Abstract:
A novel vision test device and method for measuring the ability of a subject to perceive contrasts is described, which comprises a chart for display to the subject having a plurality of visual test shapes systematically organized thereover in a predetermined array on a background of preselected luminance or reflectance level, each test shape having a preselected luminance level providing maximum contrast relative to background at its center and substantially zero contrast relative to background at its edges, the luminance (or reflectance) level of each test shape varying radially from its center outwardly according to a Gaussian distribution of preselected distribution factor.
Abstract:
An improved helmet is provided including means to telescopically acquire an image of a field of view, which comprises, a telescopic optical system including an objective lens mounted to said helmet above the line of sight of the wearer, a light-conducting fiber optics bundle mounted to said helmet for receiving the image from the objective lens, and collimating lens for receiving the image from the fiber optics bundle and projecting the image onto a helmet-mounted visor in the line of sight of the wearer. A shutter, remotely controllable by the wearer, may be disposed intermediate the objective lens and display to selectively block transmission of the image.
Abstract:
An apparatus for detecting contact between an object and the surface of a body, by utilizing various indices of refraction so that electromagnetic energy reaches a detector system only when there is optical contact. A body of transmissive material is irradiated with electromagnetic energy. That portion of the energy which enters the body through a first boundary surface is refracted, thereby striking the body surface leading to the detection system at angles of incidence sufficient to cause total reflection at that surface. Similarly, electromagnetic energy which passes through the body, strikes the object on the opposite side, and reenters the body is refracted upon reentry and totally reflected at the surface leading to the detector system. Contact between the object and the contact detecting surface produces diffusive reflection within the body at all points of actual contact. The incidence angle between the diffusive electromagnetic energy at each point of contact and the surface leading to the detection system is sufficiently low to permit passage of electromagnetic energy outward through surface and onto the detection system. Since the contact points and the detection system are geometrically related, contact locations or patterns may be recognized when they are being sought.
Abstract:
An instrument and method for optically calibrating and balancing low level luminances of lighted instrument panel displays within the operator station of a vehicle is described which comprises a self-contained, calibrated luminance source and a beamsplitter for combining and juxtaposing an image of the calibrated luminance source with an image of the luminance from a lighted instrument panel display to be calibrated or balanced, whereby the images may be compared in luminance, the lighted instrument panel display being adjustable in intensity using the vehicle instrument panel light trim capability.
Abstract:
An adaptor detachably mounted on an ocular of night vision goggles for quly adjusting the objective lens focus to clearly view far and near objects. The adaptor includes a positive optical power or close-up lens mounted in a holder pivotally mounted between a stowed, inoperative position and an operative position locating the close-up lens in axial alignment with the objective lens of the ocular. The close-up lens has an effective diameter substantially smaller than the diameter of the objective lens to raise the F/number of the objective lens/close-up lens combination for increasing the depth of focus for enhanced near viewing. Auxiliary illumination is provided by a battery powered infra-red Light Emitting Diode (LED) mounted in the adaptor and energized by a switch as the lens holder moves toward its operative position.
Abstract:
A synthetic color arrangement for a night vision inclusive surveillance system and its display is disclosed. The system partitions an input scene video signal into spectrally segregated scene components which are provided with separate processing as video signals and then recombined into a composite but now multiple color inclusive output representation of the input scene. The system in effect shifts input spectral components to a different part of the electromagnetic spectrum, the visible range of the spectrum, where operator controllable new spectral wavelength values are assigned to each different input scene spectral wavelength. Use of charge coupled device video camera elements, a video signal mixer apparatus, input wavelengths within both the visible and infrared spectral regions and signal processing according to the NTSC standards are also included. Military and non military uses of the apparatus are contemplated.
Abstract:
An arrangement for conveniently changing the illumination in an aircraft cockpit or other enclosure to a spectrum compatible with night vision infrared equipment including provision for easy return to the original illumination source. Selected LED elements are employed in multiple element arrays using a tether connected package that can be excited directly from existing wiring in fixtures.
Abstract:
A glide slope indicator system in which light from an incoming aircraft's landing light is shaped by spherical/cylindrical lens combination into a line image which strikes a linear photodiode array. By determining which photodiode in the array the center of the line image strikes, the glide slope angle can be determined. An appropriate signal is communicated to the pilot via a pair of indicator lights mounted on the runway depending upon whether the aircraft is above, below or on the desired glide slope angle.
Abstract:
An apparatus for altering the spatial frequency content of recorded patterns by selectively filtering the patterns after they are transformed into the Fourier domain. The filter characteristics are spatially and temporally variable while the real space image of the altered pattern is being observed. A laser beam is projected through a transparency containing the pattern. The patterned beam, with diffraction interference effects, is transformed to the Fourier domain at the surface of a liquid crystal light valve responsive to a spatially and temporally varying light projector. The projector activated regions reflect areas of the Fourier domain beam, while other areas are absorbed or incoherently reflected. A beam splitter redirects a portion of the reflected beam to a continuously observable image plane after transformation back into real space.
Abstract:
A vibration stabilized image projection system includes a viewing screen supported on a vibratory platform, an image projector supported off the platform in a relatively vibration-free environment for projecting an image toward the screen, and an image stabilizing lens interposed between the projector and screeen for providing an optical link between them. The stabilizing lens is supported on the platform for undergoing vibratory movement therewith in X, Y and/or Z planes and relative to the projector. The lens focuses the image at a stationary position on the screen as the stabilizing lens, screen and platform undergo vibratory movement relative to the projector.