Abstract: An all-reflective, relayed optical system is arranged along a beam path. The optical system includes a first mirror having positive optical power, and a second mirror having a negative optical power, wherein the second mirror receives the beam path reflected from the first mirror and wherein an intermediate image is formed after the beam path reflects from the second mirror. The optical system further includes a third mirror having positive optical power, wherein the intermediate image on the beam path is reflected from the third mirror; a fourth mirror having a negative optical power, wherein the beam path reflected by the third mirror is reflected by the fourth mirror, and a fifth mirror having positive optical power, wherein the beam path reflected by the fourth mirror is reflected by the fifth mirror to an image location.

Abstract: An all-reflective optical system includes an entrance aperture, an exit aperture, and a dichroic beam splitter assembly. The dichroic beam splitter assembly includes an entrance dichroic beam splitter and an exit dichroic beam splitter. The reflected portion of the beam from the entrance dichroic beam splitter passes to a first beam processing array having an odd number of powered mirrors. The transmitted portion of the beam from the entrance dichroic beam splitter passes to a second beam processing array having an odd number of flat mirrors. The second beam processing array and the first beam processing array are circumferentially angularly displaced by about 90 degrees of rotation about an optical reference axis. The dichroic beam splitter assembly, the first beam processing array, and the second beam processing array together comprise a single optical unit rotatable about the optical reference axis, and a bearing set is provided to accomplish the rotation.

Abstract: A multi-slit spectrometer is combined with a two-dimensional detector array to enable simultaneous spectral analysis of several objects, improving the signal-to-noise ratio of multispectral imagery. The multi-slit spectrometer includes a multi-slit structure defining a plurality of parallel thin slits, and a first lens for directing object light onto the multi-slit structure. A second lens collimates and directs light which has passed through the slits of the multi-slit structure onto a light dispersing element such as a dispersing prism or a diffraction grating. A third lens focuses light which has passed through the light dispersing element onto the two-dimensional detector array at an image plane. A two dimensional detector array of detector elements is placed at the image plane. The slits are separated by a separation distance equal to an integral multiple of the detector width dimension, where the multiple is equal to (N times the number of slits) plus or minus one, where N is an integer.

Abstract: An all-reflective field-switching optical imaging system includes an optical beam coincident with an optical axis and forming a nominal pupil, a pupil-reimaging mirror array spatially separated from the optical axis and having an incident beam with a first pupil the same size as the nominal pupil and an output beam with a second pupil, and a beam diverter mirror array controllably movable between a first position where the beam diverter mirror array does not intercept the optical axis and does not divert the optical beam, and a second position where the beam diverter mirror array intercepts the optical axis and diverts the optical beam.

Abstract: A system and a method of designing and mechanical packaging of a fully integrated multifunctional multispectral miniaturized sight assembly to allow its use on hand-held man-portable units. All the subsystems of the compact sight assembly, namely, a direct view day subsystem, a CCD-based visible TV subsystem, a staring IR night subsystem, an eyesafe laser rangefinding subsystem and a display subsystem for viewing the output of the TV or IR subsystem, are aligned and use a single telescope and eyepiece in order to decrease the size of the assembly. In addition, each sight assembly subsystem operates in a first and a second field of view, preferably in a narrow field of view and a wide field of view, with wavelengths from 0.45 .mu.m to 12 .mu.m, thereby creating a very small but highly powerful sight assembly.

Abstract: A corrector mirror folds the optical path between the objective and relay portions of a three-mirror anastigmat. The corrector mirror is a non-powered mirror having a nominally flat but higher order aspheric surface. By placing the corrector mirror between the objective portion and an intermediate image formed by the objective portion, the field offset of the anastigmat can be significantly increased. A large field offset makes the off-axis anastigmat ideal for use with an on-axis dewar for infrared imaging applications.

Abstract: A wide angle large reflective unobscured system includes a primary reflective element for receiving a broad range of energy, a secondary reflective element for reflecting the energy from the primary reflective element to reimage a virtual entrance pupil at a real aperture stop. A beamsplitter element is provided for reflecting a first portion of the energy, such as visible energy, to a first tertiary reflective mirror, while transmitting a second portion of the energy, such as IR light, to a second tertiary reflector. Each tertiary reflector is capable of focusing the received energies to dual focal planes wherein a compact detector array assembly can convert the images to electronic signals.

Abstract: An imaging sensor has multiple fields of view of the same scene that may be selected by the user for viewing through mechanical movements. The imaging and selection are accomplished entirely with reflective optical components (mirrors) and without the use of any refractive optical components (lenses). A movable field-shifting mirror selects between a direct view and a modified-of-view image of the scene. The modified-view image is accomplished using a multi-mirror afocal telescope. Additional field-shifting mirrors may be used to select other fields of view and reference sources, as desired, or between various detectors.

Abstract: A low cost infrared camera (1) for night vision. The camera (1) is disposed within a housing (2) having an infrared transmissive window (6) disposed at an input aperture (5) thereof. A compact optical arrangement (10) is disposed within the housing (2) to focus energy from the window (5) onto a focal plane array (20). A chopper disk (19) is positioned between the reflective optical arrangement (10) and the focal plane array (20) to establish a reference level for the array (20) and to facilitate a sequential readout thereof. A signal processing circuit (100) is included for processing the output of the array (20) for display on a standard video screen. Thus, the problems with uncooled detectors are overcome by use of a fast optical system in combination with an uncooled detector. The fast optical system provides a high signal level to the uncooled detector, thereby compensating for losses in collection of thermal radiation.

Abstract: A virtual image instrument panel display (20) has a display source (22) and reflective elements (24, 26). The display source (22) generates a beam (28) including an image to be viewed. The reflecting elements (24, 26) receive the beam and provide a virtual image of the image of the beam. The virtual image is focused on a viewing plane at a predetermined and substantial virtual distance away from the user to enable easy eye focus transition between the virtual image and distant objects. The folded nature of the optical system provides for a compact package suitable for installation in an automotive dashboard.

Abstract: A low cost night vision system for use in connection with law enforcement vehicles, marine vessels, and other nonmilitary surface vehicles. The invention includes a night vision camera having an array of uncooled detectors. A mechanism is provided for adjusting the pointing angle of the night vision camera in response to scan control signals. Output signals from the uncooled detectors are further processed into a standard video format and displayed on a conventional display located, for example, within a vehicle or marine vessel.

Abstract: An optical apparatus monitors the entire panorama in low resolution and simultaneously monitors a selected portion of the panorama in high resolution. For the panoramic portion of the apparatus, a mirror having a convex surface of revolution with a hole therein is used. The higher resolution part of the apparatus uses a pointing mirror positioned above this hole. The panoramic and higher resolution views are imaged through lenses or optical components onto a detector. The panoramic view is imaged onto the detector as an annulus of light in which either higher or lower elevational angles of the panorama are imaged further away from the detector's center depending upon how the convex mirror is configured. In this way, the resolution of that portion of panorama that is imaged further away from the detector's center is enhanced. The higher resolution view is imaged to the center of the annulus.

Abstract: A corrector mirror folds the optical path between the objective and relay portions of a three-mirror anastigmat. The corrector mirror is a non-powered mirror having a nominally flat but higher order aspheric surface. By placing the corrector mirror between the objective portion and an intermediate image formed by the objective portion, the field offset of the anastigmat can be significantly increased. A large field offset makes the off-axis anastigmat ideal for use with an on-axis dewar for infrared imaging applications.

Abstract: A method and apparatus (30) for compensating for optical aberration created by a conformal window (60). The apparatus (30) comprises a one-dimensional corrector plate (32) for providing a varying amount of linear coma, first and second cylindrical lenses (34, 38) for providing a varying amount of astigmatism and a system for adjusting the corrector plate (32) and the lenses (34) and (38) to minimize the optical aberration created by the conformal window. The apparatus (30) of the present invention provides for correction of considerable amounts of optical aberration over a wide field of regard. The apparatus is simple in design, easy to install and cost effective.

Abstract: An all-reflective multiple field of view optical system has first (10) and a second (12) reflecting assemblies which share a common package volume in a single unit. The first (10) and second (12) reflecting assemblies rotate with respect to one another to provide multiple fields of view utilizing a common entrance pupil region (14) and a viewing plane (16). Likewise, each reflecting assembly provides a multiple field of view.

Abstract: An all-reflective optical system has a first (10) and second (12) reflecting assembly. The first reflecting assembly (10) includes an afocal three-mirror anastigmat (18, 20, 22) with one or more apertures (28 A-D) in the tertiary mirror (22) to enable light or energy to pass therethrough. Light or energy reflects from the second reflecting assembly (12) through the apertures (28 A-D) to provide simultaneous viewing of a scene by a plurality of instruments (34). The second reflecting assembly (12) includes a planar mirror which provides pointing and stabilization motions for all of the instruments simultaneously without degrading image quality or pupil registration.

Abstract: A refractive inverse telephoto optical system (10) has a first lens doublet (12), a Pechan prism assembly (14) and a second lens doublet (16). The Pechan prism assembly (14) is spaced between the front negative doublet (12) and the rear positive doublet (16). The Pechan prism assembly (14) may be rotated and, as rotation occurs, the associated linear detector array is rotated around within the optical field of view.

Abstract: A wide angle large reflective unobscured system (10) has a primary (12), secondary (14), tertiary (18) and fold (16) mirror. The primary (12) and secondary (14) mirrors act as a non-reimaging afocal telescope of the Galilean type and relay a virtual entrance pupil to the fold mirror (16) which is positioned at the system aperture stop. The fold mirror (16) directs the energy to the tertiary mirror (18) which acts to direct and focus the energy at a viewing plane. The resulting telescope provides a wide two dimensional field of view which can exceed 20.degree..times.40.degree., and operates at optical speeds about F/1.0.

Abstract: An all-reflective imaging spectrometer (10) has a three-mirror anastigmat (12) acting as its objective and a reflective triplet (14) with a dispersive element (18) providing the spectrometer collimator and imager. The system is capable of imaging an object being viewed to provide a plurality of different wavelength images of that object.

Abstract: An infrared refractive reimaging afocal telescope (10) has an objective lens group (12), an eyepiece lens group (14), and a switching lens group (16). The system (10) provides a plurality of magnification modes in a compact arrangement. The system (10) utilizes lenses (40, 42, 44, 46) with diffractive surfaces to provide for magnification changes and chromatic aberration correction. The system provides for excellent image quality in all modes using a minimum number of lens elements.