Showing papers on "Night vision published in 1986"

Night vision goggle arrangement with automatic release

Abstract: A night vision goggle arrangement includes an assembly for adjusting the position of the goggles relative to a user, means for engaging the assembly with a mounting plate on a helmet, means for locking the assembly to the mounting plate, and release means arranged to unlock and disengage the assembly from the mounting plate.

Analysis of Product Hot Electron Problems by Gated Emission Microscopy

Abstract: A new tool to analyze the hot electron problems at the product level is introduced. The method combines the latest night vision technology and computer image processing techniques to precisely locate the transistors most vulnerable to hot electron degradation. A dual microchannel intensifier is coupled to a solid state camera to detect and amplify the extremely faint light emitted by the transistors in saturation. Computer image processing techniques are then employed to boost the sensitivity. Time resolution of hot electron events is achieved by `gating' the intensifier. To date, we have achieved a time resolution of l5ns, spatial resolution of l?m with a sensitivity of 10nA per ?m of substrate current. At the sensitivity level of our instrument we can even detect hot electron events which cause no degradation.

Over-door interphone system provided with a night-vision monitoring device

Abstract: An over-door interphone system for telephonic communication between a master station unit inside of a house and a remote station unit outside of an entrance door of the house is provided with a night-vision monitoring device. The night-vision monitoring device has a television camera comprising a solid-state camera sensitive to an infrared light. The solid-state camera is responsible for successfully incorporating the television camera within a less bulky housing of the remote station unit as well as for monitoring the image of a visitor by the camera without being noticed. Also, there can be utilized an illumination device producing an infrared which is hardly perceived by the visitor, ensuring monitoring of the visitor at night without a giving unfavorable impression thereto. The illumination device may be driven to operate for a predetermined period of time starting from the actuation of a calling switch, or a communication interval from the actuation of the calling switch to the hangup of a handset on the master station unit. The illumination device may be also driven in response to the actuation of an illumination operating switch or to a low illuminance level of the object. Thus, the illumination device can be operated with a minimum power requirement. The illumination device is controlled to operate in synchronous with the video signal from the television camera, providing an effective monitoring illumination free from flicker.

Judgments of eye level in light and in darkness.

Abstract: Subjects judged eye level in the light and in the dark by raising and lowering themselves in a dental chair until a stationary target appeared to be at the level of their eyes. This method reduced the possibility of subjects' using visible landmarks as reference points for setting eye level during lighted trials, which may have contributed to artificially low estimates of the variability of this judgment in previous studies. Chair settings were 2.5 deg higher in the dark than in the light, and variability was approximately 66 percent greater in the dark than in the light. These results are discussed in terms of possible interactions of two separate systems, one sensitive to the orientations of visible surfaces and the other sensitive to bodily and gravitational information.

Invisible light beam projector and night vision system

Abstract: A relatively large diameter, sharply focused beam of invisible light is produced by a projector (10) for the purpose of lighting up a person, object, etc to be viewed at night The projector (10) is used in conjunction with a night vision telescope (12) which includes a light intensifier (88) The projector (10) includes a pulsating infrared LED, or a laser diode, adapted to produce a high intensity narrow beam of invisible light This beam of invisible light is enlarged by a projection lens assembly (26) adapted to sharply focus the light into a collimated light beam of about the diameter of the projector housing (20) The light source (30) is pulsed on and off, and is on only about 10-20% of the time When on it is illuminated by a high level current which would quickly burn out the light (30) if operated continuously The intermittent operation of the light (30) at high current produces a nonflickering high intensity light beam The projection lens (26) enlarges this beam and clearly focuses it, to produce a relatively large illuminating beam having a substantially large range of use

The Constraints on Images of Rectangular Polyhedra

Abstract: This paper discusses how polyhedron interpretation techniques are simplified if the objects are rectangular trihedral polyhedra. This restriction enables one to compute the spatial orientation of a given corner and its motion from its image in terms of polar coordinates, Eulerian angles, and quaternions. One can also interpret the shape and the face adjacency from local information only. The necessary constraints are listed, and some examples are given to compare the presented scheme to existing ones. The possible nonuniqueness of the interpretation is also discussed.

Chemical Communication Among Asian Elephants

Abstract: The Asian elephant (Elephas maximus), a mammal of recognized high intellegence with a well-organized societal structure (McKay, 1973; Eisenberg et al., 1971; Olivier, 1978; Kurt, 1974), possesses a sophisticated array of sensory apparati. These sensory systems interplay in influencing both the immediate responses of the elephant and its long-term behavior. The visual system, considered the least developed of all the elephant’s sensory systems, has some color vision (Markowitz et al., 1975), visual acuity at close range (Rensch, 1959), and good night vision (Kuhme, 1962); the tactile and auditory systems are well developed and relied on heavily (Eisenberg, 1980; Gadgil and Nair, 1984). Elephants produce a variety of sounds for communicative messages (Berg, 1983); recently Asian elephants have been shown to utilize low frequencies, producing infrasound (Payne et al., 1985).

Night vision systems

Abstract: A vehicle night vision system comprising a headgear mounted night vision goggle 11 incorporating an image intensifier which produces an intensified image of a scene forward of the goggle superimposed on a user's direct view of the scene through the goggle wherein the intensity of the image produced by the intensifier is reduced when the user views a vehicle interior display via the goggle to prevent interference with the user's direct view of the display through the goggle.

Image classification at low light levels

Abstract: An imaging photon-counting detector is used to achieve automatic sorting of two image classes. The classification decision is formed on the basis of the cross correlation between a photon-limited input image and a reference function stored in computer memory. Expressions for the statistical parameters of the low-light-level correlation signal are given and are verified experimentally. To obtain a correlation-based system for two-class sorting, it is necessary to construct a reference function that produces useful information for class discrimination. An expression for such a reference function is derived using maximum-likelihood decision theory. Theoretically predicted results are used to compare on the basis of performance the maximum-likelihood reference function with Fukunaga–Koontz basis vectors and average filters. For each method, good class discrimination is found to result in milliseconds from a sparse sampling of the input image.

Imaging and detection of current conduction in dielectric films by emission microscopy

Abstract: Current conduction in dielectric films has been studied by Emission Microscopy. By combining optical microscopy with the latest night vision technology and the computer image processing techniques, we have been able to image the extremely faint light emission accompanying current conduction in a dielectric film on silicon substrate. We have found that current flows uniformly in an undamaged capacitor initially. The capacitor then breaks down after conducting a certain amount of charge and current flow becomes constricted into the failure location. To date, we have achieved a sensitivity of 10pA/µm2uniform current conduction through a 250A undamaged oxide. For a damaged oxide, our sensitivity is 50nA at 12V or 300nA at 5V, strongly depending on the degree of damage. The spatial resolution achieved is 0.5µm. With its unprecedented capability, Emission Microscopy can be readily used to study the physical mechanisms of dielectric conduction and pinpoint the location of gate dielectric failure.

Image intensifier binocular

Abstract: Method of designing a compact binocular night vision instrument with an electronic image intensifier (2) which is oriented so that its symmetry axis forms a right angle with the line of sight (19) between the night vision binocular and the scene to be observed. The total forward length thereby becomes particularly short, thus reducing the downward torque which is troublesome when the night vision binocular is carried like a pair of spectacles, attached to the head (generally called night vision goggles). The total forward length may be even further reduced if the symmetry axis of the objective lens (1) is also at right angles with the line of sight (19). These measures makes feasible a simple beam splitter system where the optical axis through one of the eye pieces (13B) intersects the common optical axis beam splitter (14), and to design an instrument enclosed in a single housing having a smooth exterior shape which is easy to grasp.

Night vision compatible and sunlight readable, lighted, word indicating pushbutton switch and indicator

Abstract: A pushbutton switch having an illuminated display or other instrumentation data or control display device is made compatible both with unassisted night time vision of the display as well as vision assisted by a night vision imaging system or night vision goggles. The display is backed with a plurality of selectively activated light sources. Each light source is characterized by a spectral range. At least one of the light sources has a spectral range compatible with the night vision imaging system. At least another one of the light sources has a spectral range compatible with unassisted night vision. In the preferred embodiment, the light source is comprised of a conventional incandescent bulb disposed within a domed glass filter. The domed glass filter has a spectral transmissivity which is compatible with the night vision imaging system. In particular, the filter has a transmissivity approximately equal to either ANVIS Green A, ANVIS Green B, or Yellow. The light source compatible with unassisted night vision is comprised of a conventional incandescent bulb disposed in a domed filter having a spectral transmissivity within the red portion of the spectrum. The display may be selectively illuminated by any one of the ANVIS colors, a combination of the ANVIS colors, or by the red night light. Therefore, every displayed instrumentation device within the cockpit of an aircraft may be immediately converted from conventional night vision illumination to one compatible with night vision goggles.

Night-Vision Equipment, Reproductive Biology, and Nocturnal Behavior: Importance to Studies of Insect Flight, Dispersal, and Migration

Abstract: The adults of well over one-half of our insect pests are active during dark or crepuscular periods and most species are highly mobile. Their mobility, along with our limited night vision, has resulted in a large void in our knowledge of their nocturnal behavior. Nevertheless, in recent years, a number of technologies and techniques have emerged that are adaptable for studying nocturnal behavior of insects in their natural environment. The technologies include the use of various forms of visible light such as flashlights, lanterns, Aldis lamps, and 6-V headlamps (Lingren et al. 1977; Rose and Dewhurst 1979); night-vision devices using natural-light intensification and amplification (Lingren et al. 1978; Greenbank et al. 1980); infrared-optical devices including video (Conner and Master 1978; Lingren et al. 1982; Riley et al. 1983; Schaefer and Bent 1984); and radar (Schaefer 1976; Wolf 1978; Riley 1980).

Light secure eyecup for use with night vision goggles

Abstract: An eyecup (24) for interfacing a night vision goggle (10) with the eyes of the user (12). A flexible curved eyepiece (28) including a wing (38) provides a tight seal of the periphery of the eyepiece (28) to the occular eye area of the user (12). The seal prevents light (22) emitted from the goggle (10) from escaping out of the confines of the eyecup (24). A fastening sleeve (26) is provided to secure the eyecup (24) about a flange on the goggle (10). An intermediate accordion section (40) allows compression and expansion and maintains the seal between the eyepiece (28) and the ocular eye area. An air vent hole (52) is formed in the accordion section (40) to prevent suction from occurring within the eyecup (24).

Binocular periscope viewing device including triple prism for image splitting

Abstract: A binocular periscope (10) viewer includes a columnar glass prism (52) disposed in a vertical optical path (24) and an angled internal reflective surface (51) for redirecting the image from a horizontal path (22) downwardly to a vertical optical path (24). An objective lens assembly (54), a night vision image intensifier tube (56) and a collimator (58) are all disposed in the vertical optical path (24) and further condition the image for presentation to a triple prism (60). The triple prism (60) includes a first prism (62) integral with a second prism (64) and a third prism (66). Prism (62) is disposed in the vertical optical path (24) and redirects the image into a forward horizontal optical path (70). Each of prisms (64, 66) receive essentially the entire redirected image, and further redirect such image into oppositely directed lateral horizontal optical paths (26, 28). The triple prism (60) is mounted to a cradle (106) which is secured to the frame (12) of the viewing system. Turning mirrors (90, 92) redirect the image into parallel common forward horizontal paths (30, 32) for individual viewing by an observer.

Obstacle recognizing device for ship

Abstract: PURPOSE:To prevent a collision against an obstacle securely by a small number crew by recognizing the size and kind of the obstacle, the direction of a stationary ship, etc., automatically on the basis of information from an image sensor and setting the best dangerous area against the obstacle. CONSTITUTION:A radar 1 for the ship acquires a reflected echo of a microwave, which is applied as obstacle information to a collision preventing and rescuing device ARPA4, which performs rough collision decision arithmetic. Information on the position of an obstacle against which the ship collides possibly is inputted to an infrared camera processor 3d. The infrared camera processor 3d sends necessary control signals to a camera controller 3a, an infrared controller 3b, and a panning controller 3c respectively to actuate an active night vision infrared image sensor 2. Then the image sensor 2 controls a focus controller 2b and a pan 2e to aim at the obstacle and operates an infrared-ray generator 2d to acquire a video of the obstacle through an infrared camera 2c.

Optical-mechanical analyser with a fixed telemetric field

Abstract: Optico-mechanical scanner with imaging and telemetry functions associated wherein the imaging beam (F According to the invention, the imaging beams and telemetry through a set of fixed optical elements arranged to separate the following two distinct optical paths such that the ranging beam passes twice through said line scanning means (M4) that which ensures a fixed direction of the independent space of the online analyzer. Application to night vision.

Modeling Approaches To Thermal Imaging Systems

Abstract: When modeling thermal imaging systems to predict their performance, there are three functional areas that must be specifically characterized: the object being imaged; the intervening atmosphere; and the sensor itself. This paper will discuss two computer simulations presently being used by the U.S. Army Missile Command (MICOM) which integrate models of these three functional areas to calculate the performance of a variety of thermal imaging systems for a range of atmospheres, scenarios, targets, and sensors. Common to both approaches is: use of the Johnson bar criteria for detection, recognition and identification; the use (direct or indirect) of the AFGL LOWTRAN code to model the atmosphere; and, finally, some methodologies for modeling staring focal plane arrays (FPAs) as the sensor detection element. The three functional areas will be discussed first, followed by discussions of the two approaches; the Fire Control Sensor Simulator (FCSS), an engagement model; and, the MICOM Infrared Imaging System Performance Model (MIISPM), a more detailed model emphasizing the sensor itself. The MIISPM is based upon the Night Vision Laboratory Static Performance Model (NVLSPM), but has been enhanced in several important ways, discussed in the paper. While both approaches provide as output the same performance criteria (probability of detection, recognition and identification, as a function of range), each model has its own strengths for different aspects of the sensor performance problem: for the FCSS, targets and scenarios; for the MIISPM, details of the sensor. Both approaches will be presented and compared in terms of the results, run time efficiency, and required hardware. Both models presently run on IBM or IBM compatible personal computers.

Catadioptric Afocal Telescopes For Scanning Infrared Systems

Abstract: Reflecting and catadioptric lenses have been used in astronomical telescopes for many years. More recently, among other applications, they have been widely used in large-aperture and man-portable image-intensified night vision equipment. The afocal telescope used with a scanning infrared system operating in the 8 to 12µm wave-band is required to match the large field of view and small aperture of the scanner with the small field of view and large entrance aperture required for long-range observation. The telescope construction used is usually a refracting telephoto. This can be configured either as a single field of view lens, as part of a dual or multiple field of view switchable system, or as the basis for a mechanically or optically compensated zoom system. However, for large, high magnification telescopes, catadioptric systems can offer advantages over refractors. Two types of catadioptric lens are described. The first has a "low" magnification (7.5 x ) and utilizes a full aperture germanium lens to correct spherical aberration. The second has a "high" magnification (30 x ) and uses a subaperture germanium element to correct the same aberration.

Recent technological advancements in image intensification in the spectral range from UV to IR

Abstract: Recent developments and advancements made in photocathode, MCP and phosphor screen technology are reviewed in light of current requirements in the UV and IR regions of the electromagnetic spectrum. The paper covers such topics as the spectral sensitivity, noise and operational characteristics of photocathodes; MCP gain and noise characteristics; resolution, bandwidth and noise characteristics of image tube phosphors; gated image tubes; and hybrid image tubes for optical communication. Finally, imaging with intensified CCD and CID cameras and multi anode MCP's are discussed.

An electronic visual aid using a luminance amplifier in night vision disorders

Abstract: The efficiency of a light amplifier system for the improvement of night vision has been tested on 30 normal subjects and on subjects suffering from night blindness including 36 patients with pigmentary retinopathy, 18 myopic patients with night blindness and 12 patients with senile cataracts. In all cases, the scotopic vision presented a great improvement and it reached up to half of photopic vision. The use of the light amplifier would certainly provide a considerable improvement for subjects suffering from night blindness and mostly for those suffering from pigmentary retinopathy. But two conditions are necessary for this: miniaturization of the device and absence of major macular lesions in the patient.

Super Inverter Image Intensifier

Abstract: Publisher Summary This chapter introduces the super inverter, and its performance in a night vision system is compared with that of other image intensifier tubes, such as the first-generation (Gen.I) three-stage tube, the second-generation (Gen.II) wafer tube, and the Gen.II inverter tube. In applications where the dimensions, weight, and local brightness control of the image intensifier are not extremely important, Gen.I tubes are preferable to ordinary Gen.II tubes. The super inverter with Gen.II first stage offers as good a performance as Gen.I three-stage and has the extra features of small size, low weight, and local brightness control. The super inverter with Gen.II wafer first stage is superior to single Gen.II inverters or wafers. Because a Gen.III version of the electrostatic inverter is impossible, high gain Gen.III tubes can only be achieved by a super inverter.

Compact Viewing Optics Using Polarisation

Abstract: A compact, lightweight viewing system that provides a magnified, inverted image of the phosphor of an image intensifier tube is described. The compact dimensions have been achieved by repeated folding of the optical path by the use of a polarising beamsplitter. The approach taken to the design, its internal structure and method of operation are detailed.

Review Of Industrial Applications of HOEs In Display Systems.

Abstract: After a short review of diffractive optics, three display applications of Has are considered : helmet mounted displays, holographic night vision goggles and holographic head up displays. Possible future research fields are introduced.

Lens Systems Incorporating A Zero Power Corrector Principle Of The Design And Its Application In Large Aperture, Moderate Field Of View Optical Systems

Abstract: A new lens design concept, based on the use of a zero (or near zero) power corrector, will be described. The logical development of the design, based on the work of Schmidt', Houghton' and others will be discussed and examples will be given of moderate field of view lenses with apertures ranging from f/0.35 to f/2. It will also be shown that the lens configuration is relatively insensitive to the aperture stop location and that for less demanding applications only very basic optical glass types need be used.

Human Factors Engineering Analysis of Marine Corps Night Attack Aircraft

Abstract: The U.S. Marine Corps has proposed sensor and display improvements to provide night attack capability for the AV-8B and F/A–18 aircraft. The aircraft enhancements include the addition of a Forward Looking Infrared sensor displayed on a new raster Head-Up Display, Night Vision Goggle compatibility, and a color multi-purpose display. A human factors engineering analysis was performed to identify the human factors impact of the cockpit changes involved. Included in the analysis were a literature review, interviews with pilots, design considerations review, and development of recommendations based on both human factors standards and lessons learned from similar projects. The primary areas researched were: cockpit lighting, color displays, and night vision sensor utilization.