Abstract:
Device and method are described for measuring transmissivity and haze in transparencies as detected through night vision goggles, including an emitter portion and a sensor portion, the emitter portion including a first light source for presenting an image to the sensor portion through the transparency and a second light source for projecting a haze producing light onto the transparency, the sensor portion including a light intensifier tube and a photometer for measuring the luminance output of the light intensifier tube and quantifying attenuation (transmissivity) and haze (light scatter) characteristics of the transparency as viewed through night vision goggles.
Abstract:
A night vision device enhancement wherein occurrence of a bright object in an input scene of the night vision device is precluded from adversely affecting reproduction of adjacent low radiance level portions of the input scene. By optically limiting or excluding bright object input scene portions from the night vision device input field the disclosed system precludes both image intensifier-related effects, effects such as blooming and current saturation, and also precludes automatic gain control-related effects such as full-field sensitivity decrease based on the bright object. Plural embodiments of the system are disclosed, embodiments based on bright object attenuation by both yet to be developed photo active materials such as photochromics and embodiments which use present state of the art liquid crystal materials and accompanying electronics. Military and non-military uses of the improved night vision device are contemplated.
Abstract:
A system for measuring crazing in a transparency is described which comprises one or more light sources disposed near a first surface of the transparency for projecting light rays through the transparency at the portion thereof having a crazed condition, optical detectors corresponding in number to the number of light sources disposed on the opposite side of the transparency, each detector positioned to detect only light from a single corresponding source reflected from the crazed portion of the transparency, and a source of power for the sources and detectors. A sequencing circuit may be included to selectively activate selected light sources and corresponding optical detectors.
Abstract:
A monocular night vision apparatus employing an infrared energy spectrum source of illumination and a camera lens and night vision image intensifier combined receiver apparatus into a small hand-held portable package that is both low in cost and reliable in nature is described. The night vision transmitter apparatus includes a laser diode energy source that is coupled to an aperture controlled and focus controlled optical system and driven by an electronic closed-loop feedback energization circuit which employs self-contained battery sources of energy. Multiple operating modes and operating intensities of the light source are provided through a plurality of signal inputs to the closed feedback loop of the laser diode energy source. Disturbance of the closed feedback loop by reflected energy within the optical transmitter apparatus is precluded by the use of feedback prevention optical alignment in the transmitter's optical system.
Abstract:
A device for measuring optical transmissivity of a transparency is described which comprises a diffuse light source (Lambertian diffuser) of controllable substantially constant luminance and preselected light emitting surface area for placement near a first side of a transparency for transmitting diffuse light along an optical axis through the transparency, a housing having a wall defining an aperture for placement near the second side of the transparency opposite the diffuse light source, and a detector in the form of a photo diode, cadmium sulfide cell or the like disposed within the housing and coaxial with and spaced a preselected distance from the aperture, the aperture being selected in size to expose all of the effective light detection surface area of said detector to the light emitting surface area of the diffuse light source.
Abstract:
A method of measuring haze of an aircraft transparency includes producing a first reading representative of the level of light scattered by an area of a transparency under test while on the aircraft when it is illuminated by a known light source, and producing a second reading representative of the level of light scattered by a predetermined, preferably worst haze condition, reference plate when it is illuminated by the light source in place of the transparency. Then, a ratio of the first and second readings is calculated to provide a quantitative measure proportional to the degree of haze in the transparency test area.
Abstract:
A novel decoy providing the deceptive appearance of a genuine three-dimensional object, such as a vehicle, is described which comprises a plurality of modular table units each of predetermined shape and assembled in an abutting relationship to form an outline of the vehicle, each said table unit supported by a framework including leg elements in a spaced relationship above the ground whereby a shadow is cast in said outline, to further the deceptive appearance of said decoy as viewed from the air, and a vertical element, supported by said assemblage of table units, in the shape of an elevational view of said vehicle, to provide a deceptive elevational view of said vehicle.
Abstract:
A method of measuring haze in a transparency includes the steps of illuminating a transparency to be measured from one side using a semi-collimated light source disposed in a predetermined angular relationship to the transparency, measuring the illumination (E) falling on a surface of the transparency from the one side thereof, then along a predetermined line of measurement through the transparency using a photometer to measure the veiling luminance (L) within the transparency from another side of the transparency opposite to the one side thereof, and, finally, calculating the haze index of the transparency by solving H.sub.i =L/E.
Abstract translation:测量透明度中的雾度的方法包括以下步骤:使用以与透明度成预定角度关系设置的半准直光源从一侧照射待测量的透明度,测量落在该透明体的表面上的照度(E) 然后通过使用光度计的透明度沿着预定的测量线测量透明体中与透明体的与其一侧相反的另一侧的遮盖亮度(L),并且最后计算 透明度的雾度指数通过求解Hi = L / E。
Abstract:
A replaceable anti-reflection shield for the glare surface beneath the windscreen of a vehicle is described which comprises a flexible panel of light absorbing material, such as black cloth, velvet, canvas or plastic, of size and configuration corresponding to that of the glare surface for placement on and conformance to the contour of the glare surface beneath the windscreen, and peripheral attaching means such as adhesive strips, snaps, Velcro.RTM. strips, suction cups, or similar devices, on the flexible panel for detachably securing the peripheral edges of the panel to the glare surface, whereby the panel is easily removed for cleaning or replacement.
Abstract:
A novel vision tester and vision testing method is described which comprises a pair of translucent displays, each transilluminated by electroluminescent lighting panels, the images of the two patterns being superimposed to provide a combined image characterized by a pattern of variable contrast. Light sensors near each light panel provide a measure of the relative intensities of the two images, which provides a measure of the contrast of each combined image. Contrast may be directly read out by processing the signals from the light sensors. The tester may be battery powered for portability.