the impinging radiant energy for display processing.